Exhausts designed for LC/ YPVS on a 350 AC

[Dvsrd]

How large is the angle difference between AC and LC exhaust flanges?  Asking because I wonder how hard it would be to adapt LC/ YPVS expansion chambers to an AC RD.
Stud spacing/ flange design/ longer adapters/ mounting brackets is absolutely not a problem. Guess I'm a better machinist than TIG welder, although I do try occasionally :)
My "problem" is that many of the alternatives for AC RDs out there look slightly goofy. A lot of clearance between engine/frame and chambers on some, or the JL classics that just don't look right to me. And so on.
Anyone tried this? Or the other way around? I'd really like a set that tucks in as tight as possible under the engine. Also, RD350 AC and LC do really not differ that much alt all in port timing, the main difference would be the width/ size of the exhaust port, so I believe LC chambers should work OK on an AC in that respect.

[rodneya]

350 AC stud spacing is narrower.
This is a set of FPP on my 350 when I was playing around with ideas. They are way long, going past the wheel at the back

[m in sc]

big difference in how they are made, remember the powervalve as well. TBH, not worth it. get a set of aircooled pipes and mod them. you can reangle them a bit at the headpipe and they will tuck right up. 

[Dvsrd]

350 AC stud spacing is narrower.
This is a set of FPP on my 350 when I was playing around with ideas. They are way long, going past the wheel at the back

I guess the length thing may partly be due to the shorter wheelbase on the AC, especially compared to the YPVS.
And partly because the headers on those are "hugging the cases" as well.
Anyway, Yamaha ended up with crossed headpipes on the last TZ350, to avoid the pipes poking out behind the rear wheel. There was a FIM rule against that.

[m in sc]

the pipes are tuned differently, the cyls are different and the porting is different . dont waste your time unless astheic > function.

when gary built my pipes for my lc, i remember him specifically telling the rz type pipes would NOT work on my 4l0 top end due to tuning.  (he thought hat was what i was asking for, i was not)

[Dvsrd]

the pipes are tuned differently, the cyls are different and the porting is different . dont waste your time unless astheic > function.

when gary built my pipes for my lc, i remember him specifically telling the rz type pipes would NOT work on my 4l0 top end due to tuning.  (he thought hat was what i was asking for, i was not)

Yes, I do realize that especially exhaust port timing on a RZ/ YPVS differs a lot from an AC. While the LC port timings are very close to a RD350 AC. The YR5 is different from the RD.  And the RD400 cylinders came in 3 different versions.
But a lot of pipe builders sell the same pipes for YR5/ RD350 and in some cases for the RD400 as well. Like Jim Lomas for example. As far as I can understand, he sells the same pipes for YR5/RD350/RD400. And the same pipes for LC and RZ/ YPVS.
Gary may build pipes specifically for one model, and I guess TSA and other custom pipe builders do the same. In any case, this is just something I am pondering a bit for the time being.

I have never built any pipes for an RD, but I cobbled together a pipe for a 80 cc kitted Suzuki 50 that ran really well, and later a pipe for a Kawasaki KH100 that also ran well, both based on formulae from the A.G.Bell book. They were two kids with KH100 in my neighbourhood, the other one had a Micron pipe and a "special" cylinder. But the one with my pipe and my rotary valve and cylinder mods ran better :) 

[Dvsrd]

I have considered ordering a set of Spec2 Classics, but would like some tweaks to my own taste. And from what I understand, Gary is not always the most flexible and customer oriented character. I have never hard any Spec 2 pipes in action, only from internet videos, and I would really like something a bit quieter. So larger diameter tubing for the silencer part (2 1/2" ish) and an internal stinger that can be pulled out, just like my old Allspeeds from 82/83.
I am not sure how that kind of request would be received though.....

[rodneya]

You could try contact Roger Allen at Wicked. He has opened a pipe shop recently and may be willing to make the pipes the way you want them.

[irk_miller]

I used Pipelyne chambers for an AC on my LC conversion top end and had to make my own set of flanges to make them fit.

[m in sc]

Gary @ specII was very accommodating for me, did exactly what i asked for and they were perfect. he -will- do tucked pipes for a bike strictly running rearsets if you ask. ie: tighter to the bottom of the frame.

if you want all that, either learn how to mod, build, or get someone to make a custom set, or buy a cone kit and have it welded to your liking, i had to do that before i could tig on my old mono-shocked H1. they were literally built on the bike. I bought a set of unwelded denco reproduction cones and fit them on the bike.

the rz pipes wont work well on an aircooled as they are, its better to start with the design for the motor and configure it to fit your frame in the way you want them fit. reach out to Roger or Gary. Maybe reach out to Jim Lomas he might be able to do something for you.