What is better? all Rockers 1.6 or 1.6 intake 1.5 exhaust?

 

That's a question with no real answer.

It all depends on the specs. of the cam and what your goals are.

 

Ah ok, the engine have the stock heads and cam.

 

All 1.6's and you need to upgrade the valve springs.

 

Just run the 1.6s,especially if it is going to be a standalone mod.

 

And most importantly, make sure they are roller rockers. Just swapping out the 1.5 stamped steel rockers with 1.5 roller rockers will yield improvements, as the stamped ones had very loose tolerances (anywhere from 1.45 - 1.55).

A quality roller rocker will decrease frictional losses and optimize each cylinder's potential due to tighter tolerances. By increasing the rocker to 1.6, you are effectively changing the cam without having to change the cam.

But like others said, keep an eye on the springs. You will be close to bind when gong to 1.6. On the stock cam, as long as you don't spin it beyond the stock rpm's, you'll be fine.

 

Hes right on that one. The stock springs will be fine as long as you dont take it past 5800 rpms.

 

I don't know, considering how cheap you can get a set of springs, especially the LT4s, it is rather cheap insurance.

 

Cheap insurance...yes.

But it requires quite a bit more work. Time is money...

 

True, time is money. But then something like this could fall into the pay now or pay later category.

 

Thanks to every one.

 

I dont know about chevy motors, but i know a mustang mag did a test with 1.6 and 1.7 RRs on a motor, the best power was made with 1.6s on the intake, and 1.7s on the exhaust. Will it work the same way for all motors? Who knows, just food for thought.