Chinadiesel type 188, enfield and exhaust pipe

[arnaud]

..so, i have been chatting with someone who got a lot more power from his chinadiesel.. it involved an k&N air filter, flowing of the head and.. tuned exhaust..
I always thought a 4 stroke diesel is not sensitive for exhasut resistance, but it seems i am wrong.
Here are pics of my exhaust bend creation;


I've come to understand it is way too restricting and even can foul the engine (muffler is a madras one with Db killer)
pricepart motorcycles (good adress vor parts and advice) has an exhaust pipe made to fit whih is 'shorter and 'thighter'but not cheap..
i am looking for tips how i can get one at a rerasonable price and more info about the lenght with/whithout/what kind of muffler is best..
Cheers!

[pietenpol2002]

We'd love to hear more regarding the flowing of the head and the tuned exhaust. Not hard to believe that engine would benefit from some work on the exhaust. Has always appeared to be horribly restrictive.

[arnaud]

Yes indeed, unfortunately, the person who gave me these hints and apparantly knows how to calculate the exhaust length at 34mm innder diameter, is hard to contact,
I suppose he is busy, or fed up with my questions..

Flowing would matter but i am a bit hesitant to remvove and install the very vulnerable cylinder head..

[pietenpol2002]

_

Flowing would matter but i am a bit hesitant to remvove and install the very vulnerable cylinder head..

It's unfortunate you're not in the states. I'd be happy to ship you a few spare heads to work at flowing. The 34mm sounds about right for that displacement, if only we knew the length. I suppose you could attach a long pipe, roll it up on the dyno and start cutting a few millimeters at a time.

BTW, how many miles on yours by now?

[arnaud]

Hi, on this engine not so much,in installed it 1,5 years ago but drove mostly jawa because of the enfield front brake..
The last engine did about 60 K when cylinder head ptoblems appeared, and after paying for a new head, but only getting heavily dmaged ones, and no refund, this happened 2 times, i gave up (Rotek, multistrobe) and later got his '13 hp'engine..

[boutje]

Yes indeed, unfortunately, the person who gave me these hints and apparantly knows how to calculate the exhaust length at 34mm innder diameter, is hard to contact,
I suppose he is busy, or fed up with my questions..

Flowing would matter but i am a bit hesitant to remvove and install the very vulnerable cylinder head..

I gave you an answer on the motor-forum

[arnaud]

Yes indeed, unfortunately, the person who gave me these hints and apparantly knows how to calculate the exhaust length at 34mm innder diameter, is hard to contact,
I suppose he is busy, or fed up with my questions..

Flowing would matter but i am a bit hesitant to remvove and install the very vulnerable cylinder head..

I gave you an answer on the motor-forum

You did!
The next is the quest for a muffler..