'Reshaping' exhaust header for sump clearance

[Guest]

So I've got a header off an 86 GSX-R 750 to mate into my 84 GSX 750 SE Kanatuna (think GS750E, 83-85). The port diameters and spacing are absolutely perfect, retaining access to drain plug and oil filter, but..... the collector on the bottom hits the oil pan. Don't really like the idea of cutting the downpipes to extend them, as one rises up on an angle and if I were to extend that one it would no longer be spaced correctly.

It appears that I need about 1/2 inch clearance, and I don't really cherish the thought of banging on the collector to mash it down to make room. Nor do I like the idea of trimming away the cooling fins on the oil pan. What do I do?

Anybody have any ideas?

[posplayr]

One idea

would be to make a jig, perhaps out of an old head or just use a piece of steel stock with holes drilled at the correct spacing. Mount the head securely and with a torch heat the pipes near the head so that they bend when you pull down on the pipe.

to get 1/2" with 18" length down tubes you need something less than 2 degrees of bend to make up for the 1/2 clearance.

You could also just use a come-along to pull on the header but getting it to move without a lot of tension would make it easier to not overdo the bend. You are not going to need much bend.

Mis alignment of the collector by 2 deg should have little effect.

Pos

[rapidray]

You don't need to modify ANYTHING if you just get the pan & oil pickup from that year GSXR! On ebay they're cheap. Ray.

[Smokinapankake]

So Ray, you're telling me that the pan and oil pickup will bolt right on? It's not a GSX-R motor, but the same as a GS750ES/700ES. The same cases anyway.
The oil pickup being what part, exactly?

[posplayr]

Well that would

you just get the pan & oil pickup from that year GSXR

be a slick swap

I know the pan on my 86 GSXR 1100 is flat on one side, so if the pans swap you probably have to also change the pickup tube inside the motor as well to match.

probly change the gasket while you are at it .

Pos

P.S. this is why you sometimes you just gotta ask; guys like Ray done this stuff a million times.

[Nessism]

Becareful making a change like this. The sump cover is part of the oiling system on some bikes. Compare the old cover with the new one to make sure there are comparable.

[Smokinapankake]

Thanks for the input; I'd be up a creek without your help. I'll get searching for a pan right away.

[hillsy]

Hang on - they're different engines, right? Your 84 is air cooled while the 86 is oil cooled? I'm pretty sure the sumps wont interchange. Even if they did, I think the air cooled motor has extra height in the cylinders / head so you will still have clearance issues with the new sump.

[Smokinapankake]

The 84 is air/oil cooled, I thought the early GSX-r's were air/oil as well. But you're right, they are different engines.
Waiting to hear back from Rapid Ray about it......

[Smokinapankake]

So looking at the parts diagrams at bikebandit, they most definitely are NOT the same bolt pattern, and so will NOT bolt directly on.

Back to square one I guess....

I may be doing what Posplayr suggested - bending it to fit.

Thanks for the help folks!

[TheCafeKid]

Not to mention the fact that they likely have different baffling systems within the sump. This could have massive effects on the ability of the oil to be picked up propperly and quickly enough to prevent sudden pressure drop on heavy acceleration. I dunno for sure about the Zooks, but i do know that some of the "Mark" kaw motors had a one way gate in the pan to prevent this from happening...and, as the two designs are certainly similar, i wouldnt be suprised to find that Zook may have done some of the same or similar.

[rapidray]

My bad, I wasn't paying attention to your post! I, for some stupid reason, was thinking 750 Katana like OIL cooed Katana motor! In this case, you may need to modify the pipe. I apologize for the confusion. Ray.

[Smokinapankake]

No worries, I haven't done anything drastic yet. Probably won't do anything drastic until I figure out how to even mount to the head. They used a wierd tapered shim thing on the early GSX-r's, and I'm told the bolt hole centers on the GSX-R mounting plate are different anyway. May have a friend here at work machine up some two piece flange/mounting plate deals.
What a pain in the a$$.