[hefferzon]

Hi!
I recently got me a 350 engine to replace an old 250 L6 in my -66 BelAir.
The engine was bought rebuilt, bored 0.060 and bolted together but never started.
As I took off the heads to check the valve size tonight I discovered that one cylinder is sleeved, which is fine with me, but the sleeve protrudes some above the deck on 1/3 of the cylider bore(i.e. not all the way a round). Just enough to feel it with your finger nail.
If I put a straight edge on the area it rides some on it.

I belive the sleeve was installed in the past, as the block havent been top decked this last time it was bored.

What can be the cause of this, and is it a problem?

As I have no experience with sleeved cast iron blocks I hope you guys can help me.

Thanks/Jesper

[BOBCRMAN@aol.com]

Sounds like the shop that sleeved the block didn't have the boring bar set correctly (level) when they trimmed the sleeve.

You can take a flat file and carefully cut the slight protrusion if there is a sealing problem. Or, get the block decked.

If the block seals up, don't worry about it. A CORRECTLY installed iron sleeve is usually made from better material than the block.

[oldbogie]

Originally Posted by hefferzon

Hi!
I recently got me a 350 engine to replace an old 250 L6 in my -66 BelAir.
The engine was bought rebuilt, bored 0.060 and bolted together but never started.
As I took off the heads to check the valve size tonight I discovered that one cylinder is sleeved, which is fine with me, but the sleeve protrudes some above the deck on 1/3 of the cylider bore(i.e. not all the way a round). Just enough to feel it with your finger nail.
If I put a straight edge on the area it rides some on it.

I belive the sleeve was installed in the past, as the block havent been top decked this last time it was bored.

What can be the cause of this, and is it a problem?

As I have no experience with sleeved cast iron blocks I hope you guys can help me.

Thanks/Jesper

The sleeve needs to be captured. By that I mean there should be a step of original bore left at the bottom which keeps the sleeve from falling into the pan. At the top it is captured by the head and head gasket.

At both ends the sleeve should be sitting square with the step on the bottom and with the deck on the top. If it isn't, there there's a good bet the sleeve isn't square to the crank centerline either. This would be a defective job by either the original installer or if you had it rebored, care was not taken to insure it remained stable. One wonders if the sleeve spun with the boring bar and is showing the block isn't square by now protruding above the deck where in its original position it was flush. The sleeve needs to be flush with the deck all the way around its diameter.

I rather think this needs to be looked at be a competent and honest machinist.

Bogie

[hefferzon]

One wonders if the sleeve spun with the boring bar and is showing the block isn't square by now protruding above the deck where in its original position it was flush.

That was exactly my thaught too. But if that was the case I belive I should be abel to see a crack or line in the bottom cylinder where the sleeve ends and the capture step begins, whitch I can't..

But as I said before, I belive the sleeve job was made sometime in the past, before this last rebuild. And if that is the case, and the recent rebore is made properly, hopefully the cylinder is square to the crank again.
I don't know any good method of measuring this exact enaugh too feel any wiser.

Thanks/Jesper

[345 desoto]

Exactly what OLDBOGIE said. Like it or not, I'd take it in and have the block/sleeve checked...if only for peace of mind...

[hefferzon]

Well I guess so, sad but true. Especially as the main reason for buying a allready rebuilt engine was to not have to be waiting for months for a shop to get things done.
Sad also that the block is already bored 0.060, which means that if the cylinder is out of angle I can just throw it away, or sleev the entire block, which is out of the question.

We'll see, maybe I take my chances leave it as it is and hope for the best.

Thanks/Jesper

[345 desoto]

Whoa! All you're having checked is the sleeved cylinder! WORST case is to have a new sleeve installed. Or BEST case, you can flat file the high spot and put it back together and run it...

[hefferzon]

Okay, but is it really a good idea to install a new sleeve without having the cylinders next to it rebored? I've heard that a slight deformation can occur.

Thanks/Jesper