Question for E.Gorr or anyone who can help

[JB200]

Let me start by saying I'm not that experienced with motor mods so if my question is elementary please forgive me. E.Gorr did a 134 kit with mid to top port and polish job and head mods. I requested mods for race gas. I recently purchased a new top end and instead of doing it myself like I usually do I'm paying a friend. I bought the high performance cometic gasket kit with the thinner base gasket. I called Eric to make sure this wouldn't throw off any of his work. He told me to measure and make sure I had room so the piston would not make contact. I passed this info on to my friend who is a very good mechanic. He measured before he took everything apart and found I had .054 clearence. The cometic base gasket is .010 thinner. So I had plenty of room for it. My question is if my head was shaved shouldn't I have had less clearance than .054. My friend does motor mods and said usually the clerance is around.020-.040. He did not know who did the work when I told him he said well E.Gorr knows what He's doing. I'm just wondering what the clerance should be if Eric did head mods. Also the crank comp. is 180lbs with brand new top end with ring end set to spec. Kawasaki's web site has 185lbs stock for my bike which is a 01 kx125. I am not flaming Eric Gorr by any means. His customer service is second to none. Something just didnt sound right so I thought I'd ask since like I said I dont know a lot about motors. Thank You for any replies.

 

[elf]

I dont think .054 is out of line for a mid to top engine. The low to mid engines will have a little less clearance. My 144 is at .048 and ported for low to mid. I think .040 - .060 is the clearance range on big bores. Less clearance equals more compression, to much and you will lose top end.The head doesent always get shaved, but the combustion chamber gets reshaped to suit the type of piston being used.Put the thing together and go ride it!!

 

[JB200]

Thanks for the reply. That explains it. I was under the impression that high compression and top end could be acheived together. So what exactly gets done to the head if you request mid to top end power?

 

[MikeS]

So what exactly gets done to the head if you request mid to top end power?

Tough call, search around Eric's site. He had some info on 2 stroke tuning and combustion chambers.

 

[Rich Rohrich]

Tough call, search around Eric's site. He had some info on 2 stroke tuning and combustion chambers.

Here's a good place to start :
http://ericgorr.com/techarticles/basic_two_stroke.html :thumb:

 

[DEANSFASTWAY]

Yeah you know youll get different comp readings if the throttle is closed or open, open will be higher . Also sometimes new rings wont seal as well as a ring thats been run in . .054 sounds good and with more clearance (less possibility of detonation )maybe you could then play with your Ign advance a bit to suit your power delivery intent also. If Eric said its good then ride it.