What to do? My project goal was to boost street torque so I started reading old threads. I ran across Frankenzuki's thread about transplanting a GS1100G Head on top of a GS1000 2V engine and I that started me thinking. I didn't want to punch out the GS1000 sleeves because at 73mm they were already paper thin. Although there are old threads on the subject what I decided to swap the GS1000 Cylinders & Head and swap them out with the following:
- GS1100G Cylinder and bore it out to accept a set of Wiseco 1100 pistons with a 10:25 to 1 CR
- Top that off with a GS1100G D Port Head w 3 angle valve job & mild street port
- Keep the Andrews S1 Cam which enhance low end punch
- Swap the VM29 in favor of a rack of Mikuni RS34 Flatslides with K&N individual Air Filters

Supposedly low mileage but corrision was evident by the intake port

Th head I removed was a S-1 model & this one is a S-6 ( last of the breed)

GS1100G Cylinder very beefy compared to GS1000 cylinders





No ill effects yet?. Yeah its running. The S-1 , S-3, S-4 are casting marks that any manufacturer adds to the mold to maintain revision & design control. The S-6 mark I am referring to is shown #3 pic right above Made in Japan. Although I am not 100%, I believe ithe S-6 denotes D-Port shaped exhaust which was introduced to increase the torque of the last of the US GS 2V motors.











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