Anyone familiar with the Holley 4150G (governed) carburetor?

Our newly purchased 1977 D800 with air brakes has a Holley 4150G on it. I have rebuilt it using the manuals and quite a few tips gathered online. The missing piece of the puzzle is how to tune this beast. The factory configuration of the various components is unlike any other Holley I have worked on.

First, the idle mixture screws are on the secondary side. Supposedly the governor magically controls the primary idle mixture per the Holley manual. There is an idle speed set screw (no idle mixture screws) on the primary side and I set it @ .020 exposed transfer slot along with the secondary.

Also of note is the distributor on this setup. It is and electronic tach drive deal with vacuum lines going to and from the carb. One vacuum line is connected to ported vacuum and the other goes to the governor dashpot.

With all of that said, is there any reason why I can't put a non-governed carburetor in the 4150g's place with a regular distributor? Being a '77 with electronic ignition the distributor is plug and play.

For what it's worth here is how I have it setup:

Primary:

-no idle mixture screws)
-64 jet (factory was 58? never had a jet that small in anything)
-Two stage PV, acted like a 1"-10" when tested

Secondary:

-idle mixture screws 1.5 turns out
-76 jet (was a 74)
-no PV


I'd sure appreciate any insight on this situation. It's getting harder and harder to find a mechanic that worked on stuff like this.

I don't see any reason you couldn't put a regular carb and distributor on it. I would ditch that other stuff.

My 77 manual says 58/61 on the primaries and 72/72 on the secondaries, nothing about the power valve. The idle setting procedure is terrible (adjust mixture according to emissions control label in engine compartment).

The imagines just show an Idle speed adjustment screw, and mixture screw limiting caps on the secondaries.

The governor system is only in the carb and the distributor according to the manual, you should be able to replace both of those and be done with that all.

Thank you both. I have a 3310 and 6AL on order!

You can change the carb & ignition system, but don't forget the main reason these governed systems were installed on big trucks in the first place. Their purpose is to limit sudden rpm changes in the motor. Big trucks carrying heavy weight don't tend to like sudden rises in rpm because sudden rpm changes tends to break stuff like rear ends and ujoints. It is especially a problem if the truck has a big block.

With the governed carb, if you stomp on the gas, the carb slowly adds rpm to eliminate a sudden jolt to the drive train and save parts. When you remove the governed stuff and stomp on the gas, the motor will respond and take out the weakest link, probably nearly instantly, depending on how much weight is on the truck.

Drive accordingly. Gene

Gene, thank you for chiming in. This is the type of info I am seeking. I have been driving a 361-2bbl 1967 D600 loaded way past the GVWR and so far so good. With all of that weight I can stand on the gas and the engine won't rev quickly. It might be different with a 440 and 4-barrel. We did get it started up on the 4150G and drove it around the yard a bit. Runs good, revs quick!

Here is a better shot. Look's like a late 70's beer commercial lol.

I assume your 361 is the Holley 2300G? Or did they use something else in the 60's models. We had a 361+governed 2bbl in a 75 grain truck growing up, thank goodness for the split axle.

I love your dump truck, I've been trying to find one like that to swap a cummins into for towing my mud trucks around. Most the ones around here are the cast spoke dayton wheels and D600's.

Thank you! I have been looking for quite some time. The '67 has a carter BBD on it. The 413 in our 'D600 has a 2-barrel Holley without a governor. I get the feeling that the governor accompanies air brakes but these things are few and far between these days. That said, I sure wish there was a medium duty truck forum, they sure are fun to own.

From a practicality standpoint the 74-77 models are 1000x better trucks IMO. Swepline era medium duty trucks have a juice clutch, Lifestyle mechanical. Sweptline era trucks also used an array of goofy, non-standard starters to work with the various hydraulic clutch bellhousings. The Lifestyle era uses a regular car style starter with a bigger case. You have never heard a denso mini-starter sound like it does on this thing lol.

Most of all I am excited to get away from the hydravac. Air brakes will be a learning curve but at least they are safer than a single master. Out goal is to get it road legal to haul aggregate for the ranch.

