I have a 2006 88" with andrews 37g cams and .030" head gaskets. I've been shopping around the idea of doing a big bore and getting head work done. Zanotti's has the 95" stage 1 kit (29774-02B) for a little over $500. The description doesn't say anything about the pistons or compression ratio for stock heads. Have any of you used this kit with the 37 grind? How much of an increase should I expect going from my setup to the 95? I'd rather not get the heads shaved, because I want to reuse my pushrods. Should I expect the same CR as stock?

 

Contact Kirby, user prodrag1320 on this site. Here quoted me a good price for boring cylinders, se pistons, rings sized to match. A lot less than the kit you mentioned. He could answer your other questions also. Here his site,

www.veetwinperformance.com

 

Your questions is an open ended one as there are several variables in play that will affect the static CR, i.e., chamber volume, deck height, head gasket thickness and piston volume.

The compression increase you will see in your situation is simply the increase that the larger bore size will produce. Assuming all other things are equal, you will see a bump in static CR from about 8.8 to 9.3. However, static is not the ratio you should be looking at; corrected compression is a better predicter of engine performance. Corrected CR is a function of the intake valve close event and, in your case, your corrected CR will increase from about 8.2 to 8.6. If you want to get the most out of the 37s, you should increase the corrected compression to somewhere between 9.0 and 9.3 which will require decking the heads.

You may be able to use your stock pushrods because the base circle of the Andrews 37 may be different from the base circle of the stock cams. The 32G has a smaller base circle than the stock cam base circle which offsets the reduction in stack up height of a thinner head gasket and decking the heads.

 

understood. I guess I was trying to keep the cost down. I was curious if I could get the CR the cams really need without doing that. My bike runs pretty well with just the cams. I am curious as to how much of an increase in performance I would get with the added displacement. The 37's are great higher in the rpms. I would like some more torque down low, though.

 

if you took the 500 and got some headwork you will fair much better then the 95.. you can have the heads decked and cc them plus clean up the ports. that will give you a lot more in the performance area . butbe careful as when decking heads you have to watch out for the exhaust valve relief in the piston 5 minutes with a dremel will fix that.
G

 

FYI...I just picked up SE 95" cylinders and cast flat top pistons (inc. rings, clips and pins) from Chicago HD. Part numbers 16549-99 and 22851-99A for $379.92 plus shipping of about $25.00. The cylinders were $239.96 with the 20% discount. Factor that against any price you get for boring your jugs.

 

I asked Andrews' tech support about about my planned '04 95" build with SE flat tops, stock '06 heads, Cometic .030 head gasket and 26n or 37n cam. He said that this setup would be good for the 37n and maybe too much compression for the 26n. I'm assuming that Andrews goes by static compression and tends to recommend minimum compression for their cams. Maybe they're trying to protect themselves from damage claims.

 

that's about as good as any price I've seen so far. I'll write that down.

 

I would do what deluxe said.

Now if your engine is stock and you have the 37G cams, then your around 160 psi and corrected at 8.1 cr... not good.. terrible for throttle response, you probobly put the cams in and was not to impressed and thought going bigger on engine size would be better for it..sure it is, but just my two cents, I would put that money were it needs to be and up your Comp ratio. Then make up your mind, before going bigger and having to worry about heat, not that that would be a problem.

 

that sounds like my bike. maybe I'll wait on the 95 and just get the headwork first. Who would you guys recommend?