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HK1837 Offline
#41 Posted : Saturday, 9 March 2019 2:33:09 PM(UTC)
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Unless you do an actual profile on the camshafts you'll never know. I did this for the VK EFI cam in the early 90's, and I do still have (I think) an original XT4 auto (HX-HZ) camshaft that I removed from a low kM VB in the 80's that I could profile if need be. But none of that interests me, I just wanted to know a comparison between the cams all taken at the same lift which is what I now have.

The HJ onwards 308/304 cam can't be the exact same cam grind as the General Purpose SBC hydraulic cam - for starters they run a different case circle and use different ratio rockers (Holden V8 is 1.6, SBC is 1.5) so to get the same valve lift at 0.004" (or 0.006" or whatever it is) the profiles have to be different. However as you can see from both GMH and GM's lack of camshaft diversity (close enough is good enough for a mass engine producer) they simply designed a camshaft in 1968-9 based upon what GM were using and specced the same duration, but didn't use it until later in 1974.

Note I also found in the last few weeks the Engineering Program Change Notice for why there was a second red 4.2L AR27A camshaft released - it was a simple matter of valve gear noise in the range 2400-2600rpm, notice was issued 3/77. Says that cam 9936254 needed to be replaced and a 26 week lead time was required to get ADR27A certification prior to HZ SOP. Cost to do the cam change was $25000. So you can see why cams didn't change very often!
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castellan Offline
#42 Posted : Sunday, 10 March 2019 8:01:27 AM(UTC)
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Originally Posted by: HK1837 Go to Quoted Post
Unless you do an actual profile on the camshafts you'll never know. I did this for the VK EFI cam in the early 90's, and I do still have (I think) an original XT4 auto (HX-HZ) camshaft that I removed from a low kM VB in the 80's that I could profile if need be. But none of that interests me, I just wanted to know a comparison between the cams all taken at the same lift which is what I now have.

The HJ onwards 308/304 cam can't be the exact same cam grind as the General Purpose SBC hydraulic cam - for starters they run a different case circle and use different ratio rockers (Holden V8 is 1.6, SBC is 1.5) so to get the same valve lift at 0.004" (or 0.006" or whatever it is) the profiles have to be different. However as you can see from both GMH and GM's lack of camshaft diversity (close enough is good enough for a mass engine producer) they simply designed a camshaft in 1968-9 based upon what GM were using and specced the same duration, but didn't use it until later in 1974.

Note I also found in the last few weeks the Engineering Program Change Notice for why there was a second red 4.2L AR27A camshaft released - it was a simple matter of valve gear noise in the range 2400-2600rpm, notice was issued 3/77. Says that cam 9936254 needed to be replaced and a 26 week lead time was required to get ADR27A certification prior to HZ SOP. Cost to do the cam change was $25000. So you can see why cams didn't change very often!


Sure I understand what you are doing as to he Holden point of reference.

So we have a HX 4.2L Cam and a HZ 4.2L Cam.

But were did the HT to the HQ V8 Cam profile come from, I don't think any Chev Cam is such at all.
Not to mention why did they time them differently as to 253 and 308 not to mention time the first LH 308 to the 253 spec.

I think that Holden were trying to limit some of the torque of the first LH 308 by retarding the timing to the 253 spec, because of the piss weak banjo diff.

Not to mention that I was looking at advertising of the HJ 308 and how many times they were rating the 308 at 240HP now why did they keep saying that, maybe it's only the GTS and later SLR 5000 that got he 250HP.

As for the HJ 5.0L Cam being that Holden just grabbed the Chev GP Cam profile well it's not the same truly at all, not to mention that both the 4.2L and 5.0L HX Cams have much longer exhaust durations and this is not done for any performance reason that I can see of, but for heating up the exhaust more, so as to burn more unburnt fuel up, so as to meat ADR Laws.
Dr Terry Offline
#43 Posted : Sunday, 10 March 2019 10:37:05 AM(UTC)
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Originally Posted by: castellan Go to Quoted Post
Not to mention that I was looking at advertising of the HJ 308 and how many times they were rating the 308 at 240HP now why did they keep saying that, maybe it's only the GTS and later SLR 5000 that got he 250HP.


AFAIK all 308 from HJ release to July 76 (HX release) had the higher comp engine with different cam timing rated at 250 bhp. This includes LH (& early LX) from engine no. HT24413.

An HJ GTS with a 308 got the same engine as an optioned up Kingswood or Premier

In my person experience of untouched cars in the day there was a much greater improvement in performance than 10 bhp suggested.

Dr Terry

Edited by user Sunday, 10 March 2019 10:39:45 AM(UTC)  | Reason: Spelling

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HK1837 Offline
#44 Posted : Sunday, 10 March 2019 10:52:51 AM(UTC)
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Originally Posted by: castellan Go to Quoted Post
Originally Posted by: HK1837 Go to Quoted Post
Unless you do an actual profile on the camshafts you'll never know. I did this for the VK EFI cam in the early 90's, and I do still have (I think) an original XT4 auto (HX-HZ) camshaft that I removed from a low kM VB in the 80's that I could profile if need be. But none of that interests me, I just wanted to know a comparison between the cams all taken at the same lift which is what I now have.

