seadooaddiction
Active Member
Sorry, not sure what u mean.
XPL Coffman build - 7760 rpm
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seadooaddiction
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I just got my motor ported by my local machinist. He had already port matched the exhaust to the sleeve on the the 1st rebuild, that alone made a noticeable difference. This off season I asked him to port the motor to what he thought best for a go fast buoy boat. Well see how his mods work in a few weeks.
Here's a number of photos.
Bottom of cylinders
Through the the exhaust manifold. Trimmed and matched gaskets as well.
Exhaust port:
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Can I just have this?
seadooaddiction
Active Member
Haha. But then what would I have?
Well you would "have" to do it all over again haha.
seadooaddiction
Active Member
He definitely raised the exhaust ports and changed the port timing a little but he's been doing it for a number of years. He also apparently uses a computer program to figure out timing and duration etc. The one thing he did differently which I haven't heard of before was using shims in the raves. Apparently he's able to control the timing of the them and also help align things nicely when valve is closed/open.
seadooaddiction
Active Member
Well ironic enough I am gonna have to do it all over again when I use the 1020 pistons I have sitting on my bench.
Keep me in mind then. I really like the work. I'm gonna have to do some 951 conversions in the future to keep up with those Kawi 1100 guys.
seadooaddiction
Active Member
You got it. Last season this thing would smoke a blaster 1100 on the straights. On the course if it was ahead it'd catch up to the 1100 on every corner. I'm not the best racer so still hard to overtake and those little things can turn. But would handily keep it at bay if the 1100 was chasing.
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seadooaddiction
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Typically his 951 porting is $250-$350. Which he says is too cheap haha.
His port matching last season was only $100 and that gave me 150 additional revs.
This port job was $250 with materials for shims, trimming the gaskets and matching the exhaust manifold runners.
mandriva
Active Member
Have tsr racing software! With this software, he calcul correct exhaust port duration,also lenght exhaust... ratio compression, build pipe, max speed piston......eric gorr is reputable guy's. http://www.off-road.gr/News-article-sid-25-mode-thread.html
seadooaddiction
Active Member
150 psi each cylinder.
Looking good. I like those Rossier heads myself.
seadooaddiction
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Yeah I've had good results with running them so far. Squish measured out perfect. 0.068" - 0.070" each cylinder.
seadooaddiction
Active Member
Prepping the racey "vintage" intake manifolds.
This one cracked me up. Feel like the boost bottle ports are pretty good indicator...
This one cracked me up. Feel like the boost bottle ports are pretty good indicator...
seadooaddiction
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Couple photos of the intake port work.
seadooaddiction
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The goodies!
seadooaddiction
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seadooaddiction
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First test run of the season and on very first fire on the water; kaboom!
seadooaddiction
Active Member
Yup. Luckily I have two spares. The boost bottle setup is becoming suspect. I will also be pulling and examining reeds as a result.
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