roller rockers

[birdy3897]

I noticed some hi-power rebuilds of these 2.5L 4cyl. use roller rockers. Where can I get some that will work on my stock 2.5L(1978). I also need a set of pushrods and lifters. Could I just use the lifters and pushrods for a car application which used the 2.5L in 1978??

 

[rodbolt]

Re: roller rockers

no<br /> the auto version of the 2.5 after about 62 was not any relation to the 153/2.5 produced by chevorlet.<br /> why would ya want roller rockers on such a low RPM application?<br />keep good clean oil in it and spend the money on cooling system maint and manifold/riser replacements.<br /> the late 70's automotive 2.5 was a 151 produced by pontiac

 

[Bondo]

Re: roller rockers

Ayuh,............<br /><br />Wrong Motor,....... The Only thing they have in Common,.........<br />Is the Displacement...........And that's Only Close...........

 

[Buttanic]

Re: roller rockers

Except for the Chevy big blocks which use 1.6 ratio rockers all the rest of the 8, 6 and 4 cylinders use the same 1.5 ratio rockers and the same flat tappet lifters. Push rod length will vary though depending on the engine.

 

[birdy3897]

Re: roller rockers

Well, roller rockers reduce friction at all rpms which in turn creates HP. These rockers are great for high rpm but will produce power at lower RPMs. Not sure on motor, I was told that the auto chevy 153 in the chevy monza was identical to the marine motor except for obvious things such as manifold setup and gaskets. If not I'm glad I know now. Is there anywhere that will indivdual roller rockers? I only usually see them sold in sets of 16?

 

[Bondo]

Re: roller rockers

Roller Rockers Might loosen up MAYBE 1 or 3hp.......<br /><br />You're Wasting your Money,...........

 

[rodbolt]

Re: roller rockers

the 151 was a pontiac design, the only commonality between the 151 and the 153 is both were produced by GM.<br /> you will find more ponies playing with your hull and prop that by a set of roller rockers.<br /> of couse Crane cams will custom grind a cam for you, they did for me in the past, and you can find an old OMC 2 single barrel carb manifold that works well. then get into some port matching and some cyl head work, when all is said and done you might pick up 20 HP. then ya gotta play with the hull and prop again.

 

[birdy3897]

Re: roller rockers

thanks for advice