Another valve spring question...

[Rat Patrol]

The following are the installed heights as per the factory manual of the intake and exhaust 6.1 valve springs -

Intake (1.870 in.)​

Exhaust (1.772 in.)

Now as has already been stated by myself and others on this forum - the general opinion amongst "Tuners" and Re-Sellers is that PSI LS1511ML spring is a straight drop in - w

This spring is advertised with a 1.80 installed height.

So how is the variation in installed heights between the exhaust valve height on the factory head accommodated with using a 1.8 installed height spring - is the extra seat pressure generated by the lower factory installed height not an issue?

I guess the same issue applies to the difference between the INTAKE 1.87 installed height - and the 1.80 PSI requirement but in reverse?

 

[Modern Muscle]

dont know who told you it was a drop in but we use shims to get the 1.80 install height for the 1511s

 

[Rat Patrol]

dont know who told you it was a drop in but we use shims to get the 1.80 install height for the 1511s

Thank you very much Chris!

I won't name names but there are vendors out there that insist they do.

That answers part A of the question.

part B - Now how do you deal with the issue that the PSI on the intake side will be compressed 80/1000 to meet a 1.8 install height - is the increase in seat pressure nothing to worry about?


Appreciate the heads up on the PACs as well....