Crane Gold Race Roller Rockers on 3400

[geoffinbc]

Basically. But you will also see guides on the intake gaskets. These are only there to hold the pushrod in position while you do maintainence on the engine. They will not suffice for aligning the rockers. So you must clip these off so they do not get in the way of the new metal guideplates you are going to bolt on.

And yes when we were working on the intake we did several trial fits. Marking off and taking down material as needed. We also did a couple torque downs of the manifold before adding the silicone to the ends so we didn't make a mess. It is very important to torque it down and see where you are. Because it will crush down a significant amount.

[AaronGTR]

Ok, I've run into a problem. I've got everything installed and the last thing I needed to do was clearance the lower intake manifold so the rockers would fit. You guys said you only had to remove a little metal for them to clear. I had to remove a lot of metal on mine, and the bottom of the four intake runners that need clearance are VERY thin. There are actually a few pinholes going thru into the casting marks in the bottom (the lowest point in the runner). Do you guys think this will be a problem? I'm thinking of filling the casting pits with some JB weld to fill the holes and strengthen the area a little, but do you think the metal will crack when it heats up? I'm really worried about this now. If I'd known I would have to remove that much metal I never would have bought these rockers. Three of them have plenty of room now, but one is still somewhat close on the corner and I can't tell if it's touching anymore or not. It's on the back so it's hard to see. The only option left though is to take the rocker off and file it. I know the directions say not to, but I only would need to take a little off the top edge (not the whole face). Do you think this would be ok? It's not like I'm running super high spring pressures so I'd need to worry about breaking the rocker. Any ideas?

[geoffinbc]

WOW. We had an easy 3/16 of thickness left. How much clearance are you leaving? All you dont even need a 1/16"clearance (but we had more than that). You must have been taking material out on the wrong angle an were forced to take off alot to make the fit.

I dont know what to say except maybe to just get a new upper and try again or abandon the plan. But these kind of things are part of modding.

[AaronGTR]

I've got maybe a 16th of an inch on the ones with the most clearance. The ones in back are closer. I don't know what the problem is. I was continually test fitting it on the car as I sanded it to see where I needed to remove. I even bolted it down and torqued it to account for gasket compression.

EDIT: I just went out and measured the clearance with a set of feeler gauges. The closest rocker is the one on the back that's under the #4 cylinder intake runner. It's about .02", or half a millimeter.

[geoffinbc]

And of coure all the rockers are lashed correctally? And the gaskets you are using are the thick 3400 plastic ones?

This is really weird because we had no problems what so ever

[AaronGTR]

Yeah, I followed all the directions from crane. Turned the engine by hand to turn the cam and adjusted each rocker one at a time at the lowest point. It said to hand tighten the nut to zero lash and then turn it an extra 1/2 to 1 turn so I turned them 3/4 and tightened the set screws. I'm using all 3400 gaskets and parts since that's the engine my car came with. I actually needed to get the updated Lower gasket anyway because it was leaking oil. I think I have enough clearance on everything now. I haven't run the engine yet though to see if there's any problems. I got everything put together last night and had a fuel leak at the inlet of the fuel rail (bad O-ring). Should have everything fixed tonight and we'll see if it runs.

[geoffinbc]

SO whats going on with the runners now? How did you fix the hole you said you had?

[AaronGTR]

I had some little pin holes showing thru the casting marks in the bottom of the runners and the metal was starting to get thin, so I built up the bottom of the runner with some JBweld on the inside. It is resistant to heat and chemicals, bonds with metal well, and I've had good luck with it before filling some holes in the UIM, so I figure it should be ok.

I got the engine started this morning and it was making some horrible clacking noises from the intake manifold so I'd say it's safe to assume that I still don't have enough clearance. I tried just taking the valve cover off to get the rockers off and inspect them, but the lower manifold is too close and I can't get the rockers off the studs. Which means I have to take everything off the engine...AGAIN. I'm getting sick of taking this thing apart. Anyway, I can't take any more metal off the manifold, so I only have two choices left. Either I file the rockers for clearance, or I take off the ones that are too close and replace them with my stock rockers. Haven't decided what I'm going to do yet.

[Blackrider]

I love Jb Weld.

Did you get someone to turn it over by hand well you watched if there where any issues?

[geoffinbc]

I just dont understand where you went wrong. Lloyd and I fired up his engine last night and got it up to full temperature. The rockers were as quiet as a mouse.

You are using Crane Gold Race 1.6:1 roller rockers right?

has anything been done to the engine? Like milled heads thinner gaskets or anything? I would say go buy another manifold and maybe take the material off the rockers.

[AaronGTR]

I'm using the same rockers you have. I don't know what the problem is either. All other engine internals are stock. I took the lower intake off and found the #3 cylinder intake rocker that sits under the #4 intake runner had a silver mark on the top edge (where it comes closest to the LIM at the bottom of it's stroke). The other three rockers that needed clearance didn't have any readily visible marks, but are still very close. I'm going to shave 1/16" of the top edge of all four to be safe because I'm sick of taking my engine apart. I found a few of my pushrods have scratches on them also. They were much lower than where the guide plates touch. The stock manifold has some grooves in it for the pushrods to clear, but I think it's not enough since the pushrods move around more with guide plates than they did before, so I'm going to grind off a little more there on the manifold too.

[geoffinbc]

Now your having pushrod problems? What the hell. Did you put the guideplates in the right spot? There are 2 different guideplates. 2 the same on one head and one different. Did you notice these diiferences when installing them?

[bszopi]

You can't install the guideplates in the wrong spots. They physically will not work. I tried when I broke one and ordered the wrong one.... So I had to wait until the correct one came in.

[geoffinbc]

Yea I guess so.

[v6h.o.]

the guide plates are not whats pushing the pushrod out...

its the fact that the rocker arms pushrod cup is further away from the rocker arm fulcrum compared to the stock GM's is what i think is whats going on

this would explain why its not nessisary to grind out the guide plate, as with these rockers im assuming they locate the pushrod further away from the guide compared to stock and compared to how the Comp magnums are.
which with the pushrods further away then the valve tip end must be pretty long as well to keep the ratio a 1.6:1,
as typically the closer the pushrod is to the fulcrum is what determines rocker arm ratio.

with what geoff and lloyd went through to install theirs and the complex huge problems your having aaron im wondering if something just isnt sitting right or setup properly. odd that you have to take that much off.