Dual 40 IDF weber or single

mcdmusic · Post by **mcdmusic** » Tue Mar 04, 2003 2:38 pm

I am currently running:
Motor Size somewhere in the 1800's
(didnt measure it)
Single Weber 40 IDF Carb (170main jets)
Engle 110 Cam
Extractor Headers
Dual Quiet Pack Mufflers

I have an extra 40 IDF brand new, is is worth spending the money to get the manifolds and linkage. The car runs great right now(not too rich or lean) but gets around 14mpg.

BTW-This is a 71 Ghia, so airfilter is chopped to about 2 inches to fit.

Eaallred · Post by **Eaallred** » Tue Mar 04, 2003 3:07 pm

Definitly worth it. 14mpg is pretty bad mileage.

Duals will run better and cooler.

You will need to rejet the carbs to run as duals, but you'll love the way it will run.

We've (Aircooled.Net) helped a number of people make the change from a single to duals. Order the intakes and stuff from us, and we can set you up with the correct jets you need. Shoot an e-mail to John at [email protected] and find out what all he needs to know to set your carbs up right.

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Eric Allred
64 Bus
64 Bug

mharney · Post by **mharney** » Tue Mar 04, 2003 4:41 pm

yep.

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69bug4me · Post by **69bug4me** » Tue Mar 04, 2003 8:25 pm

i would run the duals i fought with a single 44 till i ripped it off and sold it.
170 on the mains is probably why your only getting 14 mpg,that sounds way too big for a 40.

74supersun · Post by **74supersun** » Tue Mar 04, 2003 8:54 pm

Be mindfull of changes involved switching to dual. fan shroud 36hp style and linkage. Berg is excellent; hex petty good. Thottle response changes depending on linkage. If not step up correctly it goes from hard pedal to wide open, not good traffic.

Post by **sparkmaster1** » Tue Mar 04, 2003 9:08 pm

I'm running a single 40 on a 1776 and it works quite well. You have to have the manifold heat hooked up though. What size venturis do you have? That main jet sounds huge. I have 28 vents and I run about 140 main jet and get about 22 mpg around town. Tim

regis101 · Post by **regis101** » Wed Mar 05, 2003 6:09 pm

Hey Spark. You're one of the few people I've heard of running a single 40 ( IDF?). How is the throttle response and such? You seem to have it dialed in for your application. What is it in? My research on single 40's did not have much reply. All seem to think that that set-up is good for baja's and buggies. I read the same books, perhaps. To me, it's like, yeah-well? My inquiry to you is because I was also thinking of a single 40 on a 1679 or 1776 for our 67 bus. The aftermarket seems to cater to this set-up. Thanks

Post by **sparkmaster1** » Wed Mar 05, 2003 6:35 pm

I reset the floats to where they should be. 28 vents 55 idle, 140 main (135 might be better) F-7 tubes, and 160 air. Also 2.5lbs of fuel pressure. It's currently on a 2110 and it still runs good. The heat tubes really help, and open up the exhaust as big as you can so it really flows into the tubes. Good luck, Tim

regis101 · Post by **regis101** » Wed Mar 05, 2003 8:52 pm

Thanks for the tip(s). I'll keep your post in my files for future reference. My mechanic has had good luck with them as he says. Used to use a single on the race car with a 1914. Maybe a single was a class spec. or something. I didn't get into that much detail about it. Good thing is that he would set it up using the sniffer. Good to get a baseline. Blah, blah. Duals are cool, but for my application, a single will be just fine.

mcdmusic · Post by **mcdmusic** » Thu Mar 06, 2003 9:34 am

I have decided to stick with the single 40 IDF. And to sparkmaster1 I had smaller jets in the car, the problem was a huge flat spot. The initial fix we took a drill to the jets, then bought the 170s. It may seem to rich, but there isnt any black smoke to be seen. But does anyone know if having a 2" air filter on one side makes a difference.

Here's a picture of the motor to see.

Hope that worked

Post by **sparkmaster1** » Thu Mar 06, 2003 12:10 pm

Get the heat tubes on there. It will run even better. What exhaust are you running? I'm running velocity stacks on mine but I'm not sure if they make all that much difference. Tim

regis101 · Post by **regis101** » Thu Mar 06, 2003 8:35 pm

I read somewhere that carb(s) can have a fuel standoff. This is a fog of sorts that is above the carb roughly 4". Having too short of an air cleaner will aid in having a richer mixture. Makes sense in its own way. I picture that I want all the air to be funneled down into the carb throat. Any restriction is just that.

zenjoe · Post by **zenjoe** » Fri Mar 07, 2003 1:01 pm

That air cleaner looks way to small to do anything! I had problems when running air cleaners on my car (dual 45dells), I would tune it with the air cleaners off and drive with the air cleaners reinstalled. When I installed the air cleaners, the car ran like poop. The reason was that there was not enough room between the velocity stack and the air cleaner top. I bet you will make a whole lot more power if you put a set of velocity stacks and tall filters on your setup. It will still fit under your decklid and help you out considerably.

Zenjoe

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gcorona · Post by **gcorona** » Fri Mar 07, 2003 5:47 pm

I have the same setup as MCDMUSIC. Except I'm getting 20MPGs

I want to get better gas milage by putting a second carb, but I'm not sure I want to go with another Weber (I'm saving for an EFI conversion). Is there a more budget, dual carb setup for a 1776cc engine? My concern is better milage, not power.

Regards,
Genaro