Disappointing RB20.

[10 inch Terror]

How similar is the Imola to the RB20? I thought they were two different animals? As for gearing are you saying try 16/46 @ 5.29 Or 16/47 @ 5.40? I have a 16 front and 47 rear and don't mind playing around until I get the right combo.

[Adam_Winstone]

They are different but the Imola was about as close a small block kit as you could get, about as different as a Ts1 is to an RB. You may consider that to be very different but I don't think they are 'that' different, Super Monza and Rapido Classic... Now that is different!

Without looking, I've no idea what chain fits with 16/47 but know that 16/45 fits with a stretched chain. That comment might get people complaining that a stretched chain is a worn chain but people have used that combo for decades so it would certainly be fine for you to text your gearing with, if you have a sufficiently stretched chain.

If you said that you had a race pipe then I'd say you might find the 5.7 ideal bit with your 'mid' pipe I imagine that 5.2 would be ideal. Certainly worth a go as you might find the 5.7 is limiting your top end as the pipe acts as a rev limiter at those revs.

Adam

[10 inch Terror]

Cheers Adam. I have a pull down tensioner, so the chain shouldn't be an issue. As for the pipe, I may go Franspeed race, or a NK Race. Have you any opinion on either of those? Cheers Pete.

[Lambretta Sash]

You're plug being that colour i guess you are running sip race oil ??
Pipe wise the franspeed and nk are similar in outputs so its choice on looks and how long the last, i will say both have poor fitting stubs and i modify them so they don't leak.
Gearing wise its probably to high and 5.2 should suit.
As for carb settings on vhsh there always gonna be rich from af site,
Personally id go to a decent dyno operator who can help you sort these issues out

[corrado]

Here's my experience of gearing ......

I've got one of the early Imola kits, I bought it as a complete used engine, though the kit had done less than 200 miles. I'd blown my 175 kit up and was debating what kit to buy for it when a complete engine came up for the cost of a kit so took a punt on it. Lad I bought it off didn't build it so he wasn't sure exactly what was inside it but I knew him and he said it ran well so I took a chance. I put some new clutch plates in it while checking the gears and it had a pacemaker box and was running 5.6 ish final drive with the sprockets in it at the time. Had a PHBH 30mm and a scootrs exhaust. It ran well when opened up but I couldn't get the bottom end jetting clean even with a dyno run so I took the advice of a German guy on LCGB forums to put a TMX27 Mikuni on it. With the suggested jetting it ran like a dream, clean throughout, more power, less spitback and more MPG. I upset plenty of TS owners and startled a few power rangers as it was a rear flyer. I ruined the engine's characteristics though by changing the pipe and gearing to do a Lands End to John O'Groats run back in 2006. Fitted a JL3 and made the final drive 5.00. Numpty that I am I did it the day before I had to set off to Lands End so never got to try it beforehand. It wasn't until I got onto the M1 heading South that I knew I'd made a big mistake. First sign of headwind and I had to change down to 3rd and any incline saw me changing down to 3rd having previously been able to get up 99% of hills in 4th. It taught me a major lesson about gearing. Engine totally lost it's fun factor.
I had the opinion that if an SX200 with 8 bhp could pull 4.8 gearing then surely my Imola with double the power of the SX could also pull it .... you live and learn.

[Lambretta Sash]

Interesting reading Martin, I quite often see kits put on and not set up right with the wrong gearing and pipe on occasion.
Thinking back i had a 240 with fuel injector on that pulled sx box with 16t front and 400 x 10 rear tyre, the TS1 was the new kit on market and had to reduce front sprocket and remove the big tyre to get that performing.
These days i have an absorption dyno that helps me get them right and is probably the best bit of kit I've ever bought

[10 inch Terror]

I'm using Silkolene fully synthetic oil @ 4%, as recommended by AF. It's hard to get a decent picture, but the tip of the plug is a nice brown colour. I'm intending to get it on a dyno soon, but would like to get the gearing issue resolved 1st. I think I'll go 16 on the front and see what happens.

[Adam_Winstone]

I'd go 16 on the front with the pipe you have and evaluate that before doing anything else. A change to a race pipe would mean reviewing the gearing again... probably ending up back where you are now (15).

[10 inch Terror]

I'd go 16 on the front with the pipe you have and evaluate that before doing anything else. A change to a race pipe would mean reviewing the gearing again... probably ending up back where you are now (15).

I was thinking the very same. I have a 16 tooth in my shed and I'll try that 1st. Cheers everyone.

[eden]

0.