56ci OMC realistic power

[sabine river killer]

On a fishing style motor factory cowling trim reg foot ect no big bore just a hard build
how much power can be made with a 56

[filthy phill]

Looks like nobody is biting :cool:

[LittleCharger]

95hp

[Hounddog]

In 2004 we tested a prop dynomonitor on a 70 hp oval port. It measured 71 hp at the prop. The only change we did was put SST 60 carbs with 75 main jets and it tested at 79 hp at the prop. This as a factory non rebuilt motor. We never did run it on the water because it was not my boat.

[hupiveneilija]

Remember what rpms was that?

[Hounddog]

Remember what rpms was that?

Between 5500 and 5800 as I recall.

[ferdthe4]

In 2004 we tested a prop dynomonitor on a 70 hp oval port. It measured 71 hp at the prop. The only change we did was put SST 60 carbs with 75 main jets and it tested at 79 hp at the prop. This as a factory non rebuilt motor. We never did run it on the water because it was not my boat.


curious as to what carbs are closest to the sst60 carbs I have 1994 stock 70hp oval port rude. A 8-9hp gains with carbs and jets would sure be nice especially in that rpm range since I running a jet lower. curious as to what carbs are closest to the sst60 ones since at least for me those are hard to find and expensive. It has stock carbs right now, I do have a 1987 70hp fishing motor with a prop sitting on a stand are those carbs better than the 1994 ones?

[Hounddog]

I do have a 1987 70hp fishing motor with a prop sitting on a stand are those carbs better than the 1994 ones?

Provided the 1987 70 hp is a 56 cubic inch...it will have the big carbs...most likely they have a 69 main jet. The oval port loves fuel so I would run a 75 or larger jet with those carbs to start with. Blueprinted and slightly mod oval ports will run jets 77 to 80 with the big carbs... There is a lot of info on this site. Check the intake diameter, some say the intake is smaller on their oval port, use the intake off the 1987 if this is the case with your motor.

[ferdthe4]

Provided the 1987 70 hp is a 56 cubic inch...it will have the big carbs...most likely they have a 69 main jet. The oval port loves fuel so I would run a 75 or larger jet with those carbs to start with. Blueprinted and slightly mod oval ports will run jets 77 to 80 with the big carbs... There is a lot of info on this site.

Thank you, I've been reading around quiet a bit the 1987 is a 56ci and I thought they had the bigger carbs from what I have read, but didn't know for sure. Sure is a lot of info on here have been trying to read through everything I can. I appreciate the info very much. With that said lot of talk on here about jets and running different sizes where the heck is everyone getting these different size jets. Or am I just missing some really easy source for jets for these omc carbs.

[filthy phill]

somebody is getting a little bit mixed up about a 70hp oval port on the dyno in 2004 !!!

[MODIFIEDOUTBOARD]

On a fishing style motor factory cowling trim reg foot ect no big bore just a hard build
how much power can be made with a 56

mill head to sst 60 specs, "big carbies" , sst 60 style tuner w/ dry exhaust, front half work w/good cages = tick over a hundred been done before....

[ferdthe4]

mill head to sst 60 specs, "big carbies" , sst 60 style tuner w/ dry exhaust, front half work w/good cages = tick over a hundred been done before....

Thank you, this was my basic plan for my engine don't want anything crazy as I want to be fairly reliable as I use it fishing and hunting regularly. Maybe I'm wrong, but I didn't think 100 was really doable without some porting. I know somewhere in one of the threads I found specs of the sst 60 tuner and some pics of someone else's they made but can't find it now. Being that they are hard and expensive to come by I'd probably just mod/make mine to sst60 specs. Does anyone know the specs? length, width of opening, pics always help.

[MODIFIEDOUTBOARD]

Thank you, this was my basic plan for my engine don't want anything crazy as I want to be fairly reliable as I use it fishing and hunting regularly. Maybe I'm wrong, but I didn't think 100 was really doable without some porting. I know somewhere in one of the threads I found specs of the sst 60 tuner and some pics of someone else's they made but can't find it now. Being that they are hard and expensive to come by I'd probably just mod/make mine to sst60 specs. Does anyone know the specs? length, width of opening, pics always help.

find 3 of these 62770
http://www.ebay.com/itm/SMA5169-Evinrude-BRP-Etec-2011-reed-plate-assembly-5007349-0353266-outboard/291985032429?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2055119.m1438.l2649

mill front half to get within .050" from rod caps.

get 1-1/2 x 1-1/4 venturi carbs, 1990 & up 50's have them.le tuner

add 2" in length to sst style tuner

match ports like mod 70 did ad chamfer top of exhuast port 30deg 1/16" is very mild

[ferdthe4]

find 3 of these
http://www.ebay.com/itm/SMA5169-Evinrude-BRP-Etec-2011-reed-plate-assembly-5007349-0353266-outboard/291985032429?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2055119.m1438.l2649

mill front half to get within .050" from rod caps.

get 1-1/2 x 1-1/4 venturi carbs, 1990 & up 50's have them.le tuner

add 2" in length to sst style tuner

Dang now you have me confused on the tuner lol so add 2" to sst 60 tuner? Wouldn't that make it more like a stock 70hp tuner. I thought the stock 70hp tuner was longer than the sst60 tuners. Thanks for the tip on the reed cages I only planed on cleaning mine up and running CCMS reeds.

