I was thinking of getting a nice performances camshaft for my firebird. I wanted a camshaft that gave me a rough idle so I was thinking of one with a 108* lobe separation. But what the hell do all these other numbers mean, especially the RPM Range, what does this mean, when the engine will perform the best or what? What should I look for when picking a camshaft with a low lobe separation?

 

Personally I wouldn't recommend pick a cam that way, I prefer to pick them based on how well they match the rest of the engine & car combo to produce maximum speed. Engines run the best when the characteristics of each of their parts, above all the RPM range that each part is optimized for, are all designed and selected together as a system. But of course, to each his own...

What are the details of this car? Heads, intake, exhaust, converter, gears, weight, any specific goals you have such as HP or ET?

Others on this BBS have obtained great results in that motor with the Comp XE262H when combined with a decent exhaust system (translation: EVERY SINGLE PIECE swapped out to something that's better than LG4 stuff; the 2¼" Y-pipe and I-pipe are the real killers)

 

bone stock LG4 305. I dont kow waht it runs right now but when I get doen putting like new intake, exhaust system, rocker rollers, cam, Im hoping to run it in low 14s. What do you think>

 

Not unrealistic at all.

I'd recommend the Edelbrock TES for some other car, like a 89 IROC with a 350, and cat & cat-back to match. That stuff will be 3" diameter instead of 2¼". I wouldn't fool around with the intake too much. The Comp 1412 roller-tip rockers are a good bang for the buck. In fact, get the whole kit from Comp with the valve springs, timing set, push rods, valve springs, etc.; and the rocker arms, it's cheaper that way, and all that stuff will be new, and you can put some decent valve guide seals on it while you're swapping the springs, to get rid of the big cloud of oil smoke at startup.

My car has its original 305 block & crank, flat-top pistons, LT4 rods, a set of 186 ("double-hump") heads, a Comp XM264HR-12 cam, Edelbrock TES, and every other piece stock; it does 214 RW HP, which is about 260 or 265 HP at the crank. That's with the stock Q-Jet, distributor, intake manifold (same as the LG4 one), the L69 cat & cat-back, and all emissions devices installed and operating such that the car passed California inspection right before it was dyno'ed. Learn from that what there is to learn: namely, the stock carb and intake are good enough to allow a carbed 305 to massively outperform a TPI 350, by 30 or more HP.

OBTW - if it's a bone stock LG4, it did about 16.1 when new if it was an auto, and about 15.8 if it was a 5-speed. Your gears are 3.23 at best and might be 2.73, so that's an area for easy, major improvement.

 

well not everythign on my car is stock, check out my sig. I have a flowmaster 80, so it flows a LITTLE bit better, I have 2 inch tubing from both sides of thebottom of my car going up to the k&n for ram air induction, and the guy I bought the car from put on an electronic q-jet. So dont you think I have a little more hp and torque than stock, maybe 10 - 15 at most??? What is the definition of rear wheel horse power btw and crank horsepower, and the signifigance of the numbers? Thanks, I think Im going to start with ym exhaust first, then get new gears, then start on the engine.