connecting rod spit hole

I don't know, don't think it makes a big difference either way. Mine has over 70K on the engine with bearings installed as Norton intended. I can see the argument to close off the bleed holes, but I sure wouldn't bother unless the engine was already in pieces.
 
milfordite said:
I don't know, don't think it makes a big difference either way. Mine has over 70K on the engine with bearings installed as Norton intended. I can see the argument to close off the bleed holes, but I sure wouldn't bother unless the engine was already in pieces.
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I agree. It probably doesn't matter either way but if the motor is being built it won't do any harm if the hole is blanked off.
 
I always thought the oil hole in the rod was for oiling the main bearing, which was why the manual states it should face outwards. As mentioned earlier in the thread, there is probably enough oil thrashing around in the crankcase to do this anyway so probably not vital to have it for that reason. Plenty of other Brit twins do perfectly well without the oil hole. Just my 2 bob's worth.
 
LAB to the rescue

C

Thread 'Con rods Oil Hole'

Hi Any one know why some rods have a oil hole and otheres don't Droped a rod the other day ( dont fit a oil pipe tap) new rod ( SH) has a hole Parts book doesnt show diferent numbers though Running in at the moment all seems OK But not many Commandos riders here in SA to swap info with

Conrods with the bleed hole were introduced on the Atlas model from engine number 116372 in 1966 and approximately 10,000 engine units before the first Commando, so all standard Commando conrods should have the bleed hole.
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Now in 66 there was the at the time unseen 4CA random spark problem which gave overheating issues on BSA driveside pistons (BSA added a hole to their A65/A50 con rods) and also Triumph had issues too so maybe Norton added the hole to cure a driveside piston issue. The real cure for BSA was not more oil but the 6CA AAU with increased dwell time which got rid of the random extra spark, BSA kept the bleed hole.
 
Last edited:
I think the reaction feature started much later than when Jim first started posting.
dobba99 said:
Its not the fact that the journal hole aligns itself with the bleed hole twice each revolution which it does. Its that it is constantly bleeding off high pressure oil all the time the crank is revolving.
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