Page 1 of 1

AF RB250 vs CP SS250

PostPosted: Sun Jul 16, 2023 6:09 pm
by GP Kevo
Any thoughts? I want to build one or the other. For straight line dry lake bed racing. I'm thinking maybe the longer stroke would be more advantageous here and maybe the 2 mm smaller bore of the SS keeping a little further from the cylinder studs. Am I wrong?

Re: AF RB250 vs CP SS250

PostPosted: Tue Jul 18, 2023 9:19 pm
by dscscotty
Hi there, we (Team DSC Racing) have had great success circuit/endurance Racing here in the UK with our RB kitted engines. RB 250 cylinders are very versatile and can be tuned for good BHP & Torque without to much work, Darrell Taylor/Eric Cope, Chiselspeed and several others have had great results with RB250 engines on the sprint/straight liners events with some incredible speeds, on saying that yhere are some very quick ss cylindered engines, particularly from JB Tuning.
Good luck and keep us posted
Regards
Scotty DSC

Re: AF RB250 vs CP SS250

PostPosted: Thu Aug 31, 2023 7:09 pm
by GP Kevo
Thanks for your reply, Scotty. Does DSC use 70 or 72 mm RB barrels? Are any of you racing mono port RB 252 barrels? Just trying to get a picture of what's being used in racing these days. I took a brief ride on a mate's RB 225 a couple of weeks ago, and though it had a bit more grunt at low rpms, I think my TS1 is at least as quick once the revs are up. Everyone here assures me that the RB 250s are much, much faster.

The only racing out here is on the salt flats, and I want to see how fast I can go on a full frame Lambretta. I'm going to try a run with my TS1, once the lakes dry out and after I've built my GP200 so I have something to ride if something goes wrong. With my current gearing and exhaust I wouldn't expect more than 85 mph, maybe a little more. So far, 102 mph has been done here, and that looks to be smashed very soon, albeit on a slipstreamer custom frame. That's why I'm looking for a major upgrade in power. :)

Re: AF RB250 vs CP SS250

PostPosted: Fri Sep 01, 2023 1:05 am
by Fast n Furious
What is the altitude of the salt lakes that you have there Kev?

Re: AF RB250 vs CP SS250

PostPosted: Fri Sep 01, 2023 7:16 am
by GP Kevo
Fast n Furious wrote:What is the altitude of the salt lakes that you have there Kev?


888 meters or 2913 ft above sea level. It's where Todd Rodgers runs his modified Lambrettas.

Re: AF RB250 vs CP SS250

PostPosted: Sat Sep 02, 2023 2:49 am
by Fast n Furious
The lack of oxygen and the poor traction on salt means you ain't gonna break any world landspeed records here.
These unique conditions we cannot replicate here on this side of the pond so any advise would likley be from the heart only with best wishes.
I also think the end result will be a reflection of what rules you are working to. Is this a closed shop or open season?

Re: AF RB250 vs CP SS250

PostPosted: Sun Sep 03, 2023 8:06 pm
by GP Kevo
I just want to give it a go. I don't think any world records will fall over here but it's more for the experience of doing it. The plan is to then go to Bonneville and run them there but that is even higher elevation. I wish we could find an old airfield in the desert, but I'm pretty sure these are still on active military bases.

Re: AF RB250 vs CP SS250

PostPosted: Mon Sep 04, 2023 12:09 am
by Fast n Furious
Bad water basin in Death valley is below sea level. Just need a long enough piece of asphalt. :lol:
(gonna be in that neighbouhood area myself in a few weeks time)
Good luck to you Kev. Look forward to reading all about it.