exhaust header pipes question(s)

[Baffo]

What is the difference between no crossover (like my R65GS with the collector behind the gearbox and 1 exhaustpipe which could substitute as a crossover)
1 crossover in front of the engine or even
2 crossovers with the second one behind the gearbox
and then mostly 2 exhaustpipes for the both of them
examples:
http://www.staintune.com.au/exhausts/bmw/BMW%20R45%20R65%20R65LS%20Single%20Crossover.htm
http://www.staintune.com.au/exhausts/bmw/BMW%20R65%20R65LS%20Double%20Crossover.htm
Is it torque or power, is it to get it adjusted (carbs, I heard that without it u can never get a boxer to run nice)

[MrRiden]

Exhaust design is a real science. I've been told that the different designs are for different applications. If I remember correctly the NO crossover pipe is good for a little extra poot (technical term, see hootis) at top end but is impossible to tune for a nice idle. The single crossover will provide a strong midrange and decent idle while suffering at track type high rev acceleration. The double crossover is a compromise providing the best all round running. also the front crossover provides you with a handy place to strap the center stand while tipping the bike froward to change the rear tire. Then there is the 2 into one configuration which I suppose is also best left to the track.
Rich

[Baffo]

tnx for the insights, traded a sixpack of special brew for this:
http://westerbaen.tweakdsl.nl/R65GS/800/IMGP2493.jpg
http://westerbaen.tweakdsl.nl/R65GS/800/IMGP2494.jpg

and am planning these mufflers
http://fotos.marktplaats.nl/kopen/b/a3/cB6lqMp1yyA=.jpg
(Ducati Supertrapp Megaphones, streetlegal)

[suecanada]

The one thing I know would be better if I had just one crossover pipe...it sure would be easier to take the exhaust off and on!!! Just pull out the front with one....with two,  the centrestand or sidestand is blocking the rear crossover making removal a   process. Can't even come up from below for remounting easily. It is such a painful job that i put off taking the headers off completely anymore and just touch them up as best I can with the high temp paint.

Maybe there is a trick I am missing??? [smiley=undecided.gif]

[MrRiden]

I'll find out soon. I'm planing to remove & paint my system. do you have any preference for paint on your system?
Rich

[suecanada]

I've had very good luck with POR-15's high temp paint called Black Velvet...brushed on.

[MrRiden]

Thanks sue,
I went to their web site and it looks like this coating should be a notch above stove black paint. I was also wondering what size can to get @ 162.75 per gal I don't want to over order. Also, do you use any of their prep chemicals. I'd like to do this once and have it last a while.
Thanks,
Rich

[nhmaf]

Based on Sue's recommendations I bought POR high temp black paint for repainting my R65LS's black exhaust and I've been very
satisfied with the results.   It will fully cure after it's been heated up through running the engine - so be careful about it until then - I managed to
rub some off after it had dried but before I had run the engine, but that was my fault, and involved spilling some WD40 on the pipe as well.
I'd also recommend the POR gloss black for painting the frame - works well and looks good.

I bought a pint, I think, of each and still have alot left over for future touch ups, provided that I got the covers back on tight enough.
A pint should completely repaint your exhaust system.  for complete repaint of the frame, you may have to buy a quart and have some left over.
It is good stuff - though not cheap, I am still pleased with the result.

[Jon_P]

por-15 is great stuff. the only thing no one said is it does break down from uv. you need to paint over it, it is a metal sealer and not so much a paint. there is something that we used in the service that is alot like por-15 but alot cheaper. have to find the name of that stuff.  
they also make a great tank sealer kit that would knock kreem or any other sealer out of the tank, nice thing about it also is it is aluminum color so it makes the inside of your tank look brand new.

[Justin B.]

The POR-15 tank sealer is also a metallic grey/silver in color.  I have lined two tanks with it and so far - so good.  Oh, and you're absolutely correct about the POR-15 rust converter.  It works great as-is under the hood and underneath, but it doesn't get along with direct sunlight.

[MrRiden]

Ah! thats why the name sounded familiar. I have heard of their tank sealant before. Hmm the black paint doesn't get along with UV. Bummer, here in Phoenix that will be of major concern.
Rich

[suecanada]

Rich,

It's only the rust converter stuff that is UV sensitive I am pretty sure NOT  the high heat paint. I see no problems with UV degradation over the years. I got 8 oz of the high heat black and have used it every year for 3 years. Still some left.

It doesn't skin over like the "chassis black" frame paint which is an excellent semi-gloss frame paint that ends up looking like powdercoating. The semi-gloss matches the gloss of the original..not so shiny as glossy. So if you are doing only part of the frame say, I'd go with a more original semi-gloss. I got a 1/2 quart of the chassis black and really ya can't use enough of it over the years to warrant such a large size. A little goes a long way. This chassis black will thicken up or skin over if exposed to air OR is left stored too long after initial opening. I have tried 3 baggies and saran wrap and it still gets thick and skinned. Need to buy their thinner too. The paints DO NOT smell at all and I guess they require a special thinner.....any one guess what is might be..I have never ordered it and wished I had! No problems painting inside your house.

So get the high heat for sure....we don't need the rust converter system do we? NO RUST!

Never, never FUSS with the chassis coat to try to make it perfect as you apply it...it "flows" together if you leave it alone. Too much brushing and it'll get brush marks because it is already skinning over. Work with purpose and be forthright.....only spoon out a bit of paint at a time. As much as you think you need for a small area.

The high heat paint is very forgiving. [smiley=1drink.gif]

[nhmaf]

+1 for all that Sue states above.

The gloss black chassis paint and high heat paint are not UV sensitive from anything I've read or observed.  What is UV sensitive is the
rust treatment stuff that you would paint on first, if you had alot of rust and didn't want to sand/brush it
off.  You'd then cover this with paint like the chassis paint, which is pretty tough stuff     I've only had 1 year with the POR chassis and black velvet high heat paint, and no problems so far - though I am sure that we get less sunshine up here along the US-Canada border than you folks down near
the US-Mexico border !
 

[MrRiden]

Thanks for setting me straight on that. Once I verify that the Fat Man is bringing me a shiny new exhaust nut wrench I'll go and get the Hi Temp paint. Appreciate the info! [smiley=beer.gif]
Rich

[suecanada]

Hope ya get the wrench tomorrow morning and some anti-seize paste for after and I wish that you don't have to saw and chisel your exhaust nuts off. If they start to turn then get really tough, or are really stuck on, it's time to bite the bullet and cut them off....so say the gurus! Cheaper to buy new ones.