
xu-1 holden 6 camshafts
#1
_Ozzie Picker_
Posted 12 June 2011 - 08:50 PM
was wondering who makes the BEST camshafts for the holden 6,also valve springs.
i have a 73 xu1 with the big valve head,tripple strongbergs,extractors,and i,m toying with the idea of a new cam and springs,i want it angry sounding at idle and to perform to my engine specs,any ideas of a grind would be a great help.
the cam in my engine at present sounds to smooth,when i bought the car in the late 80,s i was given a few cams,as it had been used in some race events in the 70,s,and i just rebuilt engine with new pistons and used cam that was in engine .
#2
Posted 12 June 2011 - 10:38 PM
the comp cams grinds are new technology and would most likely make more power, plus theyre cheap because of the aussie dollar.
#3
_Bomber Watson_
Posted 12 June 2011 - 11:10 PM
More info...or just call up a reputable cam manufacturer with your vehicle specks and engine specks and they will recommend a suitable grind for you.
Choose whatever they recommend, unless your like Kev and myself, if thats the case pick four sizes bigger and run with that

Cheers.
#4
_Ozzie Picker_
Posted 13 June 2011 - 08:00 AM
i like your method bomber.
greens nice,kev i,m guessing
thanks for your help,ivan tighe made the camshaft for my methonal 350 and is a fully lumpy grind,i love it.
#5
_stretchlc_
Posted 13 June 2011 - 10:51 AM
#6
Posted 13 June 2011 - 04:23 PM
hi all,
was wondering who makes the BEST camshafts for the holden 6,also valve springs.
i have a 73 xu1 with the big valve head,tripple strongbergs,extractors,and i,m toying with the idea of a new cam and springs,i want it angry sounding at idle and to perform to my engine specs,any ideas of a grind would be a great help.
the cam in my engine at present sounds to smooth,when i bought the car in the late 80,s i was given a few cams,as it had been used in some race events in the 70,s,and i just rebuilt engine with new pistons and used cam that was in engine .
Hi Craig, Iam using Clive Cams for suppling the cam on the rebuild for my Irving Head motor. I cannot recall the specs but will be bigger than a bathurst grind. Needed to be with 50mm weber carbs as well. He was very easy to talk to, especially when you are simple like me, and his price was bloody good as well. Time frame was also very short from ordering to getting it delivered. I highly recommend Clive.
cheers
steve
#7
_Ozzie Picker_
Posted 13 June 2011 - 05:51 PM
had a look on the waggott site,and clicked on holden 6 and nothing happens,
i think they have a technical problem.
hi steve,
i will also have a look into your supplier,as i,m a bit simple aswell,when it comes to the tecko stuff with cams,i want lumpy and rev the piss out of it.

that engine of yours sounds the goods,what you putting it into?
#8
Posted 13 June 2011 - 06:57 PM
#9
Posted 15 June 2011 - 05:44 PM
Doing the club thing, hill climbs etc and still be driven on the street, I hope!!!!!!!!! I need something that I can thrash and If I bend it, it does not matter as much. The other toys are just too collectable and expensive to thrash and smash.
cheers
Steve
Edited by Bathurst72, 15 June 2011 - 05:45 PM.
#10
_HDTXU1_
Posted 05 March 2012 - 09:07 PM
#11
_double_d_
Posted 06 March 2012 - 08:17 AM
close to a 72 xu1 grind but with a 107 LSA
it sounds lumpy as at idle no power under 3300
but i like it i get all sorts of looks pulling up somewhere
i will buy my next cam from clive cams , very good to talk to very understanding and cheap
daniel d
Edited by double_d, 06 March 2012 - 08:17 AM.
#12
_Moose lc_
Posted 14 March 2012 - 08:45 PM
Cheers
Moose
#13
_oldjohnno_
Posted 16 March 2012 - 05:36 AM
It's hard to compare profiles with the limited data available from most of the grinders - Comp are about the only ones I know of that release much info on specific lobes.
Many (I'd say most) of the traditional Holden six profiles are very slow, old-school grinds, and while they'll do the job to some extent I think that there are much better lobes available today, especially from a couple of the US grinders using modern lobe design software. I've always said that if we keep building the motors our dads built in the 70's then we shouldn't be surprised when we get the same mediocre results.
For a street car I like the look of Camtechs 634A-107, some of the other grinders have equivalent profiles.
Edited by oldjohnno, 16 March 2012 - 05:37 AM.
#14
_Ned Loh_
Posted 16 March 2012 - 07:02 AM
#15
_double_d_
Posted 16 March 2012 - 04:41 PM
#16
_oldjohnno_
Posted 16 March 2012 - 05:44 PM
#17
_double_d_
Posted 16 March 2012 - 10:01 PM
would that be right ??
daniel d
#18
_oldjohnno_
Posted 17 March 2012 - 06:52 AM
i was told it is very similar to a late XU-1 cam spec
would that be right ??
daniel d
Yes, I think it would be close.
#19
_flyxu1_
Posted 18 March 2012 - 05:07 PM
I have a 629b wade or clive 3100x block 202 crank ,rollers ,lobe centre changed and its great to drive yes the idle is wild as cat piss
I love driving it and it hates hot days
Grantley
Flyxu1
#20
Posted 22 March 2012 - 06:53 AM
I run a Wade 373 XU1 grind cam and at idle it suonds as lumpy as. I run it in a 186s, anti pump up lifters, hydrolic high comp yella terra head (unleaded fuel), triple 150cd carbs and dizzy set at 16deg adv. Cam kicks in at 2800 and revs to 5000 no problems. I have a trimatic with a 3000 stall and dont have problems with idle in trafic although the temp jumps around a bit in trafic due to the cam.
