Norton Commando heads

Joined
May 22, 2004
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522
I should know this .. but I am pressed for time as usual and have not made time to research the Jobbie..

I am / was looking at a 1971 Commando head on Ebay ~ a local item here in Australia ~

I plan on working the albejeez out of the head when I get one.. all the good bits, porting and polishing etc etc ~ ( always open to suggests here too! eg : Black diamond valves, mushrooms etc)

Would a 750 head work on a 850 ~ even if it was 'worked over" ? ( The 750 has 30mm inlets as well eh!? sounds a big job enlarging ports top 32 mm ? )

Apparently there are no marking/ lettering on the head ~ pretty cheap at this point..
Thanks
 

Ron L

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Feb 27, 2004
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With enough labor and money anthing will work!! :lol: However, the bolt and stud spacing is different between the 750 and 850 heads, so it's not usually worth it to try to interchange.
 
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Apr 7, 2004
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No a 750 head can't be used with out lots of re-work. Bolt placement chambers ect. Small intake ports are not bad if fitted up to the right carbs. Even the dreded step down in size from carb to intake can have good effects to the flow in the head. Bigger is not better all the time. norbsa
 
Joined
May 22, 2004
Messages
522
Thanks Blokes
I did not realise re: bolts though..

Maybe I will just pass on this one ~ looks a tad rough as it is fitted with a helicoil too ... watch out for a 850 ~

I guess I could always switch and work and refit .. but have not replaced a Norton head.. dunno whether they are quite as easy as a Trident head ... (that was easy ~ )
 
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