The HJ onwards 308/304 cam can't be the exact same cam grind as the General Purpose SBC hydraulic cam - for starters they run a different case circle and use different ratio rockers (Holden V8 is 1.6, SBC is 1.5) so to get the same valve lift at 0.004" (or 0.006" or whatever it is) the profiles have to be different. However as you can see from both GMH and GM's lack of camshaft diversity (close enough is good enough for a mass engine producer) they simply designed a camshaft in 1968-9 based upon what GM were using and specced the same duration, but didn't use it until later in 1974.

Note I also found in the last few weeks the Engineering Program Change Notice for why there was a second red 4.2L AR27A camshaft released - it was a simple matter of valve gear noise in the range 2400-2600rpm, notice was issued 3/77. Says that cam 9936254 needed to be replaced and a 26 week lead time was required to get ADR27A certification prior to HZ SOP. Cost to do the cam change was $25000. So you can see why cams didn't change very often!


Sure I understand what you are doing as to he Holden point of reference.

So we have a HX 4.2L Cam and a HZ 4.2L Cam.

But were did the HT to the HQ V8 Cam profile come from, I don't think any Chev Cam is such at all.
Not to mention why did they time them differently as to 253 and 308 not to mention time the first LH 308 to the 253 spec.

I think that Holden were trying to limit some of the torque of the first LH 308 by retarding the timing to the 253 spec, because of the piss weak banjo diff.

Not to mention that I was looking at advertising of the HJ 308 and how many times they were rating the 308 at 240HP now why did they keep saying that, maybe it's only the GTS and later SLR 5000 that got he 250HP.

As for the HJ 5.0L Cam being that Holden just grabbed the Chev GP Cam profile well it's not the same truly at all, not to mention that both the 4.2L and 5.0L HX Cams have much longer exhaust durations and this is not done for any performance reason that I can see of, but for heating up the exhaust more, so as to burn more unburnt fuel up, so as to meat ADR Laws.


They developed the HK 253 (later released with HT) cam, and developed a 308 cam too but by retarding the 253's cam in the 308 they got the performance they were looking for and could use a common cam across both engines. All HT to HJ 253 including LH and early LX) are the same (except for the few trial ADR27A HJ's from Pagewood). All HT to the end of HQ and early LH are the same (except L34).

Up until HJ the figures were advertised. After that they appear to be proper GM20 gross bhp. The HT to HQ 308 is really 227bhp by GM20 test, the HJ engine is 250bhp. I recently got curves for HD and HR engines that show "advertised", GM20 (SAE gross) and GM1 (SAE net) figures, the GM20 figures are about 15-20hp lower than the advertised figures, which is basically what the HJ figures are compared to HQ (except for 308). There were a few edicts issued by GM in the early for all their brands to align to Corporate Standards, I bet this was one of them.

HX 5.0L cam is the same as the HJ one (and the same until VL), it is not an emissions cam, just a General Purpose Grind and will be the original 308 cam developed for HT but not used, the part number aligns with HK era. Only the HX 4.2L cam differs from the earlier two camshafts. GM used the same basic cam as the 308 one until about 1980 in all SBC's too.

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castellan Offline
#45 Posted : Monday, 11 March 2019 11:08:47 AM(UTC)
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Originally Posted by: HK1837 Go to Quoted Post
Originally Posted by: castellan Go to Quoted Post
Originally Posted by: HK1837 Go to Quoted Post
Unless you do an actual profile on the camshafts you'll never know. I did this for the VK EFI cam in the early 90's, and I do still have (I think) an original XT4 auto (HX-HZ) camshaft that I removed from a low kM VB in the 80's that I could profile if need be. But none of that interests me, I just wanted to know a comparison between the cams all taken at the same lift which is what I now have.

The HJ onwards 308/304 cam can't be the exact same cam grind as the General Purpose SBC hydraulic cam - for starters they run a different case circle and use different ratio rockers (Holden V8 is 1.6, SBC is 1.5) so to get the same valve lift at 0.004" (or 0.006" or whatever it is) the profiles have to be different. However as you can see from both GMH and GM's lack of camshaft diversity (close enough is good enough for a mass engine producer) they simply designed a camshaft in 1968-9 based upon what GM were using and specced the same duration, but didn't use it until later in 1974.

Note I also found in the last few weeks the Engineering Program Change Notice for why there was a second red 4.2L AR27A camshaft released - it was a simple matter of valve gear noise in the range 2400-2600rpm, notice was issued 3/77. Says that cam 9936254 needed to be replaced and a 26 week lead time was required to get ADR27A certification prior to HZ SOP. Cost to do the cam change was $25000. So you can see why cams didn't change very often!


Sure I understand what you are doing as to he Holden point of reference.

So we have a HX 4.2L Cam and a HZ 4.2L Cam.

But were did the HT to the HQ V8 Cam profile come from, I don't think any Chev Cam is such at all.
Not to mention why did they time them differently as to 253 and 308 not to mention time the first LH 308 to the 253 spec.