We found it on craigslist near Copco Lake, CA. The fellow that owned it replaced the 440 with one from an abandoned GTX project and then it sat for a few years until a month ago. At first it didn't come with a title and then a few weeks ago the nice gentleman called and informed me he had found the pink slip! I slipped him some extra cabbage for the courtesy of calling me and not tossing it in the trash as we were a long way down the road.

I'm sure we will have a ton of questions as we go along. All of the front and rear hydraulic controls are still intact and I have no idea what some of it does.

So your D800 has a 375 hp 440 from a GTX? Pretty cool. I have no real use for one of these but I can’t say I won’t own one someday lol. Did the D800 come with a 440 or was it a 413HD originally?

Yes it sure does! They even through in the top end from when the truck top end was transferred over. The trucks all ended up with industrial 413's. I don't ever recall seeing a 2.5 ton truck with an industrial 440. Only in an RV come to think of it. Wonder why?

So far in our stable we have the following 2.5 ton Dodge trucks:


1962 W500 Cab and Chassis, ex-ODOT plow rig
1967 D600 Tilt Bed
1967 D500 Fire Truck
1973 D600 w/ HOPTO Digger powered by a AC G-262
1977 D800 Dump Truck

The last thing on the list is a water truck. We might put a tank on the W500 but it only has a 20 GVWR IIRC.

Looks like you need to find a C600 and an L600....then start venturing into the bigger trucks.

Been a long time since I drove one of those. I started out in a swing fender 67 C800 with a 413 in it.

The governor prevents the engine from being over revved. IIRC the 413 was pinned at about 3800. There is a vacuum pump in the distributor and it would draw the throttle blades closed when it hit 3800.

If you disconnected that hose it would rev to the moon with a similar increase in MPH.

Kevin

Agreed! I missed out on a CNTT900 with a 8v71 this spring. Maybe nex time?

I was thinking of putting a 4500 chip in the 6AL. Part of me wants to keep it oroginal. The impractical side that is.

Dodge and Chrysler built industrial stuff and heavy duty stuff to last. As a result, the HD and industrial engines had limited horsepower.

413 or 440, each has a 3.75 stroke and pistons that weigh about the same. So, each is capable of the same redline, assuming valvesprings and ignition keep up.

The carb wasn't very big, so it needed small jets. You can bet the engines were set up to run rich for self protection. So, increasing jet size is probably a step in the wrong direction.

I wouldn't be surprised if that carb would work just fine with a regular carb baseplate.

R.

The one bad thing about the stock HP 440 pistons is the dome thickness, the industrial and motor home motors, 361,413, 440 and all the SB have real thick domes for long WOT hill pulling at max gross weight
I had a guy with a big class A 440 powered motorhome approach me about buying a use stock bore 440 car piston, the dome thickness was around .150 thinner on the HP passenger car motor and on a non HP 350 HP passenger car motor than his OEM motor home piston was with a hole in the middle of it

-Weight has nothing to do with the redline of this engine. --This engine is not original nor is the camshaft.
-The smallest jet I have EVER seen in a factory holley 4-barrel is 64. Why you think 59 would be lean in a big block is unfounded.
-Rich tends to kill rings and foul oil. I'm going to make the engine run correctly by installing a 750 holley and MSD 6AL with a 4500ish chip.
-This carb will not work fine with a regular baseplate. The air bleeds are calibrated for having no idle circuit on the primaries, etc.

Unfortunately philosophy and tall talk are not going to remedy this situation.

This engine was rebuilt with forged pistons so we are good there. Maybe I'll put a 150 shot on it for towing the dump trailer : )

Even though you're going to ditch the governor stuff, I'm going to throw out a website called Bindeplanet.

It's a site for IH trucks and there are quite a few that dabble in med and hd trucks. And IH did use the same carb.

BTW, what do you plan to do with the old carb?

I'll hang on to the original equipment. Thank you for the heads up on Binderplanet I read some of the threads pertaining to the 4150. It seems to be a love/hate thing. To be perfectly honest the part of the 4150G that really annoys me is the overly-stiff throttle spring integrated into the primary throttle linkage puzzle. It makes the throttle kind of jerky and that does not jive well with the two speed rear end.

My current hurdle is registration and getting the brakes checked out. Any air brake guys out there?

Farm plates here we come!