Originally Posted by brdgcrs
So I called Thompson motorsports and bought a can based on there sugestions. Just want some more opinions because I'm kind of scared lol.
I have a 98 camaro that I have completely gutted and I'm puting a 5.3l lm7 in it. The cam I have is a 236/250. Will I have piston to valve clearance issues or will I be Okay? It's a race only car and won't ever see the street again. It's getting a healthy dose of nitrous as well. Not sure how much yet but I'm starting at 200 and going up from there
What are the rest of the specs? Whether it will fit or not is all about the valve timing. Also, what intake manifold is on the car?
If you tell me the lobe separation angle and the intake centerline (or how much advance) I can estimate if it will fit.
As for performance in an LM7 with nitrous, if the lobe centers are correct and it will fit, it could be good on a 200 shot.
For example, if it is 236/250 on 115+5, it would have valve events of:
IVO(intake valve open) 8 degrees BTDC(before top dead center) at .050"
IVC(intake valve close) 48 degrees ABDC(after bottom dead center) at .050"
EVO(exhaust valve open) 65 degrees BBDC(before bottom dead center) at .050"
EVC(exhaust valve close) 5 degrees ATDC(after top dead center) at .050"
236/250 is a pretty big camshaft for a street driven, low compression 5.3 liter engine. Unless it has a 5000+ RPM 8" stall converter in it and 4.56 gears, it will be a dog on motor. However, once you spray 200 horsepower of nitrous, the results can be quite different.
Nitrous has the virtue of supplying massive torque. So much so that often times racers have to pull timing and or run a progressive nitrous controller to reduce power on the launch in order to get traction or avoid wheelstands. In cases like this, choosing a camshaft that is focuses on the very top end of the RPM range can be a smart choice. However, the downside to this strategy is that the car will likely be a dog without nitrous.