Anybody had any good or bad experiences with sleeving a 400sbc? Seems kinda dangerous to me.

 

406,

There are a few schools of thought on this. It used to be considered weak to install a cylinder sleeve in a 400 SBC. The only engine I ever sleeved was a Pontiac, and there was enough casting to accept the sleeves without breaking into the coolant passages. Not that this would matter, but boring through the core completely can weaken the case.

On the other hand, if you consider that the Ford Romeo engine runs on sleeves, and the NorthStar is sleeved, you might think that it was O.K. to blast right through and install sleeves. Those cases were designed with heavier outer castings to accomodate the sleeves, while the SBC was designed to use the cylinder as part of the structural integrity of the case.

My opinion (and I stress, OPINION) is that if it were an inner cylinder and you installed four-bolt main caps at the center bearings, you could get by with it in a moderate performance engine. I would be wary of installing it at an end cylinder, where two bolt caps are found. The siamesed design should help with the strength of the case, but I have no experience with sleeves in s 400.

If it were not a problem for structural strength, you'd probably see a lot of 400 blocks cut through and steel-sleeved for 4½" pistons for a 500+CID small block. There are a few, but it is not that common in my neighborhood.

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Later,
Vader
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"I'm'a do Things My Way - It's My way or the Highway."
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I have to agree with Vader on this one. The place I worked at we had sleeved a few blocks (various apps), and none of them were intended for performance usage. Was also done at the customers request, because the owner felt it wasnt a good idea. One came back out of those, I think while I was there about 6 or so had been done. I'd stay away from it if you are planning on a high HP or racing app, and find a new block instead.

 

Funny you should ask.

Last summer, I found out a 400 I had purchased had been hammered on by a bunch of shorttrack guys. The number 5 hole had been punched 60 over and all the others were 40.

You think I had a funny expression on my face when I checked the ring gap on that hole?

I had a local machine shop (supposely a good one) sleeve that hole.

I had put about 20 hours on it of around town driving and was scheduled to put it on a dynojet on Nov 11.

On the day prior to the dynojet, I took a road trip of 45 miles one way to check things out. After about an hour and 40 miles, the temp went from 190 to 230 in about 4 secs.

I put it in neutral and coasted a little and when I looked back down at the temp, it had gone back to 190. It did this several more times on the way home and I found that the number 5 hole had 120 PSI compression and water in the hole.

I pulled the head and there appears to be a very small crack running from the bolt hole to the number 5 cylinder. The crack runs right under the wire ring for the head gasket.
I started to put it back together and when I torqued the bolt to about 50 ft/lbs, the threads pulled out of the bolt hole.

Did the sleeve cause it?
You got me. But I don't think I will try it again. New 400 time.

PS, this was a pretty stout 400. About 500 hp.


[This message has been edited by jcb999 (edited March 14, 2001).]