gx270/gx390 crank swap?

[danny n]

i came across a good running 270 and thought about doing a little modification to it, but i was told that the block is the same as a 390 all i would need to do is change the crank, i would rather build a 390 than the 270, does any body now if this is true?

 

[jprice]

good question, i was looking into the 11hp motor,and on that one it seems the only difference is the piston.
:shrug:

 

[Strigoi]

i wonder if they have a different stroke like the GX160/GX200 engines do.

if you have both cases, count the fins and see if they have the same amount.

 

[danny n]

iam pretty sure the stroke and bore is different, but iam not sure if the crank bearings are different , if so you will have to grind the crank down to fit the 270 bearings, and maybe grind some of the block inside to clear,i only have the 270 block, so i can't compare the two, i was going by the local tool rental or lawn mower shop to see if the maybe they had an old 13 that was blown but ran out of time.

 

[Strigoi]

if the stroke is different it probably won't work. that's why you can't swap cranks between a GX160 and GX200.

 

[danny n]

does it hit the bottom of the cylinder? if its going to be to much of a pain in the ass ill just run the 270 i got it for about nothing any way , i am going to still see if i can find a 13 and look and see or if someone has all ready tried it and noes it won't work, but you never know unless you try. thanks for input Strigoi