I have been thinking about putting roller rockers on my '93 F-150 with a 302. Mainly because I can't put a larger cam with this stupid SD efi system, soooooooooo,

I read in the latest 4-wheel and offroadd, that they put rollerrockers on a 85 ramcharger with 200k and a 318. It cut the hp by like 6-7. Whats up with this? Would I end up with the same results?

 

That's not the same results Hot Rod got last year when they did the same to a 302 Ford, or in years past for that matter. I wouldn't be inclined to accept their results.

 

Maybe? 4wheel had Dyno results, they did stock dyno test, roller rocker with a stock cam, even with the cam and the rockers, it only gave the 318 6more hp than the stock config. What issue was it of HotRod? I'll look it up again.

 

I've always been skeptical of significant power gains from roller rockers (unless you increase the rocker arm ratio), but I'm still surprised at the results of the mag test.

It all comes down to friction, and their tests seem to suggest that roller rockers have more friction than standard - that just doesn't seem right.

A couple of things to note - the rollers were brand new and might run w/less friction after they break in. Maybe they were installed improperly or too loose, not allowing the valves to open all the way.

Also, the HP difference they measure is pretty minor, and may be a result of other things like temp and humidity changes. I'm assuming the test was done on the same dyno on the same day.

I agree with the bottom line - For a low rpm street engine, save your money for other things, or get a 1.7 ratio.

[This message has been edited by dirt bike dave (edited 03-09-2000).]