RB20 (200cc) - Pictures and Spec

[paulmgreen]

Great - and detailed report Dan......


Just by chance I have dug out my GP150 casing from under the work bench...... I feel a project coming on!

[joespeed]

very good detail dan.do you need to open up the spigot on the 150 case? are there any other mods needed?
regards
joe
keep us posted on your testing

[sean brady scooters]

spigot does not need altering Joespeed..........kit fits straight in........

[J1MS]

Great - and detailed report Dan......Just by chance I have dug out my GP150 casing from under the work bench......  I feel a project coming on!

Same here, old Group 3 150 engine (Indian) sitting on my bench port's already enlarged. but I still want to see a propper Dyno chart.   

[RinB]

Dan good report m8
Definately intreged about the 3 three finger boost port I believe the rb250 has the same port but still keeps the bridge
Exhaust ports.

Watch this space as I will hopefully have one on the table next weekend, & Ill do a report on the RB250 as you have done Dan.

Word of WARNINING if stroking the RB's watch the boost port fingers ,as the bottom ring can catch under the finger in the port . Make sure you check this

As for the manifold definately weld it up and reshape without any hesitation ,Ill put some pics on here later. But I think Jason has already shown this.on old forum

Also I will show what I have done to a RB225 once its finnished, you have seen some photo's but they are I can asure you work un-finnished

Smiffy

[noggin1969]

Just a question is the exhaust port manifold standard flush to the barrel or kinked at an angle like the other RB kits ? as i was looking at the exhaust you have for it

[sean brady scooters]

its entry is angled.........like the Rb..........and every other modern m/cycle.........

[corrado]

Am I right in thinking that the inlet manifold is exactly the same as the RB22? I though that they may have made it to suit a smaller carb, but then again I suppose everyone would have just modified it to suit a 34 /35 mm carb.

[sean brady scooters]

we were given an RB manifold.................but then, thats cos we are going to tune it.
....
not sure what it would be supplied with otherwise...........suppose it may depend what you ask for............

[RinB]

The reason being that as the exhaust cracks opens the initial blow down doesnt go out of the port straight but at an angle of say 40-60deg then as the port opens it straightens towards the 10-15deg.

So to help that first pulse flow without hitting the opposing exh pipe side wall the ports are angled.

I believe this is the one major thing Terry shepherd wished he had done with the TS1 barrel

Smiffy