VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1929-1932 Fuel Economy

Assuming that points,plugs,condenser,carburetor, are all adjusted properly, can anyone tell me what kind of gas mileage I can expect from my '31 2dr coach?

My speedo is out for repair. However, it seems to me that I'm not getting very good mileage. I've checked ,cleaned,and regapped the plugs. Reset the points, and adjusted to carb. The car starts quickly even when cold. Everything seems to be tuned o.k.

Gotta31 :confused: :confused:

What is the gap on your plugs and points? What type of plugs are you using? What is your timing set at?

Plugs--.024
points --.018
Plug type -- AC C87
Timing -- Haven't checked. Looking for 6v dwell meter.

Gotta31

Gap your AC-C87 plugs to .040" and set your timing at 18 degrees. You should notice a big difference on power and smoothness at idle.

You are looking for a 6 volt dwell meter or a 6 volt timing light?

You can use a 12 volt timing light with an auxiliary 12 volt battery.

Okey-dokey!!

I shudda thought about using a 12v batt with the 12v timing light!

Those plugs were gapped pretty wide. Unfortunately I didn't chech them before I regapped them but they were awful wide. Just for my info, why do you recommend setting the plugs at .040?

Gotta31 :eek: :eek:

"You should notice a big difference on power and smoothness at idle."

Also, with a wider plug gap you will have a longer duration spark and a hotter spark. And, with today's fuel you will notice a difference in power with the wider plug gap and increased timing. By bumping your timing to 18 degrees with a wider spark plug gap it will eliminate the "popping" out the tail pipe at idle as well.

Thanks buddy!

I'll give it a try tomorrow.

Gotta31 :rolleyes: :rolleyes:

Cool! I think that you will love the difference.

JYD: Would this gap apply to the 1932 as well? I have heard of the 18 degree timing setting.

Yes, all 194 engines from 1929 thru 1932.

20 miles to the gallon.

JYD is that 18* BTDC

Thanks

Yes, 18 degrees advanced.

20 MPG??? I would love to get that. I get 11 MPG burning Super in it.

Ya, 12 to 16 MPG is more realistic.

I get 10-12 mpg with a '31 fire truck with original everything and weighing over 2.5 tons. 15-18 mpg in a car is more reasonable when driving in the 50 mph range. If 35-40 mph then 20 mpg is achievable. If you only get 11 mpg in a '31 then you need to check for fuel leaks or some other problem.

If you have an original early '32 with the 212S carb then 10 mpg is about right. They get 15+ mpg with the later 235S carb.

Hi Fellas:

I re-gapped the plugs to .040 and set the timing to 18 degrees BTDC. I got instant results! Much better pick up from a cruise speed and much better fuel economy. I don't know how much better my gas mileage is because I don't have my speedo back yet but going to the same places everyday and watching the needle, I know I'm doing a whole lot better than I was.

Thanks to all of you for your suggestions.

Gotta31

Hi Fellas:

I re-gapped the plugs to .040 and set the timing to 18 degrees BTDC. I got instant results! Much better pick up from a cruise speed and much better fuel economy. I don't know how much better my gas mileage is because I don't have my speedo back yet but going to the same places everyday and watching the needle, I know I'm doing a whole lot better than I was.

Thanks to all of you for your suggestions.

Gotta31

The 1931 coach that i had gave me 20 MPG on a 150 mile trip that I took it on. that was the only time that I check it. All the other time it was just short runs.

GOTTA31: Glad that the tip on the spark plug gap and the timing worked for you. Many dudes in the past have tried this trick that I learned years ago playing around with my 1930 Sport Coupe and it also worked great for them.

Now, if you are really brave, you can bump the gap on your AC-C87 plugs to .045" and the performance will improve even more.

Hey Skip, if you go to .045 are there any problems you might have and do you have to change the timing more?

No problems. And, the 18 degree timing is actually based on a spark plug gap of .045", but the 18 degrees also works well on a spark plug gap of .040 too.

Hey JYD -- I'm gonna try that .045 gap. What the hay! If it doesn't work, I can always go back to .040. Hey, how about this little added bit?.....Is there a hotter coil I can safely put on this booger?

Gotta31

If your coil is in good condition it will work just fine for the hotter spark.