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Holden V8 253 - 253
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HK1837 Offline
#21 Posted : Sunday, 26 February 2017 4:01:03 PM(UTC)
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I think that the HK-HG single exhaust may well be more restrictive that a HQ-HJ one. HK 307 exhaust is the same as a 253 or 308 single exhaust.

The VH-VK GroupIII wasn't far off an L34 in performance, the L34 had more compression and better exhaust manifolds but less cam and far smaller tailpipes and rear mufflers. A VK GroupA was the first car GMH ever sold that had more power and performance than a HT-HG GTS350.

EGR is only applicable to autos, manual had it blanked off.

Agree, Stock HT-HJ intake is as almost as good as a Performer, HX one flows dreadfully. I have flow bench tests showing this, i'm sure I have put them up here before. It is that intake that kills the HX's performance compared to a HJ, and brings it back close to a HQ in peak power despite having the better cam and the 9.7:1 compression. The only other things that could hold it back is the flap in the LH exhaust and different spark timing (which it has).
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castellan Offline
#22 Posted : Monday, 27 February 2017 5:23:20 PM(UTC)
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A bloke I knew owned form new the HK Brougham and the HT and HG Brougham and said that the HT-G made less noise, I think they had a little muffler up near the passenger front seat.

My HX had the original dizzy and I had a HG dizzy as well and it made no difference at all.
My HX was a manual with the blocked off EGR intake and worked with the bloke who owned it before me and was the best knowledgeable mechanic I knew by far and he tossed the EGR heads away but kept the EGR intake manifold and jetted a HQ type Rochester Quadrajet rich, pointing out that they must run at X air fuel ratio for max power and fuel economy and going too lean is no good for fuel or power and what I could get with a 650 Holley but that could not match the fuel economy, I pointed to the HX manifold as being crap and how did he fit it to the non EGR heads, he just blocked one hole with epoxy and that was all he had to do.

I went out drag racing nearly every weekend and never seen no stock 308 blow my 308 away on the 1/4 sure mine was a GEM engine 0.030 over and what ever regrind grind cam they used, maybe it was a HJ spec.
That HX intake sure as hell did not reduce any power of a stock or near stock.

A mate had a HJ 308 p van just like mine same gearing with a mild TQ20 cam to my stock cam and in 3rd gear mine would walk past his. A mate with a HJ GTS 308 The same thing but he had manifold twin exhaust. another mate had a HJ p van with a 307 chev stock but for 0.030 over and 4bbl Rochester extractors twin exhaust he had no hope.

I was thinking to go the Performer intake with the 20/60 cam and L34 valves but she went like a rocket so I did not bother. the old intake had bad corrosion so I welded it up and grounded it back, thinking maybe it may warp the manifold and it would be roo ted, but it did the job so no performer was needed, so I never went down that track. I had a SLR5000 as well for 2 years and that p van at the same time, the LH SLR5000 had the cable throttle so it may of been the HJ 308 it had a stock 308 with extractors and twin 2 inch exhaust with a 650 Double Pumper Holley with 3.08 diff and 14in wheels. the only thing really going for the SLR5000 was less weight.
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HK1837 Offline
#23 Posted : Tuesday, 28 February 2017 4:59:31 AM(UTC)
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AFAIK the HT and HK 307 exhaust wee identical. The most likely reason a HT-HG Brougham made less noise than a HK Brougham is a HT-HG Brougham were all 308s.

HT dizzy has 4deg max advance more than a HX dizzy, which definitely would make a difference on the right combination of internals.

There is little difference between HT-HQ and HZ-HZ heads flow wise - they are the same flow wise and chamber wise. What you gain by using the earlier heads is the intake is no longer exhaust heated, which could only be good performance wise. The EGR manifold bolts straight on to the early heads. Your car would have performed better with the early manifold too.

Your car was not stock, 30 thou over using who knows what compression ratio and whatever grind they put on the cam. I can tell you that with the early manifold it would have produced significantly more peak power, that is a simple fact. The runners in the pollution manifold are not much different size wise to the early manifold. It is the ribs in the runners, the area under the carb and the radiuses in the runners. The exhaust heating doesn't help, but the early manifold were water heated so not a huge difference there. Flow bench results show that the pollution manifold is the killer on the stock engines. The early manifold flows very similar to the heads which you'd expect on a brand new design from scratch engine, the pollution on inhibits the heads, see below:

Stock heads flow 96.6cfm @ 10" and 152.7" @ 25".
Early manifold flows 91cfm @ 10" and 143.9 @ 25" (you can see why with L34 head mods they opened up the manifold a bit to improve it to match).
HX manifold flows 75.6cfm @ 10" and 119.5cfm 25".
Performer flows 95.2cfm @ 10" and 150.5 at 25".

That pollution manifold (unless modified) is the single biggest impediment to power production in the HX engine, and GMH dyno figures show it clearly. Same cam, same flowing heads, same compression as the HJ engine. Sure it has 4deg less total advance and a flap in the LH exhaust manifold, but it still won't rev and power drops off far lower than the HJ. The manifold is the problem. Put on a Performer and you will be back to a HJ like engine.

Early LH Torana had HQ engines. They didn't change to HJ engines until around 9/74.

Edited by user Tuesday, 28 February 2017 5:03:23 AM(UTC)  | Reason: Not specified

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castellan Offline
#24 Posted : Tuesday, 28 February 2017 12:14:16 PM(UTC)
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Originally Posted by: HK1837 Go to Quoted Post
AFAIK the HT and HK 307 exhaust wee identical. The most likely reason a HT-HG Brougham made less noise than a HK Brougham is a HT-HG Brougham were all 308s.

HT dizzy has 4deg max advance more than a HX dizzy, which definitely would make a difference on the right combination of internals.

There is little difference between HT-HQ and HZ-HZ heads flow wise - they are the same flow wise and chamber wise. What you gain by using the earlier heads is the intake is no longer exhaust heated, which could only be good performance wise. The EGR manifold bolts straight on to the early heads. Your car would have performed better with the early manifold too.

