Camshaft

[joolz6]

Good afternoon !

I need help in finding the small aluminium part that is fitted to the end of the exhaust camshaft , its approx 23mm in length and 26 mm width ( its a small cylinder shape with a grove in it for the camshaft to sit in. The one fitted to my 1955 model 20 is so badly scored ( due to bad oil circulation i think ) it sits against a bronze guide, I cant find a picture of it or even a part number . i have tried so many times to upload a photo of the part but just cant get it to upload ! If anyone can help me with a part number that would be a great help !!!

Many thanks
John

[Groily]

https://www.amoc-parts.com//store/comer ... ategory=53
I think you're describing the Oil Distributor, part # 014247 for post-54 (014246 for earlier years)
I THINK the only difference in the bits between years is 'hole or groove' to let the oil through; but both versions are in stock they say, along with nice shiny end caps and much besides, at Club Spares. Under Twin Engines page 4 for pic off the earlier one, or put 'Oil Distributor' in the quick search box to see both versions . . .

[joolz6]

Thanks for that ! Yes thats the bit i am looking for Now just have to find the bronze guide !!1
Many thanks Groily

[dave16mct]

I don't think there's any bronze guide normally. Perhaps your cap was modified for some reason. Usually the chrome cap keeps the distributor in place. The correct copper washer has to be used to avoid end loading it. Early '55 model 20 had a jet which was changed to the distributor for late '55. Perhaps yours had a jet and was converted?
Dave.

[Groily]

Not quite with you on the 'bronze guide' bit John - but I may be being thick! (Oh, and I see help has arrived from Dave, phew!)
The distributor runs in the drive side case, just behind it sits the drive side ex camshaft bush.
If your motor is stripped right down, then no problem (subject to any reaming issues) to replace the bush and / or the other two, but if it's together, it's a lot of work for a bush that actually wears pretty well on these as a rule.
Pic 2 is a completely bare '54 drive side case off an M20, outside view - you can see where the oil gets 'distributed' into the gallery that gets it up to the top end, if you look past the threaded bit of the hole where the shiny (or less-shiny) cap goes. The hole or groove/flat in the distributor aligns every rev and lets oil through.
Pic 1 is a new camshaft bush, sitting in the general area, inside view.
As to Dave's point about a jet being used on some '55s . . . I bow to his expertise.
How very unlike AMC to make all these little changes between years, mid-year, or any other time!! I don't think!

[joolz6]

You are all great !!! Now i just have to decide which camshaft bush i need lol either part number 042100 or part number 042101. I retire in nine months and i really want to get her finished by then ! ( i have only been working on her for eight years now || One day at a time !

[Groily]

If you are going to replace the camshaft bush, the one I showed isn't actually the right one. My bad. That was a timing side one with the top hat, the drive side is plain. (I just picked the first that came to hand in of my box 'o bits to take the pic.)

The part numbers for the Twins are 010474 drive side, and the flanged t/side ones are 011654. Both available, the spares site says.
The ones you refer to are, I think, for the Singles.

[joolz6]

Thanks for all the info Groily !!!! I will order all the parts that i need today !! I notice just now that Dave says to fit the correct copper washer , Any idea of this part number ? ( i cant find any copper washers for sale on here ) Just one more thing how do i access exploded views of the cam ( or any other parts for my bike ? ) You know i would be totally lost without all the help you guys have given me !!

Many many thanks
John

[dave16mct]

Strangely the copper washer isn't listed in the parts list, only a fibre one. But in the 57-64 F Neill manual it says to use a copper washer to prevent end load. It's available from our spares as 023106 (replaces 011642). Here's a link to the archives with this manual: http://archives.jampot.dk/book/Workshop ... models.pdf
Dave.