MPG with 351 Ford Racing crate engine

[dan512]

Hi!

Just wondering what mpg I should get from my 351 Ford Racing crate engine with Holley Speed Demon 750 carb.

Is 12-13 mpg for normal street driving not way on the high side?

[Grubby]

My first Cobra had a similar 351 with T5 and 3.54 gears. It got 15mpg on the highway and less in town.

John

[DWRAT]

I get.
8-10 mpg in town.
15-16 mpg highway
21.07 mpg on highway when in Eco mode. (No playing at all)

[Tommy]

My 410 ci Windsor with lots of aftermarket parts averages about 14 MPG. 80% of driving is on open roads near the speed limit.

[dan512]

Originally Posted by DWRAT

I get.
8-10 mpg in town.
15-16 mpg highway
21.07 mpg on highway when in Eco mode. (No playing at all)

So I'm quite on the high side. I get the 12-13 mpg on normal easy cruising on secondary roads, with speeds from 40-60 mph.

[Tommy]

Dan,
Who tuned the carburetor? Some builders err on the rich side to prevent a lean condition from damaging the engine.

[Ace23]

I think you will get a different answer from everyone. I have a 427 with quite a bit of overlap and I can't do better than 10-11mpg with a 3:31 rear gear. The car has a Q-Fuel 750 with mechanical secondaries and has been dyno tuned. What I have not done is part throttle tune it on the open road with a wide band. A local friend has a 445 more aggressive Windsor with a larger carb than mine with 3.46 gears and it was dyno tuned by the same guy mine was......he gets 1mpg or so better than me so go figure.

I talked to a guy yesterday with a 598ci big block making 800hp with a solid roller and a 1050 dominator and he said he runs 3:73 rear gears and can get 15mpg on the interstate after tuning his car with a wideband. This blows my mind if its true.....he would have absolutely no reason not be truthful about the MPG but who the heck knows. I don't see how you wouldn't get 5mpg with something like that

Based off my limited experience depending on rear gear and camshaft selectiong I don't see why you wouldn't be getting at least 15mpg if you are cruising.

[dan512]

Yes I was thinking along the same lines. It's just a 351 with 380hp. Don't even want to know where I'll end up if I floor t.

Maybe I should get soemone else too look at the carb setup.

[Ace23]

Originally Posted by dan512

Yes I was thinking along the same lines. It's just a 351 with 380hp. Don't even want to know where I'll end up if I floor t.

Maybe I should get soemone else too look at the carb setup.

Gas mileage really isn't that big of an issue but it is one of those things were if I should be getting 15mpg I want my 15mpg....not 8mpg. Personally its annoying getting crappy mileage.

Does your car run well? I don't think it hurts you one bit to set aside $300-$400 and get it tuned on a dyno. The other option is to buy your own wideband and tune it yourself. If you are handy enough, patient and understand carbs then the wideband street tuning would be the best option. I have no idea why people don't tune these things themselves or invest $400 in a dyno tune. Too many people set the float bowls and get the idle right and think "yeah this thing is tuned!"

[jhv48]

I'm not a proponent of dyno tuning for cruise cycles. Every dyno chart I've seen begins at 3500 rpm. The best way to set your carb for cruise is to reduce the size of the primary main jet until the car starts to buck when cruising at a steady speed on a flat surface in third gear. Say 2500 rpm. Then raise the jet size until it cruises comfortably at that speed. The bucking indicates a lean condition. Then take it for a cruise and check your plugs. That's about as close as you can get without using a Wideband.
Tune wot on a dyno!

[Bartruff1]

This is my second one and 8 around town and 14 on the road...the fuel gages are seldom more than a estimate so I just start looking to refuel after 100 miles....that is ok with me....3 hours in one of these things is about a half hour too long, so I am ready for a walk about...

[Bob Hess]

Drive it like you stole it = 4 MPG
Drive it like you're 72 years old = 10 MPG

351W by Performance Engineering stroked to 408 with a 650 CFM Speed Demon. 476 HP 467 Torque.

