365hp cam and lifters

[65stinger]

Does anyone know what the hp difference would be changing the lifters from mechanical to hydralic as well as changing the cam. Someone changed them over on my car during a previous rebuild. I am currently changing it back to original, but I was trying to get an understanding of why one would do this in the frist place. Also, does anyone know of a better way of adjusting these mechanical lifters rather than reverting back to the old time way???

 

[srthom13]

My guess for the change over to hydraulic would be for less maintenance and maybe better fuel economy. However, not knowing the history or reason of the prior rebuild -- who knows. I have a solid lifter cam on my BB and the valve adjustment/maintenance is not all that bad. The valve lash adjustment procedure as outlined in the manual is , I believe , the only way to adjust the valve lash on a solid lifter cam. If anything, it is the safest. Steve

 

[allcoupedup]

http://65corvette.nonethewiser.net/technical/VlvAdjArticle.pdf

Duke Williams and John Hinckley (johnZ) have come up with a method for accurately adjusting lash WITHOUT THE ENGINE RUNNING. This method has been proven.

Brian

 

[65stinger]

Folks, I'm am now a true believer in this forum. That was my first post, and let me tell ya, I didn't think I'd get an answer to that question. I knew for sure there was no other way to do this and you guys have proven me wrong. I haven't tried it yet, but I will be in the next couple of weeks. I have thoroughly read the procedure and it definatly makes since. Especially the valve chattering that comes with mechanical lifters. Now if only I could get some 100 octane......


Thanks again.....BIG HELP!!!!!!!!!!!

 

[srthom13]

I believe with solid lifters the engine should be run until operating temperature is reached and than shut down. Starting with the crank at the O degree mark you adjust certain intake and exhaust valve lashes. Than the crank is rotated 180 degrees and certain other intake and exhaust valve lashes are adjusted. This procedure is repeated until all 16 valves are adjusted. There are four valves adjusted per rotation and you should end up with the crank at the O degree position. This is a quick over view of the procedure. The manual outlines the exact procedure including what valves and what measurement. Intake and exhaust valves have different measurements and should be adjusted warm. I recommend using poly locks on the rockers. I manually turn the crank using 1/2 inch breaker bar with 3/4 inch socket. I found it to be alot easier rotating the crank if you first remove the spark plugs. Be careful not to hit the radiator with the breaker bar. Steve

 

[Bill75]

Solid Lifters

Regarding your origional question as to the hp difference between solids and hydraulic and also why someone would opt for solids over hydraulic;

I have never been aware of any true hp gain by using solids over hydraulics. At very high rpm's hydraulic lifters can "float", meaning the inside components of the lifter cannot maintain it's adjustment because the speed at which it's being compressed and expanded has exceeded it's mechanical limits. It therefore looses the ability to maintain the correct valve adjustment and the engine performance suffers. Solid lifters do not have the same kinds of internal components, they are basically a solid piece and can therefore operate at much higher frequencies (rpm's) without loosing adjustment.

Also thinking way back to my High School days............we put them in engines just to be cool!!!!!!! If you didn't put solids in the engine when you changed the cam..forget it!

Bill