I think that Holden were trying to limit some of the torque of the first LH 308 by retarding the timing to the 253 spec, because of the piss weak banjo diff.

Not to mention that I was looking at advertising of the HJ 308 and how many times they were rating the 308 at 240HP now why did they keep saying that, maybe it's only the GTS and later SLR 5000 that got he 250HP.

As for the HJ 5.0L Cam being that Holden just grabbed the Chev GP Cam profile well it's not the same truly at all, not to mention that both the 4.2L and 5.0L HX Cams have much longer exhaust durations and this is not done for any performance reason that I can see of, but for heating up the exhaust more, so as to burn more unburnt fuel up, so as to meat ADR Laws.


They developed the HK 253 (later released with HT) cam, and developed a 308 cam too but by retarding the 253's cam in the 308 they got the performance they were looking for and could use a common cam across both engines. All HT to HJ 253 including LH and early LX) are the same (except for the few trial ADR27A HJ's from Pagewood). All HT to the end of HQ and early LH are the same (except L34).

Up until HJ the figures were advertised. After that they appear to be proper GM20 gross bhp. The HT to HQ 308 is really 227bhp by GM20 test, the HJ engine is 250bhp. I recently got curves for HD and HR engines that show "advertised", GM20 (SAE gross) and GM1 (SAE net) figures, the GM20 figures are about 15-20hp lower than the advertised figures, which is basically what the HJ figures are compared to HQ (except for 308). There were a few edicts issued by GM in the early for all their brands to align to Corporate Standards, I bet this was one of them.

HX 5.0L cam is the same as the HJ one (and the same until VL), it is not an emissions cam, just a General Purpose Grind and will be the original 308 cam developed for HT but not used, the part number aligns with HK era. Only the HX 4.2L cam differs from the earlier two camshafts. GM used the same basic cam as the 308 one until about 1980 in all SBC's too.


I know all that.
South Africa HT-G GTS Monaro 308 is rated at 204hp Net or DIN and the HQ 308 GTS is rated as 196HP, now that's factual power ratings and the difference is in the exhaust I would say as the HT-G GTS flows better and the HQ twin exhaust is a quieter system, so theirs your lacking of 8hp that I can see.

I will have to look for the HJ 308 South African figures but I don't remember it stated anywhere when I looked last.

I have an old book that they did dyno test at the flywheel and the 308 made 196hp stock and then they just went on with adding other Cams and intakes carbys etc etc and they did the same with the 350 chev and the 351 Cleveland showing the HP and torque chart all through the rev range.
HK1837 Offline
#46 Posted : Monday, 11 March 2019 11:48:16 AM(UTC)
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They’ll probably be GM1 (SAE net) figures. They are simulated “as installed” tests. This was adopted by GM fully in 1972 and they published both SAE gross and SAE net for 1971. The SAE Standard for it is J1349. The test includes air cleaner, exhaust, belt driven accessories etc.
The SAE gross tests (GM20 to J245) don’t include accessories, air cleaner or exhaust, just exhaust manifolds. Fuel and air are carefully controlled so that the tests are repeatable and comparable. The 227bhp I have for the HQ 308 is to this test.

You can start to see already with the SAE net figures between SA HT and HQ how anything other than SAE gross start to be misleading, unless you know the engines intimately you start to wonder why they are rated differently.
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castellan Offline
#47 Posted : Monday, 11 March 2019 5:18:34 PM(UTC)
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Originally Posted by: HK1837 Go to Quoted Post
They’ll probably be GM1 (SAE net) figures. They are simulated “as installed” tests. This was adopted by GM fully in 1972 and they published both SAE gross and SAE net for 1971. The SAE Standard for it is J1349. The test includes air cleaner, exhaust, belt driven accessories etc.
The SAE gross tests (GM20 to J245) don’t include accessories, air cleaner or exhaust, just exhaust manifolds. Fuel and air are carefully controlled so that the tests are repeatable and comparable. The 227bhp I have for the HQ 308 is to this test.

You can start to see already with the SAE net figures between SA HT and HQ how anything other than SAE gross start to be misleading, unless you know the engines intimately you start to wonder why they are rated differently.


Sure I know that is a good way to know that a engine is the same engine, but that's all it's good for.

I love DIN figures as they tell the true story, look at the VB Commodores just magic power figures as you know what to expect, like how the dual exhaust can be proven to anyone that it's a good up grade option, as most back in the days you would be pushing shit up hill to convince Joh average that their is value in such an option.
I know one old mechanic who claims that if the manufacture designed it the way they did, then they know what is best.Eh? Shhh
8D11PCH2 Offline
#48 Posted : Saturday, 16 March 2019 10:12:14 AM(UTC)
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Originally Posted by: HK1837 Go to Quoted Post


LC XU-1 camshafts. In the figures above I only quote the final spec of this camshaft as used in those final LC XU-1 vehicles, I unfortunately do not have the earlier un-revised Engineering Technical Specs for this. However Fiv Antoniou quotes the following (with my notes after it):


LC XU1 (at release as quoted in service letter dated 3/9/1970):
29-57, 266deg, 64-24, 266deg, 0.345", 0.345", 53deg overlap (this is corrected in pen in Fiv's book changed fractionally in the timing, so 30-58, 65-23, not sure if this was done on the actual released letter or if someone has added it later). The duration doesn't add up here on the exhaust on either spec (64+24+180 = 268deg not 266deg), but the duration on the changed spec is 268 on both inlet and exhaust .

