Rockers

[GP99GT]

Im thinking about stepping up to a set of ZZP rockers, since ive read many good things about them (119whp at 5800 rpm stock, with rockers added 183whp at 5800 - www.easyperformance.com ).

Whats involved in changing the rockers, what other stuff would i need (gaskets, seals, etc) to complete the job, and about how long would it take to do?

[Koll]

I dont know about changing rockers while the engine is IN the car but changing while the engine is out is easy. All you really gotta do is pop off the valve covers, unbolt the old ones, pull them off. and torque the new ones down to 11 ft. lbs (on the 18-87 5.0 and 86-87 5.7). Then just put the valve covers back on and fire it up.

Oh and double check the torque settings before doing it.

It should take more than an hr.

[j0n]

should or shouldnt take more than an hour?

and that's a ****load of horsepower just by changing the rockers...u sure they didnt stab a cam in it at the same time?

[Koll]

Oh yeah. I forgot to comment on that. I think youll free up at most 5 hp, realisticly

[Tru2Chevy]

Are those the 1.9 ratio rockers? And yes, he quated the wrong power numbers on that one.

I don't remember the tq. specs, but I think you don't have to worry about setting valve lash on the 3.8...

- Justin

[GP99GT]

Numbers are correct, no other changes....i think they were split ratio rockers, 1.8 intake, 1.85 exhaust. the L36 has **** for top end, thats why it opens up so much, i asked a guy i know that used to have a GPGT like mine, he said the numbers are pretty accurate. the engine falls on its face at 5000RPM basically. i'd be doing them while the motor is in the car, the front rockers would be easy but i dunno about the rear.

[GP99GT]

not sure if these'll hotlink, but i'll try...

Stock 1.6 rockers, u-bend delete, 180 t-stat:

http://www.easyperformance.com/Tech_Info/ER_Rockers_files/Stock_Rockers_Dyno.jpg

ZZP ER Rockers, u-bend delete, 180 t-stat:

http://www.easyperformance.com/Tech_Info/ER_Rockers_files/ZZP_ER_Rockers_Dyno.jpg

[bad64chevelle]

OK well a gain of 16 Horsepower, however for the second run the humidity was a little lower also, so that may have a small effect. Raised the top power RPM too, so I think the biggest problem will be doing the back ones (not knowing what your engine bay looks like) but, i would say if you want the extra HP and dont mind throwing down the money...go for it. I'd want to see back to back dyno pulls so all the weather would be relatively the same and get a better idea for how much power truly was increased...

[GP99GT]

OK well a gain of 16 Horsepower, however for the second run the humidity was a little lower also, so that may have a small effect. Raised the top power RPM too, so I think the biggest problem will be doing the back ones (not knowing what your engine bay looks like) but, i would say if you want the extra HP and dont mind throwing down the money...go for it. I'd want to see back to back dyno pulls so all the weather would be relatively the same and get a better idea for how much power truly was increased...

yeah, i'd definitley get a dyno before and after..maybe not on the same day but maybe if someone wanted to do the rockers in the TTP parking lot or something :lol:

[bad64chevelle]

I would wonder, I mean since those conditions and time spacers were a bit spread apart there could be other factors. I am only saying this because you may find that you wont gain that 16 HP and it may be like 5-10. What I do like is the broader power band with the rockers
:cool:

[GP99GT]

I would wonder, I mean since those conditions and time spacers were a bit spread apart there could be other factors. I am only saying this because you may find that you wont gain that 16 HP and it may be like 5-10. What I do like is the broader power band with the rockers
:cool:

thats my main reason for wanting them, because the top end is blowtastic. i love the new power curve it gets with them.

[Batman]

I think 16RWH from a rocker change is pretty close. Biggest things I would worry about is uograding valvesprings and retainers while you are in there, no reason not to and it is piece of mind. Even changing springs you will probably be looking at 2- 3 hours worth of work. Only trick to springs is keeping the valve from falling in the engine. Normally you can get a fitting for your air compressor and use it to pump air in the motor, keeping the valves in the closed position. I'd spend the extra time and money on springs, but it is up to you.

[Tru2Chevy]

Lots of guys who get those rockers just order up a set of LS6 springs for $35ish...

- Justin

[GP99GT]

Yeah, the LS6 springs are the recommended upgrade for them...except from Intense racing, they are $95...show me these $35 LS6 springs :P

I dont know if i could do the springs myself, since i dont have an air compressor or anything.....unless someones got a garage and wants to help me out. I dont plan on doing this til the spring anyway...for now im doing some exhaust work.

[NJSPEEDER]

just make sure you get the appropriate tuning done to take full advanatage of the new rocker ratio. you can prolly get double teh gain with tuning as without.

later
tim