I am changing roller rockers on my 97 Z28 LT1 and I was wondering if I need to change the springs as well or will the springs be able to handle the extra compresion.
1.5 to 1.6 ball bearing. I heard this upgrade really allows the engine to breathe better.

 

It would be a good idea to get stronger springs with a shoter compressed height to handle the extra lift. You really want to avoid coil bind.

 

Thanks for the tip, but do you think I can get away with it for a little while with stock springs. I wasn't planning to change springs until I changed the heads because of the extra labor. Springs are tough because without taking the heads off you need a compressor to hold up valves. My exhalust manifold is all stock and there is not much room.
Thanks
kclark

 

Turn the engine by hand once the new sprigs are in and make sure the coils are not touching each other when the valves are fully open. Check each spring individually due to tolerance variations. Also, don't go much over 5600 RPM in order to avoid valve float and damage things.

 

Get the dual spring http://www.jegs.com/webapp/wcs/store...tegoryId=10699. They'll help with the anti float. If you want to change the springs w/o taking off the heads there is also a tool that lets you hold air in the combustion chamber that forces the valve to stick to the head.

 

In addtion to the compressed air method, if the rings are too badly worn for this to work, you can fill the combustion chamber with a long section of thin rope. Turn the engine to about halfway to TDC on the cylender you're working on, feed the rope into the spark plug hole, and then turn the engine forward untill you feel some resistance. This will hold the valves in place without having to rely on maintaning air presure, as well as avoiding the need for any special tools to retain the valves. Just make sure you have more than enough rope to fill the cylinder, and still have enough to pull it out when you're done, else you'll end up having to take the head off anyway.

 

Determine cam lift at 1.5 divide by 1.5 multiply by 1.6 take result and get spring specs and compair. I dont know the cam lift or the tolerence of your engine but there is piston to valve clearance to consider also.

 

If it's a stock cam, You shouldn't have any problem. Still do check for coil bind, About .015" between each coil is needed. If You do change valve springs, make sure You get the right spring pressure required for Your camshaft.