All HT-HG 186 except the Trimatic got the HK 186 S cam. Will check on the low comp 186 though.

When I get 15min spare I’ll put up the cam specs for all HD to HQ 6cyl incl LC and LJ. I know they will all be at 6thou or whatever it is but they are all at the same lift so comparable to get an idea.

They are not all at 6 thou, I think Holden speck is at 2 thou and some Cam grinders are at 4 thou back in the days. and lift is not all the same, not to mention all the rest of the info one can look into with regard to all the spec of a cam.

I was going to mention that.

I think castellan took HK1837's comment as "all Holden cams have the same lift". However what he meant was that they all measured at the same starting point of say 6 thou lift.

Dr Terry

Yes I did think that that was what he said.

I remember years ago what Holden measured at but have forgotten the facts, it's 2 or 2 and a half or maybe 3 thou, but some, I can not remember what brand were 4 thou and most after market brands were 6 thou.

When I put my first New cam in my 308 back in 1988 I did my homework as to what I wanted looking into what was truly what, there were claims of shoddy Cam grinds back then and I seen many a engine that was crap performing, so I went for a new Billet Cam by Waggott and that Cam lasted 500,000KM. and it worked spot on for what I wanted out of the engine, nothing lost in anyway at, all as it was more torque and power everywhere and fuel consumption just the same as stock.

One has to think hard when choosing a Cam, because it's so easy to get it wrong, I have seen it time and time again that people really have no idea. I was talking to engine builders back then and I was not impressed and I was saying no no no I don't want that you got it wrong and had to stand solid on the issue, it was the same when I bought my Kawasaki ZX10 Nija with tyres as i asked what's best for this bike but all I got was moronic backwards nonsense, so I went out and ordered in Avon 22 and 23 tyres and I got it right they were magic I did not want to skimp on tyres as that you best insurance policy that you can get above all, especially when you ride as fast as I did. not to mention that I got the same pathetic moronic madness when it came time to change the chain and sprockets I found that they did not understand what they were peddling trying to sell me a 3dr rate chain with a link clip in it, I said listen boy I ride this from just plodding along at 240KM/H mainly to flat out 280KM/H or more. I don't think that they believed that any one did such.
Now if I did not do my homework and followed such peoples advise I would most likely be dead, as I am sure many people got killed due to idiots like them who insist on rubbish, many would of been killed in fast cars do to crap brake pads not to mention Dot 3 Brake fluid as I seen this with a mate and his VZ SS after he got it serviced by Holden and they replaced the brake oil, and the peddle went down to the floor it was a wonder he did not get killed, I was following him and said what the f did you do that for, he went sailing straight through a highway intersection and it's a wonder that no one hit him when he went through, bloody lucky. but he did have a up grade rotors and top high performance pads. one has to learn never to trust such people ever.
Another mates brother got wiped out with brake fade in his XY 302 Fairmont back in 1979 hit a truck up the rear on the highway and was never the same after that. if he had up grade his brake pads he would of been fine. but the local brake man in town was a total tosser who demanded that I not up grade my brake pads, when I came in with black and blue rotors from brake fade and to reset the brake light, I did not know and put my faith in him, only to work out later that he was a fool.

As promised here are the HD through to the end of red motor 6cyl cam specs. I'll not get them all done in one go so will add as I get a chance.

Timing is shown as INLET openBTC-closeABC, DURATION, EXHAUST openBBC-closeATC, DURATION, VALVE LIFT inlet exhaust

HD 130HC, 149LC, 149HC and 179:
15-45, 240deg, 50-10, 240deg, 0.338", 0.338".

HD 179X2:
23-53, 256deg, 58-18, 256deg, 0.338", 0.338".

HR 161LC, 161HC and 186:
Same as HD except valve opening overlap of 25deg quoted.
(No 130HC figures for HR).

HR X2 and 186S:
Same as HD X2 except valve opening overlap of 41deg quoted.

HK 130HC, 161LC, 161HC and 186:
Same as HR.

HK 186S:
Same as HR.

HT 130HC, 161LC and 161HC:
Same as HK smaller engines.

HT 186LC, 186HC and 186S:
Same as HK 186S except any late HT with Trimatic and 186LC or 186HC gets the small engine cam.

HG 130HC, 161LC, 161HC, 173LC, 173HC, 186LC+M40, 186HC+M40, 202LC and 202HC:
Same as HT smaller engines.

HG 186LC (except M40), 186HC (except M40) and 186S:
Same as HT 186S.

HQ 130HC, 173LC, 173HC, 202LC and 202HC:
Same as HG smaller engines. The preliminary Technical Specifications issued November 1970 show the 202HC with the X2/186S camshaft but this changed prior to release.

LC 130HC, 138HC, 161HC an 173HC:
Same as smaller Holden engines.

LC 2600S and 2850S:
X2/186S camshaft.

LC XU1 (Sept 1971 revision, I don't have the June 1970 revision yet):
38-86, 304deg, 77.3-46.30, 304deg, 0.429", 0.429", overlap 84deg.

LJ 130HC, 138HC, 161HC an 173HC:
Same as smaller Holden engines.

LJ XU1:
44-80, 304deg, 83-40, 304deg, 0.429", 0.429", 84deg overlap. Looks almost the same cam as the final LC XU1 cam except retarded 6deg in the timing gear.
The 8/71 XU1 cam specs are 38-86, 304deg, 77-46, 304deg, 0.429", 0.429", 84deg overlap. Revised to the above in 12/71.

HJ 130HC, 138HC, 173LC, 173HC, 202LC and 202HC:
Same as HQ.

