Just about ready to start putting the motor together, brought my AFR 195 heads to the machine shop to have the valve springs installed that were recommended to go with my cam. I had the guy throw one on the spring pressure unit and check the seat pressure. Now, I have an original Gen I SBC Hydraulic roller block, still sticking with the hydraulic roller lifters and cam. The springs measured 150/155ish seat pressure. (He did a real quick check, was busy on another machine at the time). I also have an AFR hydrarev kit that I was planning on putting on. The lifters I am going with are comp super mangums. In talking with people about those they're like the Rhodes lifters that bleed off very quickly and pump up in the same manner.

Is this going to be too much pressure?? This number was measured at 1.800" seat. Cam specs are 228*/234* .529"/.522" 112*LSA. And I think 6* overlap ground in, dont have the card here in front of me.

I just dont want to snap lobes off my cam lol! If you need more info just say so.

TIA!

 

Also of concern, will this collapse a Rhodes style lifter?

I've been terribly mislead about hydraulic lifters if 150# seat pressure is acceptible.

 

First off no, that amount of pressure is still not too much for the Pro Mag Lifters (Comp R's) They will handle that load fine. In fact it's not the seat pressure that will hurt the hyd part of the lifter it's the over the nose pressure. Some setups can put 600-800lbs of pressure on the lifters and that can cause a problem.

It might be more than you need for the cam you mentioned, since that cam is pretty mild for that amount of spring AND the rev kit.

Bret

 

If its just "more than I need", I'll sleep much better tonight. I spent $1200 on the AFR heads and a considerable amount more on the rest of the parts. If somthing was going to make my engine go boom, I'd rather take the necessary steps right now to correct the situation than find out later when its already in pieces on the track.

Thanks Bret!