700 double pumper on a road car

[GJUK]

Hi,

To try and sort my running ittus on the dart, I've been told I should rebuild the carb.

Having phoned real steel they said running a double pumper on a road car is not a good idea, I'll end up having bore wash and destroying my engine.

Can anyone advise please, Am I best to change my carb to something better suited to road use?

The car does seem to be overfueling (pulled a sparkplug and its black black black)

Thoughts guys?

A new 750 vacuum pup is only £300 I might just get one of these?

Jon

[Adrian Worman]

Unsuitable on the street? Wot a load of Bananarama!

Perfectly good carbs, tuned properly will be no different to a vac sec, a Quadrajet, Carter AFB etc.

I bet more than half the peep on this board are, or have, running a DP on the road.

Get it tuned right and it'll be fine

[Les Szabo]

Unsuitable on the street? Wot a load of Bananarama!

Perfectly good carbs, tuned properly will be no different to a vac sec, a Quadrajet, Carter AFB etc.

I bet more than half the peep on this board are, or have, running a DP on the road.

Get it tuned right and it'll be fine

Exactly, a load of Bananarama!....shops do tend to say that and then next quote, yes we stock VS carbs......a properly tuned DP will outperform any VS or other carb, however unless you have a decent cam, headers, inlet and a loose -ish verter and at least 3.55's perhaps a VS will suit better for most street apps that only need to run on a 2bbl carb most of the time.

[Dave-R]

The car does seem to be overfueling (pulled a sparkplug and its black black black)

That is probably just bad carb and ignition tuning. People think you can just bolt these bits together and go fast. If only life was as simple as that in reality.

[ANTON]

I have been running a 650 double pumper on my car for two years and its great. I have had no problems.

[Blue]

I've had double pumper carbs on all my street cars for the last 30 odd years and known many others do the same. They are more tuneable than a vac sec, which I've never been a fan of. It is also a myth that they are less economical, if you are just cruising around and keeping your foot out of it, they are no more thirsty than anything else. Once you've got your timing set up correctly you can then work on the carb, don't be tempted to start messing with it first.

[Pete]

Double Pumpers all the way, the more the better (Tunnel Ram!!!)

[GJUK]

Alright thanks guys.

I will have to borrow a timing light and get it as close to sorted as I can. I really feel there are lots of problems with the car. Carb. Timing and possibly fueling. Will try and attack the timing first of all as blue suggested.

The carb (700 double pumper) was sold to me as a 750 double pumper. Is the 700 still okay for getting the most from the engine?

Cheers.

Jon

[Les Szabo]

Alright thanks guys.

I will have to borrow a timing light and get it as close to sorted as I can. I really feel there are lots of problems with the car. Carb. Timing and possibly fueling. Will try and attack the timing first of all as blue suggested.

The carb (700 double pumper) was sold to me as a 750 double pumper. Is the 700 still okay for getting the most from the engine?

Cheers.

Jon

Its ok for what you use the car for and the engine you now have. Carb size is NOT dependent on engine size alone as most calculators will show you, its whats inside the engine, your converter, gearing and use.

I ran an 850DP on a 340ci, everyone kept telling me its too big, so to shut them up I tried a smaller carb and went 2/10ths slower. In fact I lent my 850 carb to a guy running a 3500cc Rover V8 Cortina and he went 2/10ths quicker with it!!!

[GJUK]

Just really want to get the car running okay.

I hear what you are saying though.

Cheers

Jon

[John]

Take no notice of these guys chap, get your vac sec and I will give you £50 for the double pumper

[Pete]

In reality a 400 in fairly stock form does not produce a lot of Horsepower or torque, though it has the basis for a good strong engine by virtue of the Block design...I think I ran 13.1 in an "A" Body on a 400 stocker, which is basically a low compression smog engine.

However, the carb you have will be fine if you sort out the other issues.........

[Jerry Smith]

Jon, why not take the car up to John Sleath (www.john-sleath.com)and get him to set it up on the rolling road he's only in Doncaster and it will save you so much messing about,

[sinny]

Jon I had the same issue, take it to someone who knows how to set the carb & timing properly. I took it to a local guy who sorted it in a couple of hours.

[RW71]

Getting John Sleath to set it up sounds like a good plan Jon, especially as you are so (relatively) close.