Has anybody ever heard of or run 1.7 ratio roller rockers. I found these Scorpion ones and was wondering if they are any good and if they would cause any trouble. I was thinking that it would be a really nice way of increasing lift without going to a really radical cam.

What do you think?

http://www.flatlanderracing.com/scorpionrockers.html

http://www.dyno-flo.com/proddetail.a...IRA001&from=20

 

i wouldn't run aluminum rockers on the street because of fatiuge cracking. i'd also suspect 1.7 rockers for a SBC unless they were like jensels and maybe even then.

 

And a good set of rockers will cost you just as much as a good cam. Then again, with any good cam, you really don't want to use the factory rubber* rockers anyway.

(* - Borrowed term from RB83L69. It's fitting. )

 

Yes, i'm just saying that it would be a really nice way of increasing lift, without going to a radical cam with a large duration.

 

Do you know what your valve springs are rated at for lift? You can't just go putting higher lift rocker arms on without thinking about the rest of the valve train. If you lift the springs too high, you could crack one or bind one. Your valve covers might now accept rocker arms that lift that high. You might have piston to valve interferance. check these things out first.

 

If this is going to see street duty, I would not recommend that at all. Unless you plan on changinging them alot, I'd suggest steel 1.6 rockers rather than aluminum 1.7s.

Instead, get the extra lift that you want ground into the cam. Comp for example has all their available lobes listed in their cataolg; get a custom grind with the lobes you want on the LSA you want. As an example: http://www.compcams.com/catalog/230.html These are the Xtreme hydraulic roller lobes. The off-the-shelf XR cams use the 33 series lobes, but you can get your own cam ground with the 31 series, such that you could create your own cam that would be like the XR282, i.e. same duration and RPM range, but with .622"/.624" with 1.6 rockers, instead of the off-the-shelf .544"/.555". They offer similar selections of lobe designs for solid rollers; pages and pages of them in fact.

Keep in mind, if you want really aggressive valve action, don't short yourself on the valve springs. They become highly critical as ramp rates are increased. Consider a rev kit.

Other cam mfrs offer similar products. Ultradyne in particular would be someone I'd contact if I were going the custom route.

 

I'm still in the planning stages, and was just wondering about 1.7 ratio rockers, because i never knew they made them for SBC. I was thinking of maybe running these with just a hydraulic flat tappet cam to get some greater lift. But i now know that i can run my solid roller on the street, so i will probably use 1.5 or 1.6 ratio rockers now anyway. I just wanted to know opinions about them.

Thanks

 

Besides the fact that they are aluminum, anything wrong with the 1.7 ratio?

 

I've always read that the best way to get a desired lift is to choose a cam that has what you want. Now if you like your cam but want more lift without the expense of a cam or hassle of changing one, then I can see going to 1.6 rockers. I'd go with something reputable and avoid the chinese junk that's flooded ebay and discount parts houses. I'm gonna go with comp's pro-magnums because they're steel but designed with less weight on the valvetrain than an aluminum one. Even a 1.6 may require elongating you're pushrod holes and on 87 up motors it usually requires removing the drip rails from your valve covers. I'd wager to say that both would be required with 1.7's and I'd be concerned with longevity of the stock press in studs with 1.7's also. I know people who have used them, but it was on serious effort motors. For what you'd pay for good 1.7's you'd probably be alot cheaper to go with a cam.
Good Luck!