[MODIFIEDOUTBOARD]

get some pics and look. cut off stock and get some square tube and make a cowbell.
as far as intake you are giving up a lot there................

[ferdthe4]

Thanks for the advice on the ports and reed cages I think I will be keeping my eye out for more of those etec ones. The advice is very much appreciated I've had plenty of experience working on and building engines in cars, but haven't delved much into modifying outboards so the advice is appreciated. I've read through mod 70's build thread it was very helpful as well. I get the idea on the tuner is to go for a cowbell shape I keep looking around for the thread where someone posted up the length of the tuner. So right now I'm think stick with the length of the 70 tuner just make it look like a cowbell sst60 tuner.

[MODIFIEDOUTBOARD]

6277362772627726279262773
Small World 90hp etec triple tuner right in the middle.
There is a to of theory behind the geometry but it is a good picture .........................................627736279 8627726279762792

[ferdthe4]

I understand what you mean by the cowbell shape and I finally found the thread that had the inlet and outlet size specs of the sst 60 tuner barried in fast freds mod 50 secrets page 76

http://www.boatracingfacts.com/forums/showthread.php?8246-Fast-Fred-s-OMC-Mod-50-secrets-Thread-2/page76

inlet on exhaust base plate 1 1/2" x 1 3/4" outlet 2 3/8" x 2 3/8" what over all length works best in a long shaft mid is what I'm trying to figure out now. I've got a tig welder so welding up my own tuner isn't an issue trying to come up with ball park specs for when I finally get to tearing into my spare engine.

[Hounddog]

somebody is getting a little bit mixed up about a 70hp oval port on the dyno in 2004 !!!
I would not be surprised if I was. That was several years ago and the complete process took about an hour. The owner had the outfit there for a bad cdi box. They had the motor on the dyno to test the new box. They were talking about the small carbs. I happened to be there working on our SST 60 race boat. The owner of the marina wondered if the 60 carbs would make a difference on that motor. I had my break in motor 60 carbs with me that is why I knew they had 75 jets. They took off the original carbs and I put on my 60 carbs. That was all we did. We did not do any more and the motor ran fine.

[ferdthe4]

Regardless of what year you did the carb swap and dump test the info is much appreciated. Modifiedoutboard what the heck etec are those reed cages off of been trying to back search the part numbers off the ad to see what engines they were on with no luck.

[filthy phill]

curious as to what carbs are closest to the sst60 carbs I have 1994 stock 70hp oval port rude. A 8-9hp gains with carbs and jets would sure be nice especially in that rpm range since I running a jet lower. curious as to what carbs are closest to the sst60 ones since at least for me those are hard to find and expensive. It has stock carbs right now, I do have a 1987 70hp fishing motor with a prop sitting on a stand are those carbs better than the 1994 ones?

Before you change carbs you might find you have a 60hp oval port. They did not do a 70 oval port jet. Look at the back of the carb and see if it is exactly same size as the front 1.5 inches. If smaller it's a 60hp. Take a pic from front of carb and back and post it. ..

[filthy phill]

Regardless of what year you did the carb swap and dump test the info is much appreciated. Modifiedoutboard what the heck etec are those reed cages off of been trying to back search the part numbers off the ad to see what engines they were on with no luck.
If you knew anything about the oval port you would understand it matters a great deal about that dyno test. The engine was NOT a 70hp. It had the small carbs therefore just the 60hp version. The carb swap for the sst60 carbs just took the motor to the same level as the proper bigger 70hp black top carbs. If you only have the small carbs it is not a 70hp. I have enough sets of black tops here.
Far too much false information about oval ports and their carbs and blocks and heads and porting going around. In the states too many people swapping decals about makes everyone think they have a 70. Mine was 60 until I got the bigger carbs. It made massive difference from low to top end.

[filthy phill]

Those reeds are on 2011 .15hp. 25hp and 30hp e-tecs.

[MODIFIEDOUTBOARD]

Regardless of what year you did the carb swap and dump test the info is much appreciated. Modifiedoutboard what the heck etec are those reed cages off of been trying to back search the part numbers off the ad to see what engines they were on with no luck.

The late model 56ci Omc triples 70hp went to a 1-7/16 dia carb after OMC realized the 1-1/2" was not necessary to make 70hp.
The late model 2 cyl's continued to use the 1-1/2 big carbss and will fit directly and look identical to the 1-7/16 carbs on the outside.
Using SST 60 JETTING Will get you close for a start.

The etec reed cages are a modern BRP version of the ancient cages used in the 56triples.
Square ports eliminate need for porting. They will improve air flow significantly vs old cages.
Get some reeds and jet up a couple of steps �� modify front and jet up more��

[Mike Wienandt]

I have built over 15 national championship winning SST 60s. The last 8 years I have run been about 100 - 102 hp at the crank. We dyno with the exhaust housing and gearcase so we match correct exhaust back pressure. The mod engines I make for lake racers or X class inflatables are now up to 118 hp. This is with stock SST 60 carbs. I'm working on one right now that is very over due. Porting includes finger porting, Boost port reground, A lot of grinding in the transfer ports, Exhaust port reshaping and timing edges of all ports to my own specs. Stock head with welded smaller thermostat hole, then re-machine to smaller ccs and angled squish band added. SST 60 reed pedals and grinding in intake and matching the case. Bored to .030 over with Line2Line coated pistons from Pro Marine. Stock SST 60 tuner. We have over 350 dyno runs doing development work on these. Dyno all computerized so no bull crap. Can't argue with the win history.

