Re: engine combo - 1127 block, crank, piston,head in '88 750 case.
some more digging in here. here's what i found
" OK, here's the full scoop on oil-cooled cases:
There are two basic groups of oil-cooled cases, and the primary reason for the difference between them is the size of the main bearings. All of the 600's and all of the long-stroke GSXR 750's use the small main bearing setup. All of these cases are mostly interchangeable with each other.
The other group of cases uses the large main bearings, and this would include all of the 1100's, Bandit 1200's, and all of the short-stroke 750's. Short stroke 750's are any of them that had a 73mm piston from the factory, including 88-89 GSXRs and all of the Katana 750's. All of the cases from this group of engines are mostly interchangeable.
But, as I said, mostly interchangeable. During the lifespan of the oil-cooled, Suzuki made 2 upgrades that affect the case interchangeablility. The first upgrade was to the starter motor. The 1052 motors use exactly the same cases and starter dimensions as all of the short-stroke 750's, with the only difference being the color of the paint on them. The GSXR's had a dark grey, while the Katanas had a semi-gloss black. Other than that, all 1052s and short-stroke 750 cases are identical.
When the 1127 motor came out in 89 (88 on the 1100 Katana), they upgraded the starter motor. The newer starter has a larger output bearing. As a result, the cases have a larger bore in them for the starter, and the gasket surface of the starter cover has a slight hump around the starter area as compared to an earlier motor. You can change cases between the small starter and the large starter, but you must also change over to the correct starter and engine cover appropriate for the new cases.
The next upgrade was to replace the transmission output shaft bearing. The early motors used a single-row bearing, which was prone to breaking. So starting in 1991 Suzuki started to use a double-row output bearing in the GSXR 1100's. I believe that this is also the same setup used in the Bandit 1200's as well. But they never upgraded the Katana 1100s to this setup and, to my knowledge, they never upgraded any of the 750 Katana engines either.
This modification affects the cases because the location of the retainer groove is different between the 2 different bearings, and is therefore different between the cases as well. So if you are swapping cases that have different groove locations, you must have a transmission with the correct output bearing and output shaft to match the cases.
Now more specifically to your case, if you truly have a 1989 GSXR 1100 engine (the V710 number is not enough information to positively determine this), then the only 100% direct replacement cases would be 89-90 GSXR 1100 and 88-93 Katana 1100 cases. Others could be made to work, but they would all require some modification or swapping of some parts.
" ok I finally got some time to play with the motor. Grinded all the cases smooth on the inside for better oil return as the 88 cases have some casting ridges that collect alot of slug. got all the bearings including the thrush bearing (really important). It's perfect on the thrush .003 in with required .002 to .005. that was my biggest worry because the crank is beefier the the 750.
I know there is a guy from australia on this site that has done this for racing before and if you out there please hit me up.
my clutch is the 88 1052 clutch and matches up with the oil pump and transmission and is all ready to drop in.
The spot for #3 rod that you have to grind down is not much but looks like it is on an oil galley so be very careful as you will finish the build right there if you go thru. It only flattening it out a tiny bit otherwis the cases are the same
'looks like it is on an oil galley' ?
any pic of that area in particular?
Originally Posted by javadog
"If you want to f*** something up, just for the sake of doing something pointless, buy a 'Busa and have at it"
welcome to where the sun shines all year round..
1988 GSXR seven-twelve-sixteen
Last edited by NAJ2627; 03-20-2012 at 05:05 AM.