Are GT-5 replacement cylinders available?

crmachineman

crmachineman

New Member
Hi everybody.
As some of you might know, I've been making some new parts for these engines, and there is more to come, but not only am I trying to find the right parts for GT-5 owners, the cylinder bodies can be used with great effect for all the 66cc motors.

The cylinder body which came with my GT-5 engine has a transfer port design which seems to produce the best low speed torque. I believe the key is the port shape itself. If you take the head off, you will see the GT-5 transfer port shape is not perfectly rectangular. The top edge of the transfer port is angled, so that the port begins to open, favoring the rear of the cylinder.

Does any body know how to get these cylinder bodies without buying a whole engine?

:-||

-Fred
 
Yeah, that's exactly what I did. Spoke with Josh on the phone, and according to him AND the website, there is only one kind of 66cc cylinder available. I was fortunate to contact Don Grube, and He does mention that the GT-5 cylinders are what they like to call a "Big 68" as it is 68.5MM height between faces. The only cylinders I've been able to get from them is what they call a "Big 69", and those are 69.5 MM between faces. He said perhaps no one notices when they are picking them to fill peoples orders, but after purchasing about ten of these cylinders from them and other vendors, and I'm only getting "Big 69's", I figure the Chinese factory wants to get rid of the old stock. I can deck the "Big 69's" when they are to be fitted with a GT-5 engine; as least, that will bring the compression up to par, but we will still be deprived of the real GT-5 cylinder bodies.

zpt

-Fred
 
crmachineman said:
Yeah, that's exactly what I did. Spoke with Josh on the phone, and according to him AND the website, there is only one kind of 66cc cylinder available. I was fortunate to contact Don Grube, and He does mention that the GT-5 cylinders are what they like to call a "Big 68" as it is 68.5MM height between faces. The only cylinders I've been able to get from them is what they call a "Big 69", and those are 69.5 MM between faces. He said perhaps no one notices when they are picking them to fill peoples orders, but after purchasing about ten of these cylinders from them and other vendors, and I'm only getting "Big 69's", I figure the Chinese factory wants to get rid of the old stock. I can deck the "Big 69's" when they are to be fitted with a GT-5 engine; as least, that will bring the compression up to par, but we will still be deprived of the real GT-5 cylinder bodies.

zpt

-Fred
Click to expand...

there is the gt5A then there is the gt5 superrat
two completely diffent motors in stroke
there is 0.120 dif in the location of the wristpin location

the superrat also uses a diffent head then the plain gt5
hope this helps
 
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