HX 173LC, 173HC, 202LC and 202HC:
Same as HQ for export engines and manual ADR27A engines.
29-59, 268deg, 64-24, 268deg, 0.338", 0.338", 53deg overlap (ADR27A auto engines, revised April 1976 which was about when the trial ADR27A engines went into some Pagewood HJ).

HZ 173LC, 173HC, 202LC and 202HC:
Same as HX.

LH 138LC, 138HC, 173LC, 173HC, 202LC and 202HC:
Same as HQ.

LX 173LC, 173HC, 202LC and 202HC:
Same as LH until ADR27A. ADR27A auto engines as per HX auto engines.

UC and VB I do not have full data yet on exactly what engines were available across all markets, but at this stage assume they are the same as HZ camshaft wise.

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.

Note that Fiv has also stuffed up the LC 2600S camshaft specs, he has the intake open and close correct for both no-ramp and ramp, but has the smaller cam's figures for everything else.

Also thought I'd throw in the VK EFI cam. 20-76, 276deg, 60-36, 276deg, 56deg overlap. If I remember correctly this is retarded 6deg in the cam gear, so if stood at 0deg it would be 26-70, 66-30. Not that different to the initial LC XU1 cam. I remember reading somewhere in the dim dark past that the inlet closing time was extended to take advantage of the ram tube effect of the intake which gave up to a 15kpa boost to atmospheric pressure.

VC XT5 cams is:

19-65, 264deg, 60-36, 276deg.

As you can see the only difference between the XT5 3.3L and the black EFI is the extra duration on the inlet closing.

So in summary this means four basic camshafts total for all 6cyl production red engines plus the XT5 cam and the VK EFI cam:

15-45, 240deg, 50-10, 240deg, 0.338", 0.338", 25deg overlap (All smaller engines (except 2600S, 2850S) plus HK 186).

23-53, 256deg, 58-18, 256deg, 0.338", 0.338", 41deg overlap (X2, 2600S, 2850S, 186S and HT-HG 186 excl. Trimatic).

29-59, 268deg, 64-24, 268deg, 0.345", 0.345", 53deg overlap (LC XU-1 plus ADR27A automatic although 0.007" lift discrepancy in figures).

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).

19-65, 264deg, 60-36, 276deg. (XT5 blue and black)

20-76, 276deg, 60-36, 276deg, 56deg overlap. (VK EFI).

Can't find lift figures for the XT5 and EFI cams at this stage.

Edited by user Friday, 8 March 2019 11:12:05 AM(UTC)  | Reason: Not specified

99% sure it’s the same. I don’t have the HD overlaps for comparable lift (no ramps) but I have the HD AMA Technical specs and it shows the “including ramps” data and it is the same as the others.

Yes they are compatible as to the way Holden measures at that lift, but not at all to when you went and bought a Cam from another company because they can vary as to what point they take it from Holden being 2 thou I think and some Cam company's were at 4 thou and most were a 6 thou.

Even tho if one Company has a Cam that they claim as a XU-1 or XY GT-HO replacement say, but it is not at all as they can not grind he same Cam without permission and that cost them to do so. so you will see x amount of company's claiming a XY GT-HO Cam and all are different.

Repco claimed a XU-1 Cam in reco engines you could buy, but what XU-1 Cam was that, their own grind for sure as is the same with all of there stock recon engines, they must of used only one of their stock grinds I would say.

So Repco would of just had one std Holden red 6 grind, so if it was a 149 to 202 all would of got the stock Repco grind I am sure, something like a 186 S Cam I would think, as to the performance of my brothers stock 161 Gem reco engine it must of been I would say, not to mention regardless of be you have a auto or manual.

I think Repco must of made a ADR27A Cam grind as well and all would of been the same not to mention the 4.2L and 5.0L may of been the same grind as well but the Holden ADR27A for both are different.

If we could get the Repco spec I am sure it would measure at 0,006 and all the other Cam Company's have stock Cam grinds that they sold but they were not the Holden spec at all, but their own spec for that.

And even if Company's are measuring at 0.006 for a say 20/60in and 60/20exh with same lift and overlap Cam, that does not mean that they are the same truly at all as their is more to it than just that.


I remember seeing back in about 1988 at the wreckers at Oxley QLD on a wall showing all the old Holden camshafts and that one was marked X2 I believe and it had a flat type of nose, it was not totally flat but dipped down a little bit, but a lifter would not of made any difference in following, but it was just that the ramps were steeper and the nose really wide and then other Cams had a really pointy nose and some were wider.
I did not have time to really study the Cams at the time because a mate was in such a rush their.

Well it does not mater what GMH did, what maters that one can put it into some type of reality with at least 0.006 or 0.050, it so we can know what the hell we are talking about that's closer to the mark of reality for all.

Look at this info I go from Waggott Cams spec on a slant 6 Cam number 255
1ntake duration at 0.006 = 249 deg and exhaust is 265 deg
Now try it at 0.050 = 193 deg ' ' 190 deg
So you see that the intake is less at 0.006 than the exhaust but look at what is going on at 0.050 the intake is bigger now, so you see the whole picture is a lot more to it than one may think.

Two people met who are into Cars and one explains what he has done to the engine, now the other dude has the same car and all everything is the same with the engine same head work, pistons and compression, carbs and all, they start on about the Cam and yep both agree they have the same Cam spec, but do they really ? bro said the Cam is the same degree duration and even the opening and closing are the same and at the same 0.006 and same max lift, but fact is that does not mean that they are the same, because their is more to it than just that.

One dude was trying to tell me that the HJ 308 had the exactly same Cam grind as the Holden's Chevy V8's, I looked into it years ago and it's not true at all, it's not truly he same grind at all, but it may look that way to begin with.