Crane Gold Race Roller Rockers on 3400

[geoffinbc]

Well we wont know because we have not run the motor with stock rockers. And we have never been in a 3400 powered cavy.

But who cares its still gonna be cool to have these rockers. I would expect a maybe 5hp increase due to friction removal and light weight. But who really knows. More the fact of knowing that you have a stronger and lighter rocker under the covers makes it better. Plus with repeated WOT runs they should keep reliability and valve performance in check.

[quaddriver]

Re: Crane Gold Race Roller Rockers on 3400

Well it is done. My Friend and I have stuffed a set of Crane Gold Race Roller Rockers on Gen III heads. We used Gen II guide plates and cut off the plastic ones that are formed into the gasket (they get in the way). We had to grind down the intake runners where they actually touched the back of the rocker arm. We maybe took off 1/8" of material. The rockers clear the valve covers no problem.

So if anyone wants to know YES they work and all you need is a die gronder

So are we the first to do this? So far I think so

question, why gold race? the energizer, harland sharp and trick flow rockers are lower and less expensive, the comp cams rollers have less material at the rears - prolly not needing any mods....

what prompted the decision? all 4 brands have the same ratios and stud usage

[geoffinbc]

Not the same construction and quality of material. Me and Lloyd like to do things a little overkill.

[quaddriver]

Not the same construction and quality of material. Me and Lloyd like to do things a little overkill.

check out comp cams 'pro magnums' - made from 8650 steel so stronger than all AL rockers, and due to lessening of mass at certain areas, they weight 5% LESS than AL at the valve!!! about $40 less per 16 than cranes

[geoffinbc]

At the valve only. What about the pushrod side. Mass matters overall. Not just at one side or the other.

The Cranes are overall lighter. If steel was removed to save weight that means stiffness was removed too. So how do you know they are stronger?

[v6h.o.]

Re: Crane Gold Race Roller Rockers on 3400

question, why gold race? the energizer, harland sharp and trick flow rockers are lower and less expensive, the comp cams rollers have less material at the rears - prolly not needing any mods....

what prompted the decision? all 4 brands have the same ratios and stud usage

Answer:

because they are advertised and made for the 60degree engine.
narrow rocker that fits the 660 engine.

Does harland sharp, or the Crane Energizer come in kits that fit the 660 engine? they might work yes. but has anyone tested to see if they will work.
Comp makes only the Roller Tip rockers as an aplication specific rocker for the 660. which comparing Roller tip to Full Roller, the full roller wins hands down.
I suppose Any narrow body(centre bolt Valve cover SBC) rockers would work in any case. you'd still need the Crane 660 Specific Rocker studs/nuts. as they retain the M10 head thread on the stud but with the 3/8ths' top nut/stud threads for the rockers.

when it comes to purchasing rockers most people go with what is advertised as a specific engine fitment. however there are some of us that like to experiment with other brands that dont specifically advertise they will fit, even if we know they do.

and this is most likely the case here.

[Manitcor]

5hp seems like a worthy assesment, i think I may give this a shot over the spring

[Fierofiend]

So will the 3400 rockers fit on an iron head, and would there be any point to using them, if they did??

[geoffinbc]

So will the 3400 rockers fit on an iron head, and would there be any point to using them, if they did??

Nope. New heads use self aligning rockers. Iron heads are not machined for this.

To answer the above questions. No we did not choose Crane because it was stated they fit. I already know that 660 rockers are identical to SBC rockers. Infact if you buy any stamped roller rocker you can simply use your original rocker balls and bang you have roller tipped rockers. If you want roller fulcrum it gets a but more tricky. Because SBC rockers come in standars threads then you need to convert. I actually have been told that there is a kit avalible from GM that is used on the 4.3L to conver its 10mm stud holed to 3/8". So you could buy thoes studs or buy the crane studs in a package w/o the rockers.

We chose Crane because they are sweet rockers. Needle bearings machined aluminum and super strong. Sure they were expensive but the price me an Lloyd actually pay for parts we paid far less for the Crane rockers than it would have cost us to pay retail on a competative rocker of a lesser value.

[quaddriver]

Re: Crane Gold Race Roller Rockers on 3400

Answer:

because they are advertised and made for the 60degree engine.
narrow rocker that fits the 660 engine.

Does harland sharp, or the Crane Energizer come in kits that fit the 660 engine? they might work yes. but has anyone tested to see if they will work.
Comp makes only the Roller Tip rockers as an aplication specific rocker for the 660. which comparing Roller tip to Full Roller, the full roller wins hands down.
I suppose Any narrow body(centre bolt Valve cover SBC) rockers would work in any case. you'd still need the Crane 660 Specific Rocker studs/nuts. as they retain the M10 head thread on the stud but with the 3/8ths' top nut/stud threads for the rockers.

when it comes to purchasing rockers most people go with what is advertised as a specific engine fitment. however there are some of us that like to experiment with other brands that dont specifically advertise they will fit, even if we know they do.

and this is most likely the case here.

