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View Full Version : Re-sleeving a omc triple 56cu in



pdt
10-14-2013, 11:11 AM
High guys
Now im thinking about putting in new sleeves on a omc 1995/6 block. its the later block with the 920cc capacity !!!!!.
first of all need to get the old ones out and then see about getting new ones back in.
Now ive never done this to an outboard engine before so this is going to be completely new to me,
I have done the wet sleeves on the big diesels and also sleeves on tiny little glow motors, but an outboard 2 stroke never.
Now regarding getting the old sleeves out !!!!
do I need to heat the block or just press out the old ones ?
when replacing the new sleeves again is heat needed or not, and are the sleeves notched in any way so as to get a perfect alignment ?

Also, would it be better to polish the ports on the sleeves while I have them out to get a better finnish on them ? or wait till back in the block.

once sleeves are out I will be polishing the passageways of the block to get rid of any imperfections and smooth everything off nicely.

The reason behind the re-sleeve idea is that the grooves in the walls of the bore at the moment look a bit too deep for just a re-bore.
These grooves are real ugly and not many machine shops want to touch outboards where I live.
Most of the engineers have disappeared altogether in the uk nowdays, very rare to find a good engine rebuilder for sensible money.

Now if I can re-sleeve then the block will be as good as new, the sufaces are nice and true and I will get it xrayed just to be on the safe side.


any thoughts on this ?

LittleCharger
10-14-2013, 11:42 AM
High guys
Now im thinking about putting in new sleeves on a omc 1995/6 block. its the later block with the 920cc capacity !!!!!.
first of all need to get the old ones out and then see about getting new ones back in.
Now ive never done this to an outboard engine before so this is going to be completely new to me,
I have done the wet sleeves on the big diesels and also sleeves on tiny little glow motors, but an outboard 2 stroke never.
Now regarding getting the old sleeves out !!!!
do I need to heat the block or just press out the old ones ?
when replacing the new sleeves again is heat needed or not, and are the sleeves notched in any way so as to get a perfect alignment ?

Also, would it be better to polish the ports on the sleeves while I have them out to get a better finnish on them ? or wait till back in the block.

once sleeves are out I will be polishing the passageways of the block to get rid of any imperfections and smooth everything off nicely.

The reason behind the re-sleeve idea is that the grooves in the walls of the bore at the moment look a bit too deep for just a re-bore.
These grooves are real ugly and not many machine shops want to touch outboards where I live.
Most of the engineers have disappeared altogether in the uk nowdays, very rare to find a good engine rebuilder for sensible money.

Now if I can re-sleeve then the block will be as good as new, the sufaces are nice and true and I will get it xrayed just to be on the safe side.


any thoughts on this ?

You need a machine shop to bore the new sleeves and deck the sleeve once they are back in, you are best off to find a machine shop that will bore the new sleeves etc. before starting the process.

Need heat to get them in and out. Heat block to about 400 degrees for 20 minutes and the sleeves will drop out when you turn the block over. Do the reverse to put the sleeves back in. You can also have the machine shop machine the old sleeve out and press the new one in as an alternative.

Do your porting while the sleeves are out then clean up any port matching once they are back in and before you send it off for the final boring

pdt
10-14-2013, 12:43 PM
sounds like this is going to be very very expensive to get done in the uk !!!!!!!
as it still means I need to find a machine shop to do the bore work.
very different over here to in the usa for getting this type of work done nowdays.

Might have to have a look around and maybe re-think the whole thing again !!!!!!

zul8tr
10-14-2013, 02:20 PM
sounds like this is going to be very very expensive to get done in the uk !!!!!!!
as it still means I need to find a machine shop to do the bore work.
very different over here to in the usa for getting this type of work done nowdays.

Might have to have a look around and maybe re-think the whole thing again !!!!!!

Perhaps a good idea.

OUTBOARDER
10-14-2013, 02:47 PM
sounds like this is going to be very very expensive to get done in the uk !!!!!!!
as it still means I need to find a machine shop to do the bore work.
very different over here to in the usa for getting this type of work done nowdays.

Might have to have a look around and maybe re-think the whole thing again !!!!!!

Send it to WIENDANT he prefers oval port 56 and by far has most experience with the OMC 56gi . http://www.wptracing.com/sst-60

or Howard Richards (Ran OMC's Second Effort Porting, develepod M31 porting used over seas.

http://www.sacoriver.net/~red/outboard.html
http://www.sacoriver.net/~red/ref.html

if you are going that route these guys will be booked solid thru winter in a couple of months!!!!

pdt
10-14-2013, 04:27 PM
I realy do like the look of the wpt racing guys stuff.
now if he was in the uk I would be on the phone tomorrow.
but to ship a engine from uk to him and then back would cost a fortune , probably about the same as a new engine just for postage.

I don't race at present, but would like to get a lot of power from the engine due to weight limitations of the engine etc.
I would be realy happy to get it done by someone who realy knows their outboard stuff.

what sort of power can a very well prepped 56ci oval port engine put out ? what I mean is it starts life as a 70hp so what does it end up at ?

Powerabout
10-14-2013, 07:25 PM
I realy do like the look of the wpt racing guys stuff.
now if he was in the uk I would be on the phone tomorrow.
but to ship a engine from uk to him and then back would cost a fortune , probably about the same as a new engine just for postage.

I don't race at present, but would like to get a lot of power from the engine due to weight limitations of the engine etc.
I would be realy happy to get it done by someone who realy knows their outboard stuff.

what sort of power can a very well prepped 56ci oval port engine put out ? what I mean is it starts life as a 70hp so what does it end up at ?
100hp at the crank

pdt
10-23-2013, 11:19 AM
100hp WOW
that is a huge increase in power.
what modification is it that gives the major power increase when rebuilding these engines ?
I ask as I think I have found a decent place to do a re-bore or re-sleeve job that might not be too expensive.
if it turns out I can get thise block re-bored for sensible money then ill be making a nice engine out of this (I hope).


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