line honing the 8BA main bearing bore

[Tod]

Originally Posted by GOSFAST

Hi John, without having all your pieces in front of us to pre-measure them all, I will give you this tip: whatever shop you talk to about fitting different caps on your block under no circumstances let them talk you into milling the pan rails to "shrink" the holes. Generally this does need to be done but it's best to remove any material from the cap's parting lines not from the block.

Here's why, when you work on the pan rails you risk "dropping" the C/L between the crank and the cam, this COULD make for more issues down the road when installing the timing gears!

It is more labor intensive to remove the material from the caps (due to the "arc" shape on the parting lines) but it is the best route to take. Also, I would recommend line-boring over line-honing in this instance? You have much better control over where the material is removed with boring as opposed to honing. You really have no control over this when honing!

Most shops I know of would rather just mill the pan rails due to it being faster, but definitely NOT better in my opinion!

Thanks, Gary in N.Y.

P.S. If you have access to some caps I would get a decent bore gauge to help determine exactly how far off the caps will be before going in on the job. You may get real lucky and have set fit OK, you just never know on these Flatheads!

I agree. I recently did a set of caps for a local builder on one of my CNCs.

Tod

[john mullen]

Originally Posted by Ol' Ron

I made a fixture to cut the caps in a lathe with a 4 jaw Chuck. I take.005" off the cap and theh set it up in a turbanart(SP??) line boring machine

Ron, I have found front and center caps that fit perfectly, however the rear main cap is offset by .004
If you have some rear main caps that you would be willing to ship to me I would pay shipping both ways and pay you for one that I keep. returning those not used. Please advise
Thank you,
John Mullen