Limitations of Dio motor?

[stepthrutuner]

Im build one a af18 with malossi crank and corsa. 28mm pwk. pg long. and 8.4 gear. for my project honda sky.

strap it on the real dyno test.

What will be the displacement on that?

[fastplastic]

72cc malosi crank is stock stroke not sure if it is a suffer or not but the answer remains the same 72

[stepthrutuner]

The Polini Corsa is comparable to the Top Performance Trophy I run on my Piaggio Derbi Atlantis, jugs that will pull into the 9500+ range with the proper pipe. I suppose the basic port timings are in the neighborhood of 186/124. I've added 0.8mm base gasket and filed my piston top in the areas of the xfers and boost ports to achieve cylinder timings of 190/127. Eliminating the inner ridge at the bottom of the transfers and boost ports and matching the outlet of the exhaust flange with my pipe was the only grinding I did on the cylinder as I wanted to keep the cylinder basically stock and maintain some sensibility in fuel economy as this is my street ride. I run a 21 Dello phbg. To utilize the capacity of that race crank and 28mm carb won't you need to get the port timings to near race specs, i.e., in the neighborhood of 202/132 for 12,000 rpm operation? Suggest you study A.G. Bell's Two Stroke Performance Tuning for race setups if you haven't already.

[Trafficjamz]

To utilize the capacity of that race crank and 28mm carb won't you need to get the port timings to near race specs, i.e., in the neighborhood of 202/132 for 12,000 rpm operation? Suggest you study A.G. Bell's Two Stroke Performance Tuning for race setups if you haven't already.

Who are you talking to?

are you asking questions or trying to tell others how to tune a polini kit?

[fastplastic]

hope its not me my time slip tells a heck of a story compared to his non existed one lol

[stepthrutuner]

All I'm saying is to utilize 28mm flow capabilities with 72 cc the motor will have to be spun to 12,000 rpm or more whether any of you like it or not.

[fastplastic]

BITE ME lets see your time slip all those words show nothing if you dont prove it

[fastplastic]

your probably a cool dude. but with 8 posts and nothing to show us and then to give ppl that have been racing for two years or more (not claiming to be experts) advise you kinda gotta back off..... and I like the Jennings book

[stepthrutuner]

I bet you just bolted that cortessa on right out of the box. And isn't it Contessa, Mr. expert?

[kingkamehameha]

I bet you just bolted that cortessa on right out of the box. And isn't it Contessa, Mr. expert?

No cortessa hybrid

[fastplastic]

I bet you just bolted that cortessa on right out of the box. And isn't it Contessa, Mr. expert?

no bolt on's here yes its a contessa but the port work is done so, once again BITE ME *!

[Trafficjamz]

I bet you just bolted that cortessa on right out of the box. And isn't it Contessa, Mr. expert?

A "cortessa" is a word fastplastic made up.

a mix between a Contesta and Corsa.

Contessa = bad spelling

[stepthrutuner]

Yeah. I thought about that after the post. That makes my Derbi's setup a TopAir.... as I use a TP Trophy 48mm cylinder with a 5.6cc AIRSAL squish type head (down from 7.2cc from the Trophy head) to restore the compression lost by spacing up the jug 0.8mm.

I was checking out Tillotson carbs last night and ran across this site that I don't mind sharing. Lots of good 2t info there despite being geared toward karts. Chill out, guys. Peace....

http://www.iwt.com.au/techinfo.htm#

[dv/dt]

Yeah. I thought about that after the post. That makes my Derbi's setup a TopAir.... as I use a TP Trophy 48mm cylinder with a 5.6cc AIRSAL squish type head

I want a derbi! GP1 plz!

[stepthrutuner]

Yeah. I thought about that after the post. That makes my Derbi's setup a TopAir.... as I use a TP Trophy 48mm cylinder with a 5.6cc AIRSAL squish type head

I want a derbi! GP1 plz!

Chain final drive model and a billion bucks to mod it out..... no, seriously I like your screen name. You musta took some calculus.