Maybe I am not doing this right. Crane specs the spring at 130 lbs @ 1.850. The stated spring rate is 391 ibs/in. My installed height is 1.770 which is .08 less. The pressure gained from decreasing the IH from 1.850 to 1.770 would be .08 X 391 or 31 lbs. I added the 31 lbs to the 130 and arrive at 161 lbs @ 1.770. Marginal? Maybe, but others have run this successfully.
Conceptually, if there were multiple examples of others who successfully ran this set up and measured theirs at 75 lbs (just to illustrate an example), would not that imply the springs at this IH are sufficient for the parameters they run their engines regardless of pressure?
That being said, I value your thoughts on spring pressure they are not lost on me. That is why you were mentioned in my first question. I am on a budget and I wanted to do this for a reasonable cost. If that means I have to limit the RPM, that is a consequence I accept. This is not a track car, nor has it ever been or will probably be at the track. Certainly, if I was starting with a clean sheet of paper, I doubt if this is the spring I would have chosen. But to make a spring change at this point would represent a fairly major undertaking. For me this started out as fixing a spun rod bearing and has spiraled into spending an additional $1,000 to replace a cam I was perfectly happy with.
__________________
71 Formula 433, Splayed cap 400 block, 4" stroke Scat forged crank, 6.8 Eagle rods, custom Autotec pistons. SD 295 KRE D ports, Old faithful hybrid roller, Torker II, Holley Sniper Stealth, Tribal Tubes, TKO 600, 3.73 Eaton posi.
|