Alternative I-4 Engine Carburetion

Hey Mike(mayben), you mentioned in your first post on this thread that you had a weber setup as well in progress. Granted, this was 8 months ago but....would you by chance have any pics on that compuuuter of yours of said setup, throttle linkage, etc? I have a dgv w/manual choke off a datsun 510 track car sitting on the parts rack that I am considering setting on top of my 152.
 
Here is the current state of the weber dgv conversion. I've cut down the thermostat housing eliminating the mounting ears used on the sv application.

The core plugs have all been replaced, the tapped holes have had their threads chased, and a general grinding has been done to smooth out the mold parting lines and the crappy grind job done at the foundry when cast.

This manifold is going to dave the gearman's shop Thursday where he'll use a mill to do the rough hogout of the carb plenum to prepare for port matching.

Once I have a cylinder head casting selected that is gonna be used in the engine build:

http://www.forums.IHPartsAmerica.com/gas-engine-tech/1144-ultimate-IH-fourbanger.html

We'll do the port job and manifold intake runner matchup. I have a companion head (cracked so it's scrap) ready to section with the bandsaw so that a plan for the port work can be laid out. And we'll post the details with pics as that progresses.

I've removed the mounting studs for the manifold adapter and dykem'd the flange so that the outline of the plenum can be cut with the mill. That flange will be kinda "oval" in shape in order to match up with the two different size throttle plates used in the weber dgv carb.
 

Attachments

  • Weber DGV_152 Manifold Conversion 003.jpg
    Weber DGV_152 Manifold Conversion 003.jpg
    101.5 KB · Views: 1,568
A few years back when I first got the rig operational, I fabbed a new throttle pedal assembly and used a lokar-clone throttle cable with a fabbed anchor point mounted where the oem ignition coil mount bosses are.

This cable anchor will be replicated in a much simpler fashion for stopping the weber cable conduit, but the basic design will be the same. I need to have two cable setups available on this rig. I use it for wet testing the 1v carbs I rebuild so I need to be able to use the same throttle cable/pedal for both a 19xx Holley carb and the weber which I "hope" will end up being the dd carb! Prolly not this test mule carb, but a new one with functional electric choke.
 

Attachments

  • Carb end cable anchor.jpg
    Carb end cable anchor.jpg
    127.4 KB · Views: 1,349
Here's the throttle pedal I juryrigged outta scrap materials.

The pedal itself is a york/cci a/c compressor stay as used onna cat 3406 diesel inna freightliner. The mount is some scrap tubing and sheet metal. The pivot is a grade 8 capscrew used in retaining the txv onna "h"-type expansion valve for an mobile hvac system onna opel built in argentina. Don't know where the delrin bearing spacers came from, they are in the collection of stuff I have that is extra crap I never toss out!!

The basic design was ripped off from a typical lokar street rod accessory pedal. I "attempted" some engineering regarding pivot point, leverage, etc. And just lucked out! The pedal "feel" with the dual throttle return springs on a Holley 1904 is superb!

We're going into the fourth year of this project...and we will achieve our five year plan....barely! This rig is used almost daily in all kinds of weather, mainly as a tractor/log skidder and rolling tool box for maintenance/construction projects around the place.
 

Attachments

  • Fabbed throttle pedal.jpg
    Fabbed throttle pedal.jpg
    170.3 KB · Views: 1,251
Those photos are exactly what I needed to get the gears turning....many thx. Really looking forward to seeing the ultimate IH 4-banger.
 
After finding some time to scruu with the dawghauler ride, I attempted to finish off the intake manifold mod described in this thread:

http://www.forums.IHPartsAmerica.com/fabrication/846-IH-152-196-intake-manifold-rework-2.html

While not a complete failure, I did determine that the weber dgv I'd "cleaned" (but not completely refreshed) was a pos!

So over the last few days I've built up some more 1904 mixers and needed to test 'em today. Three of 'em are now ready to ship, plus one more I'm saving back for my own future needs.