[Mike Wienandt]

there are two main kinds of carbs, What I call 2 jet and 3 jet. The 3 jet is from SST 45 and also older 50 ci engines. I have never been able to make 56 ci engine run on the 3 jet carbs correctly.

[Mike Wienandt]

Was reading one of the other posts, The engine has a bad harmonic vibration that you must avoid to prevent damage of the engine. 4000-4300 it shakes so bad it screws up the fuel in the float bowl and the engine will run lean. Also at 8000, DON'T GO THERE. Run best up to 7600-7700. Everyone that I have seem go to 8000 will stick pistons.

[hupiveneilija]

there are two main kinds of carbs, What I call 2 jet and 3 jet. The 3 jet is from SST 45 and also older 50 ci engines. I have never been able to make 56 ci engine run on the 3 jet carbs correctly.

Could it possible be differential in emulsion tubes that causes this? They mix air&gas different. IMO those big variations of mainjets in 56series carbs might be about those tubes been different from carb to another.
Mains differ from 50 to 65 between them. Im talking Bp carbs now.

[ferdthe4]

Before you change carbs you might find you have a 60hp oval port. They did not do a 70 oval port jet. Look at the back of the carb and see if it is exactly same size as the front 1.5 inches. If smaller it's a 60hp. Take a pic from front of carb and back and post it. ..

Phill I'm nearly 100% positive mine is a true 70. It wasn't a factory jet. The engine label on the transom bracket the model number is a 70hp one. It's a 70hp back troller so it was a factory 70hp tiller. When I get a chance I will pull a carb to verify the throat size to be sure. Also if you go back and look hounddog's post about doing the dyno test he said he started with a 70hp. Maybe his memory is off and he had a 60hp or maybe a 60hp labeled as a 70hp. I don't know I wasn't there obviously, but going off his post he said the 70hp oval port made 71hp then they swapped to sst 60 carbs jetted up and made 79hp. When I get a chance I will pull one of my 70hp oval port engine's carbs off which is on my boat and I will also pull a carb from the 1987 56ci 70hp bridgeport to compare. Hopefully I can get to it this evening will just depend as I'm in the midst of moving to a different house and shop.

[LittleCharger]

I have built over 15 national championship winning SST 60s. The last 8 years I have run been about 100 - 102 hp at the crank. We dyno with the exhaust housing and gearcase so we match correct exhaust back pressure. The mod engines I make for lake racers or X class inflatables are now up to 118 hp. This is with stock SST 60 carbs. I'm working on one right now that is very over due. Porting includes finger porting, Boost port reground, A lot of grinding in the transfer ports, Exhaust port reshaping and timing edges of all ports to my own specs. Stock head with welded smaller thermostat hole, then re-machine to smaller ccs and angled squish band added. SST 60 reed pedals and grinding in intake and matching the case. Bored to .030 over with Line2Line coated pistons from Pro Marine. Stock SST 60 tuner. We have over 350 dyno runs doing development work on these. Dyno all computerized so no bull crap. Can't argue with the win history.

Mike for the X motors you build which block do you prefer the oval port or Bridgeport as your base...cheers

[filthy phill]

ferdthe4
No it probably was not a 70hp oval port he saw on the dyno in 2004.

read this from Houndog back in just 2016, 12 years after the dyno test was done. it is very interesting and explains why it was not a 70hp..

" The thought it best to start a thread on this topic. I for one of many thought that the 60 hp and 70 hp carbs were all the same smaller size.
When PPR [Professional Powerboat Racing] made a rule change in FV class to allow the 2000 model 56 oval port in the class it had to run with its original carbs.
That same rule still applies in T850 for any oval port. None of the OMC racers back then ever ran the oval port block in the class.
One racer purchased a new set of 2000 model 70 hp carbs and ran them on his SST60 powerhead. They did not work.
When we see these carbs listed on EBAY they normally say they are for both 60 and 70 hp motors. I have never seen the 70 hp larger bore carbs.
Craig Fraser has a complete 70 hp oval port powerhead?? Dave Elsey has seen the carbs on it and they are larger.
I have a fresh 30 over oval port with carbs. They are the small bore carbs. We need to get the part numbers off Craig's carbs and we need to test those carbs on an oval port.
It could be that the larger carbs were on some but not all 70 hp oval port models. OR we just have not seen a real 70 hp oval port. "
.................................................. .................................................. .................................................. ................................

that explains why it was not fitted with the larger carbs, and that means it was the 60hp version, it also explains why the larger sst60 carbs gave it an extra 8-9hp...
if this had been fitted with the bigger carbs he certainly would of known about them when they got changed over...

Houndog has been a around a few motors so knows his stuff, and for someone like him and a few of his friends to have not seen the bigger carbs on a real 70, just
goes to show that all its not always what it seems. always something to surprise us all.
he is 100% right about carbs being falsely advertised as for 60/70hp motors when they are just the small ones.

