Rebuilding a omc 56ci block

[phillnjack]

Hello
over the winter im hoping to rebuild my 1995 56ci 3 cylinder omc block.

The bore in the centre is my main comcern as it had deep scores,nearly grooves.
I am hoping it can be re-bored ,if not what the chances of re-sleeving it. ?
Can these engines be sleeved ?

Now i will be needing new pistons , con rods,bearings etc etc

while the block is fully stripped and all parts needing to be renewed, is there any better parts
that can be fitted to give a bit more power while its down.

seems a good time to do a few mods to the engine if its not gonna cost a fortune to be done.
I dont expect the fstest engine in the world,just a nice strong engine that will last me a fair while.

I wont be using the daft VRO as that is what caused the engine breakdown in the first place.
1 tiny blockage and kaboom 1 shot engine. Premix is the only way i will run an engine.

This block is a spare i got when i bought my engine back in april, the guy had twins fitted and showed me what had happened and let me have a complete engine for spares.
so buy 1 and get the other free,very good deal.

Now i fancy re-building it back to running condition, it will give me a good knowledge of whats inside these
little blocks while doing it.

Just want to know whats the best stuff to put on my shopping list for parts.

also want to know of any mods that i could do to get a bit more out of the engine and stay reliable.

woukld it be best to stick to oem parts as i pistons and rods ?
or would it be better to go with another maker of the parts ? like wiseco for instance on the pistons ?
if so what would be the benefit or downside to these ?



phill

[Fast Fred]

you can resleeve it, may be best to get a used block in good shape sand molded block is strongest, bridge exhaust port is biggest over all, no comp releaf hole
add finger ports, you can run wisco's

[sharpeye Mike]

Fast Fred, can you buy 56 cube pistons with the finger port holes in them or do you have to bore them out?
I think I know the answer but I thought I would ask anyway.
Thanks, Mike

[phillnjack]

But if get another type of block, would i need different main shaft from gearbox to crank?
I dont want to be having to swap stuff around that ive already got.
would sooner stick with same 1995 type engine block, and these dont come up in the uk.
I was told that my crank wouldnt fit the older block ?????? too many differences.
and the head would be different as well, dont realy want to be going older style with the engine.

ive got to strip the block down and take to a engineers shop i spoke to today, they said
they can bore it if its not to deep and said i might be able to get away with a 40thou bore max or
sleeve it .
I think there is pistons and rings around that are 40 thou over but not to sure about this.
this is what i can see from wiseco parts list.
standard is 3.1875 and plus 40 is 3.2275 price is £110 for one piston !!!!


phill

[Fast Fred]

heard about a set of finger ported 56er pistons used in a factory 56cube mod50 setup test, i just make mine. the factory test was to see what she could do
with the 6pack, big reed blocks, and exhaust. your crank will fit, they do make trick sst60 sleeves, i'd have to see it, you may just bore it away.... and be ok.

[sharpeye Mike]

I picked up a sand cast 56 er this fall that I,m planning on rebuilding this winter, I've got to say, I'm not impress for the way the sleeves line up with the ports, will have to grind on them a bit. Do you think raising the ports to sst60 specs. but only at the bridge (oval style) would be a good compromise?

It's funny how I hear about the good and bad of the oval port, a friend of mine blew his bridge port while still under warranty and the dealership replaced it with an oval port, he claims he lost over 300 rpm.
Mike

[phillnjack]

my engine has a sort of bubbly effect on the block from the cast, is this sand cast or lost foam or what ?

and from what im gathering its oval port as well yes ?

well whats the good or bad side of oval port ?

[byrdsperformance@tds.net]

The older model block's or sand casted have a slick smooth finish.
The newer foam casted will have a styrofoam cup look finish to them.

A bridge port block has a wall in the center of exaust port.

Oval port model's have no divider in center of exaust port's.

[phillnjack]

ah so i have the oval block
now this is a silly question but what are the tiny little holes above the ports near the top of the bore ?
there is one in each bore in exactly the same place on each bore.
about 1/2 inch from top of each bore.
never seen anything like this before, and ive had a fair few engines apart.

phill

[Fast Fred]

them is comp releaf holes, they are for smoothin out the idel, you need to lose them. you can weld them shut and grind them under. oval port has a wider power band overall, bridge port has a more peaky power band and makes MO hp. you can do just fine with oval