Looking at going back to a carb!!

[Cobraqcca]

Hi All-

So, not to beat a dead horse, on the EFI vs CARB debate, but, if you have a carb, how bad does it actually stink of gas. Running or just in the garage??

Original thought was to put on EFI and go - such has not been the case!!

I have a PJIII EFI on my 427W Ford Racing Crate Engine and I've had a lot of problems 'dialing her in' or even getting her to idle well....can get close but not right on...!! It started out with a defective TPS - that I think blew the ECM and now my O2 sensor appears to be fouled...I'm fed up!


I'm thinking I may want to go back to a carb for simplicity sake. No O2 sensor, TPS, ECM, AIR mix control to eventually go defunct...no electrical connections to corrode or disconnect!! And I won't have to spend all my free time trying to figure out all the tables and programming!! Besides, I think I'd be able to tune a carb just as well...at least for my driving. Only question is some calculations say 600cfm (street) and others say 750cfm (race)! Anybody done either one or both?? I'll drive maybe 5000 miles a year MAX!! At 535hp and 545 torque I don't know that I'll need the extra 150cfm - unless they would basically run the same except at WOT!!

Suggestions.....

Thanks,
Gary

[lippy]

Originally Posted by Cobraqcca

if you have a carb, how bad does it actually stink of gas. Running or just in the garage??

Not too bad at all. But I like the smell.

[ItBites]

Good luck getting 535 hp out of 600 CFM... Just sayin

[mdross1]

Originally Posted by ItBites

Good luck getting 535 hp out of 600 CFM... Just sayin

Doubt 535 hp is possible a 750 will be a better choice.If you do not run the motor that hard then 600 will work.
Once was convinced to go from 750 dbl pmp to 850 dbl pmp on a Chev 454 honestly had my doubts.Wow! what a wake up call that was.Just saying.The best thing about a carb is the tunability ease,small amount of money needed to experiment.
I too tried converting to EFI and had the same problems with failed parts biggest problem was the car was a daily driver and waiting for replacement parts was more than we could endure.Besides will always love the carb idle!

[vatdevil]

A properly set up carb has no more smell than EFI. The 750 is fine for a 427. Other than cold starts, I see little benefit to EFI on these cars, unless you're concerned with fuel mileage or emissions. Have the carb set up by someone who knows what they are doing, preferably on a dyno. Worth the money spent.

[Bartruff1]

Originally Posted by vatdevil

A properly set up carb has no more smell than EFI. The 750 is fine for a 427. Other than cold starts, I see little benefit to EFI on these cars, unless you're concerned with fuel mileage or emissions. Have the carb set up by someone who knows what they are doing, preferably on a dyno. Worth the money spent.

My Holly has been trouble free, with no gas smell...the guy that set it up..
Steven and Loosy at Full Throttle in Reno, must have done it right.

[Gaz64]

The gas smell comes from long duration cams using a carburettor.

The bigger the cam, the worse the smell is.

Sequential EFI will eliminate the smell.

If your system is sequential, get hold of a decent tuner to sort it.

Having said that, my mates 355 makes more outright power with a Quick Fuel 750 DP than it did with a dyno tuned group fired EFI system, 4 barrel throttle body etc.

[RallySnake]

I have used a bunch of carburetors on my car and none of them have been perfect. I am always changing this or that to try to improve them. the Edlebrock (or Carter) type stalls when you corner too hard. The Holley's stall the engine when you brake really hard. I am currently running a Holley Avenger 670 and after a year of tuning with a wide band A/F gauge I am getting pretty close with it. I have changed jets, squirter, cam, springs and needle assemblies to keep the mixture between 12.5 to 17 to 1 in each phase of operation.

EFI is the reason that modern car engines go for 200,000 miles without a rebuild. Carburetors never mix the fuel with the air perfectly so you always get some raw fuel washing the oil off the cylinder walls and that causes more wear. Most carbed engines will have to be rebuilt before the 100,000 mark come up. That is the primary reason that I am seriously thinking about spending $2,000 bucks on EFI. The Projection 3 system is nice because the ECU is built into the throttle body. Holley, FAST, MSD, Edlebrock and Accel make "self learning" EFI systems that should be easy to program. However, as you have seen, there are so many components that can fail. EFI systems need a steady voltage supply. You need a 100 amp alternator and a voltage stabilization device like the MSD capacitor. That may have something to do with your problem. They also will not work correctly if you have a camshaft that's too radical. Too much cam overlap drives the sensor crazy.

