Has anyone had problems with the caps walking at high rpms on a high horsepower LT1? My 396 has good parts in it but we are having cap walking problems which causes pitting in the bearings. I have Callies 4-bolt main splays, half filled block, Cola forged crank...etc etc. I am afraid it will cause major problems if I am not careful and inspecting the bearings every 20 passes or so. I will be spinning motor to around 8000 rpms now. The caps were walking already at 7000 rpms.

Does anyone make a main cap stud girdle I could buy that will fit under a Canton 7 qt oil pan? This would correct the problem.

Thanks

Tony Shepherd

EDIT: I found one on ebay: http://cgi.ebay.com/ebaymotors/Chevy...spagenameZWDVW

You guys think this would work?

 

Tony,

What is your main cap arrangement? Is it stepped? Is the register a 4 bolt register? How much splay to the caps?

Are you seeing the cap walk on the bottom of the caps? It might not be that.

Bret

 

Hey Bret. It is a stepped 13 or 18 degree(I think) angled splay caps. Yes....I can see it on the bottom of the caps and the block surface area. The machinist who did the machining on these caps was a small shop in Waco Tx. about 5 years ago. Have run this block ever since with no problems but now have them.

 

You may want to have dowels installed around the main studs, like aftermarket blocks.

 

Good idea! Ill check into that.

 

No don't do that!

You have to weaken the cap and the block to do this.

I was afraid you were going to say a stepped cap. That's part of the issue here.

Bret

 

Whats wrong with a stepped cap? What can I do to fix it? With a non-step cap.....do you machine the step off the block?

 

Yep you machine that step to 7.500" wide.

Bret

 

7.500" ???

Thanks Bret!!

 

Yeah like Bret said, a flat cap will help a lot. By moving the register out to the pan rails, you are making everything more ridged. Get some pro-gram flat caps and have the block machined so that the bore is as close to original as possible, your block has already been align-bored once for the first set, now it will need to be done a second time, and you want to have as little material removed as possible.

 

Thanks for the info.