ok perfect .
in general on an engine which is well designed, what should be the height of the bottom of the auxiliary exaust port?
ok perfect .
in general on an engine which is well designed, what should be the height of the bottom of the auxiliary exaust port?
If its done properly the Aux can be below the A port timing edge.
Here is a TM homologation diagram - with a small mod I make that puts the top corner over the small end pin.
But as the exit angle is very shallow , there is minimal effect from port linking so it makes more power.
Ive got a thing thats unique and new.To prove it I'll have the last laugh on you.Cause instead of one head I got two.And you know two heads are better than one.
Maybe it's an acquired taste but I don't hesitate to use epoxy in the transfer ducts. Better have the glassfiber kind, that way chunks won't fall out and you can arrange so that it is mechanically locked.
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Hello, after making the modification to cool the exhaust duct on a cagiva mito cylinder.
I have the problem of having the exhaust gases too cold. From the usual 550 degrees I only have 440 degrees.
The carburetion is perfect. Do I have to change the ignition advance?
I think you have to question whether he actually tested this, bacause how would it circulate, and how would it not leak.
Not only does the implementation look highly suspect - just about impossible for it not to leak , but how can the carburation be " perfect " at 550* or 440*.
Neither number are even close , on track or a dyno.
My original test was on a B homologation cylinder , unwelded at the time to reduce the exit area , and it would leak vey easily until I discovered Loctite Master Gasket in a syringe.
The later cylinders had much more vertical area for the slots and had no issues.
Ive got a thing thats unique and new.To prove it I'll have the last laugh on you.Cause instead of one head I got two.And you know two heads are better than one.
I haven't been on here in a long time, what's the trick to getting a jpg to show directly in a post (not as an attached thumbnail).
I have the jpgs loaded on Dropbox but adding the Dropbox links to the post doesn't seem to do anything according to the preview.
Thanks.
Anyway the thumbnails show high speed RECORDED pressure data (cylinder, intake, exhaust) that I promised ages and ages ago. I planned to have crankcase pressure too but will have to do that another time. Yamaha Banshee with some mods, details to follow.
thanks wobbly.
I took the tm digram and converted it (roughly) to my bore and stroke to be able to insert it into my cylinder to give me a visual idea of the difference.
woow quite a difference.
ports A and B are larger, port C is similar.
my biggest problem if i want to try to get close to your diagram is the divider between port a and port b.
either I remove it and remake one and I weld it in the right place (very difficult)
the other option would be to widen port A as much as possible towards port B while keeping the current divider (easier)
for the auxiliary exaust port I can reshuffle it with solder.
for port A I can rebuild the exaust side as well as the top also with solder.
to widen the B port I will have to convert or modify my piston 2 ring to a single ring with the ring gap in the center (something I never did) of the C port.
it's a big project but i'm looking at all the options. thank you
Hello Andreas.
i thanked wobbly for providing me with the tm certification diagram to help me understand the port layout.
for welding I am talking about tig welding.
a friend of mine is a welder for prototype helicopter projects, he has very small, pencil-sized welding tools. for example some time after having stroked a cranshaft I had too much transfer port duration so to lower the port he reshuffled the edge.
then I had the nickasil redone and finally I filled it with jb weld epoxy.
Just a little parenthesis to tell you that I speak French.
I understand English fairly well but for the spoken word I work hard with my friend (google translate) to correct myself and allow me to communicate with you.
if you see incorrect verb tenses or anything else that is not perfect it is not intentional.
thank you.
anybody recognises these exhaust ?
these had the white label with "KR1" attached to them but they seem to need a long flange on the cylinder to slide them over to fit, and the tailpipe comes out way too low for KR1's
I can't remember where I got these, but they don't fit a KR1. the support on the belly is all wrong.
both are after market and very low on weight
I understand you speak French, I also understand what you are saying (probably).
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