I recently bought a L05 with a LT4 cam installed and the company called me to inform me the pushrod wasn't change during the cam swap so he sent me the pushrods which are +100 longer than stock. Would the +100 longer pushrods will hurt the engine or help? Thanks!

 

No quick easy answer to that question. If machine work had been done , cam change or any valve train componants have been changed it could all affect pushrod length. The only way to know for sure what you need is to check. Pushrods are typically sold in + or - .100 7.100, 7.200 7.300 etc. Checkin and using the correct length pushrods ensures good valvetrain geometry which will add life to the guides etc. If you need details on checking length, just ask and we will give you the procedure.

 

On most modestly cammed street combinations stock length sticks are just about perfect. This is an area where I find that people often lose their brain and start sticking in longer pushrods without really thinking about what they are doing or why. Like an old wive's tale there's just GOTTA be someting "magical" about longer puhsrods. RARELY are they needed.

Extensive block/head machining, different thickness head gaskets, cams with non-stock base circle diameters, aftermarket heads, aftermarket rocker arms...... all can affect the length of pushrod required. But at the end of the day...... stock length is ALWAYS where you start your checking from. And you SHOULD check for proper length. There is no other way to know for sure.

However, 9 times outta 10 if the stock length pushrods are tall enough to keep the rocker arms from rubbing on the base of the rocker studs as it pivots then it's probably pretty close to the right length.

 

If the pushrod tip is centered over the valve tip while on the base circle you have the right length. As the rocker arm goes thru the lift cycle it moves across the whole valve tip outboard and inboard of the center of the valve.

 

i have been searching for the procedure to check the length with a checker but haven't found it. could someone post a link?

 

Here ya go... Comp Cams Pushrod Length Checking Info

 

thanks. i looked on their sight but didn't see it.