cylinder head

[yannickapexrtx]

Is there anyone who has milling cylinder head for raise compression
is that increase performance or not

 

[grader]

easier to split head gasket or buy thinner from aftermarket. there is not much clearance for a cut head.

 

[kinger]

The head is a interference fit with reliefs already cut into the pistons. There is some room but not a lot, the CR you add can amount to 1-3 hp.

 

[yannickapexrtx]

where you buy a aftermarket thiner gasket.is that a racing head gasket from r1 2004-2006 fit on apex 2006
tank you

 

[Rhino48]

If my 2004 R1 bike engine is an indicator, there's some room. but you need to measure the piston to valve clearance. I wouldn't mess with the thinner gasket, my bike had one and ended up leaking. so now it's just an OEM gasket.

My head is milled .010", and my bike is a bit stronger than stockers all other things being equal. I would guess about 5-10 HP at peak.

 

[kinger]

You cant compare a bike to a sled, the RPMs of the R1 engine will make more power, but down at 10-11k the gains aren't as noticable.

 

[Rhino48]

You cant compare a bike to a sled, the RPMs of the R1 engine will make more power, but down at 10-11k the gains aren't as noticable.

The gains will be noticable everywhere, in fact if you don't have pre-ignition the mid range generally benefits most.

The early R1's up to 2001 redlined at around 10,000 if I remember right - they responded well to head milling.

My point was that the basic design of the engine likely allows some milling, but one needs to measure the piston to valve clearance.

now whether it's worth it on the sled... that I doubt. I think the relatively low RPM loads coupled with high throttle openings could make ping a problem withouth race gas.

 

[yannickapexrtx]

the maximum head milling on apex is .004'', and much of people run with
13 at 1 piston with premium gaz with no problem.i don't want put a jobber
piston in my yamaha.i don't trust jobber.i search a way to raise my compression keeping a original parts.

 

[yannickapexrtx]

If my 2004 R1 bike engine is an indicator, there's some room. but you need to measure the piston to valve clearance. I wouldn't mess with the thinner gasket, my bike had one and ended up leaking. so now it's just an OEM gasket.

did you put a racing yamaha parts or another aftermarket