Thread: Johnson "70mod"

  1. #211
    Team Member hupiveneilija's Avatar
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    Water, water everywhere! And thereby seized #3.
    Thats racing😂😂
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  2. #212
    Team Member hupiveneilija's Avatar
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    Nice to have mid open also. This might block water flow a little.

    And tuner, stock left i mean down😂, picture is wrong way and other one is already shortened little but have to take little more off of the end.
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  3. #213
    Team Member hupiveneilija's Avatar
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    Okay, tuner finished! Does it look about right?
    2nd pic is cutline comparison.
    Now its time to zzzzzzz. Good night!
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  4. #214
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    length is about right for a tunnel from what I have been told on the tuners.
    But the end needs to have a flair or bell end shape etc, its to do with resonance flowing out whatever that is ha ha .

    hope i am wrong on that.
    i would of split the exhaust and put a v in each side to bring it more like the original sst60 if possible.

    what is all that welding thats been done on the exhaust lying on its side.

    by the way sorry to hear you killed the motor.

  5. #215
    Team Member hupiveneilija's Avatar
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    Alive, again! 😂😂
    Cleaned block, 0,513 head, little less ex timing.
    Tomorrow testing day for the motor and new l/u. See how it goes.

    https://youtu.be/D5BrTmrL4o0
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  6. #216
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    Did this block need new rings ?
    and did you hone it again ?

    If you were here you could skim my spare oval port head for me and then you could give that a try to see if that is
    what you need for sure.
    this needs about 0.80 thou to be taken off, maybe even 0.100 to get rid of marks caused by a broken ring.
    this will then give me a lot more compression at around 160 to 170 psi as I want to keep the reliefs for very slow running too.
    160 -170 psi would be good on my engine for wake boarding, it is good at low end now, but can never have too much torque for boarding and slow trick ski-ing... might even give me an extra few rpm up top end.

    Just for extra reference .
    I just weighed the oval port cylinder head. bare head without thermostat cover =2 kilo plus 2 grams
    ( 4 pounds 7 ounces ).

  7. #217
    Team Member hupiveneilija's Avatar
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    Went to the ramp while ago to adjust ign timing.
    Now i know what propably broke those headgaskets and how it sounds when there is too much ign advance! Ive managed to "sössiä,sohlata" with timing real bad on blue one. Now i put set screw in same lenght as blue had and daughter put foot to the pedal, voila' that same sound and adv around 27*, cant handle that much😂.

    Timing adj 19*max and now it sounds good and feels really good. With my testprop boat on trailer it takes 6500rpm and noticed that butterflies arent even fully open.👍
    Oh and changed cam on the carbs, put alu instead newer plastic one. Those are different profiles.

    So exited to see how it performs tomorrow!

    Its different block, i have few.

    Btw, with sierra 1.5mm gasket it worked but when put 1mm gasket on it was too much.
    But anyway be careful when adjusting timing, ive done something wrong in that procedure and thereby have had these problems ive got.

  8. #218
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    so basically this is normal 1991 cylinder head on a 56 block with just the exhaust raised ? and other ports cleaned up. ?
    should be real nice once its run-in.
    19 degree timing is 2 degree different ?
    why run at 19 instead of the correct 17 degree ?............what is the max advance timing on sst60 ?

    I hope this one is good for you, you have done a lot of work and have tried very hard to get to your goal.

    need video of this engine going nice .

  9. #219
    Team Member hupiveneilija's Avatar
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    And one more, retorque those head bolts 2to 3 times after warming the engine. When i put that sierra gasket in place and tightened bolts 1 round and right after that 2nd round,
    they went quite alot again.

  10. #220
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    Hi,
    How much water pressure block can take? Or is there somekind of a upper limit? How much head gasket can take abuse from high pressure?
    Ive got 1.5to1.9 in fullspeed and motor is 40*c after wot run. so i need to tighten the relief pressure spring to get flow little less and temp up.

    Needle goes between those numbers because it was REALLY ruf water today, wind is awful.

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