gx390 builld

[gman3850]

well sense i already have everything lined up on my kart instead of buying a built vc460 im just going to be building my gx390. been running the engine on and off one of my buddies cart this summer and it fiannly started loosing power, diag was low compression so it it getting to be built.

so this is what i plan on doing
gx390 block
p&p head
1.3 rockers
manton push rods
65lb springs
aluminum retainers
.020 head gasket
new piston
arc rod
69mm stroker crank
246 dur 260 lift cam
billet adjustable flywheel
30mm cvk carb w/ accel pump

now my question on this is when doing the 69 stroker crank how much needs to be cut off the top of the piston to be able to work?

 

[MancoGX390]

That should be one **** of a 390!

 

[MatthewD]

Is this for you Dingo 285?

 

[landuse]

Did i hear someone say overkill??

 

[gman3850]

Did i hear someone say overkill??

Maybe you did. and this is for my big red kart that started out as a manco 706b that is being turned into a 1 seater

 

[OzFab]

so this is what i plan on doing
gx390 block
p&p head
1.3 rockers
manton push rods
65lb springs
aluminum retainers
.020 head gasket
new piston
arc rod
69mm stroker crank
246 dur 260 lift cam
billet adjustable flywheel
30mm cvk carb w/ accel pump

Strange, I don't see any mention of rings...

how much needs to be cut off the top of the piston to be able to work?

Umm, NOTHING! YOU DON'T ALTER THE PISTON, YOU BUY THE APPROPRIATE PISTON, CRANK & ROD COMBO! As soon as you start messing with the piston, you're asking for a catastrophic failure

 

[gman3850]

Strange, I don't see any mention of rings...



Umm, NOTHING! YOU DON'T ALTER THE PISTON, YOU BUY THE APPROPRIATE PISTON, CRANK & ROD COMBO! As soon as you start messing with the piston, you're asking for a catastrophic failure

rings are accommodated with the piston and people mill these pistons to be flat tops all the time. The kart racing site and omb have alot of people milling anywhere from .04 to .08

 

[tazmannusa]

I've seen enough holes in pistons to agree with Fab on that one, unless it is the only option and there is money at the end of the race

 

[OzFab]

people mill these pistons to be flat tops all the time. The kart racing site and omb have alot of people milling anywhere from .04 to .08

Well then, I suggest you go ask them; I doubt you'll get a better response here...

.04 to .08 what? inches, metres, pork chops?

 

[gman3850]

Well I might just stay with the Honda crank and save my self the trouble than. And if I'm not gonna do that I'm gonna hold off on the flywheel and keep it under 5500. Save a bunch of money and still be a *****en motor.

 

[MancoGX390]

Well considering what I have which apart from a exhaust and air filter upgraded a "stock" GX390 it's already a beast!