triple6vett

I am in the middle of having my motor put together. It will have heads worked from Texas speed, cam, headers, cold air intake, tune.

The builder is wanting to put a cam in with 231/238 .617/.604 115/111. I am looking to hopefully put 550hp down to the wheels. What do you think the possible out put would be with this cam?

RedZ4me

are those lifts at 1.7 or 1.8 ratio? guessing 1.7 so will be higher with the LS7 1.8 ratio

triple6vett

I am assuming whatever stock is.

RedZ4me

^^^

Don't assume, many cams are spec'd at 1.7.

XLR8-R

I would say that cam is not optimum for an LS7. The intake ports flow extremely well on LS7 heads so most builders spec a cam with more exhaust duration by 10 to 20 degrees. I would look at cams specifically designed for the LS7 like Katech, Brian Tooley, RPM, etc. Even the Texas Speed LS7 cams seem to do well... Just my .02... There are a lot of great shops that don't know the idiosyncrasies of the LS7(for instance cam specs for 1.7 rockers instead of 1.8).

triple6vett

Ok, called him, he is saying 1.8

triple6vett

He builds a lot of motors and has built ls7's as well. I spoke with him about the Btr stage 4, but thought it may be a little more cam than I wanted. I don't want to be on the ragged edge but still want to make good power. This grind is what he recommended I just haven't seen these specs on any other cars.

meanjoe

Sounds like you need the BTR Stage III LS7 cam.
I put one in a motor I did. Not too crazy easy to drive if it's tuned properly and you'll have no issues reaching your HP goals.
Have you considered heads from Late Model Engines here in Houston?
They have a banging machine shop.

Good luck with your build

triple6vett

Thanks, the stage three was what I was thinking also but we talked stage four and maybe. A little smaller, then I called him and he had already went and got the cam speced as listed. I am thinking it isn't going to be what i am looking for but was hoping there may be something out there that I can compare it to see if it might work so I can be sure. Hate to waste the cam if it will put out what I want.

My heads are already done, its the stock heads sent them to Texas speed and they worked them.

XLR8-R

My opinion is that cam would not make 550 to the wheels. There is a world of difference between that cam and BTR stage 4. You don't need a Stage 4 to make 550, but you need more then that cam... I would also want to know what cam manufacturer and what lobe design if it was mine...

triple6vett

He said it's a comp cam. I am not real happy with his decision to put a cam in there without us agreeing to the final specs, however he agreed he would eat the cam if need be and I could get something else. I just hate to waste a cam if I don't need to, even if it's on his dime.

XLR8-R

Those do look like they match up to Comp lobes but lift matches with 1.7 rocker, not 1.8. In any case that looks like a good LS3 cam, but not LS7. Long story short, this is your engine and I am sure you paid a fair amount for the work, I wouldn't waste time putting the wrong cam in it. Someone will buy that cam(for an LS3), so he or you won't be losing much. Just search this forum for results with different cams and I am sure you will find the one that will give you the results you want. Texas Speed can provide the right springs, or order a matched set with the cam you choose. Good luck!

triple6vett

Awesome thanks,

I originally brought the car to a different place almost a year ago and they where putting in the ls7r cam and putting the heads on and they did not check lifter preload and the motor failed before they could even drive it to the dyno. So almost a year and a lawyer latter I am at a different place trying to get the car done and right.

Michael_D

Not knowing exactly what was done to the heads, and how well the exhaust port flows after the work, it's difficult to come to conclusions on the cam your builder spec'd. Normally, you'd want to see more of a split than 8.... But if they really work the exhaust port, it may be just fine. The intake duration is about right for 550'ish, but only if it's happy.... By happy, I mean that the exhaust can pull enough on the port. If the exhaust is choked/stalled, then it will fall on its face.

Your builder certainly didn't pull this cam spec out from somewhere dark and stinky, so he must have his reasons. Maybe he's had success with this cam, and the rest of the stuff he's doing?

Find out what Comp lobes he's using. That's as important as the valve events.....

triple6vett

This is the chart Texas speed has up for the head specs. The builder actually owns a ls7 motor, he is using it in a lower RPM situation, I don't think.he spins it past 5500 rpm. He is saying he gets 550ish out of the motor on a engine dyno and felt spin in it up to the 7000 would get the rest we where looking for. I am just worried that that small of a cam would leave a lot on the table not used. The closest I see to those specs is a stage 3 ls3 blower cam which makes no sense on a ls7, but I am no expert.


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LS7
Intake

LS7 Exhaust PRC 265cc
LS7 Intake PRC LS7 Exhaust
.200 161 114 169 119
.300 227 171 248 179
.400 291 193 308 211
.500 330 203 351 224
.600 351 209 383 235
.650 353 204 388 241
.700 353 209 393 246

Michael_D

I'd go with more exhaust duration, but same intake duration. Kinda depends on how much 'big cam' reversion you want to deal with. Despite what you will see others say, it's NOT "all in the tune".

I just finish tuning a friend's Z with LSX heads ported by Texas Speed. If you believe or put much faith in chassis dyno numbers, his is roughly 580 at the wheels. That was with this cam....

Intake lobe
Comp LXL
.362” lobe lift/.652” valve lift with 1.8 RR, .006” duration – 290, .050” duration – 238

Exhaust lobe
Comp XE RPM
.350” lobe lift/.630” valve lift with 1.8 RR, .006” duration – 305, .050” duration – 252

LSA – 114 with 4 degree advance
Lobe center – 110

IVO – 35 DEG BTDC
IVC – 75 DEG ATDC
EVO – 90.5 DEG BBDC
EVC – 34.5 – ATDC

Total valve overlap – 69.5 DEG
Valve overlap @ .050 – 17 DEG

triple6vett

Nice, I would be pretty happy with 580 at the wheels.

User Omega

You could go i bigger without loosing driveability with these cam specs. I'm running this cam with an LMR 440 making 595 wheel. Id imagine 550 on the 427 isn't out of the realm of reality.

231/246 .653”/.652” 115LSA +3 advance (with 1.8 ratio rockers)
Comp LSL/LXL lobes 54-000-11 3 bolt cam core
Cam Valve Events 0.006 0.050 0.200
Intake Duration – ID 281 231 154 13018R LSL lobe .653"
Exhaust Duration – ED 298 246 166 13163R LXL lobe .652"
Lobe Center Angle – LSA 115 115 115
Intake Centerline – ICL 112 112 112

Intake Valve opens – IVO 28.5 3.5 -35 BTDC (- indicates ATDC)
Intake Valve closes – IVC 72.5 47.5 9 ABDC
Exhaust Valve Opens – EVO 87 61 21 BBDC
Exhaust Valve Closes – EVC 31 5 -35 ATDC (- indicates BTDC)
Exhaust Centerline – ECL 118 118 118
Overlap 59.5 8.5 -70 degrees

C6Z06C6

Cute cam

triple6vett

Cute feedback, lol