750/600 816cc motor

[loudnlow7484]

I'm making solid plans to build one of these over the winter. Actually, I was going to use the 771cc Wiseco kit, to make it like a 840cc. My question here revolves around the connecting rods.

I've checked the microfiche for various years of katana and gsxr, and I'm trying to figure out what rods to use. I'm kinda hoping somebody has a bunch of connecting rods from various years kats, that could check them against a rod known to work (early kat600's) and tell me if the new ones are any beefier, especially around the small end.

Are the big ends all the same diameter? What about rod length? If the 750 rods have the same crank end diameter, then it would make sense to me to use the 750 rods, even if it required a taller spacer under the cylinders, because you wouldn't have to bore out the small end.

the 90-95 gsxr750 rods are all the same, but I can't seem to find any.
pre98 kat600's and 86-87 gsxr750 rods are the same, but I wanted something stronger.

the 86-87 gsxr750 rods are part number 12160-27A13
the 90-95 gsxr750 rods are part number 12160-17D00
the pre98 katana750 rods are number 12160-17C00
the 98+ katana750 rods are number 12160-17E01
the 98+ katana600 rods are number 12160-27A14

Hope somebody can help me. If not, I'll just buy every different rod off of ebay, make my decision, and then sell the rest off. Thanks in advance.

[Anonymous]

ok all the gixxer 750 and kat600 use 34mm rods big ends and 18mm small and the 98+ kat 600 and 750 use 34mm big end rods and 18mm small ends

now the kat 750 pre98 uses 36mm big end and 19mm small but the 88-89 gixxer which the kat motor is based on uses 19mm small ends and 34mm big ends sound strange but maybe the kat rod ends where beefed up for longer use since its a touring bike all this info is according to clymer and haynes manuals

and if you wanna big bore a 600 you cna only go to 771cc and you have to use the 90-91 wiseco kit and bore out your cylinders no exotic 840cc or 905cc unless you mix and match parts like pre98 kat 750 cylinders on the long stroke crank the 600kat or gixxer 90-92 crank or new kat 98+ cranks with a 3mm spacer under the cylinders. which will give you the magic 840cc and 905 cc depending on which kit you use but with out gettign creative and mix and matching 771 is all the new kat motors will go to.

[loudnlow7484]

Thanks for all the info, Sin!

I guess I wasn't clear. I want to put the pre98 750 cylinders, head, and wiseco 771cc kit for a short stroke motor (1mm overbore, 13:1 comp), on a long stroke bottom end..... much like the "power of the poconos" motor, or the motor fastlarry at maximum-suzuki built, except with an overbore, and high compression.

it sounds like 88-9 gixxer rods would be the way to go, but possibly would require a much bigger spacer under the cylinders.

Late model kat rods might do the trick, too. I'll have to find out how much material they have around the small end, for boring to 19mm. Anybody have a set laying around?

[Anonymous]

here ill save ya a bunch of work you need a 4mm spacer but you need half that to make the diff see links below
http://www.aperaceparts.com/usedparts.html 813 cc kit for pre98

http://gsxrzone.com/cranks.html

http://gsxrzone.com/enginekits.html

there all the gixxer engine kits made ape is a great place for race parts were i buy most of mine so if you really wanna build a killer motor there you go

[loudnlow7484]

yeah, I've been all over the ape site. what I was really looking for was a comparo of stock rods, as far as build and all.

I found that the rf900's had the same wrist pin as kat750's, so maybe the rods from that would work, as long as the crank side is the same as the kats.

[Anonymous]

yeah, I've been all over the ape site. what I was really looking for was a comparo of stock rods, as far as build and all.

I found that the rf900's had the same wrist pin as kat750's, so maybe the rods from that would work, as long as the crank side is the same as the kats.

rf900 uses 36mm big end on the rod like the kat750 pre98

[loudnlow7484]

I just can't win.

I guess I'll just bore out a set of late model kat rods and shot peen them and hope they hold. I don't know why the 600's and 750's are different in the 98+ years, since they are the same stroke and all.

Maybe I'll try it for a while with the stock pistons and all, just to make sure it holds up, then tear it down and have the rods fluxed when it's time for the wiseco's.