English French German Italian Spanish

Manx vs Inter Crank

Submitted by ken_campbell on Sun, 19/11/2017
Forums
Singles

Anyone out there familiar with the differences between the Manx and Inter cranks? I have a set of 1948 Manx cases, a Manx big end bearing and Manx rod. The flywheels that I have are Inter. All of these pieces came to me in basically one big box and the engine was assembled and running at one point. That was long ago and I don't know all of the history, so pieces may have been mixed up or gone missing. The Manx big end bearing is narrower than the Inter, so I'm trying to figure out if that is the only real difference with regards to width of the crank assembly. In other words, will the Inter crank fitted with the Manx big end bearing fit in the Manx cases? I have the appropriate bearings for the Manx cases.

Submitted by ken_campbell on Sun, 19/11/2017

Permalink

Previously Michael Rettie wrote:

Check out Ian Bennett's site here. May clarify some questions:

http://www.doddington-kent.org.uk/web_directory/bennett_cnc/norton_parts.html

Thanks. Actually I was just on there after doing some more measuring. He sells both timing side and drive side mainshafts for Inter and Manx (one for Inter and one for Manx. That jives with the timing side mainshaft that I have. It is longer than an Inter one to compensate for the narrower crank. You would think that the same rule would apply to the drive side, but the drive side mainshaft that I have is the same length as an Inter. maybe when the Manx cases were installed, they just replaced the timing side, because they had to line up the bevels and they just figured they could get away with the shorter drive side main?

Submitted by ian_allen on Wed, 06/12/2017

Permalink

Hi.

You don't say whether your's is a 500 or a 350.

Ifit is a 350 there are a few of things to note:

For 1948 the 350 Manx had

- a shorter 6.5" rod (down from 7.5"). This was combined with a piston with a very high crown above the gudgeon pin.

- a shorter barrel.

- a common crankcase casting - which means engine plates, primary chainguard and associated fixings all changed to 500 items.

- the vertical drive shaft & cylinder head nuts changed too.

Ian Bennett is very helpful and his stuff is first rate. He also does a 7" rod - primarily for Inters - which if fitted to a 48 Manx 350 enables you to use Inter/earlier Manx pistons which are far less scarce than the original 48 Manx pistons.

Cheers,

Ian.

Submitted by ken_campbell on Wed, 13/12/2017

Permalink

Previously ian_allen wrote:

Hi.

You don't say whether your's is a 500 or a 350.

Ifit is a 350 there are a few of things to note:

For 1948 the 350 Manx had

- a shorter 6.5" rod (down from 7.5"). This was combined with a piston with a very high crown above the gudgeon pin.

- a shorter barrel.

- a common crankcase casting - which means engine plates, primary chainguard and associated fixings all changed to 500 items.

- the vertical drive shaft & cylinder head nuts changed too.

Ian Bennett is very helpful and his stuff is first rate. He also does a 7" rod - primarily for Inters - which if fitted to a 48 Manx 350 enables you to use Inter/earlier Manx pistons which are far less scarce than the original 48 Manx pistons.

Cheers,

Ian.

Thanks,

The cases are 350 from 1948, but the crank is 500 or converted to 500 with a 7.5 Manx rod. I have one of Mr. Bennett's Manx barrels along with a few other bits and yes he makes nice stuff.

 


Norton Owners Club Website by 2Toucans