Honeycomb under a Carburetor
 

I know most of you guys probably don't have much carburetor knowledge, as they aren't as efficient and just aren't around anymore on cars, but I thought I'd try. I drive an 85 Toyota Pickup with the carbureted 22R. I was googling around looking at vacuum gauges, and came across this article. Gas Saving Gadgets. The author mentions a "honeycomb spacer that fit under the carburetor" as something to atomize fuel and help with economy. Has anyone seen anything like this? I could make something pretty easily on the cheap, but I have things I'd rather do if it would all be for naught.

My truck got all of 18 mpg combined before the transmission broke (5th gear went, have another trans ready to go as soon as I come up with the other parts) I'm looking to improve some. My current goal that i hope to achieve through better driving and the non broken trans is to simply get to the EPA rated mileage. If I can do that, then I'll look farther up the ladder. Right now only having 4 gears I'm estimating that I'm getting 15 mpg, which would be acceptable if I drove a full size truck, but I don't. The old squirrel motor is tired, but I still don't think it's impossible to improve on this.

I had a car that had a factory spacer under the carb that had a screen in it. I figured it was there to atomize the fuel. It's probably more the spacer thickness than the honeycomb that has to do with anything. The thicker the spacer the faster the airflow is supposed to be and helps to atomize the fuel better.

You might get better fuel burn with a MSD ignition also. I put one on a Chev 350, didn't do a tune up and never touched the rest of the ignition system. Added the ignition and it did run a lot better and started better too.

I am an old carb guy. I used to rebuild and set up carbs for people at a place I once worked. (Not going to tell you it was an military aircraft hydraulic shop.) Most everyone said they never had to adjust the carb after putting it on the car.

Whenever someone raises the subject of some kind of fuel saving gadget, I always head over to Fuel saving - a professional engineer's view .

Surprisingly, here's what was said about your case:

(Source)

As to whether the honeycomb actually increases atomization though, that's an entirely different question.

Those same parts were used on a lot of the Carbs from the late '80s American trucks.
Most had some sort of heater built into them.
I can tell you from experience that if you take one out (because it is cracked and making a vacuum leak) the truck will run worse,
so, it is easy fro me to see that it would help it to run better.
IMO find one from a reputable supplier with a heater built in and you should be on the money.
S.

These devices are called carb spacers and are a very common method of tuning carb engines. Here is a very good article from PHR about spacers and what they do:

Best Carb Spacer Cheap Horse Power - Popular Hot Rodding Magazine

Good luck with that one, the carb manufacture has been out of business for a while now (Weber) getting replacement parts that are worth a damn is hard enough. I think the closest I'm going to get on this one is to buy a higher quality carb adapter from Trans-Dapt and maybe add a few fins/veins into it ala http://www.scaryfastracing.net/

there will always be a weber. they are indeed silently gaining stock piles of brand new stuff , all the guts, gaskets and rebuild. I found one place still claiming brande new weber stuff from italy.

I spotted this thread for the honeycomb stuff. A carb can have it on either side of the venturi..now dont think I am being a smart ass by saying the air filter is what you are looking for. :D

If you would like to play with 280cfm and feedback that REWALLY works, you can still find carbs from ea series subarus all rebuilt. I was going to get the weber that starts at my little one and stays the same all the way to 258 jeeps, and realized I am already running a genius. and once again..carbs are the most efficient atomizer known to man.
331am and wolfing down chunks of stew steak. What is wrong with me...

I feel your pain
 

Hey,

Even with 5th out, 18mpg is lousy. Something's wrong. I bought the last carbureted truck the dealer had, way back when, and it's never given me a moment's trouble. Even when the thermostat stuck wide open, it never went below 22mpg, so you getting only 18 even when you still had 5th tells me you've got something seriously askew in the works.

Check your brakes and be sure you're not dragging a caliper or a shoe.

Get your wheel bearings greased. It's easy to do yourself but I choose to get it done and have somebody else do my brakes, too. About every third brake job I farm out so I can get drums and discs turned, otherwise that's nothing for a driveway mechanic.

Check your cylinder compression. While you're at it, see how well the cylinders are doing at holding compression. I think you've got some stuck rings or something, 18mpg is just awful. I think you can do rings on the 22R with the engine still in the truck. Drop the pan and pull the head, drop the crank. Might as well do the bearings too if you're going to go that far. I've never tried it but one of these days...I'm never selling this old hoopy. Not while it's still working.

Replace your PCV valve. $5, five minutes.

How's it run at really light loads? I don't know why but about every three years or so it's time for a new set of plug wires, and it manifests as bad mileage and engine misses at light loading. Weird, but there it is.