[ferdthe4]

Sorry phill I didn't find hounddog's post from 2016 about it I was merely going off what he posted in this thread. I agree that many carbs on ebay are falsely advertised and don't have the throat measurements to verify what they truly are. I will measure a carb off each of my engines one being the one on my boat a 1994 70hp. Being a 1994 it should be a oval port, and according to the model number it's factory 70hp. Can't remember it off the top of my head and I'm not at home to see it, when I get a chance I will see what carbs it has. I will also do the same on the 1987 70hp I have sitting on a stand in the garage to see what carbs it has. I'm hoping that between the two of them one of them has the proper larger carbs 1.5" throat front and back not going to call them 70hp ones anymore since apparently engines sold as 70hp may have come with either or. If I don't have the larger carbs guess I will be searching for them, which from the sounds of it is a pain since most sellers on ebay usually don't have measurements of the inlet and outlet throat to know what your getting or not. I was never trying dispute weather or not hounddog knew his stuff or not, I've appreciated all the info from him and others on here. I'm not new to engine performance, but I am some what new to trying mod outboards, and info on what parts are right is hard to find since aftermarket is nearly non existent in terms of performance parts for these outboards. Not like cars that I'm use to their are more holley carbs, edelbrock carbs, demon etc and various intakes from the aftermarket than you can shake a stick at to choose from. Versus outboards you gotta first figure out what factory stuff was the best then hunt it down and hope you have the right parts in mind and that the ones your buying are listed correctly. I know many of you piles of old engines and parts to mix and match from to figure out what works not the case for me and many others I would imagine, and unfortunately most the parts cost enough to keep me from just buying a ton and just experimenting. Sorry I don't have the money to have a small warehouse of omc triple parts, and to blow up a bunch of engines. Hence why I'm on here trying to get as much info as I can, and it is all very much appreciated. If I could squeeze 80-85 hp reliably out of one of my engines I would be tickled. I'm just a gear head that has a hard time leaving his toys alone.

[filthy phill]

some of the guys on this forum have some extremely powerful motors, and when you watch their videos its unreal what they go like.
I could not believe just how fast they are going, 70mph seems the norm on the racing v hulls !!!
Power wise these fella's have got it nailed big time, they dont just go fast flat out, they come out the corners like bullets.
Untill recently I thought it was all down to gear ratio and smaller gear cases with short mid sections but could not find a reason for this apart from
longshaft being heavier and bigger gearcase is more drag, as the long shaft with its 2.42 can swing a bigger prop.

But the guy named hupiveneilija has got his longshaft going extremely quick and its on a 17ft v hull. over 64mph with 2 people in the boat !!
Now that is fast, what will it do with just 1 person ? and what would that do on a lightweight boat like those running in Canada with the t0noat classes ?.
no idea of how many horse power but it must be very high to get these speeds.

It seems that porting is the way to go and getting rid of the rpm limiter. also the head skim to sst60 spec and what the others have already said can realy
wake up the motors.

people on here will tell you what you need to know if you want to get lots of power, they know their stuff when it comes to modifying outboards.
lots of true racers and engine builders to put you on the right track.

[ferdthe4]

I've read through hupiveneilija mod 70 thread it was very helpful I probably won't go as extreme on porting as going much past 6200 rpm with a jet just doesn't do it much better from what I've heard. I picked up those etec reed cages gonna keep my eyes peeled for another set. Will start there and make sure I have the bigger carbs and shaving the head some and see where that gets me. The oval port on the boat currently is in pretty good shape so I'd rather not tear it down. I may at some point tear down the 87 and do more extensive work on it but that is probably a ways off with life taking place.

[Mike Wienandt]

The best block for mod engines is the early 56 ci permanent mold block, not the foam block. Bridge port, not oval port . I think about 87-88 I have built with all of them . The transfer ports are shaped better and the bridge port allows you to make wider exhaust port. The port timing of All ports is critical, you must measure, there are many different versions. I have not studied the carbs details closely to see why the three jet carb does not work. But watching the fuel flow and BSFC on the dyno I can quickly see it's wrong for this engine.

[LittleCharger]

The best block for mod engines is the early 56 ci permanent mold block, not the foam block. Bridge port, not oval port . I think about 87-88 I have built with all of them . The transfer ports are shaped better and the bridge port allows you to make wider exhaust port. The port timing of All ports is critical, you must measure, there are many different versions. I have not studied the carbs details closely to see why the three jet carb does not work. But watching the fuel flow and BSFC on the dyno I can quickly see it's wrong for this engine.

Thanks Mike that was what I had thought but always nice to hear straight from a top builder of the 3 cylinders...cheers,

[ferdthe4]

Glad I have a 1987 as well. From my reading on the mod 70 build which heads are better to shave. If my memory serves me correct in the mod 70 build the oval port ones didn't require as much decking to get the bowl depth and volume to around sst60 spec. Or maybe I have it backwards and it was the bridgeport ones that were better.

[Mike Wienandt]

When milling the head, if you make it very tight spec the head will flex and not hold head gasket seal. That is one reason why I weld the thermostat hole. To give the head strength there. Would not recommend tighter that SST 60 spec unless you raised the ex port to high. You do not want more than 8.3:1 ECR It will cause engine to slow down as it heat soaks. And certainly good Fuel is required.

