mrgreen98ski Posted January 9, 2017 Share Posted January 9, 2017 (edited) I have a 1994 GSXR 750 with a 1996 GSXR 1100 engine that I put in it. last summer my chain broke and it crack my case on the 1100. I have the 750 motor still but need to be rebuilt. I was wondering if I can use the 750 lower with the 1100 crank, cylinder, pistons, rods and head. id also need a rf900 clutch I believe. Oh I would also need the 1100 head studs since the cylinders are taller. Can anyone give me any one give me some incite on this. I hope its possible I think it would make a fun beast. thank you green Edited January 9, 2017 by mrgreen98ski Quote Link to comment
Madb Posted January 9, 2017 Share Posted January 9, 2017 Hello mrgreen98ski and welcome. You can use the casings but you'll need to check the bearing code to see if they match. Think you'll need the 1100 clutch as well to match crank gear. Use the gearbox from the 1100 too. Should be good to go. Someone will be along shortly if I'm mistaken or missed something. Quote Link to comment
Madb Posted January 9, 2017 Share Posted January 9, 2017 You'll find the bearing code on the back of the crankcase. Where the engine mounts are. Quote Link to comment
Madb Posted January 9, 2017 Share Posted January 9, 2017 Oh and assuming you can use the casings, dont forget the seal for your clutch push rod on the left side as the 750 one is a solid one.. Quote Link to comment
Gammaboy Posted January 9, 2017 Share Posted January 9, 2017 I'm pretty sure the crank bearing diameters are different between the 750 and 1100? Quote Link to comment
Madb Posted January 10, 2017 Share Posted January 10, 2017 (edited) Quite possible. Tis why i said "assuming ". Crank bearing on 750 is 34mm. Any idea wot the 1100 is? Crankcase inner dia on 750 is 37mm depending on the code on crankcase and crankshaft depends which colour shell fits. Rf900 is 34mm too. Edited January 10, 2017 by Madb Quote Link to comment
Captain Chaos Posted January 10, 2017 Share Posted January 10, 2017 [thread hijack] what does the other code (the 11 numbers) mean on the back of the crankcase? All my oilcooled engines have a similar code. [/thread hijack] Quote Link to comment
Madb Posted January 10, 2017 Share Posted January 10, 2017 Hello captain chaos, i did know but now cant remember. Now it is going to bug me. I shall seek out the depths of my mind (which is very shallow as the years travel by). Think it might be something to do with pastigauge but that might have been bumped into the wrong memory department. I shall look into it. Quote Link to comment
mrgreen98ski Posted January 10, 2017 Author Share Posted January 10, 2017 I was reading on another site that sounded like you could possibly use the 1100 crank in the 750 bottom with the 750 gearbox but you had to use the rf900 clutch. They were saying that the rf900 clutch mates to the 1100 crank and it smaller in size (diameter and length) then the 1100 clutch and would fit in the 750 bottom. this is what I was hoping to get a clearer answer on. thanks for all the posts so far Quote Link to comment
Madb Posted January 10, 2017 Share Posted January 10, 2017 Depends on wether your gear shaft is hollow to take the push rod thro to the other side. Like the 1100. If the 900 clutch fits the 1100 crank gear that is some usefull info.. Could you measure your main bearings on the 1100 crank for me,plz. Quote Link to comment
Madb Posted January 10, 2017 Share Posted January 10, 2017 Oh and you will need the 1100 oil pump. 750 one wont be up to the job. you will need to split the engine anyways to fit clutch push rod seal so may aswell swap 1100 bits over. Quote Link to comment
mrgreen98ski Posted January 10, 2017 Author Share Posted January 10, 2017 (edited) 15 minutes ago, Madb said: Oh and you will need the 1100 oil pump. 750 one wont be up to the job. you will need to split the engine anyways to fit clutch push rod seal so may aswell swap 1100 bits over. So all of the 1100 lower will fit into the 750 lower case? (if the bearing codes match) I don't have anything taken apart yet. I need to build a holder for my engine stand then I will get started. Edited January 10, 2017 by mrgreen98ski Quote Link to comment
