Safe 360ci valve spring compression height question

[Brett]

I recently bought a Mopar Performance pre-magnum short block. I am using a set of rebuilt stock 1976 heads with stock valves and stock 1.5 rockers. I put the MP .430 int/.450 ext. cam in there with the exact valve springs and everything that MP recommends to be installed with this cam. The problem is that the Mopar Engines book lists this spring as having a 1.18 soild height and on my engine (and any stock engine) the exhaust valves are going to reach 1.20 and the intake 1.22 with this setup. The Mopar Engines book state that you should have at least 0.10 distance between the solid height of the spring and max valve lift and I am only left with 0.04 int and 0.02 exhaust (installed spring height varies from 1.65-1.67) and this is with using the recomended parts from Mopar. Can anyone shed some light on to this?

TIA,
Brett

 

[dodgeboy]

First you stock stamped rockers are likely closer to 1.4 to one than the advertised 1.5 to 1. I've never seen an RV type cam .430/.450 lift come go anywheres near coil bind on a small block!! Don't worry be happy.
Barry A. Lee

 

[MoPar Man]

I recently bought a Mopar Performance pre-magnum short block.

How much is a small-block short block these days? And does it _really_ come from Chrysler? (I bought a 318 short block about 16 years ago from a Chrysler dealership. It was built by a re-builder called "Ontario Reman" - had a metal tag pinned to the front of the block with the rebuilder's ID)

 

[Brett]

First you stock stamped rockers are likely closer to 1.4 to one than the advertised 1.5 to 1. I've never seen an RV type cam .430/.450 lift come go anywheres near coil bind on a small block!! Don't worry be happy.
Barry A. Lee

The other day I put a solid lifter in the #1 intake and set up for zero lash. When I measured the max lift the spring was at 1.21 which is only ..03 over the solid spring height of 1.18. Isn't this going to overstress the spring? Has anyone built a motor with the springs this close to the solid height without problems long term?

Brett

 

[Brett]

How much is a small-block short block these days? And does it _really_ come from Chrysler? (I bought a 318 short block about 16 years ago from a Chrysler dealership. It was built by a re-builder called "Ontario Reman" - had a metal tag pinned to the front of the block with the rebuilder's ID)

Was about $1,250 before taxes. I think there was something on the box the engine came in about being made in Canada but there seems to be alot of parts made for Chrysler there. Looks to be a good quality engine I just don't want to destroy it with too little spring clearance. I had to swap out the .509 lift cam for the smaller one for use with my '76 stock heads. Also selling the .509 cam and timing chain set if anyone is interested. http://fbody.kicks-ass.net:8000/enginepartsfs.html

Brett

 

[dodgeboy]

But how did the coils look! If their is space between then don't worry! Barry A. Lee Or go to the P5249847 spring. If it did not coil bind i wouldn't worry too much. I think your over thinking their conservative specks.