qane

I'm interested in running the TSP 231/237. My heads are AS stg2 milled .040. I understand there's no way the .598"/.595" lift will work with the heads as milled as they are. I know you can only flycut so much (.080?). I wonder how much I'd have to have flycut. If it wasn't a lot (.030) I could flycut all the way to .070 or so and maybe get an even bigger cam? I'm not sure how much an extra .040 on top of the .030 would give me room for, lift wise.

Also, I just read a little bit of a thread talking of 231/237 cams with lower lift. Will I still see comparable power gains from one of those cams with my compression to people with the higher lift 231/237 and unmilled heads/factory compression see? Every bolt-on in the book will be accompanying the heads/cam btw.

Any suggestions welcome. Thank you all.

Trevor @ Texas Speed & Perf.

iTrader: (3)

You could cut valve reliefs and be just fine. If you're running 2.02/1.57 valves, the absolute max you'll have to cut for reliefs would be .040" since that's how much the heads are milled. You could most likely get away with less since the valve is not coming straight down towards the piston (it's at an angle), but you would just have to check it. Cutting larger reliefs than needed will certainly give you some growing room. This is what we did on my SS last year. We knew we'd be trying larger camshafts and would need ample room, so we just cut .080" reliefs. They even help up fine to numerous 150 HP shots and a few 225 HP shots.

FYI, the max lift is not what will get you into trouble. Your typical problem areas are 10 degrees before top-dead-center (BTDC) and 10 degrees after top-dead-center (ATDC). This is when the piston is chasing the valve and the valve is chasing the piston, respectively. You could try to run a lower lift camshaft and still potentially have problems. When the cam is at max lift, the piston is far enough down in the cylinder to not have problems.

Feel free to give us a call if you have any other questions.

Trevor
Texas Speed & Performance

CAT3

iTrader: (9)

Has anyone tested to see how much room there is stock with this cam? And how much is recommended clearance wise. I was thinking of cutting reliefs, but use a .060 gasket as well, my stockers mic'ed out to be .052 crushed. So, with a -.022 off head, +.008 for gasket I come up with -.014 too much I believe, so I would need to cut .020 to be safe (in case I went back to a stock gasket). Is this right?

-Joseph-

iTrader: (12)

We've run the 231237 with 10 thou cut off with no problems, but p/v should always be checked on situations like this

critter

iTrader: (9)

I was about to leave this advice. This is a common misconception - that lift has something to do with piston to valve clearance. Instead, it is duration. In fact, lobe type (Lunati, Comp XE-R) makes essentially no difference in P/V clearance.