ESE's works engine tuner

[TZ350]

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Refreshing the Suzuki GP110 Bucket Racer for the new season.

Piston kissing the head perfectly. Moths have been nibbling the piston, Very long rod (RD400), crank webs machined back for reduced windage on the rod and maximum crankcase volume.

After untold racing miles the condition of the motor is pretty good.

[Wos]

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Refreshing the Suzuki GP110 Bucket Racer for the new season.

Piston kissing the head perfectly. Moths have been nibbling the piston, Very long rod (RD400), crank webs machined back for reduced windage on the rod and maximum crankcase volume.

After untold racing miles the condition of the motor is pretty good.

Why do the Moths have that hunger?🤣🙈

Are there mixture / end gases in squish gap trapped?

I do always a print with solder to have a picture if quish is piston parallel or opening a little bit...

To avoid trapping this dammed Aluminium Moths😮🤣

Grüße Wolfgang

[Peljhan]

Extending the cones past the end point and then cutting across the actual center point is the real trick.

Wobbly, do you have any advice or suggestion how to make complete exhaust in solidworks. I made myself an assembly with cones as parts and each cone has basic sketch for revolve operation that also has dimensions inside for where the seam weld will be, end cut and start diameter. End diameter is than expressed as grey dimension which is used as starting diameter in next cone with equation-reference and next cone also has same angle cut as last cone has.
Than I connected everything into excel, so I "just" change dimensions in excel and viola, I have exhaust as imagined with a bit of excel tweaking. Only downside from here is that I have to click refresh so many times as many cones I have.

Problem is, one exhaust funcitons great. I make than pack and go for new exhaust. Change the dimensions in excel as desired, but, all references don't get refreshed. Usually they are all there. If I click on sketch, all equations and references are there, but not working. I have to manually click the equation and just copy it for nothing and close and than it works from there on. Sometimes some cones go bananas when they are flipped inside out as socks, I also have to repair those manually.
Problem is, 20 section exhaust has about 100 equations and to do that manually I would be faster to calculate exhaust with cone layout and print it with needle printer on paper as I did 15 years ago

Should I do something differently, maybe complete exhaust made just with surfaces. Any guides would be great. Thanks.

[TZ350]

Why do the Moths have that hunger?🤣🙈 Are there mixture / end gases in squish gap trapped? I do always a print with solder to have a picture if quish is piston parallel or opening a little bit... To avoid trapping this dammed Aluminium Moths😮🤣 Grüße Wolfgang

Yes, I think you are completely right. I will try to match the curvature of the squish so it more accurately matches the piston crown.

[Wos]

Yes, I think you are completely right. I will try to match the curvature of the squish so it more accurately matches the piston crown.

I do machine squish with lathe first as a straight cause have no cnc and then with sanding paper to match radius of piston perfectly

Control you can do with paint from permanent marker... painting both surfaces and against each other rotating...later when completed with solder

Polish piston crow to mirror finish is reflecting heat...avoids overheating of piston

Polished squish area i do too ...but keeping corner razor sharp 😉

Good luck next racing season to you

Wolfgang

[lodgernz]

Yes, I think you are completely right. I will try to match the curvature of the squish so it more accurately matches the piston crown.

Rob, I gave up long ago trying to match the squish curvature with that of the piston crown.
I always turn a straight squish band on the piston at such an angle that the resulting straight piston squish band is a bit wider than that of the head squish band (which for me is alwaysw 50% of bore area).
That way it's possible to get identical squish angles, in fact I don't change the lathe settings between the two cuts (piston and head insert). Means going backwards on one of them but it works.

[Condyn]

What is the best way to determine if a carburetor is the perfect size?

Last year on the dyno we went from 41mm mikuni tmx to 50mm flat slides with mechanical pj. We gained a good amount of power with this change, as well as better ET at the track, so naturally I am curious about trying a 52mm flatslide next. They cost a small fortune, and I do not want to bore the 50’s because it could backfire (pun). In the other hand, maybe the 50’s are already too big, and I’d be better off with something between 41 and 50….

[Frits Overmars]

What is the best way to determine if a carburetor is the perfect size?

Rule of thumb: Carb diameter = square root of (cylinder capacity x rpm of maximum power / 900 ).
For engines with a rotary inlet this rule of thumb is fairly correct;
engines with a reed valve inlet can adjust their inlet timing themselves and are therefore less demanding in terms of diameter.

[skako]

Rule of thumb: Carb diameter = square root of (cylinder capacity x rpm of maximum power / 900 ).
For engines with a rotary inlet this rule of thumb is fairly correct;
engines with a reed valve inlet can adjust their inlet timing themselves and are therefore less demanding in terms of diameter.

Hello Frits,
From this formula we can then arrive at the required intake roto-port cross-section determined by Angle_Area [mm°2]

AA= Vc x RPM x 3.14 x Duration° / ( 4 x 900 ) [ mm°2]

[Condyn]

Rule of thumb: Carb diameter = square root of (cylinder capacity x rpm of maximum power / 900 ).
For engines with a rotary inlet this rule of thumb is fairly correct;
engines with a reed valve inlet can adjust their inlet timing themselves and are therefore less demanding in terms of diameter.

Hello Frits, Thank you very much.

[Wos]

Rotax 124 after 4 hours of first testings...clean burn.. green technology squish parallel..0.7 mm

Thanks to wob...frits...all together!

[Frank S.]

Watch out Wolfgang, now they have your fingerprints

[SwePatrick]

Early release!
I started dynoed my Kawasaki Overkill engine last weekend, and had to quit.
So this time then, is it actually producing any steam?

You betcha it did!

67.5 whp almost 60Nm
74.4 crank hp 10% losses
79.41 crank hp 15% losses


Pop on over to Youtube and have a look:

https://www.youtube.com/watch?v=Xz3RzMEezas

[lodgernz]

Plus harking back to my real shit fight with Patrick about converting RWHP to EngMod crank power - where he was absolutely adamant i was spouting garbage, he is now suddenly quoting exactly , and completely
agreeing with my and Neels assessment of 12.5 to 15% depending upon if its a Dynojet or not.
Everything with a grain of salt.

Wobbly, Are these figues of 12.5% to 15% that you quote, the estimated loss between crank and wheel HP on an inertia dyno?

I seem to remember that Frits long ago posted a quite detailed analysis of this and concluded that the loss would be about 10%, including tyre/roller friction loss.

Are we talking about the same thing or have I misunderstood?

[JanBros]

just wanted to share a new method of calculating exhausts. for a couple of years I've been using 2 very different pipes that give almost the same poweroutput. tried to make better pipes but not luch luck so far. So I thought : the best pipe must lie somewhere in between them. and so I calculated a pipe which has exactly the average dimensions of both . blue pipe = R, green pipe = GY, Average pipe = pink



and the result :




also made an experimental pipe. in the past I used a program of Coker racing to calculate exhausts, and that seemed to work also, but there was something funny about the diameters with that one : as you lower the rpm's, the pipe became fatter which is contrary imho. So I made a pipe using Coker length's and FOS diameters, and included a reverse-cone baffle (here compared to the AVG pipe) :

and the result is also good :