Engine and Transmission Tech

tips, technology, tools and techniques related to vehicle driveline components

Go to Thread: PreviousNext
Go to: Forum ListMessage ListNew TopicLog In


quietone
Larry Mimbs
Tennille, Ga.
(93 posts)

Registered:
07/13/2013 04:22PM

Main British Car:


sleeving aluminum blocks
Posted by: quietone
Date: December 04, 2019 02:01AM

Seems like sleeving blocks is a common subject. In the last 30 years, I sleeved a lot of aluminum blocks, mostly outboard. Originally all outboards had cast-in sleeves. In 1985 OMC started using sleeves installed after the block was cast.(In 2.7l loop charged engines) These blocks were cast in England. Since the cylinders were really thick, big bores seemed like a good idea. So we increased the bore from 3.5" to 4". LA Sleeve made the sleeves. Straight walled, 1/16" wall thickness. Open deck block. Never had a problem with cylinders. OMC did a lot of research on sleeve installation when they made the transition. One of the things that is important is heat transfer from inside cylinder to coolant. The difference in heat transfer between "hot dropped sleeves" and pressed-in sleeves is phenomenal. They said a factor of 10. A microscopic view of the bored surface ready to accept the sleeve shows continuous peaks and valleys. A hot dropped sleeve sits on the peaks only, leaving air space between sleeve and block. Air is a good insulator. If that sleeve is pressed in with proper interference and proper lubricant, the peaks are smeared over into the valleys and create a solid surface. Thermal conductivity is much improved. Ideal interference seems to be .001" plus or minus .0002. More than that causes undesirable stress in the block. Recommended lubricant is a product called LB5000. Without lubricant aluminum will gall. If sleeves are hot dropped, they need to be seated after the block cools. For some reason, the block shrinks away from the bottom of the sleeve, usually about .003"-.004". A good, solid rap on top with a metal plate and a 2# hammer will seat it. If this is not done, it is common to see the sleeve drop in operation enough to cause head gasket leaks.


mgb260
Jim Nichols
Sequim,WA
(2019 posts)

Registered:
02/29/2008 08:29PM

Main British Car:
1973 MGB roadster 260 Ford V8

Re: sleeving aluminum blocks
Posted by: mgb260
Date: December 07, 2019 01:17PM

Larry, Long time since you've been on here. Did you ever pickup a 4.0 or 4.6 block to examine those sleeve issues? Fred has a thread on flipping them around or using inexpensive stepped GM liners.

[forum.britishv8.org]



Edited 1 time(s). Last edit at 12/07/2019 01:19PM by mgb260.


quietone
Larry Mimbs
Tennille, Ga.
(93 posts)

Registered:
07/13/2013 04:22PM

Main British Car:


Re: sleeving aluminum blocks
Posted by: quietone
Date: December 08, 2019 01:48AM

It's been a while. I used a lot of thin (1/16" wall) sleeves in aluminum blocks. They tend to have too much chamfer on the bottom to suit me. Full contact at the bottom is important, so I flip the sleeve over and barely break the edge with a file. Also, a standard boring cutter leaves an angled lip at the bottom of the cut. Using a sleeve cut-off tool for boring leaves a nice square lip.
No, I have not found a 4.0 or 4.6. Not too common in central Georgia.


Sorry, only registered users may post in this forum.