The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: hephaist0s on June 07, 2018, 07:33:07 PM
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New poster, apologies if this is redundant to something. My 1982 R65 has 2 crossover pipes and the front one is rusted out. Searches for used headers usually turn up pipes with just one crossover. a) When did this change occur and why, and b) does it make a difference, and are the two styles interchangeable?
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I think the second crossover pipe first showed up on the '81 model year bikes .
The reason for it, was to increase midrange power .
Does it really do anything, no idea .
I don't think there any other differences between the two .
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I made a front crossover pipe from electrical conduit, 1" IIRC but I could be wrong. Whatever size it was a perfect fit. Cut slits in ends and attached with hose clamps...
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Bear in mind that your mileage may vary depending on who made your header pipes.
In my case I had to cut through the cross over on my wife's R65/80, when it came time to screw it back together I had a problem.
You see the original Staintune cross over was 1" ID which is a very very hard size to find. Eventually I found a steel supplier but they would only sell me a 4 metre length (get that, an imperial ID pipe comes in metric lengths - go figure), which I didn't really want at all.
Whilst talking to the guy at the steel place he mentioend that usually the only people he ever sold 1" ID pipe to were brake rebuilders and that they, like me, were reluctant to buy 4m.
I had an idea.
I got a delivered price for the tube/pipe including postage and then rang every brake rebuilder on the Eastern seaboard of Queensland, enough of them bit so that when my 4m length arrived I lopped off the lengths the brake guys wanted and sent them by post.
And that is how I got a new stainless steel cross over pipe and a 600mm piece spare for around $20 after everything was said and done....
I think it was Monte, a former resident here, who decided that he didn't need no stinking cross over and simply cut the stubs off and welded the holes closed, I remember him reporting that he noticed no difference in performance.
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I've just completed almost 3,000 klms (approx 2,000 miles) with no cross over pipe and no difference here.
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Single crossover for ever on my 03/1980.
Cross over close to the head is for better idling.
Cross over farther down is for better mid range.
What ever floats your boat. I don't think it matter that much with the R65.