Interesting comments on LS1 Cams
Discussion
Check out Come racing in Oz.
http://comeracing.com/ Sounds like a Cam upgrade is a very good idea.
Of course a tune is nice, I see they got over 300KW with just a tune, well headers and exhaust as well. But event more power with the cam.
Has anyone done a cam upgrade in the UK yet?
Rich.
The interesting bit from come;
"A recent spate of extensive dyno development testing here at COME Racing has yeilded some interesting results. Many customers often ask what is the ideal cam only upgrade for their 5.7 LS1 engined Commodore.
The real answer is, everyone is different and no one cam is the "ideal" answer to everyones performance needs. We decided to illustrate the results of one particular grind versus a stock engine and stock cam.
One overriding fact is that the stock cam is pitifully conservative and really holds these engine back quite dramatically. Not only did all our cam tests yeild significant power gains but the most important outcome is the unusually strong increase in torque right from idle through to the optimum rpm limit of every combination we tried.
The "stock" engine used for this test was a brand new crate LS1 engine which was run in and software fully optimised using HP Tuners programming. Our exhaust comprised of Pacemaker 1 3/4" 4 into one of the shelf headers and 3" bore straight through mufflers attached directly to the collectors. A MAF (Mass airflow sensor) was left in place on the stock engine as was attached to the commonly used HSV 4" intake pipe without any air box used. A stock throttle body was used for all tests.
We fitted a set of our latest lightweight "conical" valve springs to match the cam upgrade. These only have 110lbs seat pressure but will not lose 10%-15% of their "new" tension like all other springs on the market. Ours have a proprietary "treatment" providing incredible durability and life without requiring power robbing extreme pressures to keep the lifters following the cam lobes accurately. These springs are $330.00 a set.
The stock engine peaked power at 5500 rpm with 407bhp (303.5kw) and torque was maximised at 5000 rpm with 410ft.lbs (556NM) Same engine with the addition of our LSCH-246 cam (224/228 @.050" duration and .550" lift on both intake and exhaust) peaked at 6000 rpm with 456bhp (340kw) and maximum torque of 436ft.lbs (591NM) at 4750 rpm.
Most impressive in the potential acceleration and driveability stakes was the very large torque increase as low as 2750 rpm. A jump of 17 ft.lbs at that low rpm point as well as everywhere through the entire usable rpm range. The car is simply more tractable and responsive despite the significant increase in cam duration and overlap. An obvious sign that GMH has choked these engines for both emissions and drivetrain life considerations.
Our cam equipped engine was also tuned without the MAF in place as we are able to more precisely map the fuel curve this way in our opinion. Look at the oscillating power curve of the stock engine versus the cammed engine. You won't see this on a chassis dyno."
http://comeracing.com/ Sounds like a Cam upgrade is a very good idea.
Of course a tune is nice, I see they got over 300KW with just a tune, well headers and exhaust as well. But event more power with the cam.
Has anyone done a cam upgrade in the UK yet?
Rich.
The interesting bit from come;
"A recent spate of extensive dyno development testing here at COME Racing has yeilded some interesting results. Many customers often ask what is the ideal cam only upgrade for their 5.7 LS1 engined Commodore.
The real answer is, everyone is different and no one cam is the "ideal" answer to everyones performance needs. We decided to illustrate the results of one particular grind versus a stock engine and stock cam.
One overriding fact is that the stock cam is pitifully conservative and really holds these engine back quite dramatically. Not only did all our cam tests yeild significant power gains but the most important outcome is the unusually strong increase in torque right from idle through to the optimum rpm limit of every combination we tried.
The "stock" engine used for this test was a brand new crate LS1 engine which was run in and software fully optimised using HP Tuners programming. Our exhaust comprised of Pacemaker 1 3/4" 4 into one of the shelf headers and 3" bore straight through mufflers attached directly to the collectors. A MAF (Mass airflow sensor) was left in place on the stock engine as was attached to the commonly used HSV 4" intake pipe without any air box used. A stock throttle body was used for all tests.