LC XU1 (Fiv claims this is an updated cam specified for LC XU1, calls it Bathurst 1970 cam, but with no part number change):
23-65, 268deg, 58-30, 268deg, 0.345", 0.345", 53deg overlap. These figures do add up OK to 268deg on both intake and exhaust. To me it looks like the same camshaft as the earlier camshaft but advanced by 6deg in the timing gear. I'd say the original cam was actually 29-59, 268deg, 64-24, 268deg (which happens to be the ADR27A automatic 6cyl camshaft apart from 7 thou lift discrepancy!). Advance that by 6deg and you get the second camshaft.


38-86, 304deg, 77.3-46.30, 304deg, 0.429", 0.429", overlap 84deg. (Final LC XU1). (44-80, 304deg, 83-40, 304deg, 0.429", 0.429", 84deg overlap LJ XU1 retarded 6deg).

[/b]


There were only ever two camshafts used in the LC XU1. Both camshafts were retarded by 6 deg via the keyway in the LC XU1 timing gear.
The timing figures quoted in the LC XU1 Advance Service Bulletin were incorrect. A bulletin was issued to cancel/correct the incorrect timing figures in the Advance Service Bulletin however the corrected timing figures quoted still did not take into account the fact the camshaft was retarded by 6 degrees. A third Service Bulletin was released to cancel/correct the timing figures quoted in the second bulletin.

It is worthy to note the LC XU1 Recognition documents sent to The CAMS had the correct valve timing figures listed. Although the CAMS recognition date on the form is the 3rd Day of January 1972, 10 copies of the Recognition forms would have been sent to The CAMS at least 1 month before the XU1's competition debut in 1970.
So whilst the GMH LC XU1 Dealer Advanced Service Bulletin (June 1970) and a subsequent Service Bulletin (September 1970) were both issued listing incorrect valve timing figures the LC XU1 Recognition forms were always correct.

The XH cam used in the final evolutions of the LC XU1 is the same physical grind as the LJ XU1 std cam, but it was also retarded by 6 deg in the LC XU1 and installed straight up in the LJ 202 XU1. The only difference between the two XH shafts that necessitated the change in part number will have been the 6 annular clearance grooves ground into the shaft for the 202 big end bolts.

XT5 Cam max lift = 8.9mm or .350"
EFI Cam max lift = 10.2mm or .401"

Edited by user Monday, 25 March 2019 6:27:53 AM(UTC)  | Reason: Not specified

HK1837 Offline
#49 Posted : Saturday, 16 March 2019 12:40:18 PM(UTC)
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So the proper valve timing for LC XU-1 is: 23-65, 268deg, 58-30, 268deg, 0.345", 0.345", 53deg overlap? Which if you stand it back upright is the same as the XT4 auto camshaft other than 7thou quoted lift difference?

They must have decided not long before the start of LJ XU-1 volume production to retard its cam 6deg compared to that final spec LC XU-1 as the pre-release Engineering documents for LJ show same (6deg advanced) figures for LJ XU-1. The documents do pre-date the build of those last LC XU-1 though with the cam timing changed to how LJ was released in a 12/71 revision, so I guess that final LC XU-1 cam actually came from LJ development.

Where did you find the XT5 valve lift figures? I could not find it in either the XT5 engines service manual or the VK service manual supplement. I have to get an old Windows2000 machine running so I can open the file that contains the EFI cam I measured in the early 90's.

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#50 Posted : Saturday, 16 March 2019 1:29:58 PM(UTC)
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Originally Posted by: HK1837 Go to Quoted Post
So the proper valve timing for LC XU-1 is: 23-65, 268deg, 58-30, 268deg, 0.345", 0.345", 53deg overlap? Which if you stand it back upright is the same as the XT4 auto camshaft other than 7thou quoted lift difference?

They must have decided not long before the start of LJ XU-1 volume production to retard its cam 6deg compared to that final spec LC XU-1 as the pre-release Engineering documents for LJ show same (6deg advanced) figures for LJ XU-1. The documents do pre-date the build of those last LC XU-1 though with the cam timing changed to how LJ was released in a 12/71 revision, so I guess that final LC XU-1 cam actually came from LJ development.

Where did you find the XT5 valve lift figures? I could not find it in either the XT5 engines service manual or the VK service manual supplement. I have to get an old Windows2000 machine running so I can open the file that contains the EFI cam I measured in the early 90's.



Correct, the LC 3100X valve timing was 23-65, 268deg, 58-30, 268deg, 0.345", 0.345", 53deg overlap, from SOP for all 3100X prefix engines.
Advancing the camshafts would have resulted in better low/mid range torque in the 186 XU1.

