Line boring and crankshaft seal

[modok]

Why didn't you tell us what kind of seal it is?

How am I supposed to know what a "ford motorsports" block uses?

90% of the time all I need to know.... is... what size they want the hole, and people don't know,
so we have to provide COUNSELING to help them figure out what size hole they want, it's ok. but jeez, at least maybe.... can I get a rough idea of what goes in the hole.
A tolerance?, how about a part number?
I've machined a lot of holes, in 500 different kinds of engines and a lot of things that aren't engines too, holes are holes, sure don't remember them all individually.

[BillK]

So I’ve both of the halves sit about .100 above the bearings halves

Wow, That is a ton !!! And it isnt because of the line bore / hone. You never take that much off. I am betting that you are using the wrong seal. Does the Motorsports block use a special seal ? I have a couple of older Motorsports catalogs, I will try to remember to look in the morning.

By the way, this is not the type of thing that you would normally check unless you know that you did something very unusual to the block.

[leahymtsps]

Not until I pull the engine out I would have thought the machine shop would have checked these things before returning the block.What is it these days with some of these machine shops an making sure things are squared away before sending stuff out.Does the end users now days have to tell a machine shop everything that they want to check.The other day I took 3 eagle rods to a shop that wanted them to check and they acted like I was giving them something that they were not set up to do.

OTOH had you not asked for it to be done, and they went ahead and spent the time to check it and found nothing, would
you have wanted to pay for their time? In some states if you don't authorize the work you don't have to pay for it.

Tom

[BillK]

I would have thought the machine shop would have checked these things before returning the block.What is it these days with some of these machine shops an making sure things are squared away before sending stuff out.

How do you know that they didnt check it ??? If the seal is actually sticking out of the block side .100" (thats close to 1/8") I can assure you that it has nothing to do with the align hone.

Exactly which block are you working with ?? And which part number seal.

[Charliesauto]

What rope seal this is nineties ford Motorsports block.

On the older Motorsports small blocks, we bore them for a one piece seal. Solves all your problems.

[BillK]

1972ho,
Hope you didnt go away mad Everyone here wants to help. Hard to help without some information. Personally I would really like to find out what the problem is. Sounds very unusual.

[1972ho]

No sir not mad at all just can’t figure why at point in this blocks life using the same seal felpro2901 was a decent seal to use and now after a main hone of I think the shop said it was off by .006 and now I can’t get it to seal up.I have found another seal to try by felpro I just ordered

[modok]

If it was marginally tight to begin with then it could be too tight now. Measure vertically VS horizontally to see how how out of round it is, because i bet the groove and the whole thing was machined at the same time. if the crank is in it, you can just measure the gap with gauge pins, or a set of drills.
It would be easier (cheaper) to machine it for a one piece seal than re-machine the groove. There is no reason that it needs to be two piece, the crank has no flange right?
It would be an interesting educational experience to make tools to gauge the size of the groove and then hand scrape it back to size, except that I doubt we can find specifications for what size the the groove should be.

[1972ho]

Modok it does look like the bearings housing has been machined I have another block that has the rear housing and that one looks like nothing has been done with it.

[1972ho]

Finally got under there to take a picture of the seal journal and does this look like it could cause the seal to leak

[Walter R. Malik]

Will line boring the mains cause a stock diameter crankshaft shaft main seal to leak if the seal sticks up higher than the main bores when the halves of a two piece seal are installed

It can ... not always. With a rope seal you should cut to length, anyway.
It should be higher for some seal crush but, only about .010" or with a rubber type seal, the inner diameter might become altered or to big.

[modok]

Looks ok from here

[1972ho]

I don’t really want some people thinking that there might be some problems with the felpro 2901 ford seal so I’m going to fess up and let you know what I found it was one of my upper oil passage plugs that was leaking down over the the rear crankshaft housing giving the indication that the seal was leaking.And thanks for all of your suggestions?

[jsgarage]

Sorry I'm late here. A main seal opening in the front cover can be indicated off the crank nose and the cover/seal offset to (re)center it. In fact, this is a good idea to check (noting the OPs posting handle) as I've found several 351-Cleveland blocks & covers with the front main seal recess offset in two planes. That's a factory problem AFAC because Ford front covers with their seal openings are factory dowel-pinned, and a sideways offset cannot practically be caused by a line bore/hone.

As far as a rear main seal being off enough to leak- maybe over time as the neoprene ages in hot oil & gets less flexible, boring for a one-piece rear seal centered on the finished rear main bearing recess should be able to take out any reasonable offset. One needs to remove significant metal to fit a (351-W) one-piece seal (at least into a Cleveland). I've not worked with Motorsport blocks but notable seal offset at either end doesn't show up on aftermarket blocks like aluminum Fontanas. Casting skills have apparently gotten better in 50 years. Glad you found your leak problem.