18 mpg m37 "plus" more power!!!

[SasquatchSanta]

I've got some great news to share in fact it's so good I held off reporting on it until I could triple check my mileage numbers. My mileage readings have been too good to be sound true so I wanted to make one more check --- which I just finished doing tonight --- before posting this thread. My mileage reading tonight equated to 18.28 MPG!

Here is what's going on:

A few weeks ago I installed a Holly/Weber 32/36 model 5200 two-barrel progressive (mechanical) linkage carberutor on my M37 (The Pumpkin). After purchasing a Haynes manual for the C/W 5200 and spending a weekend reading and another few days experimenting and swapping jets I've got a winning combination.

I've got "LOTS" more low end torque and when you step down on the accelerator and open the second barrel the old truck runs like a scared deer. My first fuel mileage tests were made when I was still experimenting with the low idle jets so I was only geting around 12 MPG. As the jetting got better/closer the mileage started to improve. It went from 12 to 14 to 16 and now, tonight I got 18-1/4 MPG.

To check the fuel level I'm gently shaking the truck from side to side while fueling to remove the air bubbles from the tank and filling to the bottom of the large filler area in the tank inlet. In doing this I can get an accurate consumption rate on an approminate 150 to 200 mile test.
This last test was made running @ 2500 RPM (red-line) most of the time.

My truck has a fresh 230 engine that pulls 489 gears. The tires are 36" Denman Coyotes 305/85R16 with spin out hubs. Outside of the head being milled .030 and a civilian distributor installed the engine is stock. Some pictures are attached.

Langdon's Stove-Bold Six sells the carb as a kit but I found you will have to do some re-jetting. Here is what I am running for jets --- I'm not finished experimenting yet.

Primary Idle "100"
Secondary Idle "050"

Primary Main Fuel "330"
Primary Main Air Bleed "180"

Secondary Main Fuel "132"
Secondary Main Air Bleed "195"

I feel the Primary and Secondary Idle jest are as close as I can get them. The Primary and Secondary Main Fuel and Air Bleeds "MAY" be able to be improved.

I just recently learned that at mid-throttle a 14-1/2 to 16-1/2 air to fuel ratio is optimum. At full throttle about 12 to 1 is a good rule of thumb.

If you decide to play around with one of these units keep an eye on your plugs so you don't burn a piston.


More to follow.

 

[SasquatchSanta]

I should have noted earlier that the Holly/Weber 32/36 model 5200 was used on Ford Pintos, Chrysler K cars and Horizons. Technically it's only rated for a 2.5 ltr engine but given the fact that we only turn the 230 flathead engine at 2,500 to 2,600 RPM it seems to be a perfect match.

 

[Tanner]

I should have noted earlier that the Holly/Weber 32/36 model 5200 was used on Ford Pintos, Chrysler K cars and Horizons. Technically it's only rated for a 2.5 ltr engine but given the fact that we only turn the 230 flathead engine at 2,500 to 2,600 RPM it seems to be a perfect match.

Ahhh.... the famous Pinto/Omni/Horizon/Datsun/Vega/Fiat/Rabbit-Dasher-Scirocco/Beetle/etc... 2300 carb -

Now finding yet another use -

What I'd like to see used is a pair of Pontiac Sunbird or Chevy Cavalier throttle-body injectors used on a Dodge twin carb intake manifold, in conjunction with the GM 1227747 ECM, some sensors & wires, fuel pump, etc... instant cheap fuel injection...

Some good info - http://www.corvairnut.com/corvairTBI.htm

'Tanner'

 

[SasquatchSanta]

Ahhh.... the famous Pinto/Omni/Horizon/Datsun/Vega/Fiat/Rabbit-Dasher-Scirocco/Beetle/etc... 2300 carb -

Now finding yet another use -

What I'd like to see used is a pair of Pontiac Sunbird or Chevy Cavalier throttle-body injectors used on a Dodge twin carb intake manifold, in conjunction with the GM 1227747 ECM, some sensors & wires, fuel pump, etc... instant cheap fuel injection...