Daz
#21
Posted 23 March 2012 - 10:34 AM
depends what you really want to do with you rocket. Wade were the supplier to GMH for the XU1 camshafts . ( Chris Hasting at wade is great to talk to very helpfull in Melbourne 9568 2633 ) The 72 STD XU1 cam was the Wade 373 , 429 valve lift and 227 duration @ 50 thou , like what Daz has above and thats also what I run Its , good all round cam low down and up top in a 202 with 175 tripples good head and pipes . The Wade 391 grind was the 72 and 73 bathurst cam .457 valve lift and 240 duration at 50 thou and good from 3500-6500 . I also ran this cam for a while it great for all out go but I ended up puting the 373 cam back in as it had better low end TQ and was more suited for street with the STD XU1 set up I felt . If I end up on the track I'll put the 391 or bigger. ive had a couple of thes over the years and they all dial in within a degree .
Old johnno's right grind have come a long way and im sure there's a lot better , It really depends on what you want to do and more important what you set up is ,carbs , head and pipes.
Crane cams have all the valve springs collets and retainers you will need . But get an engine guy to measure your head and valve springs before you buy a big cam cause you don't want binding of the valve spings or any nasties like that because your cam is to big for your head set up .
hope this helps .
Geoff
#22
_NZ Toranaman_
Posted 23 March 2012 - 02:34 PM
Its sort of like trying to throw a big carb on a small engine, sure it will go ok once wound up but you miss out on so much.
#23
Posted 26 March 2012 - 07:16 AM
Daz
#24
_PeteXU1_
Posted 01 May 2012 - 10:09 PM
Can anyone elaborate?
#25
_oldjohnno_
Posted 02 May 2012 - 08:19 AM
It's kind of a coincidence that you're thinking about cams - I've been talking with Comp over the last few days about doing some Holden six cams. They have some blank cores in stock and we've been working out which of their .842" lobes are feasible on the little Holden core.
"Modern profile" probably isn't a real good description but it's the best I can come up with. If you look at aftermarket profiles for say the smallblock Chev you'll see that they started to change fundamentally in the early '80s and the changes are continuing right through to today. Previously lifts were lower, and the seat-to-seat duration was relatively long compared say the 0.050" or 0.100" timing. The newer designs had higher acceleration rates that allowed as much or more area under the lift curve as the old style cams but the shorter seat timing meant you could have a lot more meat in the torque curve.
They were commonly known as "hi-intensity" profiles and even now the intensity (the difference between seat-to-seat and 0.050" duration) is one of the ways to compare cams.
Prior to these changes most cams were low-lift (often less than 0.5") and long duration, much like the XU1 cams and many of the Holden cams still being used. By the mid 80s SBCs were commonly using lifts of well over 0.6" (flat tappet) and much higher acceleration rates but for some reason the little Holden seems to have been left behind. Even the Mini guys are getting better outputs from their siamese headed engines these days than what most Holden sixes are doing, cube for cube.
Basically then these "modern" cams have higher acceleration rates than the old "agricultural" profiles, and modern computer designs are able to let the cam and valvetrain survive without eating themselves up quickly. Forty years ago no-one would have believed that the lift rates of today would work for any length of time but here we are.
The trouble is few of the grinders give out much information on their lobes. Bullet and Comp do give more info than most, but the majority only specify seat-to-seat and 0.050" durations plus lobe lift. So a fair bit of guesswork and assumption has to take place. A small difference between seat and 0.050" duration (so-called hi-intensity) is usually a good thing, as is a highish lift. The 0.1" and 0.2" durations and the lift at TDC also give clues. The high lift in itself mightn't be of much value in itself (most Holden six heads dont do much over 0.5" lift anyway) but when it's combined with a shortish duration it indicates necessarily high lifter acceleration rates. As well with short durations and high lift rates a higher lift is unavoidable if you are going to maintain control of the valve. Comp supplies duration at seat, 0.050", 0.200" and lift at TDC values, and Bullet supplies lift at a variety of timing points, and these are very handy comparison tools. Comp has maybe a hundred or more 0.842" competition profiles alone in maybe a dozen groups or families. These are very different to the commonly used Holden profiles and are often modern assymetric lobe designs. I'm not saying the Australian companies can't make good profiles too, but they don't make the information available like say Comp and I'm pretty sure very few of them design their own masters. Many of them look to be very old designs, similar to what the rest of the world stopped using in the early 80s.
Harvey Crane wrote some good notes on cam basics (see here) that might help you make sense of it. It's quite possible that I'm barking up the wrong tree here but I'm hoping that state-of-the-art cams in the little Holden will work just as well they have in all the other engines. We'll see. But I'd be very surprised if a better cam didn't give another 20hp as well as a better torque curve. Just be aware that with these newer profiles you may want to use a slightly wider LSA (especially with hi-ratio rockers) in order to keep the overlap area to a reasonable level, and also that the ideal duration will be less than what you are used to for a given rpm range.
Cheers,
John
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