Tire pressure. My mileage jumped about 10% the minute I pumped tires up to sidewall maximum. New tires, time to do that again.

Rear end lube. Tranny lube, too. I guess that last one can wait until you're done inside the tranny. I used Amsoil, didn't make an appreciable difference but the rear is noticeably quieter.

While you're at it, rear end entirely. I've got the 3.73 rear and wish I had the 3.35. That one's hard to find but it's out there. Lord knows the engine makes enough torque to pull the taller gear, that's not a problem unless you do a lot of towing or heavy hauling. And frankly, if you did you wouldn't be driving a Toy. One of these days, I'll switch mine...and then my speedo will read correctly.

Engine fan - switch to electric. I haven't done that yet.

I haven't done any carb mods at all. But I read in Hot VWs about a little doolie they found to put under their carb and it's just like you described, a little spacer with some mesh. And it did make a big difference in the fuel mileage they were getting on their "mileage motor" project. So it's worth looking into.

Vacuum gauge. I plumbed mine into the carb booster line, just upstream of the check valve. Works a treat.

carb spacer?

WOFTAM

waste of f'ing time and money .
properly tuned megasquirt? yes, will be better than ANY carb.
18 mpg is atrocious, calculate your fuel bill over a year then look at buying a
lighter truck. A friend ditched his F350 for a rebuilt and tarted up Datsun pickup. Fuel savings pay for his insurance and more. He can't bully people on the road any more though ;-)

Cheers

Stephen

I had an 85 Toyota ahort cab 4x4 for 250K miles.
22r With the Carb.

It never got less than 20 (When stock) even in town and regularly got 24 to 26 highway.

I did learn two things owning it.
1. It has a Unique to that year ignition module that is real expensive (Under the coil) 84 trucks had a older version and 86 on were mostly injected.

2. i tried a webber but it sucked on the 22r engine. You get more power at WOT but nothing else was better, I put one on and took it off within weeks. The stock toyota carb worked flawlessly the life of the truck. It did not have a honeycomb or screen spacer stock (At least mine didnt.) The webber issue I partially attribute to the cheasy adapter they used between it and the stock intake manifold, a fully cast specific manifold might fix the issues. Don't know.

3. in 85 the 4x4's came both carbed and injected. I had several friends who bought the injected rigs and none of them could keep up with me offroad especially climbing dunes or big hills. The EFI would not make the top end power my carbed rig did.

YMMV

Dave (New guy from Portland.)

FYI: the the spacer has to do with Pulse tuning.
Essentially alows you the adjust (slightly) the peak efficiency area of the intake.

Spacers and this honeycomb thing are two different things.

Those tires/lift are probably why your mileage is so poor. The original was rated at 22 30 25 (city highway combined), and adjusted to 20 23 21 for the window sticker so 20+ should be possible. The best bang for your buck is installing a rear end from a carbed M4 2WD of the same year/s. It was rated for 30 40 34 unadjusted and 27 31 29 adjusted.

honeycomb
 

I think that once the mixture is through the venturi,past the throttle plate,and into the plenum of the intake manifold,it's got plenty of turbulence to help entrain any droplets that might be present,and the whole charge will be blasted to smitherines, once past the intake valve and into the combustion chamber.
I suspect that the honeycomb would only serve as a restriction and might actually interfere with some of the charge' ability to turn down the runners.
A normal spacer ( which is wide open ) adds length to the plenum,which aids in "turning" the charge along a larger radius and can help prevent "wet out" on the floor of the plenum,something the matrix of the honeycomb might aggravate.
I'd shy away from the device.

go to www.mpgresearch.com and search for screen under carb. Or,http://www.gofastnews.com/board/engi...b-booster.html

Here is something from mpgresearch.com....

85 22R Toyota carbed ...96 HP....85 EFI....116 HP

I've been making the same effort with my '88 Toyota
4wd 5speed with 222K miles and I manage between 27.5
and 29.7mpg. This includes some city driving, perhaps
25%, and some hauling, perhaps 15% of the time and up
to ~ 3/4 ton in the back: truck weighs ~3,800
unwashed, rust bucket and lots of tools behind the
seat. Those are also pretty good numbers but, now,
with the Saturn, I hope to use the Toyota only for
what it does best: hauling/mud and snow work.

Best I can do with an '86 Nissan EFI 4x4 is 25 mpg highway...in summer.

If the truck has not been maintained...such as lubed and tuned up...you can gain some there. I'd put a pint of water into the carb (slowly) to decarbon it...flush the oil with a pint of kerosene for 15 mins...advance the ignition some....lube the driveshafts...check the gear oil levels and / or replace....up the tire pressures.