Rango....1942 Willys MB

[Peow130]

Why not just run the vent tube out to a catch can? That way if it does vent, you just catch it, and your engine doesn't flood out.

[Mieser]

Originally Posted by Peow130

Why not just run the vent tube out to a catch can? That way if it does vent, you just catch it, and your engine doesn't flood out.

I was thinking about that the other day with a friend. The conclusion we came to is that the liquid fuel might get caught in the line causing an issue or two with the ability of the line to vent normally.

I thought I remembered somewhere that the bowl vents needed to be in the same air condition as the intake air supply....but I can't remember why or where I must have read that.

On my setup this are EXTREMELY tight under the air cleaner plenum, and the vents, so I don't think I have the room to attach a fitting and pass the line outside of the plenum.

I would be interested to see someone try it though.

[Peow130]

Originally Posted by Mieser

I was thinking about that the other day with a friend. The conclusion we came to is that the liquid fuel might get caught in the line causing an issue or two with the ability of the line to vent normally.

I thought I remembered somewhere that the bowl vents needed to be in the same air condition as the intake air supply....but I can't remember why or where I must have read that.

On my setup this are EXTREMELY tight under the air cleaner plenum, and the vents, so I don't think I have the room to attach a fitting and pass the line outside of the plenum.

I would be interested to see someone try it though.

I don't think that's true. I could run a tube out to the side of my jeep from the bowl vents on my 2100 and i'm 99.999% sure it'll run like it's supposed to.

I vented the bowl on the aisin carb on my 22r with a 3 foot hose off to the side, and didn't have any flooding or running issues anymore.

[Mieser]

Originally Posted by Peow130

I don't think that's true. I could run a tube out to the side of my jeep from the bowl vents on my 2100 and i'm 99.999% sure it'll run like it's supposed to.

I vented the bowl on the aisin carb on my 22r with a 3 foot hose off to the side, and didn't have any flooding or running issues anymore.

Interesting. I don't really feel comfortable just letting the fuel dump, I would probably have to catch it in a container or something.

[lebowski]

Meiser,
In post #677 can you remind me what size tire the blue jeep is running? Thanks in advance.

[Mieser]

Originally Posted by lebowski

Meiser,
In post #677 can you remind me what size tire the blue jeep is running? Thanks in advance.

Those are my old 32x10.5x15 tsl radial swampers. The blue jeep was just trying them on

[Mieser]

Well, onto version 2.0 of the slosh-proofer ultra 2000....

When I was making the 1st version RIGHT as I was punching the hole for the vent I had another idea. Dang it. I hate that. So, I started over on the top cover gasket.



Here is the current version and how it installs. The new improved idea is that with the vent in this location it will maximize the ability of the top cover gasket to prevent the fuel from washing out the vent in the most situations possible. The hole is now in the furthest location possible from both the vent and the float needle. This should hopefully slow the fuel slosh down as much as possible. The high pressure fuel ( all 5-10psi or so ) has to go out of the needle, into the bowl, travel to the other side of the bowl, though a single 9mm sized hole and back across the top of the gasket out the vent tube.



Here is the bottom of the top cover. Good thing I didn't use my original version 1.0 gasket since the hole would have been up against that square flat section at the front of the bowl. You can see that the fuel will kinda have to worm its way from one side of the bowl to the other.



Here are some new vent tube attachments I turned on the lathe tonight. The one of the right is just a short plug with a light press fit. The one of the left is both an extension to a restriction. The factory vents are approximately 0.390" in diameter. The new version has a 0.125" or 1/8" hole. It is also extended up as high as possible for my low profile carb plenum.

The top cover should now act as a baffle for not only nose up situations, it should also function as a baffle for side to side situations. With the hole in the gasket on one side and the vent on the other it should work equally well in both the right and left direction.

When tilting to the drivers side down the vent tube will be high and the baffle low which should prevent raw fuel from sloshing out into the primary. The bowl would have to fill to the point that the bowl level was above the vent tube which I think would almost be impossible.

When tilting to the passenger side down the vent tube will be low BUT the hole in the baffle will be high. The fuel bowl hill have to fill to the point that fuel comes out the gasket hole ( VERY full ) and then the fuel has to run across the top of the gasket and out the extended and reduced diameter vent tube.





I used one of these thick heat isolating gaskets to mount the carb this time. I hope this will help keep the fuel in the bowl cooler and keep it from evaporating at high engine temp in hot weather when I shut off the engine. There is a small amount of fuel pressurized in the feel line from the fuel pump to the carb, but I have seen this all used up ( refilling the bowl with the engine off ) and the fuel bowl almost depleted of fuel. This is one fairly common cause of hard starts in hot weather....



