Stitching & sleeving an 8BA- sequence?
 

As previous post stated, my 50 Merc block came up with a crack from cyl towards valve seat after being OK'd by magnaflux?? Machine shop says it will stitch it (drill and plug) and bore for sleeve. I'm in MD this week and stopped in to a machine shop looking for parts. Talked with owner who suggested I throw the block away and start over. But - he also said that if I go ahead with the cracked block, I should have the sleeve installed first and then stitch to the sleeve. He claims that boring for the sleeve will loosen the plugs if they are put in first. OK Walt, Ol Ron and other builders - what do you say?
Jack 34pu

Re: Stitching & sleeving an 8BA- sequence?
 

These guys at these machine shops crack me up (like the block) when they say they can repair a cracked block by drill and plugged. I have not seen one yet that did not leak. Be prepared to use stop leak cause that's the only (maybe) way it will work.

Re: Stitching & sleeving an 8BA- sequence?
 

Put the sleeve in first as recommended, then do the "stitching"! If I had to install the valve seat also I would do that last. The block will already be "stressed" in that area and you'd try not "stitch" anywhere directly on/into the seat insert itself!

You want to "stress" the block first with the sleeve install, again, as recommended by the shop, not the other way around! If you "stitch" first there's a chance the press fit on the sleeve will "open" (relieve) the "stitching" process!

This is all based upon common sense AND not having the job in front of us! Seeing the job may call for a different procedure!

Magnafluxing a "Flattie" is somewhat risky, trying to build a good magnetic field through that casting is difficult, must be pressure-tested on the final check! Just because you locate some very external cracks doesn't mean there aren't some you simply cannot see! We've found many down at the pan rails, with the pressure-test, over the years!

(Add) If it were an "over-the-counter" sale here I would try to obtain a "good" block first! You also don't mention the present bore size????

Thanks, Gary in N.Y.

P.S. The "small" area with the "stitched" repair will NOT be enough to affect the overall sleeve fit/press, at least at the top section of the block!

Re: Stitching & sleeving an 8BA- sequence?
 

I've sleeved and pegged many many blocks with that same crack. I do it like Gosfast said. Install the sleeve first then peg the crack. Hopefully the crack don't go down the port very far. If the seat looks good and the crack goes down a little, you can leave the seat in and put in a couple pegs below the seat down the port. If it goes down the port further it's hard to peg. You have to have a long drill and a long tap and be able to screw the peg in. I've never had one leak. Walt

Re: Stitching & sleeving an 8BA- sequence?
 

Either they wern't done right or you haven't seen very many. I've seen a lot of them repaired that way and have never seen one leak.

Re: Stitching & sleeving an 8BA- sequence?
 

I have done many with no leaks after pressure testing. .It doesn't appear you have seen and tested many .Stitching when done in the correct sequence and using a known system is a very reliable way to repair engine castings. It is done on many diesel and industrial applications as well.

R

Re: Stitching & sleeving an 8BA- sequence?
 

Some claim to stitch without using any sleeve. Also, it is mandatory to stitch BEFORE installing the sleeve in order to properly apply plugs over the complete length of a crack.

Re: Stitching & sleeving an 8BA- sequence?
 

I've had Frank Casey stitch my blocks and never use a sleeve. Once the block is pinned he grinds it down then bore it to fit the new piston. I've always uses a ceramic stop leak. never had any problems.

Re: Stitching & sleeving an 8BA- sequence?
 

Hey Ol Ron,

What does that ceramic stop leak do to the water pumps and radiator? Both will be new in my ccpu and not sure I want anything clogging them up.

Isn't it the truth that if you have a pin hole in something you don't want to leak - it will leak. If you open a hole to drain something, it will stop up in a minute or so??!! At least my experience.

Re: Stitching & sleeving an 8BA- sequence?
 

The Morossso stop leak is used as follows. Install with warer run for a few days, drain and flush cooling system. Bottle costs $20 and it works.