Im thinking of going up to 1.6 roller tipped or full roller rockers.

what size is the stud for the 2.8-3.4L iron heads? and can you use rockers made for any other type of engine on the fiero, the reason i ask, is cause SBC full roller rockers are 1/3rd the price of the full roller rockers from 99% of people selling them JUST for fieros.

matthew

AFAIK, the SBC studs are a differnt size, so the rockers are too. You would have to change to SBC studs (drill and tap the heads, I believe the SBC studs are larger) to use SBC rockers. I've only heard of someone doing it once, but it has been done.

if you get the roller tip rockers you can reuse the fiero ball and nut to mount them - you can do 1.6: ons tock springs or upgrade your springs and run 1.7:1

i ran 1.7s on my 3.4 and they were nice - installed 1.6's on a friends 2.8 turbo

[This message has been edited by Kohburn (edited 09-14-2005).]

You can buy comp magnum roler tip rockers for the 60 degree v6 from summit racing, and they come with new nuts and washers.

quote Originally posted by 2m6turbo: You can buy comp magnum roler tip rockers for the 60 degree v6 from summit racing, and they come with new nuts and washers.

yeah you can do that too - they are nice rockers

quote Originally posted by 2m6turbo: You can buy comp magnum roler tip rockers for the 60 degree v6 from summit racing, and they come with new nuts and washers.

Comp Cams P/N 1414-12. Mine were ~ $160-170 at Jegs.
Roller tips only. Not full rocker. They use the stock Fiero studs, and come with new nuts, balls and assembly lube.

What exactly is the benefit of roller rockers?

What do they do?

What will getting 1.8 RR's do for the 2.8L?

-Mulholland

I've got the full ones. Can't remember where I put my info on part numbers etc.. Seem to have lost the darn page on my compy.. Only thing I can find is the p/n for the studs..

crane part number 99148-2 at Summitracing.com

the summit catalog offers the 1.6 roller tips for like $115 w/o shipping last time I checked

quote Originally posted by Mulholland_GT_Racer: What exactly is the benefit of roller rockers? What do they do? What will getting 1.8 RR's do for the 2.8L? -Mulholland

Roller rockers reduce friction and wear. Engine spins easier with less fiction.
Also aftermarket rockers are made with tighter tolerence's which means if you buy a 1.6 rocker, It is a 1.6 ratio where stock is 1.5 but they can be anywhere from 1.48 to 1.52 due to OEM manufacturing tolerence's.

Going to 1.8's will probably get you bent pushrods. You would need to change the valve springs due to the increased lift, Otherwise the valve spring will bind and the pushrod will bend. Going to higher ratio rockers increases valve lift but does little for duration. So your power gains are smaller. If you want a higher lift, get a cam with the lift you want. The degree's, duration's and lift are matched on the higher lift cams and will create more power.

As for using full roller rockers, The SBC rockers require a 7/16" studs. The 2.8L has 10mm studs. You can either re-tap the head for the 7/16" studs or You can make/buy studs with 10mm on one side (to screw into the head) and 7/16" on the other for the rockers.

To add to what Oreif said, a higher ratio rocker also robs power from the crank because it requires more power to turn the cam to lift the pushrod to move the rocker. Roller cams are the way to go to get the valve open quickly and maintain that peak lift longer. That's why I'm considering a roller block for my next 3.4.