MP .557 Seat Pressure

[Baxter61]

What are you guys running for seat/open pressures with your .557 cam. Also, what kind of RPM are you turning? Final question, do you think stock 915 J head valves will withstand the pressure or do I need to step up to aftermarket? :thumblef:

 

[rumblefish360]

Do you find the MP spring weak or limiting? Thinking about this cam with a 1.6 rocker myself. Should prove interesting I think.

 

[Baxter61]

Havent looked at the MP springs yet. Just seeing what recommendations are for pressures to see if something I have may work.

 

[70aarcuda]

ran that cam for years...with both 1.5 and 1.6 rockers...use the mopar recommended spring P3412068 on J heads...

I shoot for around 140 lbs on the seat...probably around 350 lbs over the nose....there should be alot of springs that match that...

I know a few people who ran that cam with stock eddy springs which are about 125 lbs on the seat..

 

[JBurch]

I am using Hughes 1111 springs, installed height 1.800, 140 pounds on the seat, 315 pounds at .550 lift on a pair of Hughes ported Eddy's, using 1.6 rockers. Prior to the Eddy's, I had a set of "J" heads, Comp springs(can't tell you the number, a dual spring with damper), installed height 1.750, 130 pounds on the seat.