Are these "S" cams?

[dampking]

Hi Guys!

A friend forwarded me few pics of this set of RE Cams. These were supposed to be 1950's clipper cams but I have no idea if they are any good for AVLs.

Here's a pic



Are these "Redditch S cams"? Condition of these cams look pretty bad tho!

-Sanket

[Bullet Whisperer]

Hi Sanket,
 No, they are not 'S' cams. The slightly raised centre on the outer face [opposite to cam lobe side] suggests they are pre 1956 [narrow case] 350, or perhaps from one of the other machines of a simillar era. The 'S' cams look very simillar to the Indian 'Iron' cams, with a large letter 'S' stamped into the face of the gearwheel on the same side as the cam lobe.
 I have just recieved my latest batch of 'S' cams and they are nearly all spoken for, but, as usual, I could get more made subject to there being enough interest.
 B.W.

[dampking]

Thanks a lot for the information BW!

[Bill Harris]

Paul,

Do you know the history of the Redditch "S" cams?  What machines were they used on?  What years were they used, and what does the "S" stand for (Standard, Scrambles, Sport, or what)?  I love the history of motorcycle stuff and seeing how I'll be putting a set of your cams in the Harris Scrambler soon, I would just like to know.  Any information you have on the "S" cams will be greatly appreciated.

Royal Enfield people are good people.  Happy New Year to all you good people!

Cheers,
Bill 

[Bullet Whisperer]

Hi Bill,
 To be honest I don't know for sure what the 'S' stands for, but these cams were used in the Bullet's last couple of years' production, as far as I am aware. There was also an'R' profile set of cams made by the Redditch factory, my Father's late fifties 350 has a set of these and with various other mods can see 90 mph flat out and is a quick bike. The 'S' cams for the Electra X came about by pure chance, while I was working on the Hitchcocks testbed machine for their tuning kit for these machines - I had tried all sorts of cams, various timings, double valve springs, you name it in an attempt to get past 5,800 rpm. Some cams increased the power up to this engine speed, but we were stuck with a top speed in the high 80's, due to inlet valve bounce restricting the revs. I had a couple of sets of old 'S' cams lying around and, just so I had left no stone unturned, I fitted a set [they don't look very exciting]. I realised I was onto something when I hit 95 mph in 4th gear and in top, flat on the tank, I got 103 mph, this with a very loud exhaust and 36mm Amal MK II. It also ripped twelve teeth in a row off the [detatchable] rear sprocket, as witnessed by some surging from the rear end which made me throttle off rather quickly !
 My 'S' cams are copied from a set of Redditch 'S' cams which were used as masters for the first batch, the cam makers have this profile 'on file' now and can make them to demand, although sometimes they take a while to deliver !
 Regards,
 Paul.

[Ice]

Royce Creasey makes reference to "Scrambles" cams on page 4 of his excellent article on Modifications for Speed and Reliability found here
http://www.royal-enfield.net/articles/articles.html

Makes me wonder.

[Bill Harris]

Thanks, Paul and Ice

Very good information about the "S" cams.

Paul, I'm looking forward, with high expectations, to installing your cams in my bike.  I'll give a review of how I like them on this forum. 

Ice, thanks for the article,  I like it.  Good stuff!   

Royal Enfield people are good people.

Cheers,
Bill   

[Bullet Whisperer]

Hi all,
 Just for the record, here is the dyno printout for the testbed Electra X from a few years back, if you check out the info at the bottom left, some settings and specs are shown.
 Regards,
 Paul.

[Bill Harris]

Paul,

33.34 hp at 6000 rpm at the rear wheel.  Not shabby at all.

Cheers,
Bill

[Bullet Whisperer]

Paul,

33.34 hp at 6000 rpm at the rear wheel.  Not shabby at all.

Cheers,
Bill

Thanks Bill,
 That bike was great fun to ride and in many respects was quite comparable in performance and behaviour to my mid seventies honda CB500T - I think you got a few of them over in the states - very torquey and would get to 90 mph with ease and topping out around 105 mph. This Electra X differred only in that it did it all at lower revs than the Honda, from memory the gearing [with one off 18" rear wheel rim] got me the 103 mph at about 6,200 rpm in top gear. If my memory serves me correct, I think I had put a 19t gearbox sprocket on instead of the standard 18t, to bring the gearing back near standard with the smaller rear wheel size. It had a detatchable 38t rear sprocket / hub conversion as it had previously pulled a sidecar with lower overall gearing with a 42t rear sprocket fitted. My early tests on this machine used this lower gearing and, although the full power and revs had not been found at this time, it would have made the basis of a lively trail machine !
 Regards,
 Paul.