Weber DG carb jetting question

[Tom_in_MO]

Hi all,
I'm new here and have a question about the Weber DG 32/36 carb. Mainly I'd like to know what jetting works for the 1275 motor. Surprisingly, Pierce Manifolds, which sells Weber kits, offers the same 32/36 kit for all displacement motors from 948 to 1275. I wonder if the identical jetting works well for all three motors, or if they do some fiddling with jets depending on which displacement you tell them you have. They are rather secretive about telling these details.

Anyway, here are the jet sizes I'd like to know about: main, idle and air correction, for both the primary and secondary barrels. Any help you could give would be greatly appreciated.

Tom

 

[tosoutherncars]

Hi Tom,

First of all, welcome to the board! You'll find we're a pretty friendly bunch, with a lot of knowledge on these little cars.

As to your question... the first thing I would suggest is that you have a look at previous threads. Unlike some forums, the "Search" function on here is excellent. Try searching "DGV" for the last year, and you'll find a number of threads, including one where all the 'stock' jetting for a 1500 (which is what I have), it may also have the 1275. If not, someone will chime in soon enough!

Again, welcome aboard!

 

[blkcorvair]

Hey Tom the Jets that come with the DGV kits are usually generic "Starter" jets that are meant only to get the car running. Everyones, driving style, timing, mods, altitude is different so I found it best to tune mine to my car. Never better since. Theres loads of info on how to tune the carbs and it is somewhat overwhelming but I think pierce has some great instructions.

 

[Tom_in_MO]

Thanks to you both! I did find some good info, but haven't found anything that tells me the best setup for a 1300cc motor. Is is possible that the jetting for an 1800cc motor is good enough to run well (or at all) on a 1300cc? Seems like it'd be very rich, and there are many variables besides main jets. Blkcorvair, I see you have two 1500cc Midgets. What jetting are you using, that differs from how the carb came?

 

[68Sprite]

I would recomend installing an Air Fuel Gauge as its takes much of the guess work out of it.

 

[blkcorvair]

I forget the exact jets. I know I am (1) step richer on the Idle Jets and (2) Steps Leaner on the Mian Jets. I am running a cam and High comp though. My key was it would not idle below 1000rpm and was very rich at highway speeds. Those carbs are mostly set to factory Ford Cortina specs which I belive is 1499 or 1599 cc. So it should get you off and running, many people never re-jet them at all. But when you fine tune them, they do perform much better. (My Opinion) Definatally Install a GOOD pressure regulator though. They like about 2-3lbs at most. I put one of those liquid gauges in as well...

 

[JerryB]

"""""""" or if they do some fiddling with jets depending on which displacement you tell them you have"""""""

.....probably not especially on a stock street motor.

What you want to do is get the car drivable with the carb out of the box as is. Set the lead according to the directions as well as the idle speed and the air idle.

If you did not get the instruction sheet(s)? from Pierce when you bought the induction set up then call and ask them for instructions.

Once you get the carb idling smooth and a good transition from idle to progression then you can either use exhaust gas temps or an air-fuel ratio meter to make and jet changes needed. You will not get plug coloration due to unleaded gas..unless your way out of the ballpark...neither will the tailpipe color be an indicator.

 

[recordsj]

I have a stock 1500 with weber 32/36 dgv. What are you jet and idle setting?

 

[blkcorvair]

Theres volumes on how to set that carb. Most are out of the box and bolt on that you see out there. I forget but I dont think you want anymore than 2 1/2 turns in on the idle screw. Idle about 900. If you have it there your in good shape. In regards to timing I ran mine as far out as 18 deg BTC but ended on keeping it at 10 deg BTC. If this is a new setup out of the box for the 1500 than your jets it came with will be adequate for starting and tuning.

I personally gave up after I had it dialed in great for 4 months and it went down the tubes again. I bolted up an HS4 su to the oem manifold and havent looked back. So far I spun one needle down on the drill press and the car really performs. I now installed a wide band sensor so I can really set it up right.

 

[blkcorvair]

I would recomend installing an Air Fuel Gauge as its takes much of the guess work out of it.

 

[recordsj]

what do you mean air fuel guage? Can you provide a link or other info on this setup?

 

[recordsj]

I thought idle speed for a 1500 midget is 800 rpm?

 

[Morris]

Here's my favorite:

https://www.diyautotune.com/catalog/innov...4e50c93409da4f5

You can hook it into a lap top and it will give you your AFR to the .001 .

 

[blkcorvair]

I thought idle speed for a 1500 midget is 800 rpm?

Sorry you may be correct mine has a apt cam so 900 is best I can do.

 

[blkcorvair]

BTW you can get the car to run very well without an air fuel gauge. That will dial it in very close to perfect though. Like I said most people out there bolt em on and drive em without changing much.

 

[regularman]

Mine was never right to begin with when I got my car. I took it down for the resto and am just now getting around to checking into that. It was rather rich at speed IIRC. I bought a gunson's gas tester that I will use and see where I am at. I know I will need a new main jet for the first barrel. If the second is a little rich then It won't be a big deal because I won't be into it that much (hopefully) Hopefully I will complete my dream of having a fun car to drive that gets great MPG. Even with the old setup, I got around 30 back and forth to work and 37 on a long interstate trip. With the new gearing and rejetting the webber, I hope to do a lot better. Oh, one other point to make here. I have fooled with these webers for quite at while on all sorts of engines. One thing to do if its running rich and the carb is old is replace the float. Don't fool with it, replace it. The are not expensive and they don't come in carb kits. If you see someone who is having to mess with the float level they probably have a bad float. Those black carbon type floats absorb water from the air if left dry for a long time or if water gets in the carb from washing or whatever. A bad float will drive you insane and make you spend lots of money on things you don't need.

 

[regularman]

Oh, and one more thing. If you want to get a new float right now. You can go to advance or some other place and ask for a float for a 71 ford pinto. The pinto used the Holley 5200 which is the weber dgv made by holly under license. Since the DGV was an aftermarket carb for the Midget, nobody is going to know or see on the computer that they have that part for the midget optional carb in stock. They put that 5200 on bunches of cars back in the day and most places usually keep parts for them. Always take your old float to compare with the new one before you buy it, but they are usually under 10 bucks.