A picture of a autolite/motorcraft 2100 fuel bowl with the float removed. Fuel needle seat on the left. The two main jets in the bottom. The power valve feed just slightly ahead of the jets. The jets are recessed in the bottom of the fuel bowl along with the power valve. I think this is one of the main reasons that the autolites tend to work so well.

I lost one of the screws for the top cover. Now I have an excuse to get some nice new ones....

[Mieser]

Mini test drive this weekend....

I got the carb put back together with the new top cover slosh-o-matic 2000 gasket. The vent plug and vent extender thing-a-magigs are installed. I also have the new thick carb base gasket installed. I also loctite'd the carb adapter bolts in place.

All in all everything runs like it did before on level ground. I can't see any difference after blocking off one of the vent tubes, restricting the other, and running the single 9mm hole in the top cover gasket way over in the corner.

I took the carb top off again to check the bowl level. You can see where fuel will splash up through the hole but doesn't really make it over to the vent on the opposite side of the fuel bowl above the gasket.

It seemed to run as good or better than before. I can't think of any reason it would run better other than the carb body is now more heat isolated from the engine with the thick holley base gasket.

I didn't get it super hot, but at full operating temperature I didn't have any restart issues withe the fuel bowl being low from heat evaporation.

More testing to come....

[craigellis77]

Very cool carb tech, and thanks for posting real world updates with results.

[Mieser]

Low end stall proofing.....

This evening I decided to check out the low end grunt of the good old Buick 225 odd fire engine with its 50+lb flywheel.

Low end stall testing my Willys MB.... - YouTube

I wasn't disappointed. The carb tuning and mods seems to be paying off pretty well. I think the 1.08 size primary autolite 2100 is a great choice for this engine so far.

The video was shot up the driveway to the house. I wanted to JUST test low end grunt, not angle capability, at this point. The grade to the house isn't too steep but can lug the motor down in the right gear. I used high range 2nd gear. This was with the 35" tires and 4.30 gears in the axles.

The video will totally trip you out since I tried some shake elimination on it. Dang that is trippy!

You can see the rpm's pull down on the tach. The static idle is about 550-600rpm with 15" of vacuum at 7000' elevation. Using this technique I was able to pull the engine down to JUST about stalling but it didn't. The rpm's dropped under load down to the 200rpm range....EEKKKK! The engine just kept chugging along. That 50lb flywheel really helps! Even at 200rpm under load the engine was pulling 9-10" of vacuum. At the very low end you can feel each engine pulse.

I did notice how much the engine and transmission torques around. I might need to look for some poly engine mount replacements or something?

Question. Does anyone know if the power valve starts dumping fuel even at an idle under low vacuum? Any way to test that? I think mine is rated at like 6-8" so it shouldn't be an issue yet, but it was another thing to think about I guess.

All in all very happy.

I ordered a bunch of jets. I have like 7 sets coming.
40-41-42-43-44-45-46 ( in addition to my existing 47 set )
yeah, it was overkill, but I was able to get them for $6 a set so I figured why not. If my math is right that should cover me from sea level to 13000ft with probably a set of each end in wiggle room depending on temperature.

Once I get the jets in the mail I am going to start some more tuning!

I will try to document the process as much as I can.

Also, getting close on a Jeep T18 for the transmission swap......bye bye sm420.

[Mieser]

My jets came in!

I have never had so many options to choose from.....*evil laugh*

I am trying to be logical about it, so I swapped down one size last night. #47 to #46. Big jumps are not the right way to do it.

I do love the autolite 2100. You can indeed change jets without spilling a drop of fuel. All you need is a pair of vise grips, flathead screwdriver, and some needle nose pliers.

-pull the air cleaner off
-pull the top of the carb off ( 4 screws and the choke arm nut )
-set the top and top gasket aside
-check the float level at this time, wet ( a quarter is just about the right diameter to measure the float level at .955. It should just touch the bottom of the quarter )
-clamp the fuel line off with the vise grip ( I want to add a small valve to do this )
-pop the float spring off the needle seat with the screwdriver and set somewhere clean, don't loose the needle!
-Use the screwdriver to remove the jets
-Use the pliers to get the jets out of the bottom of the fuel bowl so you don't get your fingers smelling like gas.
-Install new jets.