[ferdthe4]

When milling the head, if you make it very tight spec the head will flex and not hold head gasket seal. That is one reason why I weld the thermostat hole. To give the head strength there. Would not recommend tighter that SST 60 spec unless you raised the ex port to high. You do not want more than 8.3:1 ECR It will cause engine to slow down as it heat soaks. And certainly good Fuel is required.

I wasn't going to go extreme on the head decking want to be able to run premium pump gas don't wanna have to buy race fuel for my fishing/hunting boat. So I don't even know if I would go as far as sst60 spec

[Hounddog]

Having Mike Wienandt add posts to this thread has confirmed most of the findings posted on other threads about the 3 cylinder 56 cubic inch OMC. The SST 60 is a spec motor and you must use original OMC parts. You cannot alter or modify parts past the given spec measurement. It is more time consuming and usually more costly to build a 100 plus hp SST 60. You MUST find near perfect parts. The motor that Mike builds will only be as good as the parts he has to work with. That being said. Some motors perform better than others. Plus the motor is only one part of a successful winning boat. Many will say the late 80's SST60 motors produced the same power as Mike's motors. A few may have. But there was a wide difference in SST 60 motors. Mike was able to equalize the motors and even out the playing field.
I do think we will see improvement in the oval port motors. The builders have played with the bridge ports since the 1980's and I do not think they have spent a lot of time...YET! playing with the oval port. For the low budget lake runner we have seen first hand in Canada that it is very easy to get good performance out of a stock oval port by just changing the carbs. We have a few T850 boats running over 76 mph, we only had one confirmed that ran over 80 mph and that was an oval port.

[filthy phill]

I read that the early 56 was sandcast blocks then went to lost foam around 1988 - 1989 when the sst60 with its hand finished lost foam block was introduced.
funny how those that worked at omc building the motors would get that wrong .

be nice to know how they used a permanent mold to do the closed engine exhaust.

[Mike Wienandt]

The early 56 block was not sand cast. It was permanent mold. The surface was smooth and shaped very well. The proto type engine tested for SST 60 was made of this, but when the engine was manufactured, it came out as foam block and did not run as fast as the prototype. The permanent mold blocks were never legal as they are faster. The foam block were cheaper to manufacture and issues like the glue lines slowed them down. Ports in the foam blocks were less consistent.
Most engines that come to me are very worn out. I can rebuild with fresh good parts and make them good. But I you say I need to win, it is much harder because then only certain parts are required to do that. Those are hard to find, impossible to make.
I need a good clean block, not hard to find. I use my own special liners. All with in the rules. I can fix the bad boost ports per the rules. But you still have a missing link.

[filthy phill]

Mike Wienandt

would it be better to use the head from the oval port 56 being as its thicker material ? part no 339221 normal thickness is 0.240 (6.096mm) at thermostat area.
if machined down to sst60 spec it still leaves 0.0150 (3.81mm) at the thermostat area, not as ultra thin like some bridgeport 56 heads.
I measured at the thermostat and at the bottom area to see if both the same and they are uniform from what I could see.

[Mike Wienandt]

Yes, that sounds like good idea.

[MODIFIEDOUTBOARD]

I understand what you mean by the cowbell shape and I finally found the thread that had the inlet and outlet size specs of the sst 60 tuner barried in fast freds mod 50 secrets page 76

http://www.boatracingfacts.com/forums/showthread.php?8246-Fast-Fred-s-OMC-Mod-50-secrets-Thread-2/page76

inlet on exhaust base plate 1 1/2" x 1 3/4" outlet 2 3/8" x 2 3/8" what over all length works best in a long shaft mid is what I'm trying to figure out now. I've got a tig welder so welding up my own tuner isn't an issue trying to come up with ball park specs for when I finally get to tearing into my spare engine.

this is for etec 90ho - 75hp triple, looks really close..................................get gasket #6 to verify

http://www.ebay.com/itm/350538-Inner-Exhaust-Megaphone-2004-12-Evinrude-75-90HP-/401285929268?epid=600523232&hash=item5d6e815934:g:3NYAAOSwTM5Yu9EG&vxp=mtr627946279562793

[Mike Wienandt]

Measure the length from powerhead gasket to the end of the tuner. Make it 1" longer than the SST 60 spec for a V bottom. It will have more bottom end yet rev high enough to make you go fast.

[hupiveneilija]

Mike Wienandt

would it be better to use the head from the oval port 56 being as its thicker material ? part no 339221 normal thickness is 0.240 (6.096mm) at thermostat area.
if machined down to sst60 spec it still leaves 0.0150 (3.81mm) at the thermostat area, not as ultra thin like some bridgeport 56 heads.
I measured at the thermostat and at the bottom area to see if both the same and they are uniform from what I could see.

This is what i said somewhere else. I got one yesterday that im going to use next, modded offcourse.

Question: wich headgasket 1mm or 1.5mm? Easiest to get here is thicker sierra but wich is better for squeeze area in this engine? And how thin you can go for it, havent decked block yet.

And thanks for writing those things, really good information and very clear said!

