Stock cast rockers vs Aluminum Rockers

[Daves69Coupe]

What are the advantages if any in using aluminum rockers instead of stock cast rockers?5494254941

[oestek]

Those look like the 390 pieces from your tear-down, huh?

There are several advantages. Note the adjusters on the aluminum arms. The roller bearings bring less friction. The more precise shaft (not worn out) means more valvetrain stability, especially at higher RPM with a more radical cam. Roller tips decrease friction. Different geometry (ratio) brings more power. Possibly improved oiling.

It all depends on how high of an RPM range and how much power you'd like this engine to make! Oh yeah, and the budget!

[moreHP]

Yeah, what he said ^

You get much more accurate rocker ratios as well for consistant lift on each cylinder.

[grenade inspector]

weight reduction in the rockers would be another benefit, the less moving mass the better.

[Daves69Coupe]

thanks for all the info guys, looks like ill be going with aluminum rockers.

I'm looking to learn alot about engines with this build.

[rrunner68]

I am a huge anti-aluminium rocker person. I had a really nice set that I paid A LOT of money for. After 600 miles, it started running really funny. Seems the rockers didn't like high RPM's much, and hammered the adjusters clean out of the rockers. If you are going to have the vavle covers off after every 12-20 passes, go for it. On a regularly driven car, I'll take my Comp forged units..
http://www.summitracing.com/parts/CCA-1621R-1/


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[Daves69Coupe]

thanks for the reply rrunner68, The summit ones you suggested are $50 a piece? Thats $800 just for the rockers. I take it you havent had any problems with these while doing events?

Im building my project to compete in road course / autocross events so its good to know what will and wont hold up to these type of events.

[rrunner68]

Nope, The COMPs have about 20,000 miles on them, no complaints. They hold lash very well.