Your car was not stock, 30 thou over using who knows what compression ratio and whatever grind they put on the cam. I can tell you that with the early manifold it would have produced significantly more peak power, that is a simple fact. The runners in the pollution manifold are not much different size wise to the early manifold. It is the ribs in the runners, the area under the carb and the radiuses in the runners. The exhaust heating doesn't help, but the early manifold were water heated so not a huge difference there. Flow bench results show that the pollution manifold is the killer on the stock engines. The early manifold flows very similar to the heads which you'd expect on a brand new design from scratch engine, the pollution on inhibits the heads, see below:

Stock heads flow 96.6cfm @ 10" and 152.7" @ 25".
Early manifold flows 91cfm @ 10" and 143.9 @ 25" (you can see why with L34 head mods they opened up the manifold a bit to improve it to match).
HX manifold flows 75.6cfm @ 10" and 119.5cfm 25".
Performer flows 95.2cfm @ 10" and 150.5 at 25".

That pollution manifold (unless modified) is the single biggest impediment to power production in the HX engine, and GMH dyno figures show it clearly. Same cam, same flowing heads, same compression as the HJ engine. Sure it has 4deg less total advance and a flap in the LH exhaust manifold, but it still won't rev and power drops off far lower than the HJ. The manifold is the problem. Put on a Performer and you will be back to a HJ like engine.

Early LH Torana had HQ engines. They didn't change to HJ engines until around 9/74.


That's what I am saying to you, that that HX intake was not a impediment at all to a stock or slightly mod engine. when everyone knew that my stock GEM 308 went so well. and with the 20/60 cam and L34 valves how could it pull 5300RPM in top with a 3.08 diff if that was the case and this is proof I have of that.
I had people with stock 351 and 350 who would not give it a go for fear of getting hosed off even one with a XC 351 and a small cam, he were a mechanic to and all but would just smile in fear of his ego getting bruised.

I have never had exhaust manifolds on any of my 308's, I only remember that my LH SLR5000 had the cable to the carby, so I take it that the HJ went to cable and the LH did at the same time. so it maybe was a HJ 308 type only with extractors and 650 double pumper Holley on it and response from both stock engines was the same, only for the lighter LH making any difference and the HQ 308 with twin exhaust had the same response, I can say that without a doubt and I did around 300,000KM in that car.

If the intake were a problem with flow I should of experienced it's lack and that is what I am pointing out. there was no such lack at all to 5300RPM but I would think there would at a higher rev or bigger cam.
I believed in big intakes were the go in my early days, but seen no problems in 308's making great power at 6500RPM and even rev to 7000RPM with HQ type of intakes I would never recommend a Torker or such to anyone on a street car. never seen a HQ type intake make max power over 6500RPM.
I am sure that the HT-G-Q-J intake flows better than a HX-Z and always did think that but I thought why bother tossing it when it did the job so well.
I can understand your point of view totally and I would of believed such as a fact, why would I want to put shit ADR27A crap like that on my pre ADR27 engine, I understand totally, but the fact is it did not rob power at all.

There may be an improvement because due to no heat was entering the intake because no EGR or hot water piping and I did a lot KM of flat out driving on the highway.
Maybe the HQ type would give a little bit better and I am sure it would at maybe 5000RPM and over, if I went to a 25/65 cam it would of been gone for sure but that type of cam loose low down torque and I did not want that, they give a bit more top end but don't truly perform better over the 1/4 and the 30/70 type cam have nothing down low but do hall and the 35/75 and up start to be crap running well one day and crap the next shit box to drive on the street, no one can live with that unless you do low KM a year.

As to the dizzy I tuned them to hear a ping and then backed them off 2 deg and ran the vac adv straight off the intake, not off the carby and she would start in an instant and people would comment on that, spinning out that it started in an instant. that other dizzy was a HG 253 auto one.

If you look into a 350 HQ intake it has the same looking ribs as a HX does, only the chev intake is a crappy cast iron rubbish, just like the Ford Cleveland crap.
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HK1837 Offline
#25 Posted : Tuesday, 28 February 2017 3:54:52 PM(UTC)
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According to GMH's dyno figures and to most road testers of the day and also to those who drove an early LX SLR5000 or SS 5.0L, ordered one and then got the pig ADR27A 308 engine it made a massive difference. It is the only thing on a manual 308 that could cause the huge performance drop from HJ to HX engines. If your engine was rebuilt by GEM it is no longer a stock 308!

No. LH was cable throttle on all engines at release. When HJ engine production began LH got HJ engines. The problem with most LH and early LX Toranas and how they went is people did not know the differences, and hardly any road tests of cars with the improved 308 HJ engine exist. One of the magazines did a road test on an early LX SS 5.0L, and they were so astounded by its performance in 0-100km/h and 1/4 mile times that they went back to the HT-HG GTS350 and HT-HO's to find anything that went as hard. They had not driven an SLR5000 since release, and those early cars all had only HQ 308 engines, no-one bothered to test and report on the LH with the improved HJ 308 engine probably as they were concentrating on the HJ. By the photos of this LX test car I think it may have had larger tailpipes and mufflers form a Holden, not the tiny Torana dual exhaust mufflers and tailpipes. I'm pretty sure the test was Modern Motor. As far as I know it is the only road test of a manual HJ type engined Torana, all the others are HQ engine or auto. This may too have been GMH hiding the car in plain sight like they did with HK 307 4spd. The other thing with Toranas is most have a 2.78 rear axle to go along with the tiny mufflers and tailpipes. A 2.78 rear axle with 13" tyres is the same as a Holden with 14" tyres and 3.08 rear axle, these cars are always slower than those with a 3.36 rear axle. So in hindsight it would have been nice to see one of those early LX's with larger exhaust and a 3.08 rear axle. One of those should have gone close to cracking 15.0s quarter and been only behind a GTS350M in performance.

