Cam compatibility

Is the cam of the 850 MKIII ES compatible with 750 engine?

Ciao

Piero

No :wink:

Did you notice how close the base circle runs to the core on "that" cam,maybe that is normal.?

An 850 MK3 cam can be used in 750 MK3 (1972) or 750 MK4 (1973) cases.

I have a hunch this is the cam in question which I asked Jim Comstock about today via PM.
It seems Piero and I are looking at the same things on eBay including brake hubs. :wink:

http://www.ebay.com.au/itm/130985527586 ... 1423.l2649

Time Warp said:

I have a hunch this is the cam in question which I asked Jim Comstock about today via PM.
It seems Piero and I are looking at the same things on eBay including brake hubs. :wink:

http://www.ebay.com.au/itm/130985527586 ... 1423.l2649

Click to expand...

Yes

johntickle said:

An 850 MK3 cam can be used in 750 MK3 (1972) or 750 MK4 (1973) cases.

Click to expand...

Why not 1970/1971 cases?

BREATHER .

though That One appears o.k. for that .

is " A N " cast in standover knorton ? ? Mnfg .

The subject cam is for a 20m3S engine and can be use through all remaining 750 and 850 and 850 MKIII.
EDIT thanks Matt
reexamined ebay ad and true it is cast AN cam (see pix 5). I would give only $10 to have as an example to show people what NOT to buy.
I had one of these (broken) but had to turn it back in to get a credit.

I enjoy about 30 cams on my shelf that represent the 1949-1975 NHT run. As far as I can tell all cam base circles for NHT as the same. The core design and size it was made on, evolved throughout the series.

This came is question looks rather over polished (sanding belt). Anyone interest should have the seller measure the journals and publish the data.

dynodave said:

The subject cam is for a 20m3S engine and can be use through all remaining 750 and 850 and 850 MKIII.
EDIT thanks Matt
reexamined ebay ad and true it is cast AN cam (see pix 5). I would give only $10 to have as an example to show people what NOT to buy.
I had one of these (broken) but had to turn it back in to get a credit.

I enjoy about 30 cams on my shelf that represent the 1949-1975 NHT run. As far as I can tell all cam base circles for NHT as the same. The core design and size it was made on, evolved throughout the series.

Click to expand...

Hi,
if i i dont lost me in translation it means that is better do not buy this cam?
AN cams are not standard?
How i can understand a standard cam?
Thanks
Ciao
Piero

:x :lol: :lol: :cry: THEY LOOK LIKE THIS

Though some say THIS is a ' Standard ' Camshaft . :wink:

Wasn't it said, somewhere, that the early Commandos had the same cam grind as the SS Dommies got in the early 1960s ?

And the Combat 750 then got the more developed 2S cam.

Matt Spencer said:

Though some say THIS is a ' Standard ' Camshaft . :wink:

Click to expand...

pierodn said:

dynodave said:

The subject cam is for a 20m3S engine and can be use through all remaining 750 and 850 and 850 MKIII.
EDIT thanks Matt
reexamined ebay ad and true it is cast AN cam (see pix 5). I would give only $10 to have as an example to show people what NOT to buy.
I had one of these (broken) but had to turn it back in to get a credit.

I enjoy about 30 cams on my shelf that represent the 1949-1975 NHT run. As far as I can tell all cam base circles for NHT as the same. The core design and size it was made on, evolved throughout the series.

Click to expand...

Hi,
if i i dont lost me in translation it means that is better do not buy this cam?
AN cams are not standard?
How i can understand a standard cam?
Thanks
Ciao
Piero

Click to expand...

The AN identified/marked cam is chilled iron....and IS a 06-1084 stock/standard grind. It is a recent engineering change to use iron not steel...(less than 10 years)
The iron cams can possibly break if the AA unit bolt is torqued to less than 14ft/lbs torque. approx 14-16 ft/lbs is where the 1/4-26 bolt breaks.....DAMHIK.
The original cams are EN32B steel. BIG controversy if chilled iron is as good or better than EN32B hardened to 56-60 RC.
My vote is for EN32B. I will be rebuilding an engine for a guy in our club and he "inherited" a AN chilled iron cam and we are looking for another cam or possibly a custom Megacycle stock commando cam grind. I have heard they will make them to order but do not catalog them.

Yes the 650SS cam profile is the commando 06-1084 cam profile, though the 650SS core blank is for a PRE 20M3S.
The cam marked "SS" is a 2S combat cam...yes..... stock/standard for a 72 Combat.

EDIT:Rohan You're correct EN32B not EN40...what was I thinking!!

The cams in the early Model 7 dommies were said to be chilled cast iron. ?
The Workshop manual for the 850 and late 750 says the cams were EN 32 B
When did this change occur - anyone ?
(how can we tell the difference ??)

The 850 tappets (lifters) were said to be cast iron Grade 14 - stellite tipped.