Its been two years now since I spec'ed out my custom cam for my LS2 427 LS7 topend build.

Specs on the motor follows:

Built by Dave Diluca of Canadian Performance

-4.125 bore LS2 block resleeved with Darton LS7 sleeves
-Diamond LS1 4.125 pistons (only shelf pistons they had at 4.125 bore at the time)
-Callies 4" Crank
-Callies Compstar 6.125 rods w/ARP 2000 rod bolts
-Morel Hyd Roller Lifters
-SLP high-flow oil pump
-JRP Double Roller LS2 timing chain
-LS7 heads/intake stock form.
-Stock LS7 rocker arms w/ Harland Sharp Mod
-PSILS1511 Beehive springs with Katech Retainers good to .700" lift:
the springs in this setup are outstanding, and have been holding up to my extreme cam with no problems, the retainers are TOP NOTCH.
-Compression right at 11.38:1

My custom spec'ed cam is the following:
-242/256 .646/.668 113+3 LSA
lift is with the LS7 1.8 ratio rockers, and they are comp lobes, exhaust lobe is not a catalog lobe.

This motor has just been a complete blast since start-up, and has run very well. I dyno'ed it after putting a soft tune in her and on a Mustang Dyno it hit 500 rwhp 440 rwtq. The dyno I used it know for LOW numbers (a high compression ETP canted valve headed race 427 dynoed near similar numbers) so i was quite happy with it. Same dyno the Katech LS7 Camaro was run on that made the 540 hp. I'm still running a single exhaust system back to a flowmaster 80 series...which interestingly is also only good to 500 hp. So, I think its doing well. I have since upgraded to ARH 1 7/8 headers from my edelbrock 1 3/4 headers.

As far as the cam goes, with the greater vast amounts of information now available, how does it look? Do the valve events coincide with what is now known to be working well? I left for Iraq 2 weeks after I put the motor in and dynoed back in August 2006, so just looking for some critiques on the cam with lessons that have been learned.

Best,
Adrian

 

I haven't seen anybody on here that has had any big results out of any ls7 stuff lately. You must be on the right track.

What rear is that through??

 

Ford 9"/M6 vehicle, no dyno tricks, all accessories including A/C hooked up, stock water pump, and on TR6's (staying extra safe), on a soft tune. I believe there is a lot more power hidden in the combo with a new dual 3" exhaust, ported LS7 intake, roller rockers, hotter plugs, and ugraded tune , all could realistically add a good 30-40 hp conservatively.

 

There are a couple of different philosophies at work in camming the LS7. One is Katech with their Torquer cam, which uses an early intake valve closing point to build midrange torque, at the expense of some HP and high-rpm extension. The other philosophy, used by a lot of tuners to get the higher peak HP numbers, is to use a later intake valve close, along with higher static compression (as much as 11.8 or more), to extend the power curve another 500 RPM or so and thus get higher peak numbers.

Your cam is pretty typical of the latter philosophy, and you wouldn't likely get a great deal more peak HP with a new cam because the tuning frequency of the LS7 intake works against you heavily over 6500 RPM, and your cam is already pushing the torque curve as far up the range as that intake will let it.

 

What would be considered an early valve closing point for the LS7 setup?

 

The Katech Torquer is 220 intake duration with 110 LSA and 4 degrees advance - which gives 36 degrees ABDC for intake close at .050. Your cam, by comparison, is 51 degrees ABDC at .050.

 

Some pretty good advice. Bigger is not always better with those heads. You will definately gain mid-high range with the torquer .220/.244 by swapping that intake with a 4brl accufab 1200+cfm with a plate. (Not for everyone due to fitment issues). Im gonna engine dyno that exact setup in a few weeks and will post up the results.

 

Get the QM600 cam it's a proven performer! I happen to have one for sale right now at a good price!

 

What are the approximate durations on that cam? I vaguely remember it being somewhere around 240/260's? I can't remember.

I agree, I think maybe my cam is just a little much, but I think its making pretty good power, the torque curve is about as flat as can be, which is great. I need to get that new exhaust installed and re-dyno after all the changes and see again where I'm at!

 

Sorry but the specs are top secret! You know how it is?

 

I've also got a QM600 that I'm probably not going to use, but honestly there would be little value in switching to that from what you've got.

Your combo is close to optimal for a max combo already. If you're hungry for more, I'd work first on the exhaust. You could probably get away with another .4 to .5 point compression with the late IVC on that cam, and the right head porting might net you another 15-20.

 

Like 71CamaroLS1 said. Your cam specs are close to the QM600 specs so it would be a waste of money to switch cams at this point. You should be able to get close to 600 rwhp with a set of ported heads.

 

Thanks for all the advice. From what I remembered, I thought that my cam was close to what the QM600 ended up being. I spec'ed that cam out, even before the QM600 came out, so I guess I was on the right track. As far as my whole setup, new dual exhaust is in the works, once I get that, I will see where I'm at. If I want even more power still, a bump in compression to 11.8:1 with a set of ported LS7 heads, and ported LS7 intake is always an option, and was in the plans. I'm feeling even better that I was on the right track! I was finally able to dig up my dyno sheet, and it is posted here. The pull started at 2800-6500 rpms. I think a new exhaust will really set me off!

Best,
Adrian

 

It's all in the cam timing and valve events! Just because your numbers on your cam are close or similar doesn't mean it's the same. What about the type of lobe your running? It all makes a differance.............

 

You are extremely right!! I know a thing or two to have been able to spec out my cam myself, so I know what you're saying. What I wanted to know was if my cam specs make sense with what is known to be working well in LS7 heads, and it appears to be so.

Best!
Adrian


PS, your throttlebody cable bracket that you made for me is still tick'in and working well

 

That's cool Haans!! I had to readjust mine since I went with a 100MM throttlebody. It still works though only at a slight angle. Traver