quisterio

Alright,

My question is what kind of gains will I see if I install 1.6 roller rockers on my engine?

The engine itself had a complete and total rebuild about 7 months ago, everything from a new crank, rods, pistons...everything is new, except the block.

To the best of my knowledge, I have the following mods.

Comp. Cam with .500/.510 Lift (Unsure Of Duration, but very streetable)
Flat Top Pistons
Edelbrock Headers
FULL MSD Ignition
Bored .30 Over
T.B Airfoil
Ported out base
Polished, Ported Stock Heads
T.B Bypass

Other mods include:

Custom Burned PROM Based On Car's Mods.
Custom Made Intake (Not really an engine mod, but it helps)
Built 700R4 Transmission
Custom Porting On TPI Plenum
COMPLETELY Removed ALL Smog/Emissions Crap
Removed Catalytic Converter
3 1/4 Inch exhaust all the way back
Flowmaster muffler
180" Thermostat

I'm very interested in doing this mod, Ive heard good things about it, and now that Im about to have the funds to do so, I wanna get on the ball lol.

Im looking for pros and cons if there are any, and which roller rockers are the BEST money can buy, or right at it.

1989GTATransAm

iTrader: (3)

It's going to depend on how much lift your heads can handle? You are at .510" lift now with 1.5 rockers. With 1.6 rockers you will be at .544".

quisterio

How do I figure that out?

Kevin91Z

iTrader: (1)

Ask the person who set up your heads.

jtrescot

.510 / 1.5 x 1.6 = .544

quisterio

Im asking what kind of gains if any would I see if I had 1.6 roller rockers installed on my engine, I can find out if the heads can handle them or not, Im needing to know if this is a worthwhile upgrade or not...

sofakingdom

iTrader: (1)

If you have stock RUBBER rockers on there now, then ANYTHING will make a noticeable improvement. You'll be going from a totally inconsistent ratio of somewhere between 1.38 and 1.45 with the bulk of them around 1.42 to 1.43, to 1.6 on EVERY valve.

If you have some kind of REAL (solid, inflexible) 1.5 rockers on it already, then the difference between the ratios will probably not be significant.

But since it's not my money we're talking about here, then of course it's "worthwhile" to me for you to spend yours.

"Improvement" has 2 determining factors: what you end up with (duh), but also WHAT YOU START OUT WITH. You can't talk about "improvement" in a vacuum.

The question about head prep is valid. Don't just blow it off. Regardless of whether the motor might run better with slightly higher lift, you won't be happy if parts crash into each other and break. Most of us would NOT consider that an "improvement", regardless of what we started out with; if what we had before the "improvement" was at least working.

quisterio

Before I had the engine built, someone who owned it before me had put some sort of a cam in it, nothing big, but better then stock.

The cam I put in there has a .500/.510 lift, and the kit that came with it had new lifters, and everything else a new cam needs....

I dont know if they are 1.5 or not, but they look exactly like the stock ones did, geared for the new cam i guess.

I am definately giving my mechanic who built my engine for me a call as soon as I can.

Air_Adam

1.5 and 1.6 rockers do look the same. The only difference is that the pushrod spot is just slightly closer to the fulcrum (pivot) on the 1.6 rockers. What kind of heads are we talking about? What cam are we talking about - specs beyond just the valve lift. What size engine are we talking about?

What I'm getting at... is that if you already have a cam thats a good match for what you have, then 1.6 rockers will be a waste of money. If the cam is smaller than what the motor would like, then 1.6 may very well be worth the trouble.

quisterio

The cam's RPM band makes power up to 5000 RPM, right at the TPI's cutoff, so the cam is almost perfectly matched to the motor.

If the 1.6's benefits are not worth 250$ then I will not buy them, Im just wanting to take another step into upgrading my engine for more power.