Installing the XH camshaft straight up in the 202 XU1 would have resulted in better top end HP.
castellan Offline
#51 Posted : Saturday, 16 March 2019 3:55:26 PM(UTC)
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OK how is this, you have a stock 202 and you retard the cam by 6 deg, what are you now going to do now to the spark timing ? if the std spec was to be set at 6 deg, now what are you going to set it to now ? 12 deg ?

What Cam hear is advanced and what one is retarded.
we will start with 20/60
25/55 ? adv or ret
15/65 ? adv or ret
Not to mention witch one should need more compression.
Now if it's a Holden red what will you do to the spark timing setting if the stock is 6 deg, so the 15/65 would have to be ? and the 25/55 have to be ?

If we look at a engine and we see the book states 2 deg advanced spark timing and then we see a year later it's saying 6 deg and then next year its 12 deg one could make the assumption that the cam timing has been changed maybe.
Look at a HT to HQ 253 V8 What does Holden recommend and what does it recommend of the HT-Q 308 not to mention the first 308 LH Torana ?
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#52 Posted : Saturday, 16 March 2019 4:48:15 PM(UTC)
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Originally Posted by: castellan Go to Quoted Post
OK how is this, you have a stock 202 and you retard the cam by 6 deg, what are you now going to do now to the spark timing ? if the std spec was to be set at 6 deg, now what are you going to set it to now ? 12 deg ?

What Cam hear is advanced and what one is retarded.
we will start with 20/60
25/55 ? adv or ret
15/65 ? adv or ret
Not to mention witch one should need more compression.
Now if it's a Holden red what will you do to the spark timing setting if the stock is 6 deg, so the 15/65 would have to be ? and the 25/55 have to be ?

If we look at a engine and we see the book states 2 deg advanced spark timing and then we see a year later it's saying 6 deg and then next year its 12 deg one could make the assumption that the cam timing has been changed maybe.
Look at a HT to HQ 253 V8 What does Holden recommend and what does it recommend of the HT-Q 308 not to mention the first 308 LH Torana ?


But you woudln't bother to retard the stock cam from it's original installed (straight up) position. GMH engineered it up to give the best compromise between torque, HP and fuel consumption..
Anyway, I don't see how retarding or advancing the cam is going to have any great bearing on when you want to ignite the A/F mixture.
At the moment the plug fires the inlet and exhaust valves are closed.
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#53 Posted : Saturday, 16 March 2019 5:12:31 PM(UTC)
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Years ago I would have been surprised by the use of the essentically LC XU-1 cam profile used in the ADR27A 202 (albeit stood upright rather than advanced). But here is why I'm not surprised.

Years ago I had a warm 202 in my 2/76 LX hatchback. It was a red VB 202 block with a blue crankshaft and rods. It had what was called a 30/70 camshaft by Waggot, in reality probably not too different to the LX XU-1 camshaft. The engine was pretty much stock 202 type pistons with 186 Yella Terra head, CAIN 4BBL manifold, 390 Holley, extractors and CDI ignition. From memory it dynoed about 100hp at the back wheels so probably in SAE gross terms maybe 175-ish hp. I had pulled that engine out and was putting in a VK EFI engine. It was sitting there unused. I had bought a nice 1980 WB tonner sans engine and box. So I re-ringed that 202, put new bearings in it and put it back together in the tonner otherwise as it was but with extractors and a red pollution manifold and carby plus a blue HEI dizzy. The gearbox was from a VK FI and the rear axle was a 3.08. I had to dress it to appear as if it was an ADR27A engine to pass rego in a 1980 WB, hence the red pollution carby and air cleaner, plus sneakily not-connected pollution devices. I half expected the thing to be a dog, but it drove really well, had great low end torque and sat beautifully on the highway. At the same time I bough a 1984 4.2L 4spd WB tonner to paint and flip, and this red 202 powered one drove better, actually had more go than the blue 4.2 4spd with 3.55 rear axle.
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castellan Offline
#54 Posted : Saturday, 16 March 2019 6:30:01 PM(UTC)
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Originally Posted by: HK1837 Go to Quoted Post
Years ago I would have been surprised by the use of the essentically LC XU-1 cam profile used in the ADR27A 202 (albeit stood upright rather than advanced). But here is why I'm not surprised.

Years ago I had a warm 202 in my 2/76 LX hatchback. It was a red VB 202 block with a blue crankshaft and rods.

It had what was called a 30/70 camshaft by Waggot, in reality probably not too different to the LX XU-1 camshaft.
The engine was pretty much stock 202 type pistons with 186 Yella Terra head, CAIN 4BBL manifold, 390 Holley, extractors and CDI ignition.

From memory it dynoed about 100hp at the back wheels so probably in SAE gross terms maybe 175-ish hp.

I had pulled that engine out and was putting in a VK EFI engine. It was sitting there unused.

I had bought a nice 1980 WB tonner sans engine and box.

So I re-ringed that 202, put new bearings in it and put it back together in the tonner otherwise as it was but with extractors and a red pollution manifold and carby plus a blue HEI dizzy.

