Kawasaki Flat Top Pistons... Source/Information?

[astral]

R&D flat tops use the Kawasaki design top. Which really has a very very slight dome to it...around 2 degrees if you laid a scale on it. Yamaha's is much much more pornounce maybe like 12 degrees.
Riva made flat tops that were truely FLAT across the top of the piston.

riva's are from r@d I thought.
The 85 mm flat tops from riva are r@d pistons(dominator).
The wiseco's do have a slight dome at 2 deg.
Also the pin to piston crown on the r@d is a bit taller than the wiseco's.
So a r@d 85mm piston will have more squish than the wiseco's if pistons are not machined.

 

[#ZERO]

The Riva flat top pistons are made by Wiseco for Riva and are completely flat with a brown/grey ceramic coating on the top and bottom. They use the thinner 1.2mm TD rings and weigh about 70 grams lighter than the conventional Wiseco Yamaha pistons which have thicker 1.5mm KD rings. The normal Wiseco Yamaha pistons have a 9-degree dome while the Kawasaki - R&D pistons have the 2-degree dome.

The Riva flat top pistons are more suited to the Riva flat top domes which have a 1.5-degree tapered squish angle toward the spark plug, while the ADA flat top domes are more suited for the Kawasaki or R&D flat top pistons because they have a 4-degree tapered squish angle. It's very important to keep the tapered squish angle around 1~2 degrees on flat top engines to promote combustion chamber turbulence and increase bottom-end/midrange power.

If you would like to use the Kawasaki pistons on your engine and don't have a problem with the ring pin alignment snagging the auxiliary transfer ports. I have a piston skirt trimming template that you can have so your skirts will clear the Yamaha crank webs.

 

[loictahiti]

I know , it's old tread but really interesting :bigok:

so #zero, you say , it's not problem, when we use a Kawi flat top piston in Yamaha cylinder, even, if the piston ring pin alignement is in the middle of the auxilary transfert ? just make good chanfered edge , that 's it

thanks