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:cool: sand molded block is strongest, bridge exhaust port is biggest over all, no comp releaf hole:cool:
add finger ports, you can run wisco's:cool:

[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:cool:. 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:cool:, i'd have to see it, you may just bore it away....:cool: 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.:cool: you can do just fine with oval :cool:

[phillnjack]

Thanks Fast Fred,
Very glad you told me what they are.
i was wondering about these little holes, they do seem very strange when first seeing them.
at first i thought a hole had burnt through ,then when i noticed all three i knew it must be stock.

So is it a must do to get rid of these when re-building ?
Do they cause a drop in normal compression ? i would think they do to be honest.
and surely a drop in compression = less power ?????
is this just on the 60hp or would the 70hp be the same ?.

and where is the best place to get some parts for a re-build ? please dont say BRP as in the uk they
are just so high prices it ridiculous.

and thanks again for info Fast Fred

phill

[chris3298]

I didn't know you could weld those holes up, I had heard it would have to be re-sleeved and that if you had a later year 56 that you could re-sleeve it to a bridge port if you wanted. I lucked out and someone on this board told me about a motor near me that was a 86 and supposedly this motor is a bridgeport and doesn't have those holes you talk about. I have only been told by a few that the bridge ports are better, time will tell when I can afford to rebuild it this winter.

I have gone to seawaymarine.com and crowleymarine.com sometime crowley marine is cheaper then seaway. I have also had someone send me this link which not sure if these pricers are any better http://www.promarineusaonline.com/ Do a google search and you will kinda part on some sites cheaper then others.

[Fast Fred]

she's just pushin comp and fresh mix out that hole till the rings clear the top of the hole. they need to be lost.:cool:

[phillnjack]

I am learning a lot more on this site than i expected to.
so many people with great knowledge of the outboard engines .

great stuff


phill

[calvin]

I have 1986 56 incher...does it have the holes?

[chris3298]

I have 1986 56 incher...does it have the holes?
I don't believe it does.

[sheuninck]

that may be the only year that does not have it

[chris3298]

I don't remember where but seems like someone had told me that the 86-87 56 had the bridge ports and I thought this person said these years didn't have the hole that the 1988 had it but don't hold me to it, it's just what I think had heard.

[LittleCharger]

The bridge port motors do not have the compression relief holes. The 1986 56er is a bridge port motor.

[Per]

The bridge port motors do not have the compression relief holes. The 1986 56er is a bridge port motor.

My -91 56CI bridgeport has them so perhaps it is a question of when they are built...
I'm about to tear down a -92, wonder what's inside that one:)

[phillnjack]

well it seems to me that any of the motors that have these holes will be
more powerfull once their gone.
The compression will go up straight away and give more power as also a little more
fresh juice to burn like fast fred says.
Seems a strange thing for omce to do to an engine,could understand if it was only done
on a 50hp and 60hp 3cylinder, and not the 70hp as well.
But after looking at the parts and other stripped engines its done to all 3 sizes of engine.

I wonder what the actual horsepower will be when holes filled and put on a dyno ?
and if skim the head as well this engine could be way up in the compression stakes.

Looking at the holes in my pics and without checking it again (too much rain) it looks like
the fresh fuel is being dumped out of the exhaust and not chucked back into crankcase.
i could be wrong but will check once i am able to get the garage open when it stops raining.
if so , then what a waste of power and precious fuel !!!!!!!!!!!

phill

[sharpeye Mike]

My 56er is a bridgeport, is a sand cast, started life as a 65 hp commercial and does not have the comp. relieve holes. Unfortunatly I dont have the year ìt was made, I don`t have the model # just the serial #...No problem It's a bridgeport and it's going to get moded and going on a 15" mid. on top of a nitro gearcase, sounds pretty sweet no?