The crane rockers I mentioned are full roller. Roller fulcrum means something - roller tip does not, tests have shown that all that happens is the tip gets dragged across the valve stem without rolling.

SInce the valves are splayed, there is no pertinent need for a 'narrow rocker' - what ever fits a SBC should fit. However, the problem with AL rockers is the rear end of them (where the pushrod goes) breaks off just before the fulcrum point. This is why even el-cheapo steel rockers are rounded there - they are strong enuf, but AL ones have huge machined sides and a square tail - it almost sounds to me from the post that the author ground some of this away....that sounds a little scary... Height however, that is a problem, most roller rockers have huge locks which require tall valve covers - something you cannot get for a gen2/3 so you have to go low profile that will fit under the original centerbolt SBC valve covers.

As for the stud, the 660 stud is hideously small, you should pull these out and if the head is not helicoiled, make it so and use stock chevy 3/8 studs. To get the spring weight you need anyways (id say in excess of 110lbs) and on a higher lift motor, you would want to do this anyways...its standard operating procedure.

[geoffinbc]

What are you talking about we never touched any metal on the rockers. only the intake. Yes you will need to use narrow body rockers. Wide bodies will contact. Look at the pic The narrow bodies are pretty close as is. A 10mm stud is LARGER than a 3/8 stud. 10mm = .394" While 3/8" = .375". It may be prectical to use 7/16 studs but for the 660 application it is not necessary. Roller tips do work. You can observe them rolling when you turn the motor over.

Have you ever worked with these rockers before? I have put them on every 660 variation and they fit every time with no clearance issues except on the GEN III and even then the problem was not valvecovers. Plus the fix was simple.

I dont know where you are getting this info from but it sucks.

[quaddriver]

What are you talking about we never touched any metal on the rockers. only the intake. Yes you will need to use narrow body rockers. Wide bodies will contact. Look at the pic The narrow bodies are pretty close as is. A 10mm stud is LARGER than a 3/8 stud. 10mm = .394" While 3/8" = .375". It may be prectical to use 7/16 studs but for the 660 application it is not necessary. Roller tips do work. You can observe them rolling when you turn the motor over.

Have you ever worked with these rockers before? I have put them on every 660 variation and they fit every time with no clearance issues except on the GEN III and even then the problem was not valvecovers. Plus the fix was simple.

I dont know where you are getting this info from but it sucks.

Ok I misread the post, I thought u removed some from the tail, my bad. Im not talking about the part of the stud that screws into the head, im talking about where the nut goes for the rocker retention

check this out: http://www.gmgoodwrench.com/gmgoodwr...384&section=ep

You can get upper thread sections of 3/8 or 7/16, but all screw in at 7/16. any time the stud is shouldered, this is where it will flex, and break if tis gonna break.

Like I said, its sop, by the time someone has gone to roller rockers, it means they are already on a high lift cam, with heavy valve springs, and this is just one more area that gets overlooked. hence my questions as to why these rockers were chosen over others incl ones cheaper and stronger that dont require any mods.

ps - what pics? are there missing links?

* never mind, found the pics

[geoffinbc]

When the rocker were on the old 3.1L stronger springs were added. I also have them on my truck and they were added with stronger springs and a larger cam.

The reason they are going on the 3400 is because we had them. When they went on the 3.1L there was no modding to do.

[AaronGTR]

Ok, I have some questions maybe you could help me with? I have a 2001 grand am with a 3400 and I want to use these rockers. The 1.6 ratio rockers would be #25759-12 right? But it says they are non-self aligning rockers and the stock rockers are self aligning so how does that work? You also said you used a genII guide plate. What's the guide plate for/do and why did you have to use a different one? I can get 'em easy enough, just need to know what they are exactly. Also, when you clearanced the lower intake runners did you move the rockers thru there range of motion to make sure they cleared all the way? I also have LS1 valve springs/shims/retainers I want to use on these heads. Would they cause any problems? Sorry I'm asking so many questions, but I haven't got into internal engine parts much yet and I figure it's better to ask before I buy. Thanks.

[v6h.o.]

the guide plates are used to keep the rocker arms from twisting off the spring.

they Guide the pushrod to keep it inline with the rocker arm.
guideplates are used on engines that dont have a self aligning or a pedestal mount or shaft mount rocker arm.

basically all that was done was he took the old rockers(cranes) and studs and guides from his old 3.1L and put them on his new replacement engine (the 3400) that is going into the Jbody.