Since I run long distance rallies in my car, I will probably stick with the carb. I have fixed it on the side of the road many times. Try that with EFI.

However, there are companies that reprogram the stock Ford or GM ECU's so you can run with EFI systems tested for millions of miles. That may be the most reliable way to do it and that is the direction I will continue to investigate. Good luck with yours.

[RodKnock]

Originally Posted by Cobraqcca

So, not to beat a dead horse, on the EFI vs CARB debate, but, if you have a carb, how bad does it actually stink of gas. Running or just in the garage?? Thanks,
Gary

Mine stinks. But carbs are simple and cheap.

Save it Chas.

[GregAgrest]

I don't get any gasoline smell from mine.

[joyridin']

Mine smells fine. I would be more around 800 CFM.

[MJJ]

why not take it to a professional and have a custom dyno tune?

[eschaider]

Originally Posted by MJJ

why not take it to a professional and have a custom dyno tune?

^^ This is your correct fix.

You are clearly unfamiliar with how to tune an EFI system so go to the professionals and stop wasting time and money. The EFI will outperform a carb in every aspect you can measure.

On the other hand if you want a carb, for what ever reason, go buy one and put it on like we all have done for decades. Smaller ones perform better at low engine speeds and bigger ones perform better at high engine speeds.

Use a wideband, as has already been suggested, and dial it in. You will surrender some drivability, mileage and cold start manners but it will work just fine - like they always have.

Sell your EFI to someone who wants and knows how to use one and repurpose the dollars for something else on the car.

Ed

[olddog]

Jerking the intake off and plopping a intake and carb on is easy, but what about ignition, fuel delivery, and wiring harness?

Assuming you have a decent EFI system, it should be controlling the ignition timing and fuel pump, too. Perhaps the fan and speedometer, as well. The EFI fuel pump is putting out way too much pressure for a Carb, so that has to be changed. If it is a return type fuel system, you should remove that. Odds are you are going to have to buy a distributor. When you remove the EFI wiring harness, you need to provide for just about everything that it connects to other than the fuel injectors, and sensors.

Then you are going to need to tune the carb and get the timing curve set up for your engine. As stated to do it right, you need to use a wide band O2. Many don't and put up with the stench and leave 50 Hp on the table. Without the dyno you will leave more Hp on the table do to the timing curve not being dialed in.

Not hard to drop a grand on intake, carb, distributor, fuel pump, etc. Then another $500 to get it tuned.

Or

Take the EFI to a good tuner. He more than likely can fix it and tune it right for under a grand.

[lippy]

Originally Posted by olddog

Not hard to drop a grand on intake, carb, distributor, fuel pump, etc.

That's an understatement. I'm using a carb (Holley HP Ultra 950). The cost of the carb + intake + fuel pump + fuel lines + fittings + filters + regulator is almost $3k. This is good stuff (Aeroquip, Aeromotive, etc.) but I was shocked how quickly it added up. And you will need to replace most of it.

I agree with the folks who said fix what you have.

[vector1]

Originally Posted by lippy

That's an understatement. I'm using a carb (Holley HP Ultra 950). The cost of the carb + intake + fuel pump + fuel lines + fittings + filters + regulator is almost $3k. This is good stuff (Aeroquip, Aeromotive, etc.) but I was shocked how quickly it added up. And you will need to replace most of it.

I agree with the folks who said fix what you have.

Lippy, if you haven't used the 950 yet you might want to trade it for a 850, the 950 is reported to not pull as good a booster signal which could make it tougher to tune and the 850 flows around the 950. I think blykins had trouble tuning a 950 on the dyno and switched it for something else.

[madmaxx]

Mine stank. Garage stank, my clothes stank, nature of beast

[tpatodd]

"I love the smell of napalm in the morning".

It smells. I love it. The Wife doesn't. <-- even better. (shhh)

[itstock]

Is there a hp limit on that system?

I've been playing with the idea of going efi (currently have quick fuel 780), it would be nice to lose a bit of the gas smell on my clothes and get a little better mpg (though I'm sure that even with efi these cars exhaust will still leave a bit of an odor).

[fordracing65]

You can buy an additive that makes your gas smell anyway you want, grape, strawberry, cherry, etc...