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Discussion Starter · #1 ·
Re: Here\'s another head question?

sorry, i don't know if the 89 internals would fit into your 86 crankcase.....maybe somebody else here would know better....

you just basically need to replace your cylinder head, right?
 

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Re: Here\'s another head question?

Yeah, is an 89 head a good choice or should I wait for something else. The other parts I was just curious about, if they don't work I can sell oterwise I would have some spare parts.
 

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Discussion Starter · #3 ·
Re: Here\'s another head question?

how much are you getting the 89 for?

if it's not too much, you might as well just get it and check how the head will fit.....if it won't work right, you can part it out...

the 87 head will bolt up perfectly....and has slightly bigger ports to work better with larger carbs....
 

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Re: Here\'s another head question?

Probally between 100-150. I will probally get it either way, it mainly depends on shipping cost.
Do you know of any sites that show a good breakdown of the aircooled bikes engines?
 

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Re: Here\'s another head question?

Between 100-150. Shipping is the biggest factor I will need to consider.
Do you know of any good sites that break down the different engines on the air cooled bikes?
 

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Re: Here\'s another head question?

The '89 is a short stroke, but it is ONLY 1cc difference than the long stroke. Suzuki shortened the stroke by 4mm, but made the bore larger by 3mm.

I do not know if the other parts would change, but I think if you were able to do it, the combustion chamber would be larger and it would drop your compression ratio a lot. That would mean you would have a lot less torque.
 

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Re: Here\'s another head question?

I had it bored out to 771. So hopefully I should not loose any torque.
 

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Re: Here\'s another head question?

the 89 stuff will interchange..you need to put everything from one to the other..the 89 stuff is 2x's better than the 86 stuff..we have taken 89 750 heads and put them on 86/87 1100 and made them run better because of the combustion chamber design in the 89 750..the swap should work..
 

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Re: Here\'s another head question?

So should I fix the 89 and go with the short stroke or stick with the 86?
 

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Here\'s another head question?

I can possibly pick up an 89 750 engine. If I remeber right this is a short stroke engine. I know the head will work but what about the con rods or the crank shaft. Is any of that interchangable?
 

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Discussion Starter · #13 ·
Re: Here\'s another head question?

the short stroke crank would give you less displacement if you were just to swap it into a long stroke motor.....why not use the entire motor?
 

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Re: Here\'s another head question?

The case is busted on the 89's engine and the tranny is shot. Can I swith the 86's case and tranny into the 89? The 86 also has the dry clutch so I would need to make sure that it would work in the 89 also. What are the pros and cons of the short stroke?
 

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Re: Here\'s another head question?

I think I finally answered my own question. Its amazing what can be found by using the search function.

Anyhow sounds like the shortstroke is problematic, so I will stick with the 86 but use the 89's head. I had the 86 bored out to a 771 any other suggestions? What cams should I use?
 

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Re: Here\'s another head question?

i would put the 89 head on the 86 bottom end...the 89 head should bump up your compression..more compression=more power!! i good street port job wouldn't hurt either...i have a friend that is a master at porting and engine building..i will put in a good word for you if you are interested...
 

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Re: Here\'s another head question?

ok guy let's back up a minute here..i have to apologize because i've been telling you wrong...i'm thinking that you had an 1100 and i've noticed after i went back and read your post again...first of all 86/87 gixxer 750 is completely different than the 88/89 gixxer 750 if you have the head already it won't work,sorry!! now 90/92 gixxer 750 will work for you...the 90/92 have bigger valves and shim style head..the 90/92 will work but it would have to be done by a good engine builder that knows about all the clearances of piston to valve and all those good things. now that 89 head would work on an 86/87 gixxer 1100.. if you would please email me and tell me exactly what you are trying to aacomplish with your bike..i like to help if i can..email
[email protected]
 

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Re: Here\'s another head question?

That's right, the short and long stroke 750's don't swap shit ! (Except gear box, engine covers, etc.) I just replied to the same question at www.robbynitroz.com's message board. Don't really feel like writing it all again, sorry.
 

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Re: Here\'s another head question?

Dude, you have the perfect parts for an awesome engine!!!!!!!!

First off the 88-89 750 heads have 1100 size valves in them stock. the 90-92 heads have smaller vavles and the 91-92 heads use shims. The 88-89 head has valves that are too big to use on the smaller bore engines.

Take the 88-89 slingshot head and cylinders, which have the BIGGER VALVES and larger bore, and put that on your 85-87 gsxr750 motor with the longer stroke. Put the appropriate cylinder spacer plate to restore the deck height and presto eight hundred and something cc's. Pretty cool huh


I've got a magizine article I'll post later...
 
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