[1985 CCX]

I get

Highway 10 mpg
City.....6.57 mpg

[Ace23]

This is kinda off topic but I REALLY wish someone made a twin screw supercharger for a 351 Windsor platform. If this was available I would buy one without a doubt as long as it was a well engineered product. Whipple / Kennebell and TVS need to step up! You would have insane amounts of power and be able to run a 351 or 351 stroked motor.....the gas mileage would be great and the exhaust wouldn't be muffled like a turbo setup.

[cycleguy55]

Originally Posted by Ace23

This is kinda off topic but I REALLY wish someone made a twin screw supercharger for a 351 Windsor platform. If this was available I would buy one without a doubt as long as it was a well engineered product. Whipple / Kennebell and TVS need to step up! You would have insane amounts of power and be able to run a 351 or 351 stroked motor.....the gas mileage would be great and the exhaust wouldn't be muffled like a turbo setup.

Easily done:
1. Weiand Supercharger: https://www.holley.com/products/supe...ts/77-174FSB-1 (Or any other 302W supercharger kit)
2. Price Motorsports adapters (351W Block,351 Windsor Heads, 302 Intake): AP-01 and AP-04

You'd need a different drive belt than comes with the 302W supercharger kits, but that s/b easy.

Let us know how it turns out.

[Karl Bebout]

I guess I understand being concerned about gas mileage with one of these cars. If I was getting 8MPG while other similar set ups got 15, I'd try to find a good carb tuner and then let it go at that, or buy a Prius to average out...

When I got away from my snorting 496 BBC, and its 12 I got this tiny little 289 and was disappointed with its 15MPG, but then its being fed by all those Webers, its running good, so I just bite the bullet and when my friends with their FI 302s brag about 27 MPG, I just raise the hood, and they shut up.

[dan512]

Originally Posted by Karl Bebout

I guess I understand being concerned about gas mileage with one of these cars. If I was getting 8MPG while other similar set ups got 15, I'd try to find a good carb tuner and then let it go at that, or buy a Prius to average out...

When I got away from my snorting 496 BBC, and its 12 I got this tiny little 289 and was disappointed with its 15MPG, but then its being fed by all those Webers, its running good, so I just bite the bullet and when my friends with their FI 302s brag about 27 MPG, I just raise the hood, and they shut up.

I agree. I don't want to change my carb, since the new one will have to be set up as well, so I'll be back at the start in some way.

Will look into finding a competent tuner to make the most out of What I have, fully knowing it's not built to save fuel but to burn it.

[Ace23]

Originally Posted by cycleguy55

Easily done:
1. Weiand Supercharger: https://www.holley.com/products/supe...ts/77-174FSB-1 (Or any other 302W supercharger kit)
2. Price Motorsports adapters (351W Block,351 Windsor Heads, 302 Intake): AP-01 and AP-04

You'd need a different drive belt than comes with the 302W supercharger kits, but that s/b easy.

Let us know how it turns out.

Alright Brian....you got me. I don't think you can get a Weiand under the stock hood and I wouldn't want to look like a 69 camaro. I was talking more about the new twin screw setups from the last 10 years that you find on the Mustang and Corvette market . I think a big problem with the Windsor is the distributor in the front. I'm going to check that link out......I knew from looking at Weiand's in the past that they didn't offer a 351W kit. Do you think the 174 series would support 427CI.....it looks like a pretty small blower. With enough money I know someone could fab up a way to get a whipple or kennebell style setup. There used to be a company called B&H superchargers that had a Windsor conversion but I don't think they are in business anymore.

Originally Posted by dan512

I agree. I don't want to change my carb, since the new one will have to be set up as well, so I'll be back at the start in some way.

Will look into finding a competent tuner to make the most out of What I have, fully knowing it's not built to save fuel but to burn it.

Get hooked up with a good tuner and I think you will be satisfied to a point.