Topic: what do i have here? cb750 cam of unknown origins

[bucky katt]

i know from another thread that we had decided that having R1 stamped into a cam likely doesnt mean a whole lot BUT maybe someone can take a look at these lobes and tell me if you think this might be an early (k0, k1)cam. i was out in the garage tidying things up (i go out to the garage alot when i cant sleep, i put a few cd's into the changer, have a beer and re-arrange/ re-organize the shop. i found a box of parts that i'd gotten along with a frame back during the summer of 2005 and among other goodies i found this cam. i'm really not a good judge on if the duration on this one is longer or shorter than another cam so maybe someone else can throw in their 2 cents worth? it's worth a beer and a plate of the best tasting linguini and marinara sauce you've ever tasted.  

[Hush]

To lose bits in your shed means you have too many bits Bucky!
Heck I know where every part of every bike I have is located, funny that as my memory is crap for birthdays anniversaries etc...just good for bike parts I guess.

[bucky katt]

yeah, i turned up another 75 750f head, complete with 7 decent rocker arms (i'm collecting them, anticipating having them lightened when i finally get to build the hot rod motor, with stock displacement to start with.

[Jerry Rxman Griffin aka MuthaF'er]

Fuzz,

Measure the lobe heights. I have a new Megacycle 125-75, a 78 750K, and a 75 750F I can measure and compare.

[bucky katt]

35.65 MM or 1.4035"

[Jerry Rxman Griffin aka MuthaF'er]

Megacycle 125-75                 36.02mm  &  35.33mm

75 750F with ~ 6,000 miles     35.73mm  &  35.33mm   R9 not that it matters

78 750K with unknown miles    35.63mm  &  35.20mm   R1 not that it matters

I will attempt to take a profile picture with all 3 later.

Anyone that is going to take measurements be sure that your caliper is squared on the lobe. I took all measurements on the top or bottom edges of the lobes to insure the caliper was perpendicular and not crossed up some.

[bucky katt]

guess i should have included both intake and exhuast LOL

35.75 in 35.32ex

so it seems i have another f0 cam. better than the stock k6 i guess but not really worth putting in is it?

[Jerry Rxman Griffin aka MuthaF'er]

Yeah but..........  Those measurements are probably a determining factor but they don't show the lobe profile, just the height aka lift. Duration and profile make a hugh difference too. I have it in my mind to trace the lobe profiles of known cams as well as take the lobe height measurements. That would be 1 step closer but it still wouldn't show lobe center and timing. Now that I have all 3 known cams out and a few days off I'll get you some pictures and try to trace the lobe profiles on light cardboard.

[bucky katt]

thanks Jerry, i truly do appreciate that. meanwhile i've even put the word out on my facebook page announcing my search for a 77/78 f cam.