Could someone with an 83 R100 (R, RS or RT) help me

[CurlyMike]

I would like to get some measurements on the exhaust.

I need the length of the front cross-over pipe to the 32nd of an inch.
I need the length of the back cross-over pipe, also to the 32nd of an inch.
I need the measurement from weld to weld on the inside of the headers for both.

I am trying to make a cross over pipe from a plumbing fixture like a couple of people have done here and need to make sure they fit where and how the stock ones do. Make sense?

Thanks. Mike

[Paul_Rochdale]

Sounds like a very needy person

[moosehead]

Mike, done this on 3 different airheads...very simple. Just did on my 78 100/7 this past winter. Also did on 82 RS both front and rear crossovers.

Here are dimensions I have off the 78 for a front crossover just completed. Used the same crossover pipe length (chromed 1 1/4" sink drian pipe extention) for the RS both front and rear as recall.

front crossover pipe length 10"

distance between front crossover at header pipes - 12" +/- 1/8"

Same for rear crossover on my 82 RS

Cut the chrome 1 1/4" drain pipe lngth to 10 - 11" (mine is 10" on the 78 but there's additional room to go to up to 11" if you want)

I put 2 dremel cuts at each end off the pipe about 1/2" deep to allow flexibility in the pipe ends to slide over the crossover pipes coming off the headers...

Slipped the 1 1/4" "new crossover pipe on and used 2 airplane clamps to tightened down.

Works like a charm

I loosened off exhaust nut only on right hand side (as well as exhaust hanger in rear) so could turn header pipe out aenough to get old rusted out crossover off and new one on. Slip new crossover on one side then line up with other and swing back (rotate) loosened header pipe and lock everything down....very easy.

Here's some pix of install on my 78 R100/7 (sorry for the crap cell phone pix)

[CurlyMike]

moosehead, thats exact;y what I needed. Have the pipe already and just needed to do the cots. Thanks for the measurements. Where did you get the clamps? Have a close up pict of them?

[moosehead]

Just standard clamps can find at any good hardware store...thin k 1 1/4 - 1 1/2" size. Mine made by Trico. you'll find them in variety of sizes in the plumbing section usually. I call them "pipe" clamps. Anything will work. Just snug them up.


l'll get a pic of the ones I use to ya shortly...

[CurlyMike]

Cool. I have some of those hose clamps. You called them airplane clamps and didnt know if there were any that were a bit heavier and still had some style.

Originally Posted by moosehead

Just standard clamps can find at any good hardware store...thin k 1 1/4 - 1 1/2" size. Mine made by Trico. you'll find them in variety of sizes in the plumbing section usually. I call them "pipe" clamps. Anything will work. Just snug them up.


l'll get a pic of the ones I use to ya shortly...

[moosehead]

Yea..."airplane" clamps...."hose" clamps.....etc.

I get the stainless steel ones (no rusting) if you have them but doesn't really matter.

[Paul_Rochdale]

I am curious why you are doing this. Whilst I have no experience of having to do so, some riders replace their old exhaust pipes with those without the 'cross-over pipe', in fact Armours, who manufacture quality ss exhausts in the UK, don't seem to sell the BMW exhausts with the cross-over pipe, and in practise, this doesn't appear to make the slightest difference in the bike's performance. Others who have tried this may disagree

[moosehead]

Mike, check your PM's....think I straightened out the confusion

[CurlyMike]

Originally Posted by Paul_Rochdale

I am curious why you are doing this. Whilst I have no experience of having to do so, some riders replace their old exhaust pipes with those without the 'cross-over pipe', in fact Armours, who manufacture quality ss exhausts in the UK, don't seem to sell the BMW exhausts with the cross-over pipe, and in practise, this doesn't appear to make the slightest difference in the bike's performance. Others who have tried this may disagree

There seems to be some debate about this. I heard it was only an EPA thing on the USA. Honestly I wouldn't mind loosing them forever, but I got to go back with what I have or spend money I dont have. The pipes are decent and need only cross-overs. I have seen several posts about this solution and it seems very viable and much cheaper.