Some good info - Corvair Fuel Injection Project

'Tanner'

I'm not familiar with what you are calling a 2300 carb. All the books and parts manuals refer to the Holly/Weber 32/36 at a 5200 or 5210.

With the kind of fuel mileage and power performance I've managed to get why entertain the complexities of fuel injection. I've checked my mileage several times and I'm still having trouble believing the added mileage.

 

[clinto]

Those are spectacular mileage figures, E. You've obviously put a lot of time into fine tuning your combination.

Fine tuning a vehicle is really what separates the "parts installers" from the "experts".

I can tell you a lot of stories about 2 Carter AFBs, progressive linkage and a uni-syn!

 

[doghead]

What what the MPG with the stock(original M37) carburetor?

 

[SasquatchSanta]

What what the MPG with the stock(original M37) carburetor?

With the combination I "was" running which was a single barrel Carter Ball & Ball carburetor off a civilian power wagon I could get upwards of 12 MPG. I had tinkered with it therefore it was probably running more efficiently than most. The problem with the old single barrel is finding inerchangeable jets.

 

[m376x6]

What what the MPG with the stock(original M37) carburetor?

All the way up into the 6 to 8 mile per gallon range usually.

Santa congratulations, that is phenominal. I had a CJ2A that had one of the Phillipine replacement bodies on it and bought a kit to install a 2300 Pinto engine in it. It was really nifty. Guy had just had the engine rebuilt in his Pinto and suddenly it started smoking like crazy. He decided to part it out. I gave him $75 for the engine and found it was just rebuilt but a valve guide had broken and oil was just pouring into the cylinder. Pressed a new guide in and it ran like a champ. That little Jeep was fun. Good gas mileage as well.

 

[M-37Bruce]

Finally some good news out of Minnesota! Hey Ernie, sounds like you had a busy summer up 'er in the Land O' Lakes?

 

[Tanner]

I'm not familiar with what you are calling a 2300 carb. All the books and parts manuals refer to the Holly/Weber 32/36 at a 5200 or 5210.

With the kind of fuel mileage and power performance I've managed to get why entertain the complexities of fuel injection. I've checked my mileage several times and I'm still having trouble believing the added mileage.

There was a Holley mfg'd version called the 2300 that was built under license from Weber; similar carb, though some variants had a carb to manifold mounting base bolt pattern that was slightly different - flowed 350cfm. I come from the air-cooled VW background & they were favored by some in the Eighties.

Re: the FI - once it's setup, it's very simple.

'Tanner'

 

[Nicholas]

I put that same carb, aircleaner setup on a couple years ago. Great improvement. I didn't change the jetting. I just have a pertronix and that carb. Starts right up and runs great. Great fence fixing truck with 11.00 16 tires.

 

[M-37Bruce]

Holly Carb

More info coming I hope?

 

[98taco3]

Very interesting! Ive been thinking about a swap since mine also has a civilian PW carb on it. Maybe this is the way to go. Did you have to adapt it to the manifold at all? How were the linkages to deal with?

 

[Cav Trooper]

I assume the original air cleaner and hardware have to be trashed? Like to see a picture of set up.

Cav Trooper

 

[Warryer]

What jets do you run in yours Nicholas?

 

[Warryer]

The large 330 jet does not to seem to exist....am I missing something? The largest they go is 210

 

[m109a2]

Good work,Ahh the old 230 flathead one of the few engines made where you can gap and change the plugs in the span of a beer.Al

 

[Warryer]

Mine is actually the Canadian 250...but yes....the engine seems simple. Do you have any carbs numbers for the Weber 32/36?

 

[gimpyrobb]

I had a weber 32/36 dgav on my 86 toyota pickup with a 22r. Not sure if that would help you guys, but that last bit of info(dgav) seemed to have a bunch of hits on google.

 

[MarkPick]

Any updates? Really interested in this mod!