[enkeivette]

Originally Posted by 94cobra69ss396

How did you enter the cam specs (IO/IC, EO/EC) if you didn't have the cam card? Did you just guess?

Also, a friend ran my engine combo for the Chevelle and it was way off and yes he did use the correct flow rates for my Edelbrock Performer RPM heads. Desktop Dyno 2000 showed 737hp@7000 & 650tq@5000. I've run my car on a chassis dyno and it made 461rwhp and 462rwtq. Given a 20% loss that's around 550hp.

If you want to run it and see what yours comes up with, here's the info for my engine:

Standard bore Chevy 454
12.25:1 compression
Heads: Edelbrock Performer RPMs 60559
Flow Intake/Exhaust
.100 76/70
.200 146/132
.300 210/156
.400 255/181
.500 294/207
.600 314/228
Comp Cams Solid Roller 11-692-8
.622 lift I/E
246 at .050 I/E
110 Lobe Center
106 Intake Center
Specs at .050
IO: 17 EO: 57
IC: 49 EC: 9
Victor Jr Intake
Holley 850 built by The Carb Shop (flows 950 cfm)
Hooker Competition Headers 3" exhaust with Flowmasters

I entered the specs before I lost the card.

[BRUTAL64]

Originally Posted by big_G

My static c/r is 8.3, so the big cam with it's close 110 lsa yields very low efficiency at cruise. A lot of the intake charge is lost due to the overlap. The 114* lsa combined with the lesser duration will help torque and fuel mileage considerably. I will build more boost, which will maintain the upper rpm power.

Yes, you are going to pick up some low end torque with the cam change. Also, going to 114 LSA is going to up vacumm and smooth out the idle some. Gas milage--maybe a little better.

I'm running Dual Quads and the 30 30 cam with 254 effective duration on 114 LSA , this being a solid lifer cam, it is more efficent.

[big_G]

Originally Posted by BRUTAL64

Yes, you are going to pick up some low end torque with the cam change. Also, going to 114 LSA is going to up vacumm and smooth out the idle some. Gas milage--maybe a little better.

I'm running Dual Quads and the 30 30 cam with 254 effective duration on 114 LSA , this being a solid lifer cam, it is more efficent.

My cam is a solid roller, but what does the kind of lifter have to do with economy?..(other than the lash decreasing the effective duration).

[enkeivette]

Originally Posted by big_G

My cam is a solid roller, but what does the kind of lifter have to do with economy?..(other than the lash decreasing the effective duration).

I guess hydraulic lifters would be heavier, and they might abosrb some of the working force, so they'd be less efficient. But I don't think it would make any noticeable sort of difference.

[BRUTAL64]

Originally Posted by enkeivette

I guess hydraulic lifters would be heavier, and they might abosrb some of the working force, so they'd be less efficient. But I don't think it would make any noticeable sort of difference.

Actually it makes a difference. Because of the design of the lobe on a Hydraulic lifter cam -you lose a little of your duration. It has to have a 'set' designed into the lobe to lock the lifter from bleeding down. Solid lifters don't have that "set" in the lobe so the lobe can be more agressive.

We are talking flat tappet cams here. Rollers are a differnet story. Yea, I know I'm stuck in old Tech.

[BRUTAL64]

Originally Posted by big_G

My cam is a solid roller, but what does the kind of lifter have to do with economy?..(other than the lash decreasing the effective duration).

Sorry, missed the Roller part. The trouble with trying to do work and this at the same time.

In the case of Roller Cams, there is almost no difference in lobe design. There is a difference in lobe design between the two lifter types with a flat tapped cam.:

[BRUTAL64]

Originally Posted by big_G

My cam is a solid roller, but what does the kind of lifter have to do with economy?..(other than the lash decreasing the effective duration).

In tests-- way back when, we and other people found solid lifter FLAT TAPPET cams to get better gas milage than the hydraulic lifter types. Rollers have no such issue.

For example, we found a solid lifter cam would make more power than a hydraulic cam with 10 degrees more duration. All other points being equal.

[enkeivette]

Three guys, all making stupid amounts of power out of carbed V8s... talking about fuel economy.

[BRUTAL64]

Originally Posted by enkeivette

Three guys, all making stupid amounts of power out of carbed V8s... talking about fuel economy.

Yea, it is pretty funny.

[Vettezuki]

Originally Posted by enkeivette

Three guys, all making stupid amounts of power out of carbed V8s... talking about fuel economy.