Base circle diameter on a normal camshaft?
Thread Starter
Race Director
Joined: May 2001
Posts: 14,165
Likes: 9
Base circle diameter on a normal camshaft?
Hey guys, for my ongoing boredom and autocad project I need to know what the diameter of the base circle on a normal camshaft is. Also if possible I need to know the diamter of the cam journals and of the cam itself.
Any clue?
Any clue?
Melting Slicks
Joined: Oct 2002
Posts: 2,896
Likes: 349
From: Smithfield VA
Re: Base circle diameter on a normal camshaft? (Nathan Plemons)
What do you call a normal cam shaft?stock? I have two cam here, one is a stock LT-1 and the other is a COMP XE 224/236-114. The cam journal is the same (as it should be) at 1.867" diameter. The base circle measurment is different for each cam and the is even a slight difference between the intake and exhaust lobes on each cam.
Stock LT-1 base circle:
IN - 1.2445" D
EX - 1.231" D
Comp 224/236 base circle:
IN - 1.086" D
EX - 1.067" D
Not sure what dimesion you are looking for for the "cam itself", total lobe?
I took all the measurments with a digital caliper. Hope this helps.
:cheers:
Stock LT-1 base circle:
IN - 1.2445" D
EX - 1.231" D
Comp 224/236 base circle:
IN - 1.086" D
EX - 1.067" D
Not sure what dimesion you are looking for for the "cam itself", total lobe?
I took all the measurments with a digital caliper. Hope this helps.
:cheers:
Drifting
Joined: Dec 2002
Posts: 1,861
Likes: 4
From: Houston TX
Re: Base circle diameter on a normal camshaft? (racerns)
That's kind of odd that the Comp base circle is smaller than that of the stock cam, as the larger base circle allows for a more aggressive ramp and general lobe profile (not to mention higher lift with the same duration)...hmmm.....
Melting Slicks
Joined: Mar 2002
Posts: 3,108
Likes: 126
From: S.L.C. UT
Re: Base circle diameter on a normal camshaft? (CorvetteZ51Racer)
The Crane and Comp cams that I have checked base circle diameter on all had reduced base circles. I think were ground that way to help clear a 3.75 stroke of the popular 383.
Drifting
Joined: Dec 2002
Posts: 1,861
Likes: 4
From: Houston TX
Re: Base circle diameter on a normal camshaft? (tpi 421 vette)
Yeah, I am pretty sure that's exactly why the Comps had the small base circles, but there are many problems associated with small base circle cams, so given a choice, I'd avoid them. When I go to build my new motor, I'm going to go with a Dart Iron Eagle block with the BBC cam size. Yes the cam is heavier that way with more valvetrain inertia, but it also is stronger and results in less spark scatter due to the increased torsional stiffness of the cam.
Thread Starter
Race Director
Joined: May 2001
Posts: 14,165
Likes: 9
Re: Base circle diameter on a normal camshaft? (Nathan Plemons)
Well it's for my cad drawing of the motor, I know that information about the small base circle cams is readily available but nobody seems to know much about the stocker, probably because it is different. I just didn't know if there was a set size for a "normal" base circle, apparently there isn't.
Thanks for the info though :cheers:
Thanks for the info though :cheers:
