BBC Cams Tease
Thread Starter
Racer
Joined: Aug 2002
Posts: 289
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From: Albuquerque NM
BBC Cams Tease
I was looking at the specs at some of the cams that I have for my LS6 here in my garage and yes they have some interesting specs. What I'm throwing up here are the specs as read from the Manufacturer who I'll not mention. The specs are based on old timing specs as opposed to the newer specs. I'm sure that when see you them the BB fans will know which cams they are. They are as follows:
#1 Cam
Duration@050" int 262 ext 273
Cam Lift int 342 ext 365
Valve Lift int 561 ext 600
Center Line 116^
Timing BTDC=19 ABDC=63 BBDC=77 ATDC=16
#2 Cam as follows:
Duration@050 int 264 ext 270
Cam Lift int 330 ext 341
Valve Lift int 541 ext 560
Center Line 118-15'
Timing BTDC=17-30' ABDC=66-30' BBDC=78 ATDC=12
So with things set-up correctly@11.9:1 compression, single 850 4bbl, single plane manifold, etc... what would the characteristics of these cams be respectively (ie rpm, power range,etc). Also which would make more effective HP/torque and why?
:rolleyes:
#1 Cam
Duration@050" int 262 ext 273
Cam Lift int 342 ext 365
Valve Lift int 561 ext 600
Center Line 116^
Timing BTDC=19 ABDC=63 BBDC=77 ATDC=16
#2 Cam as follows:
Duration@050 int 264 ext 270
Cam Lift int 330 ext 341
Valve Lift int 541 ext 560
Center Line 118-15'
Timing BTDC=17-30' ABDC=66-30' BBDC=78 ATDC=12
So with things set-up correctly@11.9:1 compression, single 850 4bbl, single plane manifold, etc... what would the characteristics of these cams be respectively (ie rpm, power range,etc). Also which would make more effective HP/torque and why?
:rolleyes:
Safety Car
Joined: Mar 2002
Posts: 3,780
Likes: 442
From: Southwest MI
Re: BBC Cams Tease (VetteLS6)
Also which would make more effective HP/torque and why?
I just went thru the cam selection process for my 468 replacement motor. when you say "effective......". The first question people will ask is, where do you want to make power, RPM wise? You need to consider, gearing, weight of car, head/port size, exh system, driving style/use, etc.
I wanted my setup to come on strong ("be effective") ~ 4000 up to 7000-7200. With your gearing, heads, etc etc, you may want a 3000-6000 cam.
You'll get GOOD experienced based advice here (427Hotrod, Mountainmotor, etc) but paint them a good picture of your complete package, and what you want when you're done.....
PS: BTW, I went with the Crane 134691 580/600 256/266 110LSA, set straight up. But i've got big heads, low gearing, and a hi-rpm bottom end.
Thread Starter
Racer
Joined: Aug 2002
Posts: 289
Likes: 0
From: Albuquerque NM
Re: BBC Cams Tease (66427-450)
Hi, I was wondering when a reply going to show up. I have a few cams here at home that drop in the car for various reasons.... The questions at the bottom of the post were supposed to be just based on the engine alone with chassis configurations removed from the equation. Lets say the engine is a dyno motor with prepped 074 heads (int 2.25" ext 1.94"), Headers (primary 2 1/8" length 32" Collector 4"X10"). I hope this clears it up a bit any inputs would be useful.
Larry :D
Larry :D
Race Director
Joined: May 2000
Posts: 12,712
Likes: 2,264
Re: BBC Cams Tease (VetteLS6)
These two cams are very close and the only way you are going to see what actual difference they make is to run them on some simulation programs, preferably more than one, so you can cross check the results.
Off the top of my head I'd say the second cam will have a fatter torque curve because it has less effective overlap. With CI manifolds top end power will be very close, but with headers, the first cam might make a bit more top end power because of the slightly longer overlap event.
Duke
Off the top of my head I'd say the second cam will have a fatter torque curve because it has less effective overlap. With CI manifolds top end power will be very close, but with headers, the first cam might make a bit more top end power because of the slightly longer overlap event.
Duke
Thread Starter
Racer
Joined: Aug 2002
Posts: 289
Likes: 0
From: Albuquerque NM
Re: BBC Cams Tease (chewy)
Very good, I routinely run the L88 Cam in my car and have run the ZL1 off road cam as well....from what I here it is better suited for a Mechanical Injection System than a single 4bbl very peaky and almost dead dead below 3000. (4400-7200rpm) I did race the car at Snutterton with the ZL1 cam installed and it worked well given the fact the engine rarely dipped below 4500 (1st gear end of back stretch). In my opinion neither is good for street application. Most of the time I run the LS6 cam the car came with. Currently the L88 cam is installed seeing how I do tend to drive harder than most. Both of the above cams make excellent power when you push them were the LS6 falls short. The question is which does better on the dyno? For those with the simulation programs the vehicle weight is 2844lbs (certified weight ticket) less driver.
