56" omc cooling

[calvin]

Which year/years 56 inch motor is the best for mods or stock rebuilds?

[Powerabout]

Thanks Bill

PM box fixed

[Bill Gohr]

Which year/years 56 inch motor is the best for mods or stock rebuilds?

You are going to build a powerhead for stock I would use nothiing but an Oval port powerhead

[sharpeye Mike]

That sounds great but can you mod an oval port?
If so what kind of mods can you perform?
Has anybody ever ran a stock motor on a sst60 exaust tunner?
Thanks.

[Powerabout]

I am about to try a sst60 tuner on a stocker but I am pretty sure I will;
loose bottom end
get nothing on top
need to rejet
so waste of time on stock porting

[ima75man]

I am about to try a sst60 tuner on a stocker but I am pretty sure I will;
loose bottom end
get nothing on top
need to rejet
so waste of time on stock porting

why would you lose on bottom end? how about mid-range? i thought everybody ran stock moters.....i found out just modifying a stock tuner would help some..

[Per]

If the head you are using has a "G" stamped after the part number that would be the later one,

As far as those service bulletins from 90, 91 92, and early 93, most of them can be disregarded, lots of those were quick fixes trying to cover engines that were failing like popcorn so we really don't need to do all of them and remember if you have a 90-93 with a replacement oval port powerhead and the correct water pump you need to disregard them all.

Excellent information!
If I only had known that when i rebuilt my engine. I've spent countless hours on the Internet trying to find all info from those service bulletins

[Bill Gohr]

Well depending on the boat you would most likely lose bottom end with the 60 tuner, because, it is designed for peak power on a tunnel boat, at high rpm's.

If you're looking for absolute peak power when you mod one of these you would be best to use a pre-90 bridgeport, that was before the casting got changed, or the most reliable would be a 94 and newer with the revised cooling system.

[calvin]

Which year motors are oval port?
I have a 87 and a 88 56 incher.

[Bill Gohr]

Which year motors are oval port?
I have a 87 and a 88 56 incher.

1994 and up are oval port