We fitted a set of our latest lightweight "conical" valve springs to match the cam upgrade. These only have 110lbs seat pressure but will not lose 10%-15% of their "new" tension like all other springs on the market. Ours have a proprietary "treatment" providing incredible durability and life without requiring power robbing extreme pressures to keep the lifters following the cam lobes accurately. These springs are $330.00 a set.
The stock engine peaked power at 5500 rpm with 407bhp (303.5kw) and torque was maximised at 5000 rpm with 410ft.lbs (556NM) Same engine with the addition of our LSCH-246 cam (224/228 @.050" duration and .550" lift on both intake and exhaust) peaked at 6000 rpm with 456bhp (340kw) and maximum torque of 436ft.lbs (591NM) at 4750 rpm.
Most impressive in the potential acceleration and driveability stakes was the very large torque increase as low as 2750 rpm. A jump of 17 ft.lbs at that low rpm point as well as everywhere through the entire usable rpm range. The car is simply more tractable and responsive despite the significant increase in cam duration and overlap. An obvious sign that GMH has choked these engines for both emissions and drivetrain life considerations.
Our cam equipped engine was also tuned without the MAF in place as we are able to more precisely map the fuel curve this way in our opinion. Look at the oscillating power curve of the stock engine versus the cammed engine. You won't see this on a chassis dyno."
If it helps, I've done quite a few cam changes for the stock ls1 but fitted with an ls6 intake which have been dynoed and mapped with an aftermarket mappable ecu, MBE (not by me, I prefer the DTA). They never saw much more then 400 hp without the ls6 heads. These were engines on bench dynoes in the UK. I also used aftermarket beehive springs so nothing to special there. As for the cam grinds, they all come from the same source even in OZ. Maybe it's the stock ecu that makes so much power but I'm not at all convinced about that idea.
I also saw a brand new stock crate 2003 ls6 make 395 hp without any mods and that was all it would do despite air intake attempts by boffins from an exclusive marque over here (they used the same dyno cell for Merlin engines). It had a pas pump and alternator fitted so this may explain the drop compared to GM's figure. It also did an 8 hour stepped break in period first. If they could make more, GM would have already done it imho.
I hear about stock 450 odd hp ls1's all the time but don't believe it. The people in the link may well be making the power claimed but I suspect the exhausts have a big contribution as may some other factors.
Boosted.
>> Edited by Boosted LS1 on Monday 30th May 00:00
I also saw a brand new stock crate 2003 ls6 make 395 hp without any mods and that was all it would do despite air intake attempts by boffins from an exclusive marque over here (they used the same dyno cell for Merlin engines). It had a pas pump and alternator fitted so this may explain the drop compared to GM's figure. It also did an 8 hour stepped break in period first. If they could make more, GM would have already done it imho.
I hear about stock 450 odd hp ls1's all the time but don't believe it. The people in the link may well be making the power claimed but I suspect the exhausts have a big contribution as may some other factors.
Boosted.
>> Edited by Boosted LS1 on Monday 30th May 00:00
Unsure how they were getting 407hp from a stock LS1.
No SAE standard mentioned.
Probably with no accessories and drive belt along with using an electric w-pump.
Once you go above around 220 intake duration or over 50 degrees of valve overlap (total/advertised duration); you are losing torque over stock until you get to around 2-2500rpm.
1] Some validated stuff with more realistic power claims I've seen for LS1's have been on this site:
www.samsperformance.com ....(click on "Research & Development" ...then on "Best Packages" graph.
2] This test was carried out by David Vizard (he shouldn't need any intro!):
www.popularhotrodding.com/enginemasters/articles/chevrolet/smallblock/0503em_ls6/
3] This one is good in that it also mentions the strict SAE standard being used (as does #2]) by the Katech facility (so hp figures are honest) and also the fact that the both the Gen 3 and 4 respond really well even to mild cams that have a closer LSA than stock ('01 & '02 LS6 cams tried here but reground with a 110 and 112 LSA respectively. Which is more the norm for engines like this):
http://hotrod.com/techarticles/113_0504_ls2/
Cam-only changes (no headwork) to LS1 work well as the stock factory heads are good for over 465hp and they breath better than LS6 at mid-lift (0.250" which is where the valves spend most of the time open).