[phillnjack]

well what mods are gonna be done to it ?
i want to know what you exactly mean by mod it.
do you mean your gonna be cleaning up the bad alignment between ports and block ?
drill the pistons where the bridge is ?
shave the bridge due to heat etc ?
or do you have lots of other little goodies lined up for it ?


I had a look at the ports on my spare block and its all lined up real nice, it could do with a bit of polishing in
the exhaust and intake though.



phill

[sharpeye Mike]

Hi Phill, I'm doing the finger ports this time around to see what the big fuss is all about. Fast Fred is an advocate for finger ports and I value his and others opinions on this site and then I'm raising the port heights close to the sst60's specs., shaving the heads, CCM fiber reeds and a few more mods that a friend want's to show me.
Have you had a chance to read the secrets of the mod 50 part 1 and 2? Lots of info.

[phillnjack]

yeah ive started looking to day at the mod 50 section
wow

there is so much info and so much of it just goes right over my head.
not only very technical but the language difference between uk and usa is unbelievable.
so many different names for different things.

but a very good and interesting read, i shall keep on reading it untill it sinks in my head.


Looked at my rods today and not very good news at all, looks like one of them had big end trouble.
got to getthe crank out and check it out, if the cranks gone bad and i need 3 rods this might
cost to much to be a viable project.
I took the best of the 3 rods and stripped them, boy thats gonna be difficult to put the
small needle rollers in with my big sausage fingers ha ha

what i did notice is that the rings look like normal rings !!!!! i thought they were supposed to be
some key stone effort ?????
is this normal to have just ordinary flat rings ?

phill

[Fast Fred]

so, if i had a block with exhaust releaf holes and i was lookin to make it go. i'd take a copper pipe, spank it into a finger to fit behind the hole, shoot the mig wire down the hole, low wire speed with a fair amount of power, try to close the hole just before your in the cyl. the copper pipe acts as a dam for the weld but will not stick:cool: do my port setup, then send it to the machine shop. :cool:

[sharpeye Mike]

How big of a deal is it to remove the sleeves? I'm thinking about doing some behind the sleeve port work and cutting the finger ports while the sleeves are out. I'm not happy the way the sleeves are lining up with the ports so seems like a no brainer.
Mike

[phillnjack]

thats a good question about removing the sleeves.

mine is ok for lining up of the ports.
But if the sleeves come out then ill get new sleeves instead of a re-bore
then i can keep it stock size pistons and rings etc.
always handy for future bore job.

what sort of prices are the sleeves for these engines ?



phill

[chris3298]

thats a good question about removing the sleeves.

mine is ok for lining up of the ports.
But if the sleeves come out then ill get new sleeves instead of a re-bore
then i can keep it stock size pistons and rings etc.
always handy for future bore job.

what sort of prices are the sleeves for these engines ?



phill

I was quoted like like 200 per hole if I needed sleeves and I think people on here have talked about get your wife out the house and put it in the oven and heat it up to 350 and the sleeves come out.

[phillnjack]

and i take it you have to do the same putting them back in, 350 in the oven

200 per sleeve thats about £120 in english if converting from dollars..not too bad i suppose
better than scrapping the block if the scores are too deep.
getting them out is not the problem, its putting them back in that worries me ha ha ,
need to get it dead right first go i suppose


phill..

[chris3298]

I think that is what I read on here some where was heating the block back up and dropping them in but like you said they have to go in a certain way, I have no clue how. Really is very cool that they can be resleeved like a diesel motor, gas motor in a car it's just throw the block away when you can't bored it anymore.

[byrdsperformance@tds.net]

Yep heat block drop in sleeve's, aligned, holdem down with lite press.

Hope you understand a new sleeve is undersize an has to be bored to fit a standard piston:cool:

[Fast Fred]

at the machine shop, they will mill the old sleeve out, then press in a fresh one. Sea-Way has used cases, have gotten New SST60 cases from Sea-Way. yup have said, i'm not usein this case cuzz of poor alinement.........

[Fast Fred]

oil the bridge....