HQ 350 intake is junk, no brainer there. The cast iron manifold on a 350/350 Corvette engine isn't all that bad though, and the same manifold was used on a HT GTS350.
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castellan Offline
#26 Posted : Tuesday, 28 February 2017 9:22:03 PM(UTC)
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It's a stock reco engine.

All them stock Repco and Gem reco engines were just slapped together std size valves and a stock type cam timing reground cam, I have asked what stock cam spec they used but they did not know, as most people would think that all cams are the same.
A 0.030 or 0.060 over bore makes no difference in power and in fact 0.060 could loose power.

You had to ask Repco or Gem if you wanted a higher performance engine but most of there work was just stock reco and no one I know thinks they are anything worth talking about, oh I have a std Repco reco, most who know would say you poor bugger feeling sorry for you. they were made to a price and not as well made as a new Holden engine.

Repco and Gem could make good reco engines but you had to pay for that extra, like you could get what they called a XU-1 reco engine and that is what I would call a stock XU-1 reco.
The cam in them XU-1 could be like any of the ones Holden made but as far as I know they made there own spec cams, that is not to much different to the Holden one, due to copy right laws all cam grinders can not make the same grind unless they pay for that right and they don't like to fork out for that.

I would think that Repco and Gem stock reco engines would of made one cam grind for all red Holden 6 cyl pre ADR27A and one for all ADR27A. The same with the 253 and 308's.

When I reconditioned my 308 I knew what I wanted and that was a stock type of engine that no one would know it was not stock, as it had not a hint of a lumpy cam at all and the fuel economy did not change, but went a hell of a lot better. oh you could not hear that it had a bigger cam, but on a real cold morning with the exhaust pointing close near a wall and one time up high in the mountain's on a cold day it was giving the game away.
I used the stage 3 heads as it was the cheap way to go, but I believe using the L34 intake valve and keeping the std exhaust with a 3 angle grind and leave the port stock and just a little intake port work in the right spots and a bit off the combustion chamber near the intake valve would gain a bit better performance but cost a lot more.

Back in them days I only dragged only on outback roads that were marked out and we would go more than the 1/4 all the way to top end speed at times.
With the 3.08 diff and 14in wheels if the engine performs real well like with free system and extractors well tuned at the 1/4 mile I could go into 4th gear very close to coming to the line, but with a 3.36 I would have to go into 4th, if one truly knows what you are doing then you can get your times down much better, but most people don't know that.
The test drivers were 3rd rate back in the days and the times they got proved that they were hopeless, not to mention turning up testing a car that is running like shit and having bugger all mechanical knowledge at all, because they never fixed the problem.
If they were great testers they could of pointed out how to get the best out of a car in so many ways, how about this, make the distinction to make sure you get twin exhaust on any 308 or be disappointed and if they bagged the handling, they should of pointed out what too do with it that makes it handle so much better, like better shocks and modify camber and caster better tyres just for starters.
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HK1837 Offline
#27 Posted : Wednesday, 1 March 2017 7:16:18 AM(UTC)
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I don't agree that road testers didn't know what they were doing. The good ones like Rob Luck, Bill Tuckey, Mel Nichols, Peter Robinson etc. They always calibrated the speedo first (to provide corrected mph and km/h), they always used two people in the car, and always throttle lifted for shifts. The 1/4 mile times were always averages too of many runs. From memory I think it was the Phase III that they actually got to hook up off the line and pulled a 14.1 or 14.2 or something like that, but the average was higher 14's.

Agree they didn't correct the tune of cars, and this was a problem for the higher performance manual GMH cars as they were always very careful to mask their true potential. Ford also made it hard to get the good cars to test, the fast times reported and quoted over history for I think it was the Phase II were actually of a Series Production race car as they couldn't get a normal road car to test. One of the HQ GTS350 tests they got an auto and manual car, and they were scratching their heads as to why the auto car was like 3-4 seconds quicker to 100mph, and slower or near equal over the quarter. Same exhaust, same rated engine, same diff ratio. The manual car had been fiddled with, just like they did with the HT and HG press test cars, but no-one ever found GMH out on the HT and HG as the engines were not the same. The 308 manual cars were also rarely if ever provided for testing with dual exhaust, only single, unless it was the LH SLR5000 which always had a 2.78 rear axle and pea shooters. Even at the HK Monaro release at Surfers Paradise, the only powertrain combo missing was 307 manual (which would have had a 3.36 rear axle), and the auto 307 was conveniently fitted with air and steer. Then the GTS327's performance (or lack of it) wouldn't be questioned. It was very carefully orchestrated. It was only ever a few road testers that got hold of properly tuned cars and sort of let the cat out of the bag. Rob Luck did it with the GTS327, and Mel Nichols got a HG GTS350 but never got to record times on that HG - when he got it back for testing it was back to how all the other GMH provided HT GTS350's were. There is also only two 308 manual HQ or HJ road tests I know of where the cars have dual exhaust, the Premier SS of John Bagshaw and there was a HJ GTS sedan as well. Both were 308 manual with 3.36 and ER70H14. The HJ's figures are remarkably better and its performance is surprising. I'll see if I can find those tests and give the figures.
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castellan Offline
#28 Posted : Wednesday, 1 March 2017 3:43:33 PM(UTC)
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Everyone I know would rev a 308 or 350 to 5500 in all gears, wood ducks.

Yes it's also hard to get off the line with the rubbish tyres they had back in them days especially with an open diff, I remember dragging in a mates HQ GTS 308 auto open diff with 205 tyres against another mate in his 350 auto corvette, and not knowing this HQ, all it wanted to do was bag them up, I was fighting to get traction up to about 50 KM/H but from then on there was nothing in it until I hit 180KM/H that the corvette only started pulling away.
I thought I would get a handle on it on the next run and give Andy's corvette a fright and he knew it, so he stacked up the revs at about 5000 and tossed it into low and the bugger jumped off the line like a toad, I was wishing I had my car and I would of had him.

