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
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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
Looks like nobody is biting :cool:
95hp
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.
Remember what rpms was that?
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?
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.
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.
somebody is getting a little bit mixed up about a 70hp oval port on the dyno in 2004 !!!
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 Attachment 62770
http://www.ebay.com/itm/SMA5169-Evin...19.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
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.
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................
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.
Attachment 62773Attachment 62772Attachment 62772Attachment 62792Attachment 62773
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 .........................................Attachment 62773Attachment 62798Attachment 62772Attachment 62797Attachment 62792
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/forum...hread-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.
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.
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.
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. ..
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.
Those reeds are on 2011 .15hp. 25hp and 30hp e-tecs.
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
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.
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.
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.
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.
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.
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. "
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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.
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.
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.
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.
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.
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.
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.
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.