[Mike Wienandt]

Are both head gaskets the same quality material. The really old black OMC ones were best but can't get them anymore. As far as the thickness, Check the squish clearance. Don't want less than .040" or 1mm
Does the piston stick up above the block, any amount then use the 1.5mm
Good luck
Mike

[hupiveneilija]

Thanks,
Jani

[ferdthe4]

Measure the length from powerhead gasket to the end of the tuner. Make it 1" longer than the SST 60 spec for a V bottom. It will have more bottom end yet rev high enough to make you go fast.

Thank you for the advice my issue is still how long are sst 60 exhaust tuners? Maybe I've been looking through all the wrong threads but I haven't been able to find what the length of sst60 tuners are.

[hupiveneilija]

7.69in from powerhead gasket.

[ferdthe4]

7.69in from powerhead gasket.

Awesome thank you very much that is what I needed.

[MODIFIEDOUTBOARD]

7.69in from powerhead gasket.
yep

[Mike Wienandt]

Yep you got guys

[filthy phill]

is the e-tec one a bit too fat at the top though ?

the volume of the e-tec looks miles bigger from the pictures than a similar one for sst motor like heavy kevi makes.

it only has to be a couple of mm in each direction and it will be miles out.

any dimensions of this one ?
.

[filthy phill]

Measure the length from powerhead gasket to the end of the tuner. Make it 1" longer than the SST 60 spec for a V bottom. It will have more bottom end yet rev high enough to make you go fast.

Please dont think I knocking you mike, I am not, I am
just trying to clear something up.
if this exhaust is going on a longshaft that has a different adaptor plate thickness I believe ( could be wrong , again ) wouldn't the tuner length need to be different yet again
especially if running on a fishing boat .?
I understand this is correct length on a short mid for v bottom, but if fitted on the longer 20 inch mid what should the length then be ?
I ask as its dealing with a totally different gear ratio and going inside the longer bigger can,

Most people doing the tuner mod will be running the short mid and the 1.86 ratio on race boats rather than 20" with 2.42 on a average speedboat/fishing boat.

.

[Mike Wienandt]

No problem Phil. Im going to guess here but I think for best engine performance the tuner length to powerhead should be maintained. For a 20 " would usually be on a larger boat that would require more bottom end power to get it up. If your application only runs 6200, my pipe numbers are to short. I know those numbers are great for running 7400. You do not want to run over 7800 in any application. You can't get a Jet to turn those rpms. Typical longer pipe gives you more low end power, but can limit the top rpm ability. As you shorten it to get higher rpms, you will loose bottom end power, The torque peak is moving up. You have to decide what your application can tolerate. Hope this helps.

[MODIFIEDOUTBOARD]

6280062799 close enough to "modify" it is tapered

[hupiveneilija]

Ive spun mine 7800 with stock tuner. Boat went 57.5kn. It doesnt need to be cut at all if you dont like.

[Mike Wienandt]

If you can pull a good prop load at 7800 rpms, I would agree don't shorten it. With the longer pipe it will, get on plane better and have more low end power with the long pipe. you may want to bring your rpms down and try bigger prop yet. I could see that working in drag applications. There it's all about acceleration, over reving out the back door does not matter as much.

[hupiveneilija]

Yes i know. Now i have same ph in place with shortened tuner, no proplem on going plane. Have to see how it goes when i get jetting right.
And im short of prop for now.

[skeg]

Great thread

[filthy phill]

its surprising how an engine thats been around for 30 years still gets so much interest and is still about the best bang for its size.
I know mercury have their 60 that can be hotted up, but it still cant beat a real hot 56, and out last it in normal recreational guise.

when anyone says johnson or evinrude the mind thinks of the mighty 3 cylinder,
when people say mercury you automatically think of the tower of power,
when they say Force it reminds you to take out the rubbish .

/

[ferdthe4]

The thing that gets the mercury 60hp 3 cylinders which started as 53ci roughly then got bumped to 59ci in the late 90's was they were a blind bore so you can't shave the head to bump compression up easily. They were good engines I had a early 90's 60hp merc for a little while didn't hop it up at all but it ran well. The omc triples are just hard to beat for the power to weight and price. The larger three cylinder yamaha's are great the 70-90hp ones, but I don't have one because they seem to command pretty high dollar for a good one. Enough so for a decent tiller version that I would almost just consider a new FI four stroke as much as I hate to say it. That and I've just been partial to omc starting with my first outboard I acquired in college for nothing was a 1965 johnson 9.9 that I fixed up and used through most of college hunting and fishing. I beat the hell out of that motor friend of mine still has it and uses it to this day on a little fishing/hunting boat. All I did on it was replace points rebuilt the carb and she never failed. After that I had 1975 25hp johnson, then 1988 johnson 40hp two cylinder, then a nissan 40hp three cylinder, then the merc which I put a jet lower on, and now the evinrude 70 which I'm wanting to mod some. Hadn't modified any of my outboards in the past just repaired them. Just about all of them didn't run when I first got them. Sorry I still haven't gotten to measuring the carbs on my engines I need to just been busy moving things, working on and fixing up the new place you know that annoying thing known as life that gets in the way of fun stuff.

