Ariel Owners Motorcycle Club

Lad’s,

I have two camshafts in my possession for my 350 engine build. The first camshaft I have is a single lobe with what I believe to be matching followers and push rods.No markings on the cam itself though there is a F stamped in the cam gear.

The second camshaft i have is a two lobe marked A6-664 however I do not have the followers or push rods to suit. This cam has a T stamped in the cam gear,

I have to send a cam and followers away to Draganfly for exchange and was leaning towards sending the single lobe as i have the followers and push rods.

Which would be the better cam for me to run in the 350, standard piston. I believe the twin lobe cam to be a more sporty cam but with a standard piston is it really required.

If the single lobe will work well and without issue I will send that one off, if the two lobe is a much better cam I will chase up followers and push rods to suit.

Some pics below of what I have.

Cheers

Josh

The single lobe cam is 1750-54 used 1954-58 on all ohv singles except HS and should be used with the wide followers and ally or steel push rods depending on head material.
The other cam is 1760-34 usually known by its drawing number as it is stamped on the end. Usually called the side valve cam it actually started life in the top of the range models E, F and G of 1929-30 but can also be used in all later machines with good effect either with a standard piston or a high comp one to truly release the potential. I have recently built a 350 single using one of these cams and a pair of the wide followers, a bit noisy but it flew once it came on cam at about 3,000 revs. This was on a std comp piston, once the piston was changed to high comp it pulled very well from much lower down, incredible difference. The timing with this set up is close to MK2 HS spec, slightly less radical with std narrow followers. You will need the shorter push rods 1856-34 for iron head or make your own up for ally head engine using 1855-99 ally tube and old ends.
All listed here https://draganfly.co.uk/product-categor ... ottom-end/
Disclosure - I have a financial interest in Draganfly

Roger,

Thanks for the follow up, sounds like the two lobe cam might be worth the effort in obtaining followers and push rods.

So, the followers to suit the two lobe cam would be the 1800-31F’s and I would need the 10 3/8 (1856-34) push rods, is that correct?

I think I may be able to obtain a pair of followers from the guy with the frames/cases I had discussed with you via email, will be heading there tomorrow. Is there a way of distinguishing the correct twin lobe cam followers Roger, assuming they had numbers/were stamped?

This will all be fitted up to a single port iron head.

Cheers

Josh

Single lobe cam has more lift and overlap than the twin-lobe side-valve cam.
And the followers won't wear out as quickly.
For an easy comparison of cam timing and lifts see the table at the end of Paul Jameson's doc 'The definitive article on Ariel cams' in the online library:
http://www.arielownersmcc.com/members_o ... rticle.doc.

SG

As far as I know, all twin lobe cam followers with a cup for the end of the pushrod are the same. Twin lobe cam followers without a pushrod cup suit the VB and various pre-1932 engines.

Josh
The single lobe cam will outperform the twin lobe cam. The A6/664 1.5” base circle cam will also experience a much higher cam follower wear rate than the single lobe cam. So the better setup of the two is the single lobe cam.
What Roger Gwyn has advised is that it is possible to use the wide foot follower on the A6/664 cam, with correct length pushrods and it will give a performance increase with a valve timing similar to one of the factory performance HS cams. I have run 1954 HS Mk1 cams in a 350 with excellent results. So with the cams and followers that you have, the best performance will come with the A6/664 cam and wide foot followers. To get the same performance otherwise you would need to have the single lobe cam converted to HS profile.
David

Thanks to everyone for the information. I have obtained a pair of two lobe cam followers and will look at getting both the single and two lab cam and matching followers exchanged through Drags.

Cheers

Josh