Hello All,


This may be a newbie question but this is how we learn haha.
Last Summer I did an engine pull and I replaced the my stock J heads and put on a set of 69 Big Valve C Heads. This heads where built by the previous owner. Heavy Duty Springs, Roller Rockers, 5-Angle Valve Job Hardened Seats and Bronze Silicon Valves( I think, I may have that wrong) and Mondello Pushrods. My question is what effect does pushrod length have on the engine. Im using an Edelbrock .472 Cam and Lifter Set. I believe the Cam in the engine the C Heads were on had a slightly larger cam. But the Mondello Pushrods are slightly longer than my stock pushrods by about an 1/8 of an inch if I remember correctly. It was definitely noticeable. But Ive been thinking about this since I installed them. Can anyone shed some light on this?


Ive attached a very bad and blurry picture of the heads from last summer.

 

You need these and the knowledge to use them and/or a knowledgeable person to help you

http://www.summitracing.com/parts/pr...Fchhfgodf2YAWA

 

I'll try to help and give you a suggestion.

Get a sharpie marker, mark the top of the valve stem, one or all of them, your choice. Turn over the engine a couple or more times. Now look at the top of the stem to see where the roller tip crossed through the ink of the pen.

If you can carefully measure the witness mark the roller tip made, it should start about .030 from the inside edge and stop about the .030 from the outside edge.

If the roller tip starts too early, the push rod is too short.

If the roller tip stops later than .030 push rods too long.

This won't be a cure all suggestion, but it might help to get you started on the right path. An adjustable/checking push rod is the way to go to make sure. Lifter preload is important part of this.