I personally have gone from an SAE J-607 corrected 313rwhp (bolt-ons & PCM) to 357rwhp with just a mild cam (USA custom ground Comp-Cam) which has less than 215 @ 0.050" duration.
Yes the stock LS1 cam is conservative. Main problem with it is the wide LSA it's on for easy emission compliance and a nice smooth idle.
It's also very much a compromise too as it's used in the Gen 3 6.0L truck engines.
Specs: [214/222 @ 119* for the GTS]
196/207 @ 116* or 198/209 @ 115.5* (for the non-HSV LS1 engines depending on model).
'01 LS6 is 204/211 @ 116* 0.525"/0.525"
from '02 it's a 204/218 @ 117.5* 0.551"/0.547"
>> Edited by sid447 on Tuesday 31st May 01:40
>> Edited by sid447 on Tuesday 31st May 03:03
>> Edited by sid447 on Tuesday 31st May 03:07
No SAE standard mentioned.
Probably with no accessories and drive belt along with using an electric w-pump.
Once you go above around 220 intake duration or over 50 degrees of valve overlap (total/advertised duration); you are losing torque over stock until you get to around 2-2500rpm.
1] Some validated stuff with more realistic power claims I've seen for LS1's have been on this site:
www.samsperformance.com ....(click on "Research & Development" ...then on "Best Packages" graph.
2] This test was carried out by David Vizard (he shouldn't need any intro!):
www.popularhotrodding.com/enginemasters/articles/chevrolet/smallblock/0503em_ls6/
3] This one is good in that it also mentions the strict SAE standard being used (as does #2]) by the Katech facility (so hp figures are honest) and also the fact that the both the Gen 3 and 4 respond really well even to mild cams that have a closer LSA than stock ('01 & '02 LS6 cams tried here but reground with a 110 and 112 LSA respectively. Which is more the norm for engines like this):
http://hotrod.com/techarticles/113_0504_ls2/
Cam-only changes (no headwork) to LS1 work well as the stock factory heads are good for over 465hp and they breath better than LS6 at mid-lift (0.250" which is where the valves spend most of the time open).
I personally have gone from an SAE J-607 corrected 313rwhp (bolt-ons & PCM) to 357rwhp with just a mild cam (USA custom ground Comp-Cam) which has less than 215 @ 0.050" duration.
Yes the stock LS1 cam is conservative. Main problem with it is the wide LSA it's on for easy emission compliance and a nice smooth idle.
It's also very much a compromise too as it's used in the Gen 3 6.0L truck engines.
Specs: [214/222 @ 119* for the GTS]
196/207 @ 116* or 198/209 @ 115.5* (for the non-HSV LS1 engines depending on model).
'01 LS6 is 204/211 @ 116* 0.525"/0.525"
from '02 it's a 204/218 @ 117.5* 0.551"/0.547"
>> Edited by sid447 on Tuesday 31st May 01:40
>> Edited by sid447 on Tuesday 31st May 03:03
>> Edited by sid447 on Tuesday 31st May 03:07
So what cam would be a good swap for a supercharged engine, still retaining stock valvesprings...
I really should be happy until I build another engine, but I still want more power lol I dont mind swapping the cam, but cant really be bothered with the valvesprings on this engine too....
Another 50-60bhp if it came cheap enough would be nice as long as ths std clutch holds up.
I really should be happy until I build another engine, but I still want more power lol I dont mind swapping the cam, but cant really be bothered with the valvesprings on this engine too....
Another 50-60bhp if it came cheap enough would be nice as long as ths std clutch holds up.
Hello Stevie,
The stock LS1 valvesprings need changing regardless.
Have a read of this; a brand new crate LS1 giving valve float @ 5500rpm.
www.compcams.com/Community/Articles/Details.asp?ID=-1044516358
Try and get a set of Comp 26-915's (293lbs) or the '02-on GM LS6 springs (260lbs).