[filthy phill]

yeah I had one of the 1991/2 model year mercury 60hp, fantastic engine idled great ,good amount of power and surprisingly good on fuel.
u did not know until I got it that the heads could not come off or would never of got it.
But it came on a boat /engine trailer package that was all like new for a good sensible price.
I have had a few of the 49ci omc and can say that they were more powerful than the merc but not as smooth on the idle and all around reliability.
I find the 1995 oval port 56 miles ahead of the mercury 60 of the early 90's and also more powerful than the later mercury offerings.


with your lower unit being a jet, if you modify the motor for more power you can just have the impeller in the jet pitched up a bit to give more speed and thrust.
from what I have read too many rpm is not a good thing for the jet housings/bearings ?? dont realy know about that as plenty of the jets went into military use.

its nice when people on here walk you through everything they have done to the powerhead to get the realy high power from the motors, but we need to
remember that most of these guys race and are not worried about re-building every few weeks (sometimes each race meeting).
I like longevity and just a little more power and put a lasting engine 1st.
A lot of the performance on the motors seems to come from just cleaning stuff up like bad casting marks, this can only be a good thing for any motor.

[filthy phill]

Tried to make a new thread but the forum is not letting me
today I measured port specs on my oval port spare block. I got some very surprising results and measured it loads of times to make sure of accuracy.
What I found might help some people who are looking to modify their oval port, and or save them stripping one down to see what is in there or not .

I measured all the ports on my 1995 oval port 56 motor. Cylinder block part number 0436908
I have read on a few places about how much smaller the oval exhaust is compared to the bridgeport exhaust. !!!....err thats is not exactly true if we are talking of area of the exhaust ...
Maybe some blocks are different ? I dont know and can only say what is here is exactly what I have in front of me.

The standard fishing motor oval exhaust is WIDER than the sst60 spec for APBA, the other ports are also slightly wider. ?
here is the results
sst60 exhaust width of each port is 1.075 x 2 = 2.150..........oval exhaust width is 2.185039 ( 30.5 thou wider )
sst60 Boost port max width is 1.255...................................oval port boost port is 1.29921. ( 44 though wider )
sst60 Transfer port max width is 1.5800........................... oval port Transfer width 1.633858. ( 55 thou wider )

Some of the heights of the ports on SST60 are higher by a fair bit , but there is room to take any or all of ports to the same height.

Sst60 exhaust port height is min 1.450 and max height 1.520...........oval port height is 1.500 standard ( lower by 50 thou )
sst60 boost port height min.....1.860 and max height 1.950..............oval port boost port height 1.88976 ( within sst60 spec )
sst60 transfer port height min. 1.825 . and max height 1.890...........oval port transfer port height 1.948819 ( lower by 104 thou)

Not sure if the sst60 measurement for transfer top is with or without chamfer ???

exhaust and transfer port roofs are up a fair bit higher than the sleeves, so are capable of being taken up to sst60 spec.


Going by these measurements, with a bit of work on the exhaust and a touch on the transfer port height, the oval port would be able to breath a lot better.


ALL the ports behind the sleeves need to be cleaned up a lot and the sleeves themselves have some terrible edges on some of the tops of the ports that are
more like a serrated knife edge than a proper nice clean port, they definitely could do with cleaning up.
OMC did not take any care when assembling the 56 oval port motors, no attention paid to detail at all.
Sleeves look like they have been put in without them being finished off.

The exhaust outlet to afaptor from the bottom of the block itself needs to be cleaned up inside as far as possible to get rid of some very bad casting
marks, this can be done with a small flexible shaft and small wire brushes/wheels etc, not an easy task but it would pay off big time to let the gases flow better.
with the use of a tiny endoscope ( very cheap on ebay with 6 built in lights) a lot can be done to the exhaust as in polish it up to flow better.

for those who might be interested, I have made a sort of port map drawing to show the oval port versus the SST60 spec for APBA rules..
( nothing like true map or scale) just to show the port sizes and heights. sst60 specs in the blue boxes.

[filthy phill]

For anyone interest here below is a diagram of the port heights on the 56 ci Oval port motor from 1993 onwards ( not to scale ) it shows
the oval port heights and SST60 heights.
Also showing some recommended heights (m.w) to allow it to rev higher and raise the powerband range.

.
62851

[Davidblanchard]

I believe I still have the port angle gauges I used when porting this engine while working for the OMC race group years ago . i do not remember the exhaust port beging oval like that ? when I did it it had more of an " eye brow " shape to it.. the exhaust chamfer looks good ...

[filthy phill]

No the port is not that shape, thats only my drawings , dont take too much notice of the shape. I am not an artist by a long way ha ha
here below is a real pic of the Exhaust port.
with this pic you can clearly seethe bottom is a lot narrower than the top, I think keep similar shape just go wider with the port by about 1.5 to 2mm each side,

Below the Exhaust Port pic is a picture of the Boost Port, and this shows the wonderful "Glue Lines" strategically put in by OMC to keep everyone happy !!!

.62853
.
.

Here is the things so many people talk about, the dreaded "GLUE LINES.. these realy are a problem and are on all the 56 oval ports, all the bridgeport motors made by the
lost foam process including the sst60 motors. these glue lines are pretty easy to get rid of, just as well because there are loads of them in the blocks that can all be got rid of.

