Hit the dyno today...

jcp123 · Dec 1, 2007

Here's my combo:
Originally C-code 289
Bored .030 over, 302 crank, 306ci total
Edelbrock Performer intake, Carter AFB carb
Hooker headers with 2" duals and h-pipe, Dronemaster Delta 40's
Pertronix Ignitor solid-state ignition, 45k volt coil, 8mm Pertronix plug wires
Stock cam, original heads

160.3hp @ 4300
229.5tq @ 3100
A/F went on a straight line from 14:1 @ 3100 to ~12.5:1 @ 4950

Measured on a Dynojet, corrected to SAE standard.

I think there's more power on this combo. I learned at least where the gains are to be had.
-The air filter's been on there for 4 years. Only has 1800 miles on it, but it has a lot of varnish from evaporated fuel
-Solid fan is mounted on a spacer sans clutch, grabs a lot of air
- Carter carb - can't remember what the CFM #'s are on it, but I seem to recall it's only 425cfm or so. The lean A/F #'s give me pause there, though. I'm going to have to find the build sheet for the motor.

I don't need a whole lot of power, but I think I'd have another 20hp in it with just the first two, easy.

What say you?

Fast63 · Dec 2, 2007

IMHO that is about right for rear wheel horsepower. You possibly might need bigger primary jets or smaller metering rods on the primaries, but if it's onlt 425cfm, you could get some more power out of a 600cfm I think.

C0V3R · Dec 2, 2007

12.5:1 at redline is actually not far from right. Low 13's would be ideal usually depending on the combo. You might have 10hp in it if you fix the fuel to be a little leaner up top and a little richer down low.

I would borrow another carb if you can, as you might not get as much as you would hope just by swapping.

iskwezm · Dec 2, 2007

Many years ago when i built my first engine in high school, i had a .060 289,Performer 289,try-y's,Intake,stock heads(54 cc i think),comp cam 270* and Edelbrock 600 carb. it made 305 RWHP at about 4600 rpm.The place it was dynoed though the dyno was broken, so he made come back and do it again,same results.

Then I thought i knew it al and changed heads and cam and lost hp

brianj5600 · Dec 2, 2007

I think the dyno was broke too. That combo would have been over- achieving to make those numbers at the flywheel. It would have to make around 350 at the flywheel to put 306 to the rollers. I think the dyno got fixed possibly explaining the loss in power with head/cam swap.

jcp, with stock heads and cam you should not expect much. The fan is hurting power for sure. A thermostatic clutch fan or electric fan will show noticable gains. The intake, carb and cam could be swapped for a big improvement. A stealth or rpm and 600cfm carb would help and are not too uncommon to find used for reasonable money. Intake swaps are quick and easy too. If you have ever seen the stock cam specs, they are incredibly small, and a major hold back. I really doubt there is a lot left in current form. What is you total timing? There is some power there.

jcp123 · Dec 2, 2007

Oh, I know I can't expect that much out of stock heads + cam. My expectation was around 150, so the 10hp I got on top of that keeps me happy enough. As I said, I don't need much - this is a cruiser, after all, and with the open rear end, there's only so much she can lay down at once. But it showed me there's some more to be had with just a little effort.

Now that you mention it, though, a bigger carb wouldn't necessarily help much on top of a regular Performer intake, would it?

I think I'll just get the fan clutch'd and drop a new air filter on top and call it a day. Maybe down the road I'll get her dyno tuned, as well.

mikethebike · Dec 2, 2007

Try a Holey 600 vacum secondary carb. I think you'll pick-up the additional h-p you are looking for. Plus the Holley will carry you much farther up the h-p scale when you build a stronger engine later. And replace that filter!

iskwezm · Dec 2, 2007

brianj5600 said:
I think the dyno was broke too. That combo would have been over- achieving to make those numbers at the flywheel. It would have to make around 350 at the flywheel to put 306 to the rollers. I think the dyno got fixed possibly explaining the loss in power with head/cam swap.

Actually he dynoed his own car to see if the numbers were the same for his car and they were. My car ran 12.90-13.10's @110 with that combo, so i think it was right.

iapexl8r · Dec 2, 2007

what is your total timing set at (36 total would be a good start on premimum fuel)?? there could be a few horses hiden there add that to a knn free flowing air filter and a clutch or electric fan you could see some notable gains!!!

Hey Mario are you going to the dyno day @ bottle fed on dec 15?????? Whats up I want to see that turbo lay down some #'s

chris

iskwezm · Dec 3, 2007

iapexl8r said:
Hey Mario are you going to the dyno day @ bottle fed on dec 15?????? Whats up I want to see that turbo lay down some #'s

chris

Hey Chris.........I have been so busy with the baby comming and working on the house, I havent had time to drop the engine in.Its been on the stand in my garage for about a month and half now. Hopefully i can find 2 hours to drop it in before the end of the year

what dyno day is this?????

iapexl8r · Dec 3, 2007

somthing with that marlon guy (in the valley with the alingment shop). but the dyno is in camirrilo at bottle fed racing. When is the baby coming???? your stoked
If you need an extra hand with the stang shoot me a line ivanpomy@sbcglobal.net. Chris

iskwezm · Dec 3, 2007

iapexl8r said:
somthing with that marlon guy (in the valley with the alingment shop). but the dyno is in camirrilo at bottle fed racing. When is the baby coming???? your stoked
If you need an extra hand with the stang shoot me a line ivanpomy@sbcglobal.net. Chris

Baby is due in February...........

Thanks for the offer

Ive been waiting for some warm weather to mix up some paint and shoot the engine compartment, then its just a matter of dropping it in, which i have down to a science

jcp123 · Dec 3, 2007

iapexl8r said:
what is your total timing set at (36 total would be a good start on premimum fuel)?? there could be a few horses hiden there add that to a knn free flowing air filter and a clutch or electric fan you could see some notable gains!!!

chris

No idea on the timing - it runs on 87, though, which I like. There may be a little to be had there, but I don't want to run any more than 87.

ratio411 · Dec 3, 2007

jcp123 said:
Now that you mention it, though, a bigger carb wouldn't necessarily help much on top of a regular Performer intake, would it?

I wouldn't be so fast in assuming that!

A dual plane intake tames the cfm rating of the carb.
Dual plane intakes actually like larger cfm carbs.
Alot of folks don't think about this fact either when they go around telling folks with dual planes to use 500 cfm, while they tell the folks with single planes to use 750s.
The other way around would probably serve folks better.
Dual planes need larger cfm, then on top of that, a 3310 750 vacuum (for example) can't overcarb your engine anyway... When in proper tune, a vacuum carb won't use the rear venturis unless the engine needs them.

I say find a larger carb, and make sure it's vacuum secondary.
Holley 1850 and 3310 are the most common vacuum carbs.
Carters (Edelbrock) are NOT vacuum carbs.

Fast63 · Dec 3, 2007

ratio411 said:
Carters (Edelbrock) are NOT vacuum carbs.

Hey man, you've got your head on straight

jcp123 · Dec 4, 2007

Not so hot on Holleys anymore...had two of 'em, the first and the last on my Dad's '73 Mach 1. Ran great for a week or two after a dyno tune, then never ran as well again. I thought their finicky reputation was hogwash from Holley haters until I saw with my own eyes.

As to the intake...I was comparing the Performer vs. the RPM...both dual plane. Am I correct in assuming that the RPM would make a larger carb more worthwhile than the Performer?

Hit the dyno today...

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