The gearbox was from a VK FI and the rear axle was a 3.08.
I had to dress it to appear as if it was an ADR27A engine to pass rego in a 1980 WB, hence the red pollution carby and air cleaner, plus sneakily not-connected pollution devices.

I half expected the thing to be a dog, but it drove really well, had great low end torque and sat beautifully on the highway.

At the same time I bough a 1984 4.2L 4spd WB tonner to paint and flip, and this red 202 powered one drove better, actually had more go than the blue 4.2 4spd with 3.55 rear axle.
d'oh! Eh?

What a WB with a red intake and carby on it.Whistle

And a 30/70 Waggott Cam is about the same as a HX 3.3L Brick wall Eh? what BS every 30/70 Cam I have driven be it 202 or 308 has very lumpy idle and f all power down low, ones grand mother could not take off the line with such without stalling it and they will rev to 7000RPM easy.
I don't see no ADR27A 3.3L doing that, not even a 3.3L EFI coming anywhere near it.
HK1837 Offline
#55 Posted : Saturday, 16 March 2019 7:42:08 PM(UTC)
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You obviously didn’t read what I wrote. I never said it was an ADR27A 202. It was a 202 with Yella Terra head and 30/70 cam with extractors disguised as an ADR27A red engine. The point was the ADR27A auto 6’s got the same cam timing retarded 6deg as the LC XU-1, which might seem too big for it, but the 202 I had ran the same carby and intake and roughly the same compression (about 9.5:1) with a slightly bigger cam. I don’t think I still have the Waggot cam sheet but it was 30/70 70/30 advertised, probably timed at 6thou or 4thou. The pollution red 6 auto was 29-59, 268deg, 64-24, 268deg which is a little smaller. The VF EFI cam (20-76, 276deg, 60-36, 276deg, 56deg overlap) bought back upright is 26-70 66-30 which is even closer to 30-70 70-30 and run fine with a si flex carb too, seem it done plenty of times.
The 30/70’s you are talking about may have very different lobe centres or far more lift or both.
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castellan Offline
#56 Posted : Saturday, 16 March 2019 7:46:42 PM(UTC)
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Originally Posted by: 8D11PCH2 Go to Quoted Post
Originally Posted by: castellan Go to Quoted Post
OK how is this, you have a stock 202 and you retard the cam by 6 deg, what are you now going to do now to the spark timing ? if the std spec was to be set at 6 deg, now what are you going to set it to now ? 12 deg ?

What Cam hear is advanced and what one is retarded.
we will start with 20/60
25/55 ? adv or ret
15/65 ? adv or ret
Not to mention witch one should need more compression.
Now if it's a Holden red what will you do to the spark timing setting if the stock is 6 deg, so the 15/65 would have to be ? and the 25/55 have to be ?

If we look at a engine and we see the book states 2 deg advanced spark timing and then we see a year later it's saying 6 deg and then next year its 12 deg one could make the assumption that the cam timing has been changed maybe.
Look at a HT to HQ 253 V8 What does Holden recommend and what does it recommend of the HT-Q 308 not to mention the first 308 LH Torana ?


But you woudln't bother to retard the stock cam from it's original installed (straight up) position. GMH engineered it up to give the best compromise between torque, HP and fuel consumption..
Anyway, I don't see how retarding or advancing the cam is going to have any great bearing on when you want to ignite the A/F mixture.
At the moment the plug fires the inlet and exhaust valves are closed.


Well they did with the original LC XU-1 and the next, but as to stock Cams they do, as they did change the same Cam position in the HT-Q 253 to 308 and not to mention the first LH 308's.

I am quite sure that the Ford F100 250 log cam was advanced because of the grunt that my dads had, would kill a XB 250 for torque.
Look at the Valiant slant 6 Dodge trucks I drove as well had impressive performance to drive and they were low compression, I think that the Cam or the timing may of been different to the sedan and maybe the hemi 245 was low comp in them as well, look at all the Cam grinds that the 6 cyl Hemi had in sedans one for the 1V carby and 2 grinds for the 2V just for a start.


What happens is that when you change the Cam adv or retard it, well that is your reference point that is what is telling your timing light is coming from, it's not your reference point coming off the crank is it. it's coming from the cam as the spark is in regard to the Camshaft that it's connected to.

When you look at the spec of a Cam and in relation to the Intake, lets say 20/60 for example, now if you make it 15/65 then you loose dynamic compression, so their is a rule that for every deg more that your intake valve closes you have to up our static compression to counter the loss, that's why we see the compression increase with a hot Cam engine. as lets say you increase your stock 202 red from 9.4:1 to 10.5:1 on 97 octane what would be the point, as you could go backwards with power and fuel economy easy. but if you had a big Cam 10.5:1 would be a good thing, but 9.4:1 would be a stupid thing.
Remember the later the intake valve closes has the biggest effect of all.

Now what it we make it 25/55 well we may have to run a lower compression.
I think that the jetting may change for sure with any mod as that is all to too with volume efficiency.