Put everything back together.
Don't take the vise grip off the fuel line till the top cover is back on

I tried to clean off one of the old plugs, that didn't work. I need to pick up some fresh plugs for testing. The leanest cylinder is 5 or 6. Pulling the plug on 6 is pretty dang easy so I am going to use that one for tuning...

I did notice a pretty big seat of the pants improvement with just one jet size change. From my research I should be in the 44 range so I am still rich I think. I thought I saw the #6 plug lighten up a bit, but I can't tell for sure. It was reading pretty rich overall. Not fouled, but very rich with a pretty heavy carbon deposit at the base of the isolator and the flat. The engine felt more peppy in general and a little more snappy. Idle vacuum is starting to go into the 16" range at 7000ft elevation.

I wonder if I have to adjust the idle mixture with new jets? I did readjust it a bit. I probably needed to go back out to 2 turns and tune in again.

I am going to find a cool little box to hold all my new jets tonight and pick up some new plugs to use for tuning.

[desertCJ]

I know it kinda goes against the "old school" theme of your build, but an o2 sensor could make tuning a lot easier.

[Mieser]

Originally Posted by desertCJ

I know it kinda goes against the "old school" theme of your build, but an o2 sensor could make tuning a lot easier.

yeah, I can't say I haven't been looking

I am going to give some plug reading a try. Its a lot cheaper than a wideband o2 gauge. Dang it, people did it by the plugs for decades!

[SideshowBob]

It's not that hard, think perfectly toasted marshmallow.

[Mieser]

A little experiment.....

Test drive #002 - YouTube

I need a better camera, but it was fun to splice together a little video and music.....

[b4wscrambler]

The fish tale at the end was a nice touch.

[Mieser]

Originally Posted by b4wscrambler

The fish tale at the end was a nice touch.

Thanks.....it was fun too This little jeep feels VERY stable, probably one of the most stable FEELING vehicles I have ever driven. Most flat fenders seem to feel too tall and kinda floppy. Not this one, it just seems to be almost unnatural in its perceived stability. Honestly, I don't see how it can actually BE that stable since its only 72" wide, but still, its fun!

[Mieser]

It sounds like the T18/D18 swap is going to happen. I am basically replacing my sm420 and shorty adapter. I was originally going to add some Tera 3.15 gears to the t-case but have decide to try and build an underdrive instead...

/forum/jeep-willys/1023228-dana-18-quadratrac-underdrive.html

This will give me a stupid low crawl ratio for playing in the snow and super technical sections.

Without the need to milk every last bit of gearing out of the standard transmission, transfer case, and axle gear ratios to break the 100:1 range, I can now open up my options on axle gears.

So the question is basically 4.88 gears or 5.38 gears for the D30/44 combo I have now? The existing 4.30 gears just don't cut it really. I constantly right between 3rd and 4th at 40-45mph when going uphill.

I'm leaning more toward 4.88s since they are a little stronger, little cheaper, and a little more common than 5.38s in the D30 low pinion front.

This thing will never be a 75mph down the highway kinda rig. If it can do 60mph all day I will be happy.

Thoughts?

[desertCJ]

4.88 and keep a D44 swap in mind for the front down the road. I can personally vouch for 4.88 gears in a low pinion 44 behind a HO 5.0. They took a beating and I never once had a problem with the gears. Axle shafts and u-joints (4340 and CTM) are another story.

[Mieser]

Did a little more carb tuning tonight...

I would say one lacking area on the autolite 2100 is the ability to adjust the accelerator pump linkage.



There are 4 positions in the pump arm ( red circle ) AND 4 holes in the lever arm (green circle) on the throttle shaft. There is no cam as far as I can tell like on a holley.

Anyways. The rod that links the pump arm to the lever arm ( yellow circle ) will NOT work properly in all positions. Basically you end up having to rebend the arm a bit to make the arm change length a little bit to use different pump settings. You basically have to fiddle with it.....

Using the outer two positions on the pump arm is pretty easy. There is a small tab on the bottom of the linkage rod that needs to be in the right place before the rod will pull out allowing you to change which hole you want to use.

The inner positions on the pump arm are almost impossible to use if your factory connecting rod was on the other two holes. You would have to bend it a LOT and I don't know if it would be long enough.

So how does it work....( I think? )

Pump arm. (red) As you move further away from the pivot point you make the arm less sensitive and your accelerator pump shot will be smaller for a given distance of travel from the lever arm that is connected to the throttle.