The test back in the days were very limited with times only to 130KM/H and crap like that, not real test like I got in mags from Germany that my uncle would send too me, showing the full story to top speed and never a half arse test or something running like crap.
I know that people here in Australia are very naïve and don't really care about things in depth that much, so they could get away with the half arse test that go no where in reality to proving anything much as fact.
So when we look back on them old test, one can hardly say it's gospel.
Fair to say some 60' and 70' test did say how many miles were up on the test car and the conditions cool or hot.
I does not take much to point out the diff ratio and if it has whin exhaust or not, can't be much of an enthusiast if they don't mention that or just daft.

That HQ 350 auto and manual test was to do with twits taking the manual out to 5500RPM in 1st 2ed 3rd wood ducks.

Barry Lake was a good test driver as was Robinson and Tuckey, but uncle Peter Hannenberger showed him what a amateur he was, poor Bill did not even understand geometry or the function of what the dampers truly was.

That XW GT-HO in Wheels was a 351 Windsor with 16.7 at 100mph with a 3.0:1 diff and the GTS350 was 18.9 at 100mph with a 3.36 diff.
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HK1837 Offline
#29 Posted : Thursday, 2 March 2017 7:43:13 AM(UTC)
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Agree there is little point revving a HT-HQ 308 or HQ 350 to 5500rpm. Different story for HJ 308 that makes peak power at 5000rpm, HT-HG GTS350M's that will easily spin to 6000rpm and the HK GTS327 Tonawanda engine that is most effective revving to 6500rpm (this is why Des West took off and was never headed in 1968 Bathurst, using the full 6500rpm and a 3.36 rear axle).

HQ GTS 308 auto was still 3.36 rear axle IIRC, so not surprised that with an open centre it wheelspun. My first car, a HQ Deville with 2.78 rear axle used to do the same thing but not as bad.

Most of the tests of the higher performance cars I have show 90mph and 100mph times. I think the 90mph was the done thing as until the V8's of the later 60's not many Aussie cars could crack 100mph. Even the 186S HK-HG only just got there. Very few 6cyl Holden or Torana road tests I have seen indicate a top speed over 100mph. We simply didn't have the roads or even the tyres available. GMH had to get a local manufacturer to make the high speed H rated tyres for the GTS327 as none of the tyres available in Australia were suitable for the top speed of the car, and imported Pirelli or Michelin radials were not available until later and they also added a massive premium to the car's price.

Agree old road tests are not gospel but they are not by any means useless. They provide valuable insight into the real story, not the stories people believe today, for example how well GMH hid the true performance of the GTS327 and the 350 manual cars.

HQ 350 auto vs manual is a clear highlight of the hobbling of the manual car, nothing to do with how they were driving it. They tested the auto in drive and manual shifting too, and there were multiple tests using different manual cars that ended up with the same/similar results.

The test I have with the same figures is in SCW in 12/69. The 18.9 for the GTS350 is one of the hobbled press test cars. Mel Nichols and Peter Robinson both recorded 0-100mph times in different HG GTS350's (one with the HT Tonawanda engine, one with the McKinnon engine) just either side of 16.0s flat. AMC did full tests on an untouched 38,000 mile HG GTS350 that did 15.95s 0-100mph testing identically to the old road tests. This car did a 14.78s quarter (3.08 rear axle), the GT-HO was 14.8s average as recorded by SCW (Wheel's sister magazine), with a fastest of 14.4. This is not the road test I was referring to though with the Series Production car being tested, I'm pretty sure that was a PhaseII. Here is an cool quote from the SCW road test, not sure if it was the same text as Wheels had:

"Line it up at the traffic lights and you can still get done by a 350 GTS Monaro - which is cheaper by a very large margin. And you can be held all the way up to the open road speed limit. After that you will gradually win out, but methinks any self-respecting Holden owner who has thrashed your pants even as far as 50 (mph), will go straight to top (from first) and settle back to an idle as you push a pointless argument up to the level of your own terms (70mph plus). But don't be mislead - we're not advocating open road drag racing; we're just trying to illustrate that the engine has been tuned specifically to be fastest from Hell Corner to Skyline at Panorama. You'll do any point-to-point as quickly in either a Monaro GTS 350 or a standard Falcon GT. And you'll probably be more comfortable".

Note that the comparisons being made to the GTS 350 are for the nobbled cars that tested a full 3 seconds slower to 100mph than they should have (if you know Quadrajets you know this is extremely easy to do). Peter Robinson actually states that he was no longer sure that the Falcon GT was the best local GT. Remember though that this is in comparison to the XW GT-HO's (HO and HOII), the XY GT-HO was not released until mid 1971 long after the HG GTS350 was no longer a new car, so no back to back tests were ever conducted.

Edited by user Thursday, 2 March 2017 7:45:33 AM(UTC)  | Reason: Not specified

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castellan Offline
#30 Posted : Thursday, 2 March 2017 10:10:57 AM(UTC)
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When you point out that a auto and the manual car with the same engine have seen the near same times come up, yes I know that's true, we see the near same 1/4 times come up at times and think hang about, but if the test points out the diff ratios in all cases then we can see why and if they did test all the way to top speed then we can see the true picture.
One case was the Falcon XR6 VS the XR8 the test only went up to 1/4 mile and speed did not go to top end, the bastard was speed limited as well and that's another thing, no one knew that the ED Falcons were speed limited, the testers did not say anything about it,
When I bought my new 1993 XG Falcon ute it would cut out at 210KM/H I took it back to Ford and they did not have a clue why, the top mechanic could not work it out, he thought it the fuel filter.
A mate bought a 1994 XG ute and it was speed limited to 180KM/H he ended up late for work on the first day with his new car and he was furious when he rang Ford.
I had a VY SS ute and it was speed limited at 210KM/H I could not live with that, so I got it removed.
Hell my 66yo Grand Dad drove at 200KM/H back in 1979 and thought nothing of it, as it was just normal thing that most people did in his country. so they could not conduct half arse test over there, like we do here.

