Bolt-on Full Roller Rocker for Gen III

[bszopi]

Ok. The price of the Comp one is the kit I think. But the rockers are still slightly more ($32.99 vs $29.99). Of course, they are also 1.75 vs 1.7 ratio.

[geoffinbc]

I would still go for the Cranes. They are billet aluminum vs cast steel. That small of a ratio difference aint worth it. Or you can just jump to the 1.8 ratio

[smilinguy99]

Re: Bolt-on Full Roller Rocker for Gen III

http://www.cranecams.com/?show=browseParts&lvl=3&prt=2059&action=partSpec&p artNumber=144750A-16 Looking at these rockers for the LS1/LS6 and new Vortec engines I am pretty confident they will bolt onto a Gen III engine without modification to the lower intake manifold.

LIM interference isn't the only parameter that needs attention. The best lever arm length over the valve for geometry IS the Crane Gen I rocker. The length is 1.375". Typical SBC rockers will bolt up, but the geometry is a little off as the lever arm length is 1.40". I would suspect the lever arm length is 1.40" for these too. But I dunno.

By all means buy one or better yet, two rockers and test them. Just don't overlook other measures of fit.

sg99

[smilinguy99]

I have a 60v6 3100 in a corsica as a currently broken daily driver that I am in the process of overhauling.
Why are we spending all this money trying to get power from this turnip of an engine.
A small block chevy will be more reliable and have more streetable power than we will ever get with one of these 60v6 engines.
Daily driver maybe, hotrod at any reasonable cost, never.
Of course I am not too old to learn!!

The V6/60 has some nice features that many folks on this board find quite useful. It is light, compact, durable and packs quite a bit of displacement in roughly the space of the average ricer motor. And if you are talking about a pushrod version, it is pretty simple too. Some folks with some pretty basic modifications have been able to drop their ETs significantly while those who have gone the turbo route have been able to get in the 12s pretty easily. Likely spending less money than your average ricer to do the same thing.

When making comparisons with this motor, think dollars, displacement, and available power per unit of weight. In these respects it compares favorably with smaller motors.

Of course, it does have some drawbacks. Except for a few bolt-on items, you are on your own. Personally, that's what I like about it.

sg99

[Guest]

I have a 60v6 3100 in a corsica as a currently broken daily driver that I am in the process of overhauling.
Why are we spending all this money trying to get power from this turnip of an engine.
A small block chevy will be more reliable and have more streetable power than we will ever get with one of these 60v6 engines.
Daily driver maybe, hotrod at any reasonable cost, never.
Of course I am not too old to learn!!

With an attitude like that, the back button is your friend.....

Do a little looking around here, some members (myself included) have been able to get over 200 HP at the wheels for little money invested.

Other more extreme examples include The Cuman Bros 2.5L 660, making 350HP (IIRC) N/A, somone else that was making somewhere around 700HP from a turbo pushrod engine and GMs DOHC 3.9L (or was it 3.6L?) twin turbo engine making 1700HP.

I'm changing some parts on my engine and am shooting for 300+ HP at the wheels when it comes back out.

Then for my next chassis (AWD) I plan on making no less than 700HP at the wheels, all from less than 3.4L most likely 3.1L
Oh yeah the torque is speced out to be 550+ ft/lbs, so more than enough to move my 3200 lbs Jimmy down the track and around the corners.

[Cliff8928]

With all this talk of the increased ratios etc.. What's the limit on this for clearance on the stock components. How will it be affected with the 1.8 rocker on my 3400 with the stock springs, etc. Anyone know if there's potential for valve/piston clearance issues? Will the valve springs bind?



Cliff Scott
89 BerettaGT
04 AleroGX

[geoffinbc]

I dont think anyone has ventured into that area. But even with a 1.8 ratio thats only .491 lift at the valve. Now this is just a guess but I believe you can even go over .5 a bit and still be ok. I know on the iron heads .5 is not a problem.

Springs are another story. That will have to be checked with a feeler guage.

Someones gotta do it all first. The parts are out there I guess its just a matter of time.

[GinoBeats]

I have a set of the Crane Race Rollers 25759-12 1.6 Ratio I'll have to do some digging around and reading again but I thought it was a more or less drop in with the proper sized rocker studs.

[geoffinbc]

What engine? On Gen 1 and 2 yes it is a direct drop in. On Gen 3 you have to clearance the intake manifold, get guide plates and heat treated pushrods.

[GinoBeats]

Its for my '04 3400 I still have to order the valvetrain parts for the engine. I got my camshaft back in, it is a high lift unit as well.

[geoffinbc]

Then you must modify the lower intake to fit the rockers. See pics above.

[bszopi]

And you'll need 8mm studs versus the standard 10mm, since GM went to 8mm holes in the heads starting in 03.

[GinoBeats]

Thanks guys, going to put all of the info together so I can prepare everything to be assembled and ready to go once my pistons come in.

[geoffinbc]

And you'll need 8mm studs versus the standard 10mm, since GM went to 8mm holes in the heads starting in 03.

Thats ARP P/N 1347221 the bottom is M8X1.25 and the top is 3/8-24

Or if you buy the rockers that this thread has been talking about then they will come with all the studs you need. You know if Crane would get off their asses and just get some guideplates and different pushrods sell it in a 12 pack they would create a whole new product line for Gen III motors.

[Cliff8928]

I dont think anyone has ventured into that area. But even with a 1.8 ratio thats only .491 lift at the valve. Now this is just a guess but I believe you can even go over .5 a bit and still be ok. I know on the iron heads .5 is not a problem.

Springs are another story. That will have to be checked with a feeler guage.

Someones gotta do it all first. The parts are out there I guess its just a matter of time.

I was just wondering if anyone ventured there yet. I would consider being the guinea pig for this project while i still have 2 cars around the house. So what should be done at a minimum?

-LS6 valve springs
-3.1 "T" valve seals (i think i have some extra from the 2.8, are they the same?
-Conversion studs?
-new full rockers for the "LS" engines
-Pushrod guideplates from 94-95 3100

Which rockers will most likely offer the best increase in performance? and are they adjustable, or do i need new pushrods?

sorry if I'm not doing most of the research on this one, I'm just strapped for time with work and stuff around the house (newest project, wallpaper removal)



Cliff Scott
89 BerettaGT
04 AleroGX