The pushrods are also marginal (too thin and lightweight, so prone to flexing) and GMPP recommend changing them with any up-grade.
Either the '01 or '02-on LS6 cam could work well with a blower (no v-overlap @ .050"
) though the std Camaro cam shouldn't be too bad anyway.
>> Edited by sid447 on Tuesday 31st May 01:33
The stock LS1 valvesprings need changing regardless.
Have a read of this; a brand new crate LS1 giving valve float @ 5500rpm.
www.compcams.com/Community/Articles/Details.asp?ID=-1044516358
Try and get a set of Comp 26-915's (293lbs) or the '02-on GM LS6 springs (260lbs).
The pushrods are also marginal (too thin and lightweight, so prone to flexing) and GMPP recommend changing them with any up-grade.
Either the '01 or '02-on LS6 cam could work well with a blower (no v-overlap @ .050"
) though the std Camaro cam shouldn't be too bad anyway. >> Edited by sid447 on Tuesday 31st May 01:33
Here's a bit more on the LS1 valve float problem Stevie:
www.popularhotrodding.com/enginemasters/articles/hardcore/0409em_gmpp/
www.popularhotrodding.com/enginemasters/articles/hardcore/0409em_gmpp/
I had thought about a Z06 cam, but its ground on a different base circle ? SO I assume I would need longer pushrods too, aka LS6.
I also have a GT2-3 LPE cam which will work well, but it also needs a valvespring change. I was saving it for my other engine, which I have ported heads for. But have run into a piston problem, so cant build it.
Now considering a stroker kit...as if Im not already broke
I also have a GT2-3 LPE cam which will work well, but it also needs a valvespring change. I was saving it for my other engine, which I have ported heads for. But have run into a piston problem, so cant build it.
Now considering a stroker kit...as if Im not already broke
LS6 cam base circle is,
19.0mm (LS1 19.7). But LS6 valves are 0.6mm longer than normal Gen 3 so it still gets away with using the same 7.400" pushrods as the LS1.
Comp Cams are also 19.0mm BC. So with just a cam change you'd need 0.7mm or 0.027" longer pushrods.
What are the specs for the other cam?
What parts are you short of? Maybe I can get some from here.
>> Edited by sid447 on Wednesday 1st June 08:58
19.0mm (LS1 19.7). But LS6 valves are 0.6mm longer than normal Gen 3 so it still gets away with using the same 7.400" pushrods as the LS1.
Comp Cams are also 19.0mm BC. So with just a cam change you'd need 0.7mm or 0.027" longer pushrods.
What are the specs for the other cam?
What parts are you short of? Maybe I can get some from here.
>> Edited by sid447 on Wednesday 1st June 08:58
GT2-3 Camshaft specifications: 207/220 duration @ .050 .573/.580 with 1.7 ratio rocker arms 118.5 CL
Although Im almost sure I read it was a 119.5 LCA though. Above is taken from LPE's website.
I chose it for its close resemblance to the Z06 cam, but with more lift. Original intention when I bought the cam about 15 months ago was turbocharging, but I have no doubts that cam will work very will with a blower too, and some guys on LS1tech have started using it with good reports...
I want smooth idle, perfect road manners, and power.
At the minute Im looking ate replacing rods and pistons now. I think I have a guy on some cheapies that will work. Im sure they will hold up fine with about 15psi...or more if it wil take it lol After all, the std ones are working now with 9psi.
If indeed the Ross piston was flawed, they say they can make me a replacement set no probs...
That might work good for me, as I could get a set made to suit a stroker crank with the cheap rods I'll then also have.
Although Im almost sure I read it was a 119.5 LCA though. Above is taken from LPE's website.
I chose it for its close resemblance to the Z06 cam, but with more lift. Original intention when I bought the cam about 15 months ago was turbocharging, but I have no doubts that cam will work very will with a blower too, and some guys on LS1tech have started using it with good reports...