.62854

.
:cool:

[filthy phill]

Davidblanchard
you said "I believe I still have the port angle gauges I used when porting this engine while working for the OMC race group years ago"
Does this mean you had a race version of the oval port motor in the planning ?

[Fastjeff57]

What is that "glue"?

Jeff

[filthy phill]

It is not glue, it is the glue lines.
When they use lost foam to cast the blocks the foam is in layers glued together. Glue spills out when it's pressed and drys.
Then when the alloy is cast it also casts in the glue lines. These lines vary due to amount of glue pushed out, some are ridiculously bad. Even the sst60 race engines come with glue lines.. it is pretty easy to remove if you have the block stripped down.

[filthy phill]

It is not just the internals that get left with nasty looking marks, the outside is not a work of art by a long way.
The later cylinder heads also have these stupid " lines" on the outside, it fools many people into thinking the head is a 3 part piece when its just one solid piece.
The lines on the heads look like they are gaskets sticking out the sides. took a mould of a head with the gaskets on then just copied, no time taken to finish them off to look nice.
Pretty poor show from a once great motor manufacturer.

here is what I mean.

.62855

mine will have all this crap taken off and maybe polished up like a mirror or maybe sand blast finish. /

[LittleCharger]

For anyone interest here below is a diagram of the port heights on the 56 ci Oval port motor from 1993 onwards ( not to scale ) it shows
the oval port heights and SST60 heights.
Also showing some recommended heights (m.w) to allow it to rev higher and raise the powerband range.


.
62851

You need the deck heights as well to make things relevant

[filthy phill]

I will re- measure again tomorrow, as I have written down in a couple of places the deck height cannot be right
so will re-measure that again tomorrow with 2 different sets of callipers to make sure.

[filthy phill]

ok been down and measured the deck height of my spare block, got some pretty surprising results, so checked it 3 times with 5 different sets of callipers.
the cheap and expensive make analogue callipers are mine, but the others belong to a machinist.
(I was very surprised how accurate the cheap digital ones are, I expected them to be way out. )..

temp in garage is 63 deg F ..

1, Analogue callipers (my cheapo cheap make) .............. 6.345, 6,350, 6.351. ( head moves around a bit )
2. Analogue callipers (moore and wright)........................ 6.3501, 6.3501. 6.3501
3. Digital callipers (cheap make ).................................. 6.3502, 6.3501, 6.3501
4. Digital callipers (expensive Japanese ) ....................... 6.3500, 6.3500, 6.3500
5. Digital callipers Neiko ( never heard of them before).... 6.3500, 6.3500, 6.3501.

so after all these measurements I would say the deck height is 6.350 inches... that was the biggest surprise to me.
the reason I done it again today was because I had it written down as 6.300 and was sure this had to be wrong..( it was wrong by 50 thou).

Now I know there will be people who say this is not right, but I can assure you it is exactly what it is. I would of thought it to be bigger ?

.

[ferdthe4]

phil thanks for the measurements, and port picture helps a lot. Sorry been busier than a one legged man in a hookey pookey dancing contest lately. still need to measure my two engines carbs to see what they have.

[Davidblanchard]

What is that "glue"?

Jeff

When the block was made it was first pieces of foam they " glue " the foam together using wax.
during that process they do not try to remove the excess wax and because of that this is what you see .

I remember asking about that . and at that time they just looked at me like i was crazy. I believe the comment was

" So you want us to hand remove all excess wax from the bock ???? ALL OF THE ???"

[Davidblanchard]

that's because when the glue it the foam parts touch a " glue plate " that come up out a hot bath of wax and touches off on the foam
part and the assembled to its mate for cooling . timing and temperature are everything here . and that was not controlled very well at the time




It is not glue, it is the glue lines.
When they use lost foam to cast the blocks the foam is in layers glued together. Glue spills out when it's pressed and drys.
Then when the alloy is cast it also casts in the glue lines. These lines vary due to amount of glue pushed out, some are ridiculously bad. Even the sst60 race engines come with glue lines.. it is pretty easy to remove if you have the block stripped down.

[filthy phill]

if a brand new motor was offered at a very low price it could of been expected, but the omc motors were NOT cheap and it was dreadful to send the motors out like this.
I mean seriously how long would it actually take to clean up atleast the glue lines in the port areas with a grinder on a production line before sleeves went in ? 10 minutes per block, no more than that.
I am not talking of perfectly polished ports, but atleast to an acceptable degree.
They could not even be bothered to line up the sleeves correctly, it realy is a wonder they did not go bust a long time before they did.

Being as omc were trying their best to keep emission's down to keep the government's happy this alone could of helped a long way, if the engine breathes easier the emission's are less, as too is
fuel consumption and longevity.
Even the SST60 racing blocks came out with the lines in all the port holes and everywhere else the same as fishing motors, such a shame .

.

[88workcar]

I would like to speak to a few of you guys, I'm in Louisiana, text me your numbers if you will, just text your name. I can talk best from 5am to 4pm mon-fri if that works for any of you. I have to build a 56 and want it right. It will be for a 13' Allison to drag race 660'. Thanks Jason, 985-519-0367

[88workcar]

I have Mike's shop number but have not reached him, left a few messages.