The HQ-J 308 makes it's peek power in reality at about 4500RPM as does the HQ350 and there is no point in going past that rev as all you will do is loose performance and you times will be slower over the 1/4 4000RPM in 1st then 4500 in 2ed and 4500 in 3rd is best and let the Torque do the work.
Hey remember the HK GTS 327 Monaro at Bathurst never went over 4500RPM in 1st 2ed and 3rd Harry pointed this out and if he seen them going past that, they would cop it over the hear from him and all. the other fools racing would only loose time and use more fuel, and that's why Harry was a master that got races won.
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Dr Terry Offline
#31 Posted : Thursday, 2 March 2017 10:53:15 AM(UTC)
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Originally Posted by: castellan Go to Quoted Post

A mate bought a 1994 XG ute and it was speed limited to 180KM/H he ended up late for work on the first day with his new car and he was furious


He was late for work because he couldn't go over 180 km/h ??

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HK1837 Offline
#32 Posted : Thursday, 2 March 2017 11:53:07 AM(UTC)
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Originally Posted by: castellan Go to Quoted Post
When you point out that a auto and the manual car with the same engine have seen the near same times come up, yes I know that's true, we see the near same 1/4 times come up at times and think hang about, but if the test points out the diff ratios in all cases then we can see why and if they did test all the way to top speed then we can see the true picture.

The HQ-J 308 makes it's peek power in reality at about 4500RPM as does the HQ350 and there is no point in going past that rev as all you will do is loose performance and you times will be slower over the 1/4 4000RPM in 1st then 4500 in 2ed and 4500 in 3rd is best and let the Torque do the work.
Hey remember the HK GTS 327 Monaro at Bathurst never went over 4500RPM in 1st 2ed and 3rd Harry pointed this out and if he seen them going past that, they would cop it over the hear from him and all. the other fools racing would only loose time and use more fuel, and that's why Harry was a master that got races won.


In the HQ's case the manual car should be and is quicker, if the manual car was in the same state of tune - it had its Quadrajet fiddled with. There is no other viable explanation - GMH simply did what they did to the HT press test cars. And they did do 100mph tests on these and the auto was quicker.

HJ 308 is a very different engine to HQ 308, that is a fact, and it produces its peak power higher in revs than HQ. This is a simple fact to grasp!

HK GTS327 was revved to 6500rpm all day by Des West and it was the fastest car consistently there. One of the HDRT cars had a 3.36 rear axle too and it is the car hot on Des's tail for the first 4-5 laps. Harry's XT GT's couldn't even come close to the HK's on track despite how hard they were driven. By the end of the 6th lap a photo at the bottom of Conrad shows only Monaros up the hill, the Fords were so far back. It was only pit stops at differing times that saw the order of cars get screwed up until they'd all finished their last stop and sprinted for the finish. Simple mathematics shows that two stops for the Monaros with their larger fuel tanks and three for the Fords meant that they were never going to win despite blinkered reporting that showed a Ford in front when it blew an engine. In reality that snapshot was not long after the leading Monaros second stop and before the Ford was scheduled for its third.

I think you are thinking about 1969 with Harry giving an earful, and yes he yanked Brock out of the car for going too hard. Those Monaros won in 1969 by doing it easily, if needed they could have gone harder (although admittedly it doesn't necessarily guarantee they'd finish either if they went harder). People incorrectly say that the PhaseII would have trounced the Monaros in 1970, but that is far from the truth. 1970 was a slower race despite the crash on the first lap, and 1969 fastest laps were quicker as well as the race time. As it was both of the leading Fords in 1970 were ailing and another half a dozen laps may have seen their demise. Don Holland's LC XU1 was less than half a lap behind (although it is incorrectly reported as coming third a lap behind which is incorrect).

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castellan Offline
#33 Posted : Thursday, 2 March 2017 8:26:30 PM(UTC)
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Originally Posted by: HK1837 Go to Quoted Post
Originally Posted by: castellan Go to Quoted Post
When you point out that a auto and the manual car with the same engine have seen the near same times come up, yes I know that's true, we see the near same 1/4 times come up at times and think hang about, but if the test points out the diff ratios in all cases then we can see why and if they did test all the way to top speed then we can see the true picture.

The HQ-J 308 makes it's peek power in reality at about 4500RPM as does the HQ350 and there is no point in going past that rev as all you will do is loose performance and you times will be slower over the 1/4 4000RPM in 1st then 4500 in 2ed and 4500 in 3rd is best and let the Torque do the work.
Hey remember the HK GTS 327 Monaro at Bathurst never went over 4500RPM in 1st 2ed and 3rd Harry pointed this out and if he seen them going past that, they would cop it over the hear from him and all. the other fools racing would only loose time and use more fuel, and that's why Harry was a master that got races won.


In the HQ's case the manual car should be and is quicker, if the manual car was in the same state of tune - it had its Quadrajet fiddled with. There is no other viable explanation - GMH simply did what they did to the HT press test cars. And they did do 100mph tests on these and the auto was quicker.

HJ 308 is a very different engine to HQ 308, that is a fact, and it produces its peak power higher in revs than HQ. This is a simple fact to grasp!

HK GTS327 was revved to 6500rpm all day by Des West and it was the fastest car consistently there. One of the HDRT cars had a 3.36 rear axle too and it is the car hot on Des's tail for the first 4-5 laps. Harry's XT GT's couldn't even come close to the HK's on track despite how hard they were driven. By the end of the 6th lap a photo at the bottom of Conrad shows only Monaros up the hill, the Fords were so far back. It was only pit stops at differing times that saw the order of cars get screwed up until they'd all finished their last stop and sprinted for the finish. Simple mathematics shows that two stops for the Monaros with their larger fuel tanks and three for the Fords meant that they were never going to win despite blinkered reporting that showed a Ford in front when it blew an engine. In reality that snapshot was not long after the leading Monaros second stop and before the Ford was scheduled for its third.

