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brucey

Tiger Cub Distributor Type Camshaft into Side Points Engine.

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I have acquired a new 'R' Cam and gear from an early Distributor Cub and want to fit it to my later Side Points Engine.  I am running electronic ignition so points etc are not an issue.

I am getting an earlier type outer cam bush (blind type) to match the 1/16" smaller diameter outer end of the earlier cam shaft.

The gear and inner shaft fit into my engine without issue and the overall length looks the same (including the slotted distributor drive of the cam shaft) 

I will drill into the blind bush from the inside of the gearbox case to supply oil to the outer camshaft bearing.

Is there anything else I need to do?  It looks as simple as that!

 

As always, any advice appreciated.

Edited by brucey

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Blimey, surely I’m not the first person to have done this🤔😳

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You will find there  is two types of gearbox/cam cases as the o/d of the cam bush are smaller on the distributor engine I managed to get the correct one for one engine  The other engine I made a sleeve to fit over the bush and into the case I made little top hat to fit over the end of the bush and bonded them on with epoxy glue Tried the R cam made it harder to start and lost some bottom end power Reverted to standard cam The engines can vary in power a lot one engine runs sweet the other not so yet both built to the same spec

 

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4 hours ago, naichuff said:

You will find there  is two types of gearbox/cam cases as the o/d of the cam bush are smaller on the distributor engine I managed to get the correct one for one engine  The other engine I made a sleeve to fit over the bush and into the case I made little top hat to fit over the end of the bush and bonded them on with epoxy glue Tried the R cam made it harder to start and lost some bottom end power Reverted to standard cam The engines can vary in power a lot one engine runs sweet the other not so yet both built to the same spec

 

Many thanks for the information. I have a lathe and some phos bronze so if the worst comes to the worst I’ll turn a new top hat outer bush. 

My Armac Cub is running an ‘R’ cam and goes very well so worth a try 😊👍

Not too hard to swap back if it doesn’t work. 

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yes I found out 2 type side gearbox cam case I using distributor cam in mine points in the side then have plane cover on end blank the small hole to adjust the distributor I had new big end and and long stroke oil pump conversion merriden  done it just put all together now 

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Ok, the solution is quite simple😊

I got a special bush from UPB. 

The OD matches the later Cub side points gearbox cover and the smaller ID fits the outer shaft of the earlier distributor R (or standard) camshaft.

with the bonus that it is a blind bush so should reduce oil leaks  

A small amount of fettling will be required which includes drilling an additional lube hole to supply the outer camshaft bearing. 

Photo of old (top) and new (rbottom) plain closed bearings attached .

Hope this helps others. 

 

cam bush.jpg

Edited by brucey
smaller photo file size

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well been thinking about that just going leak oil out so I better get one of them bushes have you got the part number I will get one upb thank brucey   

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2 hours ago, freelander andy said:

well been thinking about that just going leak oil out so I better get one of them bushes have you got the part number I will get one upb thank brucey   

Just speak to Bob. However I would warn you that I ground about 1mm off the outer end of the camshaft to give me the required clearance at the end of the closed bush. I also skimmed about 0.1 mm from the ID of the bush on my lathe to give me the required fit. Also as said previously, an additional 3mm diameter lubrication hole needs to be drilled at an angle from the inside of the gearbox case so it breaks through just over half way down the bush. 

If you are not happy carrying out these operations, get an expert to do it. 

Another option would be to do what Naichuf has done and simply make an ally cap to cover the open end of the bush sticking through the gearbox case. Not sure if this needs the additional lube hole🤔

Hope this makes sense 😊

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