[jgill21]

Ok, so I'm looking at a top end rebuild on my 93 300EX. I was wanting to bore out my stock cylinder from 74mm in diameter to 75mm and use a 75mm wiseco along with it. My question is: Is there a distance between the piston and the inside walls of the cylinder that I need to be aware of? Thanks!

 

[SlammedRanger]

Take the piston and cylinder to a competent engine machinist. They will make that piston work with the cylinder bore. They will also measure the cylinder for out of roundness and look for any scoring in the cylinder wall to see if you need a bigger bore then your already wanting to do. If you are a michinist and are boring it yourself then look at your factory service manual for piston to cylinder wall clearance spec.

 

[jgill21]

Ok, I will try that. Do you think that the increase in diameter will affect the head gasket and or head?

 

[SlammedRanger]

You will need a head gasket made for the size bore you go with. Preferably a mls(multi layer steel) type. Sold by cometic or a brand of your choice. The size of bore will have no effect on the head. But it is a good idea to have the head surface skimmed to be sure it is perfectly flat. They are almost always warped very sligtly and skimming ensures a flat surface to get a good seal and will keep the headgasket from getting wet around the edges from oil seeping.

 

[jgill21]

Great advice, Thanks!

 

[SlammedRanger]

No problem! Always glad to help!

 

[jgill21]

Update: Piston arrived and was sent out with cylinder to machine shop. Gotta wait another week :frown:

 

[jgill21]

Update: After waiting more than 2 weeks for the machine shop to finish, I managed to snap a ring when putting them on the piston. fml

 

[jgill21]

FINALLY!! After snapping a ring once I got the cylinder back and having to wait a few more days, I finally got the quad running. Runs fantastic. Thanks for your help! :biggrin::funnyhonda:

 

[SlammedRanger]

Awesome! Glad to hear about another honda still ripping!