I think you are thinking about 1969 with Harry giving an earful, and yes he yanked Brock out of the car for going too hard. Those Monaros won in 1969 by doing it easily, if needed they could have gone harder (although admittedly it doesn't necessarily guarantee they'd finish either if they went harder). People incorrectly say that the PhaseII would have trounced the Monaros in 1970, but that is far from the truth. 1970 was a slower race despite the crash on the first lap, and 1969 fastest laps were quicker as well as the race time. As it was both of the leading Fords in 1970 were ailing and another half a dozen laps may have seen their demise. Don Holland's LC XU1 was less than half a lap behind (although it is incorrectly reported as coming third a lap behind which is incorrect).


Everyone knows that HQ 350 manual is faster than the slush box T400 auto.
They just went and rev the bugger too much, and I know that almost impossible to teach people not to do that, because everyone loves to rev a V8 right out.

The HJ 308 is bugger all in it to a HQ 308 a little bit bigger cam and the compression means bugger all because the cam needs more static compression. just because the Net max HP says 5000RPM that does not make it so with the DIN HP. there would be only a bee's whisker in it.

A stock HK GTS327 may rev to 6500 but with that stock cam there is no way it would perform well at that, to make max power it would need a 30/70 cam at least to make max power at 6500RPM.

Yep Harry and the 1969 you are correct.

When it comes to the grate race that's just one thing, but out on the highway non of the Holden GTS could cut it with a XW GT-HO Windsor or Cleveland powered Phase 2 or Phase 3 and everyone should know that is a fact, the 351 HO Windsor has a bigger cam than the Chevys and the Phase 2 had a 40/80 cam and the Phase 3 had a 40/80 cam as well but less lift than the Phase 2, the Phase 2 was a bastard to drive and the Phase 3 was a bit better but you grand mother could not drive such a car with a huge cam like that, pig rooting away and even taking off would be a pain, but the Holden GTS 327, 350 could be driven by anyone.
Even at my age I would hate to drive a car with a 40/80 cam on the street every day, on the race track it's fine. on the road driving with such a big cam you would not have a licence for long because it makes you want to open it right up all the time and it's 4000RPM to 7000RPM time Dancing Angel
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HK1837 Offline
#34 Posted : Friday, 3 March 2017 10:37:26 AM(UTC)
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I'm pretty sure that isn't the case, the manual car's 1/4 mile trap speed was lower indicating less power, thus it was fiddled with. And this is not only one car.

Nope, as I've stated multiple times the HJ engine performs significantly better than the HQ. It was well known back in the day that the later LH SLR5000's were the cars to have, not the early ones with HQ engines. It is around 25hp (peak) difference but also significant torque improvement. I have the original GMH dyno curves for the earlier 308 and these engines are not 240hp.

The 6500rpm useability of the engine is the key for the GTS327 engine. Not the 5500rpm as indicated by the tacho redline. In the road tests at the press release Journos were not allowed to rev it past the redline, and it was this performance that was reported in the magazine articles at the time that people have perpetuated over time as "gospel" as you say. At Bathurst most driver's proved that the engine was quite safe and useable to 6500rpm and this was why the 3.36 diff cars were more effective on a lap by lap basis.

Again, the last statement is based upon what people think the GTS350's could do based upon road tests of controlled cars. GMH did their job very well in this area. All you have to do is read Mel Nichol's and Peter Robinson's articles on the GTS350's and how astounded they were that these later cars were nothing like the ones that GMH gave them to test early in HT. Like 3 full seconds quicker 0-100mph - in fact as fast or faster than any XW GT-HO they ever tested. As far as both were concerned the GTS350 was a far superior point to point car than a GT-HO or GT-HO II. As I said prior though none of this is relevant to a GT-HOIII unless you want to compare the eras of two cars that don't overlap at all in availability. The GT-HOIII may well be and probably is the superior car in outright performance, but by real numbers alone on paper it isn't by much. This was one of the whole points of the AMC article when they tested the untouched GTS350 to prove that what Mel Nichols and Peter Robinson experienced was in fact 100% accurate and had remained largely unknown by most other than the few HT and HG GTS350 owners who knew how well they actually performed. I agree with you that a solid lifter and big cam, big port angry thing with 3 or 3.25 gearing and close ratio manual box is never going to be comfortable to drive compared to something with a little less power but better gearing and more useable torque. However the real numbers in terms of 1/4 mile, trap speed and 0-100mph don't lie. There is a reason why people are paying $250k+ for GTS327 and GTS350M right now, and it is a reason greater than rarity. It is because people with money (some would say more money than sense!) are realising that these are the GMH performance cars to have, the top of the tree cars are these. For years people paid overs for GT-HO's as they knew all about their performance, but now people realise the significance of the GTS327/350 their values have gone up. These are the only true factory GMH race cars that anyone could buy off the street and won Bathurst on tyres that were optional tyres for the street car. None of the other GMH/Holden Bathurst wins are even close to claiming that, even the 1972 XU1 that won in the last year of Series Production was not what it pretended to be.
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castellan Offline
#35 Posted : Friday, 3 March 2017 12:39:03 PM(UTC)
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I believe the HT-Q 308 had 240 SAE HP and the HJ had 250 SAE HP and the HJ cam would be ok to represent that.

What I am pointing out about the Holden Chev powered engines is that, one may rev as far as you like but there is no real point over the 1/4 on the touring race track you may rev it more due to some good reason as to why, but not as a rule, if the SAE HP says max power is 4800 and with race exhaust it may just have that, but to rev beyond that point is fruitless, you would be best to keep it between the max torque, say 3000RPM and max HP 4800RPM because that's were you will get your best performance out of the engine.
The redline means nothing much to people who understand why Holden put it there.
You work out you gearing for what best suits the track you are on or what you want out of it.

Faster than any GT-HO tested all the way to top speed ? BS.
I do prefer the rear end handling of the HK-T-G-Q to the Falcons any day but the falcons front end was better and at high speed 180KM/H plus, give me the Holden any day.

