lightened cam

[rustynuts]

what does the "X" stamped on lightened cam gear signify? any good or bad characteristics? any unique installation suggestions?

[Rubone]

I am not sure but perhaps "experimental". H-D marked various first year and pre-production parts as EX. The earliest "Lightning" cams were definitely different than later ones. I have had both and the lobe shape is not the same. Don't remember if there was a distinctive mark. Later lightened cams are the same lift and duration as non-lightened versions. How about a picture of the lobes?
Robbie

[Chris Haynes]

And a picture of the backside of the gear. Later gears were stepped. Early and late '36 cams had the same profile but later ones had the timing slightly retarded.

[rustynuts]

more photos

here ya go. not stepped or recessed on motor side. "X" also stamped on motor side. cams appear pretty long duration to me. yes i know- not NOS. thanks.

[rustynuts]

so... what we got

early lightened gear. where are all the motorheads? was there a meet this weekend i didn't hear about? oh well, thank you for the 2 post!

[Bobber59]

Lightning cam? Is this one?

Just came across this one from a documented 61ci Knucklehead Hillclimber. Any ideas what this is? Obviously, a lightened cam...the lobes are quite abit higher than a stock knuck cam and it has a keyway. I'm told this is quite possibly a factory "Lightning" cam, maybe early model since there are no timing marks. Can anybody help identify this cam?

Thanks,
Jim

[Bobber59]

What cam is this?

No interest...or...nobody knows?

Jim

[T. Cotten]

I took both of mine off the shelf, and still couldn't make sense of any differences.

Some real specs would help.

...Cotten

[Bobber59]

Specs...

It was removed from a 1936 Knucklehead motor RIGHT CASE HALF with '36 belly numbers. That may mean nothing, I just provide that to avoid claiming I own a complete 1936 motor. The gear width is different from the stock cam width of .570". This cam's drive gear width is .525"; It is a "thinner" drive gear and that is clear to the eye without measuring it, however it has the same diameter of the stock gear.

Cam lobe height is: 1.285".

Base circle diameter is: .84"

Lift: .445 (?)

No markings on this cam and as the pics show, it is both lightened and has a keyway. No timing marks on the drive gear.

I'm wondering, early 1936 cam?

Thanks Cotten, hope you have some idea.

It "allegedly" came installed in a vintage VL frame Hillclimber that had been stored in a museum (Auburn Trailor Museum owned (?) by Vince Martinico) prior to it's purchase. At some point this VL hillclimber had been the property of a retired HD dealer who had it in his shop until he closed the shop's doors in 1968. That's all the info I have at the moment; I'm waiting on some documentation from the seller. The seller did say he rode this VL framed-Knuckle-motor'ed Hillclimber down his dirt driveway and his comment was, "This thing hits a mean lick"!

Jim

[T. Cotten]

Jim!

Now that I can view your photos, I see you've got a keyed gear, perhaps cut from the original.
The bump part is something else again.

The Lightened or Lightning or whatever-they're-called cams that I have encountered had the gear and lobes all cut from one billet.

I only measured one presumeably from a '37; The other escapes me right now, but was a fossil anyway.

Guessing the base circle with a dial caliper shows the lobes vary around .870", with a very consistant full cam height of 1.216" or so.

However,
By dial indicator between centers, the lift is anywhere from .345"
to .356"

Yours is radical.

....Cotten

[koanes]

I pulled the cam out of my 38 motor, I believe this to be the original cam,low mileage motor, wear patterns on journals match bushings, etc. It does not have the step on the back of the gear and measures up the same as other later cams. I compared it with a stepped back cam that I believe to be the earlier version. The base circle measurement and the lift are the same but the earlier cam has more duration. I took a couple of blurry pictures of the cams and did a trace of the lobes for a more accurate measurement. The lobe width is around .030 wider on the early cam. I know this is crude but I didn't have time to set up a motor with a degree wheel to get the opening and closing specs on the early cam.

[koanes]

Jim, I think Tom is right, your keyed cam is probably not oem. I have never seen a stock cam that was not drilled through (hollow) and press plugged on the cover end.

[Bobber59]

Thank you gentlemen...I have heard my cam may be early aftermarket or homemade....the condition of the cam is really in pristine shape with NO cam wear!

Tom, it sure looks radical and the meaurements I provided appears to make this a .445 or so lift. I have a stock cam, it is one piece as you state and about .350 lift. The lobes on my "lightened" cam look "banana shaped", as Lee Wickstom described it.

Koanes...I concur on the "plugged" end of my stock knucklehead era cam I'm comparing this high lift cam to. This "lightened" cam I've provided pics to appear to be an enigma!

Tom and Koanes....my stock cam, not this high-lift cam in my pics....has the longer duration lobes as shown in your pics. Quite different than the "banana" shaped lobe on the pictured high lift cam.

At .445 lift, I'm hoping it's "streetable" for a bit of local hotrodding, maybe even some off street stuff.....might try my hand at some MILD hillclimbing...that could become addictive!...but it won't be my "touring" unit!

Thanks again, guys.

Jim

[Bobber59]

Mystery solved!

Spoke YESTERDAY to the builder of my '36/40 Knuckle hillclimber motor and he informed me that my "lightened" cam in the pics I provided is actually a Sifton cam, yes..... a .445" lift. I do belive it has been worked in some way but the builder was a man of few words and I didn't get more than this info from him! Oh well....is there still a legendary "Lightning Cam" out there?

Jim

[D.Mac]

[QUOTE

It "allegedly" came installed in a vintage VL frame Hillclimber that had been stored in a museum (Auburn Trailor Museum owned (?) by Vince Martinico) prior to it's purchase. At some point this VL hillclimber had been the property of a retired HD dealer who had it in his shop until he closed the shop's doors in 1968. That's all the info I have at the moment; I'm waiting on some documentation from the seller. The seller did say he rode this VL framed-Knuckle-motor'ed Hillclimber down his dirt driveway and his comment was, "This thing hits a mean lick"!

Jim[/QUOTE]

Jim,
It might be worth checking with Vince Martinico on the history of this motor. I believe Vince was friends with Sam Arena, who had the HD dealership in San Jose in the '60's. Could that be the shop it came from?. I remember Sam had several old hill climbers in a back corner of the shop. Sam rode for Tom Sifton, and was quite succesfull on the flat and the slant- how about 4 AMA national hill climb championships '46 to '50, see AMA hall of fame.
Doug.