Their was a mod that was done to the IT Yamaha that you cut 15mm out of the front of the pipe before the expansion chamber, now that is a 2 stroke but you had to change the jetting and if you did a little port work the same again so fact is anything that you do, to get the best out of it you will need to deal with the jetting.
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#57 Posted : Saturday, 16 March 2019 8:12:31 PM(UTC)
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Originally Posted by: HK1837 Go to Quoted Post
You obviously didn’t read what I wrote. I never said it was an ADR27A 202. It was a 202 with Yella Terra head and 30/70 cam with extractors disguised as an ADR27A red engine. The point was the ADR27A auto 6’s got the same cam timing retarded 6deg as the LC XU-1, which might seem too big for it, but the 202 I had ran the same carby and intake and roughly the same compression (about 9.5:1) with a slightly bigger cam. I don’t think I still have the Waggot cam sheet but it was 30/70 70/30 advertised, probably timed at 6thou or 4thou. The pollution red 6 auto was 29-59, 268deg, 64-24, 268deg which is a little smaller. The VF EFI cam (20-76, 276deg, 60-36, 276deg, 56deg overlap) bought back upright is 26-70 66-30 which is even closer to 30-70 70-30 and run fine with a si flex carb too, seem it done plenty of times.
The 30/70’s you are talking about may have very different lobe centres or far more lift or both.


Sure any 30/70 could be anything even at 0.006

I don't think that the Cams can be compared to anything that you are talking about from the reference point that you are coming from.

If I came up to someone who is into hot engines and said that the ADR27A red 202 Cam is very close to the LC XU-1, so you should try put one in, what do you think Anxious smart move hey ? will he thank me after he has done this or try to kill me.

I thought it was a WB with a red six intake and stock carby and 30/70 Cam and TY head.

I have a 6 cyl Waggott Cam called 409 that is 30/70 and I am sure here is another 30/70 that they made if I remember correctly.
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#58 Posted : Saturday, 16 March 2019 8:34:36 PM(UTC)
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Originally Posted by: castellan Go to Quoted Post
Originally Posted by: 8D11PCH2 Go to Quoted Post
Originally Posted by: castellan Go to Quoted Post
OK how is this, you have a stock 202 and you retard the cam by 6 deg, what are you now going to do now to the spark timing ? if the std spec was to be set at 6 deg, now what are you going to set it to now ? 12 deg ?

What Cam hear is advanced and what one is retarded.
we will start with 20/60
25/55 ? adv or ret
15/65 ? adv or ret
Not to mention witch one should need more compression.
Now if it's a Holden red what will you do to the spark timing setting if the stock is 6 deg, so the 15/65 would have to be ? and the 25/55 have to be ?

If we look at a engine and we see the book states 2 deg advanced spark timing and then we see a year later it's saying 6 deg and then next year its 12 deg one could make the assumption that the cam timing has been changed maybe.
Look at a HT to HQ 253 V8 What does Holden recommend and what does it recommend of the HT-Q 308 not to mention the first 308 LH Torana ?


But you woudln't bother to retard the stock cam from it's original installed (straight up) position. GMH engineered it up to give the best compromise between torque, HP and fuel consumption..
Anyway, I don't see how retarding or advancing the cam is going to have any great bearing on when you want to ignite the A/F mixture.
At the moment the plug fires the inlet and exhaust valves are closed.



What happens is that when you change the Cam adv or retard it, well that is your reference point that is what is telling your timing light is coming from, it's not your reference point coming off the crank is it. it's coming from the cam as the spark is in regard to the Camshaft that it's connected to.



The advance or retard of your camshaft is not the reference point for your timing light. Sure the camshaft drives the distributor but the distributor is timed in relation to TDC of the crankshaft/pistons not the camshaft.
castellan Offline
#59 Posted : Sunday, 17 March 2019 2:44:30 PM(UTC)
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Originally Posted by: 8D11PCH2 Go to Quoted Post
Originally Posted by: castellan Go to Quoted Post
Originally Posted by: 8D11PCH2 Go to Quoted Post
Originally Posted by: castellan Go to Quoted Post
OK how is this, you have a stock 202 and you retard the cam by 6 deg, what are you now going to do now to the spark timing ? if the std spec was to be set at 6 deg, now what are you going to set it to now ? 12 deg ?

What Cam hear is advanced and what one is retarded.
we will start with 20/60
25/55 ? adv or ret
15/65 ? adv or ret
Not to mention witch one should need more compression.
Now if it's a Holden red what will you do to the spark timing setting if the stock is 6 deg, so the 15/65 would have to be ? and the 25/55 have to be ?

If we look at a engine and we see the book states 2 deg advanced spark timing and then we see a year later it's saying 6 deg and then next year its 12 deg one could make the assumption that the cam timing has been changed maybe.
Look at a HT to HQ 253 V8 What does Holden recommend and what does it recommend of the HT-Q 308 not to mention the first 308 LH Torana ?


But you woudln't bother to retard the stock cam from it's original installed (straight up) position. GMH engineered it up to give the best compromise between torque, HP and fuel consumption..
Anyway, I don't see how retarding or advancing the cam is going to have any great bearing on when you want to ignite the A/F mixture.
At the moment the plug fires the inlet and exhaust valves are closed.



