RB 20
Posted: Sat Apr 16, 2022 12:59 pm
If you were building your ultimate Rb20 motor what would be your perfect ingredients
60 stroke crank
Cassette type clutch
Fran SuperTourer pipe
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Re: RB 20
Posted: Fri Apr 22, 2022 3:29 pm
Re: RB 20
Posted: Mon Apr 25, 2022 11:06 am
I had an RB215 built by Dan @ Scooterotica for my TV175 a few years back now - and it was a cracking engine... making 28bhp & around 19 ft/lb torque.
Build spec was; RB20 cylinder kit, 62/116 Crank, GP200 Close Ratio box, AF Cassette Clutch, 34mm Delly, Fran Race pipe, 17deg static timing with BGM stator with AF Mid flywheel... and Dan's fast road tune with porting spec @ circa 130 trans / 190 ext.
I changed/upgraded a few things on it like; SIP Vape (Sport) Ignition, one of the LTH cnc Reed manifolds and a Chiselspeed Easy Clutch conversion (no performance gain, but much nicer clutch action) - and I swapped the 34mm carb for a 30mm vhsh for a short time, but ended up going back to the 34mm, as the although the spit back was greatly reduced with the 30mm, the improvement on fuel consumption was negligible and I felt the 34mm suited the engine & my needs better.
The biggest improvement though was upgrading to the AF 5-speed box, as there was always that nasty gap between 3rd & 4th with the GP200 box, which the 5-speed did away with and really transformed the the engine and the way it rode...
The ignition & manifold upgrades added a bit more power also, and I think the best dyno result I got with the upgraded parts was; circa 29.5bhp & just over 21 ft/lb torque. I did also buy a Pipe Design Bullet exhaust for it, but never got to trying it out as I ended up selling that scooter on before I ever got around to fitting the pipe.
So (based on my experience) my ultimate spec would be;
Build spec was; RB20 cylinder kit, 62/116 Crank, GP200 Close Ratio box, AF Cassette Clutch, 34mm Delly, Fran Race pipe, 17deg static timing with BGM stator with AF Mid flywheel... and Dan's fast road tune with porting spec @ circa 130 trans / 190 ext.
I changed/upgraded a few things on it like; SIP Vape (Sport) Ignition, one of the LTH cnc Reed manifolds and a Chiselspeed Easy Clutch conversion (no performance gain, but much nicer clutch action) - and I swapped the 34mm carb for a 30mm vhsh for a short time, but ended up going back to the 34mm, as the although the spit back was greatly reduced with the 30mm, the improvement on fuel consumption was negligible and I felt the 34mm suited the engine & my needs better.
The biggest improvement though was upgrading to the AF 5-speed box, as there was always that nasty gap between 3rd & 4th with the GP200 box, which the 5-speed did away with and really transformed the the engine and the way it rode...
The ignition & manifold upgrades added a bit more power also, and I think the best dyno result I got with the upgraded parts was; circa 29.5bhp & just over 21 ft/lb torque. I did also buy a Pipe Design Bullet exhaust for it, but never got to trying it out as I ended up selling that scooter on before I ever got around to fitting the pipe.
So (based on my experience) my ultimate spec would be;
- 62/116 Crank.
34mm Carb.
Fran Race Pipe.
Vape Sport Ignition.
AF 5-speed Gearbox (with circa 4.81 final drive).
AF 6 plate Cassette Clutch (or better still LTH 7 plate).
Easy Pull Clutch Conversion.
Re: RB 20
Posted: Wed May 04, 2022 7:23 pm
I concur. Great speccartmel808 wrote:I had an RB215 built by Dan @ Scooterotica for my TV175 a few years back now - and it was a cracking engine... making 28bhp & around 19 ft/lb torque.
Build spec was; RB20 cylinder kit, 62/116 Crank, GP200 Close Ratio box, AF Cassette Clutch, 34mm Delly, Fran Race pipe, 17deg static timing with BGM stator with AF Mid flywheel... and Dan's fast road tune with porting spec @ circa 130 trans / 190 ext.
I changed/upgraded a few things on it like; SIP Vape (Sport) Ignition, one of the LTH cnc Reed manifolds and a Chiselspeed Easy Clutch conversion (no performance gain, but much nicer clutch action) - and I swapped the 34mm carb for a 30mm vhsh for a short time, but ended up going back to the 34mm, as the although the spit back was greatly reduced with the 30mm, the improvement on fuel consumption was negligible and I felt the 34mm suited the engine & my needs better.
The biggest improvement though was upgrading to the AF 5-speed box, as there was always that nasty gap between 3rd & 4th with the GP200 box, which the 5-speed did away with and really transformed the the engine and the way it rode...
The ignition & manifold upgrades added a bit more power also, and I think the best dyno result I got with the upgraded parts was; circa 29.5bhp & just over 21 ft/lb torque. I did also buy a Pipe Design Bullet exhaust for it, but never got to trying it out as I ended up selling that scooter on before I ever got around to fitting the pipe.
So (based on my experience) my ultimate spec would be;
62/116 Crank.
34mm Carb.
Fran Race Pipe.
Vape Sport Ignition.
AF 5-speed Gearbox (with circa 4.81 final drive).
AF 6 plate Cassette Clutch (or better still LTH 7 plate).
Easy Pull Clutch Conversion.