I then decided to figure out the real deal on these weber dgv units. Not much too 'em, basically except for the progressive throttle/dual venturi design, they are dam near identical in configuration and operation to a Holley 22xx. Not any more "exotic" actually than a Holley 1904...it's pretty obvious that the Holley "aa" series pots used on the ihc six cylinder motors in the 50's greatly influenced the design of the weber, the japanese back in those days weren't the only copy cats in the motor vehicle industry!

The key factor regarding these carbs is the extreme "tunability" of all circuits with removable calibration components. That's great if the tuner has a full set of all the various tuning parts in multiples (not just "jets"), and a dyno to run the rig on! But that's not hardly practical in the real world.

So...the off-the-shelf new offerings of these carbs are set up inna ballpark fashion so at least the motor will start and idle. That is in regards to a new carb! And keep in mind, these so-called "weber" carbs are sourced under manufacturing license from plants all over the world, so the actual "quality" of the carb and it's setup will vary tremendously. I've now seen 'em out of china, u.s., italy, france, mexico, and the one I have is outta spain. No doubt korea is in the mix also. That is also why the retail price for these items is all over the place.

The unit I have was reclaimed from a pinto race motor inna sandrail. Supposedly "built" carb but according to the guy who bought it, it never worked worth shit. And like most "race-prep" carbs, the entire mechanical choke system on this one had been butchered and removed.

After giving it a super-douche but no fresh parts, I stuck it on the test motor with the infamous "adapter" (whatta joke!) like most folks use. That's like trying to cram a 2" plug into a 1" hole!

Results...the accel pump is a no pumper and the diaphragm housing leaks like hell. Raw fuel poured down the gullet, the idle mixture screw had no effect on idle quality, etc.

So back to the bench...this time I did the "kit" (it was already clean). All calibration parts that are changeable check out as the correct spec for the model, so at least none of the tuning parts were botched when compared to the out-of-the-box version.

Stuck it back on...it's somewhat better but still no accel pump (I had checked it in the solvent tank before re-assembly and it did squirt, but obviously not enough volume). But at least now it has something approaching an idle quality....but the accel pump still leaks to the outside!

Back to the bench, pulled the new pump element out and re-installed the original. Tested again in solvent and finally...no leak. The new pump element was bad! This kit was a new "empi" brand (made in china), the last one of those I'll ever use!

Then I looked again at the accel shooter check valve that retains the shooter...someone had gutted it out in the hopes of increasing flow and it had no check valve, only a lead plug! That ain't a part ya can just conjure outta of nowhere...so I modded the screw and added a Holley pump check ball. That made the difference, now it squirts ok.

After the third attempt at testing I managed to get the idle quality decent. But certainly not any better than any average Holley 1904 onna 152 or 196.

Performance is absolutely no difference as compared to a nice 1904! In fact, tip-in is worse! There is a distinct "lag" when the secondary begins to open that tells me the jetting throughout the entire carb range is way out of kilter. And...it's obvious the pump shot is not healthy enough for the 196 even with the restrictive intake manifold setup. But...it's not adjustable in any fashion! And tuning parts are not hardly out there for making much difference, so it looks like I'll be playing with orifice drills.

Big disappointment here! It's possible that a new dgv might perform better but it would come out of the box with the same calibrations as this one, so "new" doesn't really gayrontee anything.

I'm not gonna waste any more time trying to tune this dawg now as it's gonna end up on the stroker motor and I'd have to do it all again. It is drivable at this point and that is all I care about so it can go back into tractor service.

Surely once an intake manifold is properly prepped to take advantage of the potential this carb might offer for a fourpopper, I'll see this exercise in a different light.

This is a shot of the passenger side of this jury-rigged mount.
 

Attachments

  • DGV Final 003.jpg
    DGV Final 003.jpg
    100 KB · Views: 1,173
Here's the driver side shot.

I now have the throttle cable set up to mount directly to either a Holley 1904, a 1920, or a 1960 for test purposes, in addition to the weber.

