Roller Rocket arms Combination 1.5 /1.6

**eleve2003** · 02-06-2006, 04:07 PM

Hey i was talking to my cousing that have a 66 chevy nova fully modiffy and i was telling them that i wanted to put Roller rocket arms with the 1.6 ratio. they wonder why i was going to do all the same... so here is my question

They have a guys that builts their motors and always adds 1.5 exaust and 1.6 intake RR...

he says that thats how they work better on the old style engine heads... does anybody knows how would this go for newer motors???

the engine builder is pretty good since he has gone to NHRA and won some of their event. also this is a guys that builts engines in mexico for the most part so im just wondering if someone here in the US has try this combination. if nobody has tryed it... what would this cause that the engines he builts are so stunnin??

**hammertime** · 02-06-2006, 06:06 PM

Running the steeper ratio on the exhaust would help a single pattern (intake & exhaust lobes the same) cam breath a little better through a restrictive exhaust port. What kind of motors is he building? If he's limited to a stock casting, or one of the nostalgia classes that require exhaust manifolds, that would help.

I don't see anything in just rocker ratios that would make any engine stunning, as you are not taling about a huge difference - maybe 2-4 degrees duration @ .050" and .033 lift on a .500" gross lift cam. I'm guessing if his engines are that good, he has a lot more tricks up his sleeve than that.

**eleve2003** · 02-07-2006, 03:36 PM

Ohh YeaH... my bad.. i didnt write down all the thing he does to the engines.. since my question was more towards what effect does this combination have on the valve train.. ( which u already answered) but here is some more info on his stuff..

Yeah the guys does complete high performance engines... he has no dyno or anything to that extend but the numbers that the cars pull with his motors are pretty good.. he does mostly SB with ported heads with cams High compression and the whole thing (headers KNN filters.. msd.. etc).. he does all kind of stroker combinations.. but he saids that he gets the most out of the engines by having that 1.6 1.5 rr combinatin... and still those engines are streetable with Mexican gasoline which is not as good as we wish..

Also he get his parts mostly from summit.. and im not talking of top off the line but the cheap kits available... he just knows how to put them together... ohh and the engines are nothing special... they are junk jard motors just machines and checked..

but seriously my cousins where surprise that i was thinking of doing just 1.6 on all and no do the combination..

But how would this work with newer engines??? do u guys see some point on doing this??

**mrr23** · 02-08-2006, 02:27 PM

for the LT1 motor, GM put the 1.6 roller rockers on when they made the LT4 version.

**eleve2003** · 02-09-2006, 03:05 PM

Very true... .. but i quik question... do you guys think he does this to have as intake flow with lots of torque down in the powerband... since this is the only reason i could think. since the exhaust has less of on opening to keep more compression... does it make sense??

**hammertime** · 02-09-2006, 08:04 PM

Seems to me you are taking small pieces of a big puzzle and putting a lot of faith in their ability to make power. The camshaft he's using, compression he's running and head work he's doing makes so much more difference in power than rocker arm ratios alone.

The camshaft is an engine's brain. It has the greatest effect on how much power can be produced by the rest of the parts. Look at what a T-Rex cam can do with stock heads. Rocker ratios can only slightly alter what the cam grinder intended for it to do.