First time posting questions - hope this works right.

I need some guidance on installing rocker shims and the proper torque procedure for the rockers. What I have is an 82 F250 with 351W and C6. As far as I know eveything is stock and the engine has about 173,00 on it. Replacing cam, lifters, timing set, and switching stock 2v set up with 4v Edelbrock intake and Holley 600 vac secondaries and electric choke.

The rockers in the heads have a sled fulcrum between each intake and exhaust, which is new to me coming from a chevy background, and uses bolts not studs. I installed the cam/lifters and timing set. The cam kit came with shims for the rockers - 16 thick and 16 thin - but no measurements on them for thickness. Instructions did say that they would decrease preload approximately .030", .060", or .090", so I assume the thin one is .030 and the thick is .060. I have never shimmed rockers so this is a bit new to me.

The instructions in the cam kit state - "on engines with bridge-pivot mounted rocker arms, the shims are placed between the pivot base and the cylinder head", and "on engines with pedestal or shoulder bolt mounted rocker arms, the shims are placed between the shoulder and the cylinder head." Am I assuming correctly when they state "bridge-pivot" that they are refering to the sled fulcrum? I spoke with several different people at Summit about the shims but was not satisfied with the answers I received.

Also, after looking at various manuals I am still not positive on the proper procedure (sequence) to torque the rockers. Can anyone tell me where to place these shims (under or above sled), what thickness I should use, and the proper procedure to torque the rockers?

Any help for an old timer that is getting frustrated would be greatly appreciated.
Thanks.


FYI - in case;
Crane Cam kit - Summit part #CRN-443904
Int. Dur. - 260
Int. Lift - 272
Exh. Dur. - 456
Exh. Lift - 484
Hyd. flat tappet lifters
Competition Cams double roller timing set - Summit part #CCA-2135
Edelbrock Performer intake (egr)
Edelbrock EGR plate
Holley 1850 - converted to electric choke

 

Unless the heads or block have been machined you won't need the shims, just TQ everything back to stock specs.

 

http://static.summitracing.com/globa...s/crn-453e.pdf

The link above details how to pre-load lifters/torque pedestal rockers. The shims do indeed fit between the fulcrum and the fulcrum sled, although you won't know for sure if you need them until you bolt a couple of the rockers up.

 

Thanks much for the info, I really appreciate it.

As far as I know neither the heads nor block have been machined. Most everything that I have found so far is all original. My main concern was not knowing what to do with the shims and wanting to make sure I knew the proper procedure to torque the rockers. With the info that you two have provided I feel confident that it won't be a problem now at all.

Thanks again,
Rusty

 

Crane Cams has a good write up on this procedure. Check it out.

http://cranecams.com/pdf/453e.pdf

 

The Crane Cams instructions at the Summit site are good, but they appear to be for installing roller rockers. I am keeping the stock rocker arms, so would this procedure, one cylinder at a time working on both intake and exhaust, be the same. Or, should I go by what I found in the Haynes manual for valve adjustment (even though the valves aren't getting adjusted) where you mark the balance at 0 deg, 90, 180 and then torque 6 rockers in the first position, 4 in the second and 6 in the third?

Thanks,
Rusty

 

Should be the same for roller or stamped rockers. You're shooting for the right amount of lifter preload with the correct torque on the rocker bolt.

 

I fooled around with both methods last night and just wasn't satisfied with how some of the lifters were sitting when I went by the manual. The crane cams directions worked out perfect.

Conanski - you were right, they all torqued within 3/4 of a turn and I did not have to use any shims.

Now on to the bottom end to try to figure out how to get this oil pan off to replace gaskets.