got the top end torn down now theres bigger problems

[Cory9584]

I got the top end off and the bores dont look too bad but the right side rod has about 1/2in play at the crank. The cool head is also beat up on that side. Now i guess im also looking at a new crank and rods. Also on the bad side the mixture screw is missing, im guessing that caused alot of this

[bloodmoney23]

so get the new screw, pistons, bore and you may be able to get away with just crank bearings depending on how long you rode the thing while it was acting up. You should be able to just hone the cool head but make sure that both domes are done exactly the same. No matter what you will have to pull the crank out and see what the problem really is. But this is also a perfect chance for you to put a stroker kit in it, or a nice aftermarket crank.

[Cory9584]

I think im definately going to buy a new hot rod crank. I dont know which to buy though. How will a 4mm stroker change the engine?

[machwon]

It really depends on what your end use of the motor will be. Std. stroke cranks will work fine the stock or ported cylinders. Adding a stroker crank will change the port timing of the cylinders and will not get as much benefit as it could with a set of properly ported cylinders.

Without porting I would estimate the stroker crank to be a 5 hp gain on stock port cylinders, 10 hp with the proper porting over a similar stock stroke motor. If you do buy a crank I would recommend the long rod crank. This will also require the long rod pistons and custom cut cool head domes. It is a much better set up in the long run if you're thinking about performance. I recommend staying away from the spacer plates.

[Cory9584]

how much of a price difference is there between the stroker and stock pistons? also who sells the stroker cool head domes?

[machwon]

The stroker pistons list for $190 a pair I think. Try one of the sponsors here and see if they have them. Otherwise good performance shops should be able to hook you up. If you can't find any pm me and I could help you out.

[Cory9584]

i just measured my cylinders to get a rough idea where they are and their a hair over 2 1/2 inches. Is that normal?

[machwon]

2.520" would be stock bore cylinders, 64mm. Sounds like there stock bore.

[Cory9584]

good to know, so i guess ill be aiming for 64.5 pistons with a stroker crank which is about 380cc

[bloodmoney23]

have fun when your done......since your strokin it and everything you may wanna think about porting the carbs. You should be good w/o but it would prolly be a good idea.