I want smooth idle, perfect road manners, and power.
At the minute Im looking ate replacing rods and pistons now. I think I have a guy on some cheapies that will work. Im sure they will hold up fine with about 15psi...or more if it wil take it lol After all, the std ones are working now with 9psi.
If indeed the Ross piston was flawed, they say they can make me a replacement set no probs...
That might work good for me, as I could get a set made to suit a stroker crank with the cheap rods I'll then also have.
Yes that's nice,
and as you say close to the '02 onwards ZO6 cam.
If it's on 119.5 LSA it should have very good manners.
For example I'm on 212/212 112LSA and that gives me 42 degrees of valve overlap @ advertised duration [0.006"].
The yardstick for keeping good drivability is to keep it under 50 degrees of o-lap.
You'd need to be changing springs every 30 or 40,000 miles with that amount of lift though!
Turbo cams are normally split-patterned the other way i.e 224/220, 220/216 etc.
and as you say close to the '02 onwards ZO6 cam.
If it's on 119.5 LSA it should have very good manners.
For example I'm on 212/212 112LSA and that gives me 42 degrees of valve overlap @ advertised duration [0.006"].
The yardstick for keeping good drivability is to keep it under 50 degrees of o-lap.
You'd need to be changing springs every 30 or 40,000 miles with that amount of lift though!
Turbo cams are normally split-patterned the other way i.e 224/220, 220/216 etc.
My new heads have valvesprings rated for 0.600". Not sure what make they are though, as they came with the heads.
Thinking about it, I could be tempted to buy better springs and stick 1.8s onto it when I put it together !
LS1 heads really do flow when the valves are opened
Are there any benefits to be gained just by swapping to aftermarket 1.7 rockers, compared to std ones ?
I have a set of YT's I was going to save for the new engine, but could just as easy bolt them onto my current one until then.
Thinking about it, I could be tempted to buy better springs and stick 1.8s onto it when I put it together !
LS1 heads really do flow when the valves are opened
Are there any benefits to be gained just by swapping to aftermarket 1.7 rockers, compared to std ones ?
I have a set of YT's I was going to save for the new engine, but could just as easy bolt them onto my current one until then.
Short duration and big lift is the way to go with The heavier Commodores and Monaros.
Don't think you have too much of a weight problem though do you?!!
Stick with the stock rockers...
This type is continuing to be used on the LS7 (7000rpm) so can't be too much wrong with them.
C-C Techline said the same too when I queried up-rating the stock LS1 rockers.
You don't want springs that are too stiff.
Valve spring pressure:
On the seat: 90 lbs for the LS6 vs. 76lbs for the LS1.
Over the nose: 260lbs for the LS6 vs 220lbs for LS1.
www.idavette.net/hib/02ls6/page2.htm
>> Edited by sid447 on Saturday 4th June 11:48
Don't think you have too much of a weight problem though do you?!!
Stick with the stock rockers...
This type is continuing to be used on the LS7 (7000rpm) so can't be too much wrong with them.
C-C Techline said the same too when I queried up-rating the stock LS1 rockers.
You don't want springs that are too stiff.
Valve spring pressure:
On the seat: 90 lbs for the LS6 vs. 76lbs for the LS1.
Over the nose: 260lbs for the LS6 vs 220lbs for LS1.
www.idavette.net/hib/02ls6/page2.htm
>> Edited by sid447 on Saturday 4th June 11:48
Here is a nice priced kit with springs etc.
www.sdpc2000.com/catalog/1981/products/1089/LS1-Hot-Cam-219-228-Duration-0050-Hydraulic-Roller-Camshaft-Kit.htm
Its designed to go in a stock engine.
Ive heard of people saying the overlap is a little high but ramp rates are nice and dont hammer the valve train.
The most widely respected cam seems to be the TR224 from Thunderracing. It has high ramp rates though.
The Cams you guys are talking about look a little "girly" to me. Any reason why a juicier cam isnt a good idea?
