I have a question on machine work on a block. First, what is the purpose of sleeving a block? What does it do? From what I understand, if I have a 350 ci motor, it would consist of boring the block out, and installing sleeves which would return the displacement to 350 ci? Is it possible to sleeve a block and lower it's displacement? I have a 400 that is bored .060 over. Is it possible to sleeve it to a 406? Or that's not what sleeving is about. Also, it's a 509 high nickel block, 2 bolt main. Can this have splayed caps to make it stronger or would that actually make it weaker? I'm not actually planning on doing this, but just pondering the possibilities of what can be done to a block. Thanks.

 

Sleeving is typically done when you want to save an otherwise unusable block. Often done to maintain numbers-matching, sometimes to stay within class rules for displacement. A .060"-over 400 block may well be a good candidate, assuming you can get it done for less than what an aftermarket, or unbored, block would cost you. But, doing all 8 holes is pretty rare, from what I've seen/heard - usually only done when one cylinder has been scored excessively or otherwise damaged beyond safe overbore.

I can't say I've ever heard of sleeving a 400 block. But, I don't know why it wouldn't be possible.

The only people I can imagine sleeving to reduce the displacement significantly are those who do things just to say it can be done, or to be different (basically the same crowd).

Splayed caps would make a 2-bolt block stronger. It would be pricey, though. See above comment about an aftermarket block. It wouldn't surprise me if a new Motown 4.125" bore block with splayed caps wouldn't be cheaper than sleeving and splaying a factory block.

 

Yea, you usually sleeve a block that has a hole/crack/big gouges in one cylinder. boring it out won't save it, so you bore it out completely, and press in a sleeve, then bore the sleeve to match the rest. after 2-3 sleeves it's usually cheaper to get a new block - sleeves (more importantly the install) cost big $$$$

 

A 400 is actually 400.9", when new.

When you bore it .030", it's a "406". Personally I don't think such a thing exists; it's a .030" over 400, as far as I'm concerned. Which happens to have about 406 cubic inches. That doesn't make it some special motor deserving of a whole new numerical designation IMO. But that's a different rant.

So no, you can't take a .060" over 400, and "bore it to a 406"; unless you know where to get a boring bar that puts material back on the cyl walls. I think the last one I saw was in the same store that has the square drill bits and the offset starter bolts for putting a starter for 12.8" flywheel on a motor that doesn'thave that bolt pattern and the ring gear spacers that take space OUT of the rear so you can put a 2 series gear on a 3 series carrier. But they're all sold out, I hear.

The cost of a sleeve is such that a 400 block is cheaper than about 2 of them. So if one cyl is damaged, sleeve it; if 2 are damaged, well, maybe sleeve it if you don't have an extra in stock; if 3 or more need sleeved, it's now a boat anchor or a table base. Likewise, .030" is as far as a 400 block can reliably go, and if you try to bore a whole pile of them to .060", you'll scrap a certain percentage of them. So yo're already beyond the commonly accepted maximum.

The "high nickel" crap is just that, crap. Don't worry about it. Even if it was true, or made any actual difference, it wouldn't make any difference. The 509 block is a 509 block, period; just like any other 509 block.

Yes you could have the splayed caps installed, and no they do not make it weaker. The old tale you hear about "4-bolt main 400s are weaker" doesn't have anything to do with the bolts. Rather, the early 400 castings, all of which got 4-bolt caps installed on them at the factory, had less metal in the main webbing area; and the later ones, which all got 2-bolt caps, have more metal there. So the best deal is to take a late-model block, which happens to have 2-bolt cpas, and install aftermarket 4-bolt caps. Kind of a moot point if you've got a .060" over block that has non-runnable cyl walls; that block has reached the end of the line already. You need another one regardless. Splay your new one instead.

 

That's why I asked about sleeving.

 

That's why I answered....