Yes 1/4 time and speed can lie or not tell the whole truth, bad take off slow gear change and not making use of the power to it's best advantage can make all the difference and we are on about stock cars here, not fully bombed up engines, as that will make more of a difference to the top speed at the end of the 1/4 and that your dealing with a car that's been built for the 1/4, hell I beat a real well worked 400 chev with a 350 crank in it, over the 400m but he went past me around about 404m at about 100KM/H faster, but I won !
400m does not tell the full story but 1000m tells a lot more.

What the cars did at Bathurst and such means nothing to me or the value of the cars, Bathurst is just Bathurst and look all the people who went and bought new the GTS 327 350 HK-T-G-Q and the XU-1's never bought them to race, but just as a better car to drive over the rest of the other stuff.
Back in the day I would of watched Bathurst but that would not influence what car I bought, as it would do with is it right for me.

Well talk about tyres in them years, you trying to scare me ! I remember the crap we had and I would change them when nearly about half worn because the compound would get harder and got even worse handling and not to mention how many times there were stars starting in the sidewalls, real good tyres did not come out till Brimstone RE71 for 14in wheels and now tyres for the old 14in wheels are just crappy rubbish again, because everyone is now got 17in or more low profile crap and I have come across some crappy 17in and 18in low profile tyres that have shit steering response and crap ability.

At the Warwick Monaro show some years ago a dude had fitted some new tyres of that era, the tyre company's made such, so such people could show there cars as original, well this bloke had a trip down memory lane with them on the old HQ 350 and I could see in his face what he experienced ha ha! yep them were the days of crap tyres and they were what was the good radials at the time, not the bloody rag rubbish.
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#36 Posted : Friday, 3 March 2017 1:18:51 PM(UTC)
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Anyway....... Holden got 260hp out of the 253 in the Hurricane. Pretty impressive. I love the little 253.
What specs were the 253 I the Hurricane?
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#37 Posted : Friday, 3 March 2017 8:44:43 PM(UTC)
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Originally Posted by: wbute Go to Quoted Post
Anyway....... Holden got 260hp out of the 253 in the Hurricane. Pretty impressive. I love the little 253.
What specs were the 253 I the Hurricane?


260HP at 6000RPM 260LB at 3800RPM and a Rochester Quadrajet 10:1 compression, it had a solid lifter cam and std valves I would say. they may of totalled it, if it had a 308 in it, but I think it was more about trying to sell the 253.

It were made to put a spin on the new Holden V8's coming out.

Holden were coming of age with a new evolved V8 that was way ahead of the old out dated heavy chev V8, the small 253 was to be tipped to be the main selling engine for Holden's giving Australians a nice willing type of performance over what the Ford 250 slug was, just a torque type of thing that gave up the ghost after 3500RPM boring as.
But Australians mainly had a fear of V8's thinking such were a prestige thing or too sporty, all them old sods that grew up with them old 6 cyl Grey motors were just hard to convince, and they thought the 6 cyl red motor was a rocket ship.

I thought the 253 a good engine for the job of good highway driving and towing for the average Joh Blow and the 6 cyl is just does the job for the wife of town driven car.
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#38 Posted : Saturday, 4 March 2017 12:37:38 PM(UTC)
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Originally Posted by: castellan Go to Quoted Post
I believe the HT-Q 308 had 240 SAE HP and the HJ had 250 SAE HP and the HJ cam would be ok to represent that.

What I am pointing out about the Holden Chev powered engines is that, one may rev as far as you like but there is no real point over the 1/4 on the touring race track you may rev it more due to some good reason as to why, but not as a rule, if the SAE HP says max power is 4800 and with race exhaust it may just have that, but to rev beyond that point is fruitless, you would be best to keep it between the max torque, say 3000RPM and max HP 4800RPM because that's were you will get your best performance out of the engine.
The redline means nothing much to people who understand why Holden put it there.
You work out you gearing for what best suits the track you are on or what you want out of it.

Faster than any GT-HO tested all the way to top speed ? BS.
I do prefer the rear end handling of the HK-T-G-Q to the Falcons any day but the falcons front end was better and at high speed 180KM/H plus, give me the Holden any day.

Yes 1/4 time and speed can lie or not tell the whole truth, bad take off slow gear change and not making use of the power to it's best advantage can make all the difference and we are on about stock cars here, not fully bombed up engines, as that will make more of a difference to the top speed at the end of the 1/4 and that your dealing with a car that's been built for the 1/4, hell I beat a real well worked 400 chev with a 350 crank in it, over the 400m but he went past me around about 404m at about 100KM/H faster, but I won !
400m does not tell the full story but 1000m tells a lot more.

What the cars did at Bathurst and such means nothing to me or the value of the cars, Bathurst is just Bathurst and look all the people who went and bought new the GTS 327 350 HK-T-G-Q and the XU-1's never bought them to race, but just as a better car to drive over the rest of the other stuff.
Back in the day I would of watched Bathurst but that would not influence what car I bought, as it would do with is it right for me.

Well talk about tyres in them years, you trying to scare me ! I remember the crap we had and I would change them when nearly about half worn because the compound would get harder and got even worse handling and not to mention how many times there were stars starting in the sidewalls, real good tyres did not come out till Brimstone RE71 for 14in wheels and now tyres for the old 14in wheels are just crappy rubbish again, because everyone is now got 17in or more low profile crap and I have come across some crappy 17in and 18in low profile tyres that have shit steering response and crap ability.

At the Warwick Monaro show some years ago a dude had fitted some new tyres of that era, the tyre company's made such, so such people could show there cars as original, well this bloke had a trip down memory lane with them on the old HQ 350 and I could see in his face what he experienced ha ha! yep them were the days of crap tyres and they were what was the good radials at the time, not the bloody rag rubbish.