I stuck on a hly20-14 throttle lever extension to the weber universal throttle arm. The holes lined up perfectly! Then just use the ball stud fitting to actuate. Without the extension lever, the throttle pedal action and an "over-center" effect and it was near impossible to launch the rig smoothly. The return spring anchor is a homebrew item using a a stainless mending plate.

The big problem with using this carb on the 152/196 intake manifold is the gross mis-match of the adapter to the manifold plenum.

No doubt other folks doing this conversion feel successful because when comparing any new carb to their grungee old, woreout 1904, an improvement is noticeable. Hell, just having an engine that will idle is a big deal!

But...no doubt comparing an old, tired 1904 witha fresh one will yield huge improvement in overall drivability!

One more thing...if you are gonna use one of these weber or weber-clone mixers, ya must incorporate a fuel pressure regulator with gauge!!! Imperative!! The 5>6psi output of a stocker fuel pump on any IH motor will overpower the fuel inlet system and also upset the idle quality very adversely. These carbs are rated for 3.5psi, I found 3psi worked even better for idle quality.

By the way...those folks that claim the Holley 5200 is "nearly the same" as the weber 32/36 progressive, I gotta say..."not by a long shot"!!! Virtually nothing interchanges component-wise, the calibration components don't even use the same "system"! Yes...the mounting flange pattern is the same...but it's also the same as many hitachi, solex, mikuni, and denso carbs! The 5200 was developed as a total emissions carb, the weber dg series is decidedly not an emissions carb...though a later variation was more emissions-friendly.
 

Attachments

  • DGV Final 004.jpg
    DGV Final 004.jpg
    109.1 KB · Views: 1,318
Last edited:
Michael-have enjoyed your thread and find your comments on what did not work to be just as valuable as what did work. Since I have installed webers on two of my early scouts, read with interest recommendations on need to regulate fuel pump pressure. Independently confirmed pressure difference between IH stock pump and what is recommended for webers. Have now installed regulator (and guage) on 1962 (152) with generally positive results - idle marginally better however full throttle acceleration is noticeably smoother with no lag. Am now proceeding to install regulator and guage on second Scout (1963 with 196).

Thank you for your contribution.
 
Great feedback lonnie!

Since our visit last Thursday nite, I've received quite an additional education regarding these weber mixers! I've hooked with a dude back east who does these weber setups for a living on Jeep apps and as replacements for all those $1600 asian carbs on Nissan, toyota, honda, etc. In turn, I swapped him some insider info regarding how we deal with the 1904 and 1920 mixers, so the knowledge base is ever expanding for all of us, a market he's moving into.

Ya just never know where this kinda stuff takes ya, that is what makes it so enjoyable!

My man also has let me in on how much of the internals as the new carbs come from marelli (mostly the spanish production we see here) need to be swapped out before attempting to tune in for a particular app! And what he has taught me is exactly what I figgrd already is wrong about 'em...I just don't have the extensive volume of parts on hand like I do for Holley stuff!

So...a parts list is being put together right now so I can obtain an inventory of the good tuning parts (the marelli-supplied needle seat is shit I was told and I'd already figgrd that out!!). The source for these "correct" parts is not the commonly-known suppliers pimped so heavily on the 'net.

Once I have the parts on hand, I'll set up a new dgv and install out of the box and report. Then perform the setup mods and compare. Once we have the good setup locked in for the average street/trail 152/196, then we'll discuss it in detail, the plan is to offer these as kits in the future that will require nothing other than a careful installation.

You are right about the fuel pressure deal! I've never delt with any other carb that inlet fuel pressure so dramatically affects! I've found that 3psi seems to be perfect for the pos dgv carb I'm using now, but it does not have the "good" needle/seat.

On Friday, my s80 testdawg will come back in the shop so I can try out the mods I got trained on! I've already significantly improved it since my last update here, so I now have a much better handle on what's going on. The "transition" stumble/gap as the secondary begins to crack is what is a pita right now, but I also know how to deal with that...so stand by for an update soon!

I knew this guy was the real deal when I told him how my carb had been modded for a "full race" app! He rolled on the floor and said that he sees the same thing constantly, then he explained "why" they do that shit, which is totally useless!!
 
Back
Top