engine boring.

[richardpr]

i am going to install some wisecos in my 99 gsx rfi and wanted to know if a bore to .5mm would be fine and not too much.

 

[Dr Honda]

You need the pistons before you cut your cyl's. Basically... you measure the pistons, and then cut, allowing for the tolerance that Wiseco specs.

If you just take 0.5mm out of your cyl's... they could be too big... or too small.

 

[richardpr]

when i mention boring it to .5mm being too much i refer to exceding the tolerances which you could bore it to. as in cars you can't bore an engine over for example .040" because you would have overheating issues

 

[Dr Honda]

OK....


0.5mm is fine. There is a lot of "Meat" in the sleeve... and the cooling capacity of the engine is high. I think there is one company that makes all the way up to 1mm oversize, and they are fine. (that's about 0.40")


When you put the engine back together... you have to make sure that your RAVE valves have enough clearance, so they don't hit the new pistons.

 

[CReynoldsMIZ]

SBT actually even sells 1.5mm pistons, but I dont think anyone would recommend them. In my 97 XP someone replaced it with a PMC engine, and when I took the head off they have 1.5mm oversize pistons installed in them and it runs great except i definitely had to do some rave valve trimming when i replaced the raves

 

[richardpr]

Gonna do the rave trimming myself since nobody here does it, and no shop in the states want to do it without the cylinders and pistons