Here are couple of pictures for powerhead. I have also weighted rods and pistons, they are within .5grams the same. Crankshaft and flywheel are on the way.
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Here are couple of pictures for powerhead. I have also weighted rods and pistons, they are within .5grams the same. Crankshaft and flywheel are on the way.
Are you going to blend the exhaust ports in the pic it looks like some mismatch still between block and sleeve.
will be interesting to see how those heads work. You may need head studs if the compression is real high as then tend to blow head gaskets without them
They are matched, picture may lie. I dont know what psi will be but head maker did it so that the compressionratio is aprx. 7.2:1, i think, with stock ex.port. Since I have raised the ports its lower now.
edit; I think he said that stock comp ratio was 5.9:1.
what is that metal wall behind the exhaust bridge ?
not seen this before, my block definitely dont have a wall behind the exhaust port.
did you put this there ?
what ?
are you saying this is normal for the 56 bridgeports to have this thick dividing wall in the exhaust behind the liner ?.
so this means the blocks used for bridgeports are not the same as oval port and sst60 motors.
Its the same lostfoam cast as sst60.
its is cast in the same way as SST60 yes, but it is NOT from the same casting as the 60/70hp fishing motor. they are different.
plus the sst60 also different height of block from top to bottom.. piston go over the top of the block on sst60. they do not go higher on normal block.
different casting numbers on the blocks too.
Phillnjack - I mean Filthy Phill,
The reason the deck heights are different and pistons stick up past the deck is from people machining them to the minimum specs and using the longest allowable rods and cranks with maximum throw allowed. The bridgeport blocks are the same. Different sleeves. It's called a bridgeport because of the bridge in the middle of the exhaust port. The oval port is called an oval port because of the oval shaped exhaust port.
Kevin
hupiveneilija,
Did you have any problems with the head warping when you welded up the chambers?
Kevin
con rods for sst60 are same as 70hp bridgeport. part number 394462 same length no different.
piston no for sst60 and 70hp bridgeport part no 394461 same pistons.
crankshaft for sst60 is what was used on 65, 70, 75 hp to 1986 (after that fishing motors went to multi spline) part number 328788 same throw 4 splines.
these are all omc specs and part numbers.
so no idea where the myth of the long rods and longer throw cranks come from.
I do know that is what fast fred would use in a special mod 50, but not what omc used for the sst60 motor.
Yes, they are the same connecting rods and cranks. No, they are not all the same size. Everything has a tolerance. This is why guys pull apart piles of engines to build one.
not talking about guys trying to re-create a sst60 and building one up, were talking about a genuine OMC sst60 block being different to a fishing motor block.
would it realy
what about the large gap where the SST60 piston normally goes into the head.
Genuine sst60 head is not flat like the fishing motor head, it has a recess for the piston to enter.
I would of thought compression is going to be pretty low with this head on a fishing block thats NOT been decked to allow piston entry into the head.
.
what ?
you saying that you could put a fishing motor head on a genuine sst60 and the piston would not hit the head ?
I really dont know, havent done myself, sorry.
I was wondering FastFreds "most positive trough" comment while ago, but then it opened to me😂. Toleranses. Thats why you need piles of motors as said.
I have worked with one I got, allthough I got one spare yesterday to play with if Ive done something really wrong, like transfer timing😊.
Some stuffing.
are these white plastic cards staying on
and what is that blue filler
Yes they stay, are between reedstops and frontpiece. Dont go anywhere.
Blue thing is marine epoxy. Same stuff on the crankcase.
What about egt meter for a tuning aid? Any help with that. And is there some target temp to aim or is it dependable for the mods i have made?
temp needs to be 140 ish if its too low its going to wear out fast. the 56 usually keeps good temp as long as good thermostat is in the motor.
DO NOT RUN WITHOUT THERMOSTAT.
Egt; ExhaustGasTemperature!
I'll quote Dave Bush on this one
"Pyros are a good reference tool
Yes and no. Most likely it will be dead before you see any temp changes even with fast pyros if bad detonation is happening. Temps usually drop a little then it dies. Sometimes you see a slow rise then the drop... Bottom line we have found when lake testing you have to take the time to do it the old fashion way and look at the piston tops and spark plugs period. A few minutes here saves thousands. Forget about the pyro. Pyro placement is a complicated thing in itself. Also, we have found you need a pyro in each cyl. with a fast hertz logging rate to do it right. If you can , do it,it is good info but it wont keep things from blowing up. Only you can. Or if you have det sensing you see it in real time (and if detonation is present) you simply let off the gas, change the fuel or timing and watch the rattle go away..We used to hurt alot of parts when living only by the Pyro. Now we look at it more for reference for cylinder to cylinder mapping. Hope that helps..... "
Thank You LC, just what I wanted to hear.
will you be putting finger ports in this motor ? if so how will you be doing that.
Things go forward. Just use grease to get those needles in place. Foto will show how ive grinded rods to be even. Use old pistons with new rings and honed the sylinders.
Was it a flex hone with small balls or 3 leg hone.
Are you sure the rods are still good at the crank end on the inside ? From pic looks like chrome has worn away.
Back together! Waiting for going back to the boat and startup. Have some work with the boat because transom has been done completely new and also have to blueprint the hull.
Has anybody tried those newer 70hp carbs with black plastic top? Are they worth nothing compairing to the older version?
Also went older pack with appropriate stator. Should be unlimited.
Really exited to see how it works, or dont😬.
Be interesting to see if it goes with that cylinder head, from the tiny size of combustion area it looks very strange .
have checked to see how many cc it is ? and what is the cranking compression now ?
will you run the engine on the stand for a while before putting on boat to run it in nice and slowly ?
That is the boat where the 70mod is going to.
that should be good for about 50 to 52mph with your mod engine. at around 6500 rpm with a good 23 pitch prop.
what make is the jack plate ? or did you make that yourself ?
i have never seen one the same as that before.. looks realy good.
the boat looks familiar, pretty sure i have seen these in the uk too, they look nice and sharp, plenty of rails so should be good in the rough stuff.
looks like its going to be a real good offshore racer, plus looks good even in the garage.
If you had a pad on that deep Vee it would run faster and be more stable (minimal lateral rocking) at speed. The right pad dimensions will reduce water drag. The pad would require a higher engine set since to do it would remove some of the bottom Vee.
Details here on why a pad:
http://www.aeromarineresearch.com/pu...B_jun2011.html
complete article available from Jim Russell see lower left of article.
If it is that slow, then i have to put stock motor back to the boat. It went 57.5mph with it.
if you got 57mph with the boat and motor why on earth have you stripped it down ?
what speed and rpm are you expecting to get from the boat motor combo ?
and what size prop ?
I dont know, for fun? Or maybe i want to try if i can make my motor rev higher and go faster. Go figure..
is the boat an Argo 16 or Argo 15 ?
Its 17. By the way, jackplate is Panther450.