Lever arm. (green) As you move further away from the pivot point you are increasing the stroke of the accelerator as it relates to throttle movement.

Link Rod. (yellow )This basically connects the the two arms. On the autolite 2100 this is the only way to adjust any free-play or pre-load on the accelerator pump.

On my engine the picture above is where I am at so far. I am basically on one of the smallest accelerator pump settings you can get. I am on the outer most hole on the pump arm and the 2nd hole from the center on the lever arm. The link rod is adjusted so there is just a SMALL amount of 'slop' in the accelerator pump arm. This seems to help the engine feel a little more snappy off idle. I think it allows the throttle plates to SLIGHTLY get ahead of the fuel shot from the accelerator pump.

If anything I think that the accelerator pump is still a little fat. I get a slightly hesitation at about 2000-2500 rpm when snapping the throttle under no load. Under a load, as in driving, there is no flat spot at the same speed.

Still tuning.....

[SideshowBob]

Do you have spare new plugs? Have you run it at just idle with fresh plugs? Maybe you are rich at idle and then when the pump hits it's a flood of gas?

Hesitation is usually a sign of a lean condition though, not rich.

[Mieser]

Originally Posted by SideshowBob

Do you have spare new plugs? Have you run it at just idle with fresh plugs? Maybe you are rich at idle and then when the pump hits it's a flood of gas?

Hesitation is usually a sign of a lean condition though, not rich.

I do have a spare set of plugs that I am playing with for tuning.

Maybe hesitation was the wrong word to use.

With no load, just revving the engine, it will snap from the 600rpm idle to about 2000 but then slightly slows down in rate. Before I started tuning the accelerator pump I would get a slight grey/black puff at this 'hesitation' point at 2000rpm. I was still getting a slight puff last night before I started messing with the link rod between the two levers. I basically think the link rod was a little to short/tight and was causing the fuel to be injected RIGHT as the throttle blade started moving. When I adjusted the link rod so that at an idle it was NOT into the pump at all about 80% of my 'hesitation' at 2000rpm went away.

I took it for a quick drive last night. Under load I can't feel or see a flat spot all all. Win Win.

Its still not as 'snappy' as I would like but I think its still jetted a little fat for my elevation. I'm at #46s right now, according to some other autolite 2100 jeep convesion guys I should be in the #44 range at 6500ft.

I am going to work my way down slowly using a fresh plug in #6 to tune it in.

[Mieser]

So Jalbrecht42 sent me some measurements form his CJ2A retromod.

/forum/jeep-willys/690670-1947-willys-cj-2a-retro-wheeler-build.html

He is 41.38" to the top of the tub. I am at 42.88" to the top of the tub.

Now, he is running 31s and I am running 35s, for a 2" difference in tire height.

BUT!

My MB is only 1.5" taller than his CJ2A at the top of the tub!

So basically I have a 1/2" Suspension DROP from stock CJ2A springs! This is with 1" superlift rear springs all around, my different shackle lengths, my custom frame measurements, etc.

I'm not going to point out that the CJ2A windshield is about 2" taller than an MB windshield either Overall if you include his windshield and cage my MB is lower overall than his basically STOCK flat fender on 31s

That is messed up!

[Willys 4x4]

On the carburetor accelerator adjustment I've seen people replace the strait rod with a threaded rod with a throttle ball from and Edlebrock or Holly kit on one end that you can thread in to refine the adjustment even further.

[SideshowBob]

Originally Posted by Mieser

I do have a spare set of plugs that I am playing with for tuning.

Maybe hesitation was the wrong word to use.

With no load, just revving the engine, it will snap from the 600rpm idle to about 2000 but then slightly slows down in rate. Before I started tuning the accelerator pump I would get a slight grey/black puff at this 'hesitation' point at 2000rpm. I was still getting a slight puff last night before I started messing with the link rod between the two levers. I basically think the link rod was a little to short/tight and was causing the fuel to be injected RIGHT as the throttle blade started moving. When I adjusted the link rod so that at an idle it was NOT into the pump at all about 80% of my 'hesitation' at 2000rpm went away.

I took it for a quick drive last night. Under load I can't feel or see a flat spot all all. Win Win.

Its still not as 'snappy' as I would like but I think its still jetted a little fat for my elevation. I'm at #46s right now, according to some other autolite 2100 jeep convesion guys I should be in the #44 range at 6500ft.

Yeah, sounds like a rich burble stumble. Rich condition generally just kinda sounds like you are down a spark plug or something. When you are driving it the load on the engine probably make it much less noticeable.