GS1100 16V Stock Piston Dimensions

[Guest]

Can anyone give me the stock compression height, as measured by them, or from an official blueprint, of a 16 valve GS1100? I would just need the measurement from the top of the wristpin bore to the top of the piston crown. I assume 80-83 all used the same pistons. Mine is an '83 ED. I just received some lovely ZX11 pistons from Ebay for $50 and need to do some measuring. If they won't work, there's lots of ZRX owners who would like to have them. Thanks in advance.

[quexpress]

"ZX11 pistons are about .040" less on compression height" than GS1100 pistons. This means that you will need to shave the cylinder block by that difference in compression height (after measuring it, etc.).

See http://forum.oldskoolsuzuki.info/cgi...num=1302401424

Note: I will (eventually) be doing the same thing with GSF1250 pistons.

Do you know of a good machine shop in your area to do this?

[Roger P.]

Um, that's me actually..

I was repeating what someone told me, but was not actually confirmed with direct measurements. Finding a proper machine shop comes later, although I'm sure a decent shop can bore me some 76mm holes without too much hassle. It's an 1150 block, so plenty of meat.

[gearhead13]

Do you know what wrist pin size is on the ZX?
I am pulling my engine apart soon and I could measure the compression height for you. They are JE pistons but measurement should be close.
EDIT: just checked and they are 18mm pins.

[gearhead13]

I measured my JE pistons and they are 17.93mm or .70" from top of pin hole to top of piston.

[Roger P.]

Thanks for that. Do you know the CR of those 1170 pistons? I can use this info to do some calculating. I guess a more relevant question is whether you have zero deck height with your JE pistons?

[gearhead13]

Thanks for that. Do you know the CR of those 1170 pistons? I can use this info to do some calculating. I guess a more relevant question is whether you have zero deck height with your JE pistons?

Well, they are rated for 10.25-1, but that would depend on what deck height they used to rate the CR. I would guess a 0 deck height
Being 3mm bigger than stock, the CR would go up without an increase in compression height or a change in deck height.
My 80mm pistons are flattop too, but are rated for 11-1.

[7981GS]

I can measure some stock pistons today if you would like.

Daniel

[Roger P.]

Thanks. That would be great. The more info, the better.

[7981GS]

18.40mm from top of piston pin hole to piston crown.
Sorry for the delay, I HAD to go for a ride!

Daniel

[Roger P.]

Z pistons dey are no gut.

Oh well, another idea shot to hell. These ZX pistons are only 0.632" from crown to the top of the pin bore, or just a hair over 16.5mm. That leaves me about .075" down the hole, way too far. Maybe some FJ1200 pistons then........nevermind.

I guess you have to pay the piper sometimes.


Might be decent blower or turbo pistons though.