I am in dire need of a camshaft so I can finish up my 427 project. I have posted in the LS1 internal engine section but that was more of a big cube cam thread, opposed to LS7 cam thread. I've also gone to several sponsors but haven't gotten too much information. All I've done is look at what other people are using, look at what the manufacturers are making etc... I've looked for off the shelf cams that might work but none seem to fit the application, or the budget.

Here's what I'm looking for... Heads will be LS7's, so a good amount of traditional split it desireable to help out the exhaust side of things. Lift in the .600"-.650" range, .660" max due to spring. Smog is not a concern, stock cam will be put in come that time. Some lope at idle, similar to a 224/224 112, or a little more, not TRex lope, too much. INSANE TORQUE, peak HP is not a great concern. Redline will be around 7000rpm, but will rarely be seen. Car is 100% street driven, needs to have acceptable driveablilty, no need to be stock-like though. That's all I can think of. Here is the setup:

-GM LS7 heads
-GM LS7 titanium intake and sodium filled exhaust valves
-GM LS7 1.8:1 rockers
-GM LS7 intake manifold
-Holley 90mm TB
-Stock or Comp replacement lifters
-PRC springs and retainers, .660" max lift
-4.125" bore
-4.000" stroke
-6.125" rods
-10cc dish pistons
-0.051" compressed head gasket thickness, 4.160" bore
-0.013" deck height(above deck)
-SCR of about 10.85:1

Here's the specs of a cam I had in mind, custom: 222/244 @ .050", .620"/.635", 114 LSA, XE-R Lobes, +4 advance. Unfortunately, it says it will have a DCR of 8.7 which is a little high for 91 octane, not sure if I believe this calculator. Should I raise the intake duration to bring down the DCR, or raise the LSA, or reduce the advance...!!?!?!. Very confused here. Need cam experts' opinions.

Thanks so much!

 

Katech has a LS7 cam (220/244) close to what you are thinking about.
If you are worried about the DCR being too high why not just go without the intake advance?

Katech cam thread:
https://ls1tech.com/forums/generation-iv-internal-engine/559046-heard-about-another-katech-z06-prowling-woodward-over-weekend.html

 

I cannot afford Katech's cam, simple as that. And the cam's DCR is way too high. Something like the Torquer cam but with less DCR is what I'm shooting for.

 

Call Comp-Cams technical help line, they can design a cam to your exact needs!

 

BWAHHHHHHHHHHHAHHHHHHHHH, I hope that's a joke. They'd probablly give him a grind for a 67 chevelle knowing those brainiacs. Mike, I really don't see the need for the intake advance. Your making it very intake biased, and I'm not a fan of that for N/A applications. With the small intake lobe, your gunna peak early already. Adding the advance will only make it sooner. I'd use the numbers you have, but make it +0. This will add 4* to your IVC, which should get you bellow 8.5 DCR. This will also put you on the exaust biased side, which is what is needed with the poorer flowing exaust port.

 

Ahh... I wasn't sure where the cam was going to peak, so I figured a +4 advance in similar to my TR224. The dyno graph of Katech's Torquer(220/244 110) peaks around 5900rpm. Will the higher LSA on my cam idea lower or raise the peak? I'm thinking I could even retard it a little bit, or maybe just do that with the timing set afterwards. Thanks Jason!

 

I understand that we may not fall into some people's budget. We spend A LOT of development time/money on our Optron valvetrain dynamics test cell to find just the right combination. We don't sell 1000 cams a year to offset these costs so that is why it's a bit higher than most cams, but you know you're getting a proven package.

 

I would suggest a 232/248 .630"/.651" 112LSA. XE-R lobes. Good intake/exhaust ratio with a DCR of ~8.3 pretty much where you'll want it with your SCR of 10.85. I would also suggest calling up comp and asking them about the Renegade lobes (its an off the books lobe) for the intake and see if they have one around 232 that'll bump your lift up to .65X for the intake, because thats where peak flow occurs on the heads.

Best Regards!
Adrian

 

That grind will have 16 degrees of overlap. I'm looking for around 5 or less so I have even a slight chance of passing smog by running an alcohol mixture.

 

Well i guess you just changed your mind on that then, thought you said you were going to swap back in the stock LS7 cam

 

You're right. I really can't make up my mind weather or not I want to swap cams come smog time, or try to get one now that has a chance of passing. I suppose if I can meet my goals while passing the sniffer then that would be my best option. I'm looking on both sides of the fence though. The Katech torquer cam seems to be a VERY nice grind with exceptional power. I'm making that my starting point and adjusting to make a decent DCR.

Who is using a 232/248 that you know of? Is it avaliable off the shelf or custom ground? Any dyno charts, video clips? Thanks man!

 

The 2* increase in intake duration along with the 112LSA will drag the band out a bit farther. I'm not sure of the advance on the Katech cam, but I would imagine the grind you listed will peak in the early 6's and carry to the late 6's. Increasing to the grind Haans listed will increase power, so in some instance you'll have to decide what you want. HPE has a line of LS7 cams. I would call up Erik, you know he's good to deal with.

 

Mike,
No one in particular is using that exact cam that I know of. I'm sure there are people out there using something similar, but its something that I came up with keeping in mind what you want, and I think it'll be a good cam considering your needs, if you want some more of that power. It'll probably make a little less torque in the low end then the grind you listed, but it'll make it up as you start turning rpms.

FWIW, I'm going to run a 242/256 .646/.668 on a 113+2lsa with 11.5:1 CR in my 427. Its XER/Renegade lobe and I think it'll really kick some ***!

Best Regards,
Adrian

 

I had a very informative talk with Richard at WCCH about cam options. He suggested that I increase the intake duration slightly, and decrease the exhaust duration slightly, and then perhaps run a tighter LSA to pick up some low end power. Here are some options I've been working with...

224/242, .615"/.646", 112 LSA +0, XE-R Lobes... Overlap of 9 degrees, DCR of 8.49
226/240 .619"/.645", 112 LSA +0, XE-R Lobes... Overlap of 9 degrees, DCR of 8.42 (+2 advance for a DCR of 8.56)

Any thoughts?

 

I purchased this from Lingenfelter thinking about putting it in the new Z06 (I haven't bought one yet, LOL). 7 degrees of overlap and I was going to advance it to a 110 ICL.
LS1-GT1-1 228/242 .665" / .665"(w/1.8RR) 114 LSA

 

here's a bonafide result from a 230 / 240 on a 114 +2 - other add ons were UD pulley, ported intake and electric water pump, no cats, sd tune...YMMV

DYNO GRAPH

 

Is this RWHP or crank horsepower? Traver

 

thats at the rear wheel

 

I assume that graph from A&A is a higher than stock compression LS7 427? The torque is pretty high.

-Mark

 

If you fix the exhaust ports on the LS7 head and make a cam to fit you can still have a smog legal setup. The big cubes can pass smog with more overlap than stock cubes for some reason, but I would still say that 9 degrees is too much.

Bret