Which rumblestick?
Thread Starter
Drifting
Joined: Oct 2001
Posts: 1,699
Likes: 1
From: Westampton NJ
Which rumblestick?
I'm trying to decide on a new cam if there is significant wear in my current lobes/lifters. Here's the stuff already in the engine:
Unknown cam (hydraulic flat)
High-rise dual-plane intake
600cfm vacuum secondary electric choke carburetor
Forged 11:1 pistons (2.4cc dome, TRW)
.030 overbore = 355ci
Forged crank
Pink rods
Pocket ported (gasket matched) 186 heads (2.02/1.60 with unshrouding)
DynoMax Ceramic Headers
4-speed
3.55 posi rear
I currently pull 9" of vacuum at idle at 6,000' with a lopey idle. Also, estimated lift is .474" at the valve (intake and exhaust, 1.5 rockers).
I'd like to keep a nice lopey idle and around the same vacuum if not a little more...remember, I'm at about 11:1.
Unknown cam (hydraulic flat)
High-rise dual-plane intake
600cfm vacuum secondary electric choke carburetor
Forged 11:1 pistons (2.4cc dome, TRW)
.030 overbore = 355ci
Forged crank
Pink rods
Pocket ported (gasket matched) 186 heads (2.02/1.60 with unshrouding)
DynoMax Ceramic Headers
4-speed
3.55 posi rear
I currently pull 9" of vacuum at idle at 6,000' with a lopey idle. Also, estimated lift is .474" at the valve (intake and exhaust, 1.5 rockers).
I'd like to keep a nice lopey idle and around the same vacuum if not a little more...remember, I'm at about 11:1.
Burning Brakes
Joined: Sep 2000
Posts: 1,199
Likes: 1
From: NewCastle IN. USA
Re: Which rumblestick? (rainman69)
Are the HP and Torque figures in your signature what your getting with the current cam? If so, then that might be tuff to beat!
check for some dentification numbers on the cam while you have it out, hopefully you can find out just what it is. that would help point you in the right direction.
RJ
check for some dentification numbers on the cam while you have it out, hopefully you can find out just what it is. that would help point you in the right direction.
RJ
Safety Car
Joined: Feb 1999
Posts: 3,631
Likes: 14
From: Fountain Hills AZ
Re: Which rumblestick? (rainman69)
Cam choice will depend mostly on what you want and on what you're willing to give up to get it. Your 9'' of vacuum and the lope is indicative of a big cam but, at 600 rpm, it is more likely a moderate cam being forced to idle at too low rpm (or due to another problem that's unrelated). Cams are usually replaced because they're bad or because the owner just wants a different cam. If it's bad, it'll be obvious and you don't need to measure for "significant wear". My guess is that you just want a new cam. BTW, how did you determine the lift of you current cam?
Thread Starter
Drifting
Joined: Oct 2001
Posts: 1,699
Likes: 1
From: Westampton NJ
Re: Which rumblestick? (Vetterodder)
I measured the amount the lifter was out of the bore on the base circle and the eye-balled max it was out...then I multiplied by 1.5...not the most scientific, but a ballpark.
