Bore question....

[grassman]

I got a cylinder head from a friend that was already bored. I measured it today and it came out to 87.66 mm... Does that make it a 416 needing a 87mm piston?

[honda400ex2003]

i would say it needs a 87mm piston with oversize rings but i would def get it checked out for roundness and such too. it may need a hone to clean it up anyway. you would most likely be better off to just go 88mm with a new piston. im not really sure how much a hone will take off, if any at all really. over size rings are usually .5 and a bit more than that so you may be able to get a 87.75 mm ring for it. ill do a bit of checking and find out. steve

[honda400ex2003]

you can get 87.5 mm rings but it doesnt look like you can get 87.75 rings. steve

[400man]

what about excesive piston/cylinder wall clearance? would it be too much?

[honda400ex2003]

if he tries to run .5 rings it most likely will have too much gap. im no machinist that bores though so i dont really know for sure. i would say just get it bored to 88 and call it a day but thats just me. lol steve