Madb Posted January 10, 2017 Share Posted January 10, 2017 I do believe so as the 600 750 900 1100 share casings design tho the 1100 /900 have hydro clutch and 5 speed box. The sticking point will be bearing shells for the 1100. If they're 34mm mains you should be able to match up a set. It's all trial and errors. You will need some plastigauge to check your clearance. Not a quick swap unless all your codes match. Bearing shells are not cheap. May be better off getting another engine. But i like a challenge. But I'm mad and crazy!(Someone has to be!) Where abouts are you? Quote Link to comment
mrgreen98ski Posted January 10, 2017 Author Share Posted January 10, 2017 In the cold Midwest, I live in South Dakota. I like a challenge also. I am tempted to see about the rf900 clutch basket fitting in, I kind of like the idea of having the 6 speed. Maybe the 750 gearbox is to weak? I even kicked around the idea of having a machinist remove the riveted gear on the 1100 clutch basket and have them install it on the 750 basket. there again ill need to open both up and see if this is possible. I'll get may stand built by the weekend and ill get my measuring tools out and go to town on it. I wish I had a rf900 basket I could measure. Here is where I got the idea from (sorry its a post from another site. but it is their water-cooled section but no years mentioned. http://www.say what now!?.com/forums/16-water-cooled-gixxers/123604-has-anyone-swaped-1100-crank-rods-pistons-750-a.html Quote Link to comment
mrgreen98ski Posted January 10, 2017 Author Share Posted January 10, 2017 And the letters in the boxes are the bearing codes? Quote Link to comment
Captain Chaos Posted January 10, 2017 Share Posted January 10, 2017 6 hours ago, Madb said: This number? yes that one. Quote Link to comment
Madb Posted January 10, 2017 Share Posted January 10, 2017 Haha. I was going to suggest meeting up but can't afford the air fare every other weekend. Good thing this internet eh. Yes. Them are the codes. Quote Link to comment
Madb Posted January 10, 2017 Share Posted January 10, 2017 The codes on the crankshaft refer to the outer diameter of the journal of the main bearing on the crank and the code on the casing refers to the inner diameter of the casing. You will need the workshop manual to match up the bearing shells. When you have strip the engine we can talk thro it then. Funny you talk about swaping gears on the clutch. I'm hoping to do the same too. Tho I'm building up a 750/ 900. Me no money at mo so you'll get there before me! Quote Link to comment
Madb Posted January 10, 2017 Share Posted January 10, 2017 (edited) Gears from 750 box wont hold the 1100 torque so best stick to the 1100 box. Edited January 10, 2017 by Madb Quote Link to comment
Madb Posted January 10, 2017 Share Posted January 10, 2017 Brrrrrrrŕrrrr. Hate the cold! Starting to turn cold over here in England now. I'm from the sunshine state. I so miss that big yellow thing in the sky. Quote Link to comment
mrgreen98ski Posted January 10, 2017 Author Share Posted January 10, 2017 Brrr is right!! That's what I was thinking that the gearbox probably not as strong. I have rebuilt motorcycles down to the lower end but never split a case. I guess there's always a first. I got the need to ride that will push me through this project. I have the shop manual for both the 750 and the 1100. Quote Link to comment
mrgreen98ski Posted January 11, 2017 Author Share Posted January 11, 2017 here are the codes. GSXR750 AAB ABB GSXR1100 BAA ABA Quote Link to comment
mrgreen98ski Posted January 11, 2017 Author Share Posted January 11, 2017 ok so once I open it up and get the letters on the crank I assume I use this chart for the bearing Quote Link to comment
Madb Posted January 12, 2017 Share Posted January 12, 2017 Yes thats the one. If you look in your 1100 manual it will tell you the dia of the crank shaft main bearing. Hopefully they'll be the same size. Quote Link to comment
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