SST60 Specs

[mercrazy]

I was just reading a post from "Lil' Blue Rude" about 70hp port style and size....Is there anywhere in these posts where the SST60 specs can be found ? Info like the years of blocks that can be or preffered to use to build a mod motor. If anyone knows or has the info that would be great to see .
Thanks

[Powerabout]

http://opcrace.com/PDF/60.pdf

[Popa Sam]

SST60 spec sheet can be found on opcrace.com website. The permanent mold cast blocks are preferred for mod motors. They were found on 1986 and 1987 70 hp motors. They are not legal for SST60. The bridged exhaust motors were sold through 1992. The 4 spline crank was sold through 1988. 4 spline cranks were cast through 1982. 1983 and newer were forged.

[Powerabout]

Whats different about the perma mold blocks that makes them illegal?

[mercrazy]

Thanks
This was what i was talking about this is goooooood stuff keep it coming .
Fantastic!!!

[mercrazy]

Thanks again for the info.

Is there any spacific years of the standard 56.1 cubic inch that will work the best when looking for a motor to modify???? Looking at putting together some stuff for a future project, so i'm starting my homework now.....If anyone has any mods/tips that there willing to share that would be great as well ...Things like good flywheels, carb#'s ,bad blocks or what ever. It would help to get this lake racer project together.


Thanks

[Sam La Banco]

The permanent mold blocks are more rigid, the transfer passages are molded much cleaner and the entrances to them are much better shaped for flow. Also the water passages promote better cooling.(cooler water to the block from the exhaust cavity.

[Powerabout]

Bill Ghor said even the cooling system changed 5 times over the life of the 56
There was several SB's on middle cyl getting hot and the mods to fix that.
I guess the sst60 block was an early lost foam or did it change along with the production versions?

[Sam La Banco]

I think the 60 motor is the worst one, they will run very hot.

[Lil' Blue Rude]

Can anyone tell me what I can do to solve the over heating problem? Are the SST60 carbs the best single barrel carbs for these motors or is there a better carb?
Thanks Guys

[Popa Sam]

Can anyone tell me what I can do to solve the over heating problem? Are the SST60 carbs the best single barrel carbs for these motors or is there a better carb?
Thanks Guys

The biggest improvement in the cooling was moving the tell-tale outlet to the top of the block rather than the side. It allowed steam a place to escape. Always use a 6 blade impeller rather than the 3 blade that is available. Cooling is one of the advantages of the permanent cast block. The sleeves have 360 degree support by aluminum which dissipates heat much better than having a void behind the boost port with the lost foam cast.

Any of the "no choke" carbs with a 1 1/2" opening and a 1 !/4" venturi work well. I've tested all the different versions of these carbs and never found a difference in performance with any of them.

Of course these are my opinions and I'm sure you know about opinions!!!

[Powerabout]

Sam
Have you ever tried the plastic top carbs from stock 70?
Cheers

[Popa Sam]

No. I never tried the plastic tops.

[Lil' Blue Rude]

I run flat top 50hp on my 45 cu OMC and I gained a mph on top over the older style non choke flap 50hp carbs. Don't know if the same would apply for a 3cylinder, or a prop. I run a outboard jets. Thanks for the info.
P.S. I'm always up for listening to opinions.

[calvin]

Is it better to run thermostats or rectrictor washers in the 3 cyl omcs?

[sheuninck]

the 49 ci thermostat is 120 degrees. cold to reduce salt water damage. put an automotive 180 degree one in it.

[Lil' Blue Rude]

This will sound like a dumb question but I'm gonna ask it any ways. What is the idea behind the SST60 having a sqaure exhaust tuner? Is it because of the limited space in the mid or is there somethin else behind the idea? I've always read that rounding of sharp edges and corner helps air flow so why wouldn't a round exaust tuner be a better choice?
Any help would be great.
Thanks

[Powerabout]

the adapter is square so the tuner is as well I guess?
For same basic area a square tuner has a lot more internal volume

[Fastjeff57]

The tuner is designed to add some resistance to the exhaust belching out, so it doesn't matter that square pipes flow less well.

Jeff

[Lil' Blue Rude]

Does it matter if the tuner is Sqaure or round? I'm trying to figure out if they are square because it's just easier to build them that way or if it is because of the limited sapce in the midsection forces the need for a sqaure exhaust to get the correct area for the tuner.
Like I said I know it's a dumb question.

[Sam La Banco]

A round pipe would be more effective in calculations, but there no sense making the tuner round after the first part of the exhaust system (in this case, the exhaust manifold) has a different cross section. Most probably for space savings and ease of manufacture reasons.

The most important tuning getting done in a 3 or 6 cylinder outboard, happens in the exhaust manifold. (inter-cylinder tuning)

[Fast Fred]

180deg is too hot, 140deg is where you want it. moded each one, the solid molded case is nice, the SST case ported up nice as well.:eek: