I have a solid roller cam for RB and I need some help identifying it. It has #'s on the gear end, B 286/500 2S3-14 68-03-7 CR. With 1.7 T&D rockers, at zero lash, approx .890 lift measured at valve. Possibly a regrind? I have very little history/info on this engine.
Any info on mfg, ect will be very helpful.


Thanks, Brian

Looks to be a Crane part number 688671.

.500/.500 lobe lift, 320/338 advertised, 286/306@.050, 114lsa.

.850 lift with 1.7’s
lash .026/.022

I believe you correct sir. I took another look at the cam, and the first letter is a R. Thanks for your help.
Also, the specs for lobe separation is 114*. Is this what the cam should be installed at?

Thanks again, Brian

I would install at 108 or 110,,,

It was installed at 100.5*. The intake valve lash was in excess of .060". When I put the lash at zero, there was NO measureable valve to piston clearance(for 19* of crank rotation). I changed the cam install CL to 109* and now valve to piston clearance is acceptable (even with zero lash, more with .020" lash). Most likely going to change this cam. There are other problems, most notable, spring retainers hitting guide seals before max lift.
Anyone have a cam suggestion? B1 heads on a 622 ci, 2200lb bracket car.

Thanks, Brian

That be a big cam for a big motor with big heads
AKA, that is way bigger than any cam I would use on a bracket motor

B1 heads have a very small exhaust valve compared to the intake. 2.30"/1.78". With the size of the motor you have, I think that the cam would be a good fit. At least an 1150 carb, maybe bigger, or tunnel ram with dual carbs.

How high do you want to rev your motor? Most of the B1 racers I know of are not bracket racers and they shift from 8600 RPM and up
Al, where do you guys shift your big C.I. B1 motors?

Have you used a cam that big on a B1 headed engine before?

Scott Koffel could hook you up on a cam. My 605" runs like a champ and consistent as hell.

Interestingly, Crane shows the .050 events as:
32/74 for the intake
92/34 for the exhaust

Those numbers don't equate to a 114lsa.
It works out as a 115lsa installed at 111.

This is where the degree comes in handy to see which it really is.

I can't imagine any scenario where that cam being installed at 100 would have been the hot ticket.

I don't think it's too big of a cam for a big cube B1 motor at all.
I looked up the lobe specs..... Doesn't look like it would be too hard on parts provided it has the right springs.

I'm touching up some 572-13 heads for a customers 588.
His motor had a cam that was 284/304-114, in at 114....... .510/.500 lobe lift, 1.7 rockers.

The OP says he measured .890 lift at the valve.
For .890 lift from a .500 lobe the RR would have to be 1.78.

I would carefully measure this again to verify the net ratio.
If it does indeed repeat as .890 lift, then I would run a different cam and make sure I had the lift down to a more bracket friendly range.

Also, no mention of whether they are single shaft or paired T&D's.

If single shaft, I would back the lift down quite a bit so I could run less aggressive spring loads.
But the first step is to verify the RR.

That's more cam than we have run in ANY of the B1 stuff I've done. My old S/ST and bracket Cuda was right at .855" lift with an MC head at 525 cubes. Last freshen up was at 404 passes. Previous ones were between 350-400. Never had any issues with any valvetrain stuff. Car managed to go 171mph at 2975lbs so made some steam. Mostly run in S/St and went a best of 162@10.90.

Our dragster is a B1 original and lift is .800" gross. Car has been 7.30's in Vegas in the summer. Heads are CFE prepped B1 originals with single shaft rockers. Done a number of B1's and never needed a cam that size to make something run well.

Guess what I'm saying is that's a fair amount of cam and likely more than is needed to make the engine work. All mine have been custom grinds but I've never had that much lift. If I were building an all out deal maybe we would build something with more lift but at that point Id bet it would be closer to .950 with a PSO head..

Nope, mush smaller for a 544 C.I. B1 headed bracket motor with a set of Harland Sharp single shaft 1.65 ratio rockers That cam made peak HP around 7300 RPM is what I remember with stainless valves
That motor made 920 HP on race gas with the B1 cast single four intake with a DAM Best Dominator that was suppose tp flow over 1200CFM is what I remember now, that was three ears ago on a new Super Flow dyno in Nampa, ID.
I have a set of B1-MC with Ti intake valves that I will buy and use a set of either T&D or Jesel paired shaft 1.7 ratio rockers on my next bracket build with a Koleno block to make a me a new 555 C.I. Bracket motor I'll call around on the cam selection then to get some valid input after I have some flow numbers, should I call you on this also? If so, I will