What happens is that when you change the Cam adv or retard it, well that is your reference point that is what is telling your timing light is coming from, it's not your reference point coming off the crank is it. it's coming from the cam as the spark is in regard to the Camshaft that it's connected to.



The advance or retard of your camshaft is not the reference point for your timing light. Sure the camshaft drives the distributor but the distributor is timed in relation to TDC of the crankshaft/pistons not the camshaft.


Agree.
HK1837 Offline
#60 Posted : Monday, 18 March 2019 7:58:56 AM(UTC)
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Originally Posted by: castellan Go to Quoted Post
Originally Posted by: 8D11PCH2 Go to Quoted Post
Originally Posted by: castellan Go to Quoted Post
OK how is this, you have a stock 202 and you retard the cam by 6 deg, what are you now going to do now to the spark timing ? if the std spec was to be set at 6 deg, now what are you going to set it to now ? 12 deg ?

What Cam hear is advanced and what one is retarded.
we will start with 20/60
25/55 ? adv or ret
15/65 ? adv or ret
Not to mention witch one should need more compression.
Now if it's a Holden red what will you do to the spark timing setting if the stock is 6 deg, so the 15/65 would have to be ? and the 25/55 have to be ?

If we look at a engine and we see the book states 2 deg advanced spark timing and then we see a year later it's saying 6 deg and then next year its 12 deg one could make the assumption that the cam timing has been changed maybe.
Look at a HT to HQ 253 V8 What does Holden recommend and what does it recommend of the HT-Q 308 not to mention the first 308 LH Torana ?


But you woudln't bother to retard the stock cam from it's original installed (straight up) position. GMH engineered it up to give the best compromise between torque, HP and fuel consumption..
Anyway, I don't see how retarding or advancing the cam is going to have any great bearing on when you want to ignite the A/F mixture.
At the moment the plug fires the inlet and exhaust valves are closed.


Well they did with the original LC XU-1 and the next, but as to stock Cams they do, as they did change the same Cam position in the HT-Q 253 to 308 and not to mention the first LH 308's.

I am quite sure that the Ford F100 250 log cam was advanced because of the grunt that my dads had, would kill a XB 250 for torque.
Look at the Valiant slant 6 Dodge trucks I drove as well had impressive performance to drive and they were low compression, I think that the Cam or the timing may of been different to the sedan and maybe the hemi 245 was low comp in them as well, look at all the Cam grinds that the 6 cyl Hemi had in sedans one for the 1V carby and 2 grinds for the 2V just for a start.


What happens is that when you change the Cam adv or retard it, well that is your reference point that is what is telling your timing light is coming from, it's not your reference point coming off the crank is it. it's coming from the cam as the spark is in regard to the Camshaft that it's connected to.

When you look at the spec of a Cam and in relation to the Intake, lets say 20/60 for example, now if you make it 15/65 then you loose dynamic compression, so their is a rule that for every deg more that your intake valve closes you have to up our static compression to counter the loss, that's why we see the compression increase with a hot Cam engine. as lets say you increase your stock 202 red from 9.4:1 to 10.5:1 on 97 octane what would be the point, as you could go backwards with power and fuel economy easy. but if you had a big Cam 10.5:1 would be a good thing, but 9.4:1 would be a stupid thing.
Remember the later the intake valve closes has the biggest effect of all.

Now what it we make it 25/55 well we may have to run a lower compression.
I think that the jetting may change for sure with any mod as that is all to too with volume efficiency.

Their was a mod that was done to the IT Yamaha that you cut 15mm out of the front of the pipe before the expansion chamber, now that is a 2 stroke but you had to change the jetting and if you did a little port work the same again so fact is anything that you do, to get the best out of it you will need to deal with the jetting.


Yes in the aftermarket cam world you tailor the grind to the compression, and the stall and the gearing and the weight and the intended use plus other factors. But not in GM (or GMH). They used as few camshafts as possible. GM used the same hydraulic cam for SBC engines ranging from advertised 8:1 right up to 10.25:1 on engines from 307ci up to 350ci possible on small and bigger too. GMH did the same with 6cyl cams in low and high compression 149 through to 202 which range from 7's to 9's in compression, and also did the same in 308 and later 304 ranging from 9.7:1 in HJ right through to low 8's in VL plus it was used in the low compression 308 in Bedford. They used a common camshaft too in low compression 253 starting in HT right through to the 9.8:1 L34. What GMH appear to have done wherever possible was to do was advance or retard camshafts to achieve "close enough" rather than Engineer a new camshaft

I would bet the ADR27A 6cyl auto cam is exactly the first LC XU1 cam but not advanced, I would even hedge that the lift is the same and that they didn't bother correcting for the 7 thou difference (less than 0.2mm). The only reason the part number would have changes is so the cam could be modified to fit the 202. Why they did it with the trimatic and not manuals? It can only be they wanted more power but in the manual it wouldn't pass ADR27A emissions.

Edited by user Monday, 18 March 2019 9:34:52 AM(UTC)  | Reason: Not specified

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