Rich
www.sdpc2000.com/catalog/1981/products/1089/LS1-Hot-Cam-219-228-Duration-0050-Hydraulic-Roller-Camshaft-Kit.htm
Its designed to go in a stock engine.
Ive heard of people saying the overlap is a little high but ramp rates are nice and dont hammer the valve train.
The most widely respected cam seems to be the TR224 from Thunderracing. It has high ramp rates though.
The Cams you guys are talking about look a little "girly" to me. Any reason why a juicier cam isnt a good idea?
Rich
Valvetrain longeivity. Piston to Valve contact issues with big lift. How many broken valvesprings have you read about ?? Ive read quite a few on LS1Tech.
Idle quality, emissions, economy.
If you have std rod bolts, some see that as a concern if venturing above 6k often.
And you really dont need or want a big cam when you are using forced induction. And I wouldnt want to own a car I was trying to get power from if it wasnt blown one way or another.
Its the only way to get REAL power for sensible money.
Idle quality, emissions, economy.
If you have std rod bolts, some see that as a concern if venturing above 6k often.
And you really dont need or want a big cam when you are using forced induction. And I wouldnt want to own a car I was trying to get power from if it wasnt blown one way or another.
Its the only way to get REAL power for sensible money.
ringram said:
Here is a nice priced kit with springs etc.
[url]www.sdpc2000.com/catalog/1981/products/1089/LS1-Hot-Cam-219-228-Duration-0050-Hydraulic-Roller-Camshaft-Kit.htm[/url]
Its designed to go in a stock engine.
Ive heard of people saying the overlap is a little high but ramp rates are nice and dont hammer the valve train.
The most widely respected cam seems to be the TR224 from Thunderracing. It has high ramp rates though.
The Cams you guys are talking about look a little "girly" to me. Any reason why a juicier cam isnt a good idea?
Rich
Hi ringram,
That's the GMPP "Hot Cam" for LS1/6 that you mention on the SDPC site.
It's on a 112LSA with .525"/.525" valve lift.
There's a dyno test of it fitted to a stock LS1 here:-
www.popularhotrodding.com/enginemasters/articles/hardcore/0409em_gmpp/
Have a look on Sams Performance site that's mentioned in an earlier post on this thread; you can compare a 224/224 along with a few other cams (228/228, 224/220, 220/218 and a little 212/212 and of course the stock 196/207 is there as a yardstick).
Sad fact of life is that a lot of people believe if big is good then bigger must be better.
If you decipher the "Best Packages" graph, you will see the hairy-chested bigger cams don't get going until above 2750rpm and so incur a moderate to considerable fuel consumption penalty in normal use. As they've lost considerable low-down power for the gain above 6000rpm.
The 212/212 there, on the other hand actually makes more average torque (hence, power) than ANY of the other cams if you go only by this graph which runs from 2300 to 6350rpm.
In reality the 212/212 would be outperforming all of them right down to 1000rpm and all the way to 6350.
So here is an ideal street cam that idles fine, has no detrimental affect on economy at steady speed cruising compared to stock, and will give good power all the way to the limiter at 6200rpm.
Using the example of a 224/224; they would be good to rev all the way to 6700rpm or more (depending on LSA).
But the consequence of making regular visits to 6500rpm and more in a big engine like this means expensive parts have to be fitted; and in spite of that you will probably halve the engine's durability and also lose a good amount of reliability too.
The girlie cam I have (a 212/212 in fact) makes more power than a 383ci Gen 3 stroker fitted with a 232/228 up to 3000rpm and is ahead of almost any other cam you care to mention up to 5000rpm, peaking at 5600rpm with just short of 360rwhp (corrected to J-607).
Serious naturally-aspirated power all well within the stock rpm limit.
Never saw the point in revving a big ohv V8 like a little dohc-4. Sort of misses the point of having a nice big easy-going engine.
Gen 3 engines are very good, no mistake; but they won't last long being revved to almost 7000rpm; which is what you'd have to do if they are fitted with big cams, no point in fitting one if you didn't.
http://impulsengine.com/performance/moreav.shtml
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