Large or Small Camshaft Bearings

[Darren Groves]

My 'GE' engine has a camshaft that runs directly in the block, according to one of the Triumph suppliers this is a large bearing camshaft, excerpt from their website:

 

Small for engines with replaceable bearing fitted to cylinder block, originally fitted to TC engines, 1147-1286cc pre 1969.

 

Large for all other models, where cam runs in cylinder block. Bearings can always be removed for this range to be used on early models.

 

But this is a reply from another trader

 

GE blocks should be small bearing cam size. 

 

The MKIII profile cams we do are ground on to large bearing cams designed to fit in the later large bearing blocks (GK prefix 13/60, Spitfire MKIV, and 1500, etc).

 

My current camshaft is a Newman TRIS/280/405 PH2 (bought via yet another trader), according to the Newman website this is a Large Bearing.

 

Can anyone clarify what I should have, or know the diameter of the bearings of both types so I can compare to my old stock Herald cam that's gathering dust in the garage.

 

Thanks

 

[Pete Lewis]

I make early 1.8402" 1200up

 

1360 up 1.9654

 

if thats any clue

 

pete

[Darren Groves]

Thanks Pete, out of interest where did you get those measurements from?

 

I found this on the Piper Cams website:

Small 46.755mm Journal and Large 49.94mm Journal available.

 

I measured my old standard 13/60 cam and they were just shy of 50mm, so definitely looks as if it is a large...

[Pete Lewis]

in the H V & S workshop manual  page 1.104   

 

sorry  I  only type in inches 

 

Pete

[Darren Groves]

Thanks Pete, missed it in the WSM.