will the engine blow up?????

overkill131313

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well I have a blown up 809 triple (crankshop race engine)....one dead cylinder and piston, and a screwed head!......and one dead 779 (stock) with a bent rod, but top end is good.....I was going to save some money to get a new crank for the 809 and put the stock 779 top end on.....well no money saved yet so I'm going to put the stock top end on the race 809 bottom end.......how long will the crank last????? go until it wont go anymore.....the kid wants to sled and I need to get my sled running since I sold the turbo tank last summer.....really how can one tell if a crank is bad? engine still ran on 2 cylinder and still beat a 700 side by side.....but I know a lot went through the engine.....not much left of the piston....my next question is what base gasket do I use? the one that the race engine had or the one that the stock engine had??? Im going to be putting a stock head on it also so I don't have to run race fuel....not much left of the shaved head that was on the race engine.....do I just check the squish? and how much should I have? a million questions but worst case I build the engine and crank goes.....then I need to buy a crank....but wondering if it will run.....lol any info would be great from the triple guys!
 

pfi572

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Call Ralph @ 1 (780) 524-4330
Split Second Performance
He will help you out.
Good luck
 

overkill131313

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I hate phoning people cause their time is money.....I don't want to waste their time.....just looking for some "Cheap" info.......lol I really should just give the block to someone and do it right but no money.....
Call Ralph @ 1 (780) 524-4330
Split Second Performance
He will help you out.
Good luck
 

slededjr

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If I'm understanding your write up correctly, you want to put a stock 780 top end on a ported 809 bottom end? If so you can do it. Both have the same 68mm stroke. As far as base gaskets go, try the stock size first, there should be holes punched in each to tell you the thickness. You don't want to have a squish any tighter than .060". Your jetting will most likely have to be altered due to the bottom end being ported. Try everything stock but the main up two sizes to be safe.
 

CUSO

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I would be cautious about this.
the cooling jackets are different and the 779 has a steel bore opposed to the nikasil.

Funny thing, I have a 779 with a squeaked piston, bottom end is fine. Future go-cart project.
 

overkill131313

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well the crankshop race engine is really a 779 bottom end with a nikasil 809 top end.....so the stock 779 top end I know will fit......do you want to sell your 779 bottom end down the road? lol
 

overkill131313

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yep remove the 809 top end and put on a stock 779 top end....which base gasket do you mean "stock" I know you count the holes but the race one is different that the stock top end.....I will have to go count the holes again but I know they were different
If I'm understanding your write up correctly, you want to put a stock 780 top end on a ported 809 bottom end? If so you can do it. Both have the same 68mm stroke. As far as base gaskets go, try the stock size first, there should be holes punched in each to tell you the thickness. You don't want to have a squish any tighter than .060". Your jetting will most likely have to be altered due to the bottom end being ported. Try everything stock but the main up two sizes to be safe.
 

overkill131313

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do I just use the right base gasket to get the right squish....I know the base gasket affects the port timing and I heard the triple likes as big as you can go and shave the head to the right squish but I just want a running engine....not a 215 hp race fuel engine that it was! lol
 

overkill131313

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I just opened up the new gasket kit and there is only one base gasket.....and it has no holes.....I just went out to look at the other 2 engines and they have no holes either......it has been 2 years since I looked at these engines but I thought they were different......guess it gets the one I have in it! lol that makes it easy.....how do I change the squish then on these triples....I know twins have the holes in the gasket to count
 
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DRD

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If you are using a stock head the gasket in the kit should be ok, give it a quick measure to be sure it's not on the tight side.

If memory serves the case was probably bored to fit the 809 top end, watch the gasket and jug alignment.
 

slededjr

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Exactly. Measure the gasket to see what it is. Install and torque the cylinders and head then measure squish. If too tight use thicker base gasket.
 

overkill131313

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its been years and yes my mind is playing tricks on me as I get older....I forget everything.....lol so do I just put a piece of solder down the spark plug hole until it hits the cylinder wall and turn the engine over by hand then pull it out and measure it with micrometer?
 

DRD

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Head is 22, jugs are 21, I just torque everything 22, your wrench isn't good enough to tell the difference.
 

CUSO

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I might entertain an offer.. Maybe a trade for some lights?

well the crankshop race engine is really a 779 bottom end with a nikasil 809 top end.....so the stock 779 top end I know will fit......do you want to sell your 779 bottom end down the road? lol
 

overkill131313

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I remember what the difference in the base gaskets was now after having both apart today......the stock 779 has a .020 base gasket and the race engine has a .080 shim with 2 base gaskets adding up to .100 ish.....the head looks like it was cut down .130......the set up now I have is stock 779 gasket of the old engine is .020 and the new one in the gasket kit is .015....what is the tolerance on the squish??? .060 plus????? trying to figure out which one to use? lol
 

DRD

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I'd go at least .070 or so to be safe. I ran a stock head on my race gas 809 for a few days, squish was huge, .090" solder didn't even touch, compression was down around 100 and it still hauled azz.
 
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