340 propshaft question

Post by **340cbr** » 24 Feb 2007 01:27 am

How much power does the original 340 flanges from the prop shaft can handle and how many miles they hold before starting to wear?

I just came up with a solution of keeping the original flanges but welding them to a pipe made of steel, having the original bushes from the flanges to cope with vibrations. Is this a good option or just a waste of time and money?

And how much weight is acceptable for a propshaft? The original one weighs arround 3kg but one made from steel will weight a lot more... Can these be an issue?

Waiting for opinions

Post by **classicswede** » 24 Feb 2007 08:40 pm

They can cope with quite a bit more power than std and sometimes they will not cope with a std engine for very long. The problem can be on ocassions with the splines shearing or the rubber debonding.

If will not be able to weld the ends on as the rubber will melt.

Post by **340cbr** » 25 Feb 2007 04:14 am

So you think that the stock flanges will not cope with.. let's say, 150bhp?

How about the weight?

Post by **germ** » 25 Feb 2007 11:21 am

i am not sure but i guess it depends on the condition of splins and rubber?

Post by **pettaw** » 25 Feb 2007 11:22 am

100bhp possibly if you treat it gently. 150 bhp? No way

Post by **classicswede** » 25 Feb 2007 01:15 pm

You could put 150bhp through the stock prop if in good nick and you were gentle with the power. The problme with doing that is if/when it goes you risk damaging the bellhousing shaft or the gearbox one.

Post by **340cbr** » 25 Feb 2007 08:43 pm

The solution that I have found arround here is the stock flanges but without the alluminum tube.. with a steel one.

Good solution for 150bhp?

Another problem is that it will be a lot heavier than the stock one... Is this an issue?

Post by **foggyjames** » 25 Feb 2007 10:32 pm

The rubber is there to allow it all to flex a little, as well as to soak up some of the vibration. Replacing them with universal joints would make it a lot stronger.

The splines themselves are relatively strong, but the clamping technique isn't great.

cheers

James