HT-HQ 308 is CLAIMED 240hp, but in actuality it is 226hp SAE gross. As I said the original curves for it are on public record. GMH re-rated all their engines during HJ to probably reflect the actual power not the claimed power. The HJ 308 was accurately rated at 250hp@5000rpm. The HJ 253 (same engine as HT-HQ) was rated at 175hp@4800 (HQ was 185hp@4400). All the 6cyl were treated the same. The peak torque of the HT-HQ 308 vs the HJ 308 also shows the bigger camshaft and more suitable camshaft timing used in HJ, HQ 315lbft@3000, HJ 320lbft@3400. Fred James says it quite clearly on page 24 of his Engineering Report of the 253 and 308 that for cost and compromise they simply stuck with the same camshaft as the 253 and retarded it 5deg to achieve the target peak power output with only some compromise on low end torque and idle (which is what retarding a camshaft does). He says this was a compromise, and that subsequent testing showed that "remarkable top end power increases can be obtained without an appreciable low end torque loss just by cam changed alone". Given the part number of the HJ camshaft it puts it right back not long after the initial 308's use in HT, so it will the HJ's cam profile he is referring to.

I didn't say fastest to top speed. I said fastest to 100mph. XW GT-HO as tested by Wheels and SCW: 0-100mph 16.7s. HG GTS350's (2 x different cars) as tested by Mel Nichols and Peter Robinson - 0-100mph in "just over" 16.0s. AMC issue 51 test on untouched HG GTS350 - 0-100mph 15.95s. It can't be any clearer that that!

Edited by user Saturday, 4 March 2017 12:39:10 PM(UTC)  | Reason: Not specified

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#39 Posted : Saturday, 4 March 2017 5:38:27 PM(UTC)
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Ok 226HP SAE Gross, that would be about right for Gross, but it still must be 240HP Net.

Remember that the HJ 253 got a smaller cam than what it had in the HQ and the book I have states HJ 253 has 185HP at 4400RPM, but if we look at the HX 253 export that does not have EGR ADR27A it's rated in SAE Gross at 174HP at 4800RPM, so that maybe the correct Gross as the same export 308 is 250HP.
As for the HJ 308 cam specs I can't find anything that plots the true spec to work it truly all out, as one that is rated as such does not tell the full story at all because one can take the points of such at below 0.050 lift as meaning any true meaning especially at 0.002 or to 0.006, I am sure it's bigger and the most important part is the exhaust being much more so and that's to get more heat in the exhaust to burn unburnt fuel before the cat converters came out in the USA, as there EPA laws came out way before ours.
Here look at this 308 HJ exhaust valve is open 11 more deg and the 253 is 18 deg more but a smaller cam than the HQ 253 and the compression is up 0.4 too and all in the HX to cover for the loss in real time compression, it's the dynamic compression that the different cams create, so one has to increase the static compression to cover that aspect and in the case of the cam in the 308 HJ I would say that the dynamic compression has not changed any more than a 308 HT-Q was, if any.

I have seen people put the small chamber heads on stock holden 6 cyl red motors and get nothing gained at all and the same with stock 351 they drop 302 heads on them and got nothing at all, most likely had to retard their dizzy timing and lost every thing they were looking for, like most idiots do with bombing up they engine, and just create a grenade or a ticking time bomb.

The Wheels and sports'car world publication, muscle cars of 1986 has.
XW GT-HO Windsor 351 3.25 diff VS Holden GTS 350 3.36 diff
Ford Holden Ford
0- 30mph 2.8 sec GTS350 in 28 sec and the XY GT-HO 2.3 sec
0- 40 mph 3.9 vs 3.9 3.3
0- 50 mph 4.9 vs 5.6 4.8
0- 60 mph 6.7 vs 8.1 6.4
0- 70 mph 9.2 vs 9.7 8.3
0- 80 mph 11.2 vs 12.1 10.4
0- 90 mph 14.4 vs 15.2 12.4
0- 100mph 16.7 vs 18.9 15.2
400m 14.4 vs 15.6 ----
0- 110 mph 18.5
0- 120 mph 22.5 sec

We don't have the XW Phase 2 times.
I don't have AMC book no 51 was it tested both directions with 2 people up in it.

Edited by user Saturday, 4 March 2017 6:02:42 PM(UTC)  | Reason: Not specified
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#40 Posted : Saturday, 4 March 2017 8:08:04 PM(UTC)
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226 hp SAE gross would be less than 200hp net, not more!

HJ 253 didn't get a smaller cam, the engine was identical to HQ. It was the 308 that got revised. The HX 253 got the smaller cam. The book you have has the HJ release figures and they didn't change them despite the 308 being better. They were all revised mid HJ, they all went down to more realistic figures but the 308 went up.

The export HX engines are the same engines fitted to HJ in 1974. There was a small change in 1/75 to seal the fuel bowl and seal the idle screws. For whatever reason GMH changed the HJ engine figures for HJ release in internal documents but didn't put it in public documents (like owners manuals) until later in 1975. A cynic might say they tried to talk the bulk of the engines down to make the HX engines look better on paper than they were.

Cam is bigger, end of story. The same cam grind was used in all SBC's in 1968-9 up to 300hp regardless of the compression. It was used in 8.5:1 up to 10:1 engines. The HJ cam was not used as the engine had more compression or they would have revised the cam back again when the 308 dropped to 9.4 then 9.2 and again even lower at 304 introduction and then again in VL. the cam is an optimised cam for the 308, not a compromise like the 5deg retarded 253 cam.

That GTS350 test is the nobbled GST350. This is what I've been talking about. True total figures were never obtained, only those by Mel Nichols and Peter Robinson on HG's and this is why they were both so surprised after having driven the cars GMH supplied during HT. The lack of a full test was why AMC mag did it as the car they used was a time capsule, and the AMC tests were done identically to how they were done in the day, with two drivers, full tank and throttle lift shifts. The figures are averages of multiple runs.

Edited by user Saturday, 4 March 2017 9:02:58 PM(UTC)  | Reason: Not specified

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