Wednesday, October 26, 2011

Customer Bike Spotlight: Magnus's Finnish Triumph

"Hi Tyler, Happy you like it! Been watching the Salt Ghost DVD a few times during the rebuild...

The bike is a 1953 6T Thunderbird sold new in Sweden back in -53. (Still got the original bill of sale and title. I´m the 5th owner!) It was cut up in the 70's as a typical Swedish chopper. In the 90's it was found in boxes and rebuilt to look more or less like this. When I got hold of it a few
years back it was fairly beaten up and ran like a sack of shit compared to now.

The engine is rebuilt with .060 oversize pistons and new valves. Still have the original cast cylinder and head. High lift cams and balanced flywheel. Changed the pointsplate and bearings on the Lucas K2FC magneto and got a new ATD for it. Scrapped the single Dellórto carb that came with the bike for twin Amal 928s. Now it runs beutifully. I also rebuilt the gearbox, primary and clutch. And got a new generator so I sometimes got lights...

- Wheels are 21" and 18" on Akront rims.
- Triumph TLS front brake.
- Magura and Tomaselli controls.
- Moon oil tank.

Have not decided on paint yet. Kind of dig the raw finish. It won´t do any records on the salt but for beating around the gravel roads of Finland it´s a blast!



Anonymous said...

Hello all,
I just have a question, i'm gonna install 2 carburators on my 6t pre-unit and i'd like to know what is the best amal choice ??

Thanks a lot

Anonymous said...

Florian, I can only speak for myself, but the intake on my cast iron head was 26,5mm. The intake manifold was 27mm. I ported the head to 27mm so there were no sharp edge and ported the manifolds facing the carbs to 28mm. So I went with a pair of 928 Amals (28mm bore). I also fitted a balance tube between the left and right manifold. To create whats called Venturi effect (google it), I guess the head would have to be ported out to 28mm as well. Then it´s a matter if jetting. I went with a 170 main and a 106 needle jet for now. The Amals I got from Lowbrow came with a 180 main.

A wise man said: Two carbs, twice the trouble. But it looks cool.

The camring in my magneto is slightly worn so I can´t get the ignition timing dead even between cylinders, so with two carbs I can carefully adjust the enrichment screw to get the left side a tiny bit more gas.

There are people with lots more knowledge about this stuff. I´d check with Wes White at Four Aces for his input. Everything seemes to matter: What sort of cams, compression, ignition and so on. The 6T came with a variety of carbs over the years from a single SU carb to a single Amal 376 monobloc so it´s not really set up for dual carbs. Also a lot of pre units out there are fitted with a later model 9 stud cylinder and aluminum head and most of them are made for two carbs already. So it´s a matter of what your particular engine looks like. Think most Bonnevilles use Amal 930s.