I have an '86 Dodge B250 Dayvan. At sometime in its rather hazy past, someone has removed pretty much all of the emissions equipment. My aim is to make the vehicle run as well as it can. Obviously I'm not interested in quarter-mile times - it's a van. Torque is what I'm after.

Now to the point. The air pump and its pipework has been completely removed from the van! From what I have read on this (fantastic) forum, it would be a reasonable assumption that at least the mini-cat is now junk. In any case, I am keen to replace the entire system (the manifold is already new, but that's a different story).

I have a choice then:

(1) replace the air pump and pipework and use a stock type exhaust.

(2) replace the air pump and pipework, but use an exhaust with a single cat with air.

(3) leave it now without the air pump and replace the exhaust with a system with a non-air cat (is this even possible?).

I think I favour option (3), but cannot put any engineering behind that. So I'm keen to hear the expert opinion of you guys.

Here in the UK the van does not need to pass a visual inspection, in fact, it doesn't technically require a cat at all (I believe they became mandatory in 1992). However, I don't want to be cavalier about polluting the atmosphere. It does have to pass an emissions gas test though.

Thanks,

Richard.

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'86 Dodge Ram B250 Dayvan, 225, Mopar ECU EI conversion w/ Pertronix Flamethrower.

I've had exhaust systems with the cat removed pass the tail pipe test. If they don't check for the cat you might get by.
In the past I've had a Dodge Aspen that passed tests with a shell of a cat in place, still was clean on the test. My M.G. Midget passes with some fiddling and it has some aftermarket bits in the intake and exhaust.
If you need to PM me when you decide what to do, I expect Dodge Van bits are about like me getting parts for the M.G. here in the states.
R. Klaus

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66 Valiant, 225.
84 Van, 225.
71 Maxi-Van, 318
60 Valiant wagon, 225
87 Maxi-Van, 318 4spd

Thanks for the reply, but I don't really want to run without a cat at all. Only if someone can demonstrate that I'd lose significant torque would I consider it. Getting stock parts here is not so hard, but I'm expecting to have a system custom made, probably using stainless.

My primary question is whether I should be putting the air pump back or not. Secondary then is whether to go stock or something else.

R.

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'86 Dodge Ram B250 Dayvan, 225, Mopar ECU EI conversion w/ Pertronix Flamethrower.

Richard,my vote is for #3.I'm no expert but my "drug" is vans(Dodge of coarse)and I'd trash the cat if not required in UK.I've got a 79 that had an air pump but came factory without a cat.My 80 and 83 had the air pump/cat removed by POs so cann't say if it makes a differ on torque but I think not.I did have a 90 with 5.2,tbi and a cat and the pump put air in header pipe just ahead of the cat.That van was just a "play with it and see what happens"so I removed the cat/air pump and it ran better,although I'm sure the cat was shot.In any event I'm sure none of us want to pollute any more than need be but I'm sure your van in proper tune without that stuff will be just fine. Good luck

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83 B-150 slant 6,4 speed. 79 B-300 360 pathfinder 4x4. 74 W-300 318 4x4 git-r-done 80 B-100 sl6,4speed

Definitely go without a catcon. Carburettors and catcons were a shotgun wedding at best (where "best" really means "bloody awful combination"). The proper function of a catcon is wholly contingent on consistent, accurate, precise fuel mixture calibration, which even the feedback carbs were scarcely capable of attaining and maintaining, even when they were new. Obviously you don't want to pollute more than can be practically avoided, but putting together a non-catalyst system will facilitate other configuration options with respect to carburetion, ignition, etc. that will improve engine efficiency such that your overall contribution to air filth will be reduced more effectively than if you were to use a catalyst in this particular application.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

To answer the question I think you are asking, I think yes. If you are going to have a cat, you should have a smog pump. The thing needs oxygen to work. Without the smog pump it's just going to fail.

If the PO managed to succesfully block off or otherwise eliminate the smog tube inlet in the head, get a cat with a direct inlet. (I run my 87 b150 /6 with the upstream/downstream tubes & valve with the downstream tube attached to a bung in a stock headpipe in place of the mini cat, and one no-air cat in them main cat position. This is only because I happened to have all the other parts on hand. Starting from scratch, I'd have done what I'm suggesting above).

I recently wet through a similar adventure with emissions equipment, catalytic converters, and AIR pumps with my brother's 1983 Dodge van.

When he purchased the van, it had no emissions equipment left. It originally was a feedback carburetor with catalytic converter and AIR injection.

I replaced the old catalytic converter with a new high-flow version and replaced the AIR pump with one from a junked van. I got the system installed and working and the van passed emissions great. The van no longer had a computer controlled carb, but I managed to tune it to get about 18 miles-per-US gallon on the highway, so I don't think it was running terribly rich.

Fast forward one year. My brother only uses the van occasionally to haul his band gear around so the van doesn't have too many miles put on it each year. My brother returned the van to me complaining of poor mileage and a rattle in the exhaust. It turns out that the catalytic converter core had literally melted and fallen apart, blocking the catalytic and the muffler. The consensus diagnosis from this board was that the non-computer controlled carb had been running too rich (for the catalytic anyway) and had caused excess fuel to be combusted in the catalytic converter, effectively melting it. I cut out the cat, removed the AIR pump, and replaced the muffler. A full tune-up and a more fuel efficient carburetor got the van back up to 20 MPG on the highway.

My point is that unless you need the catalytic to pass a visual or some other type of emissions exam, don't use one. If you do insist on using one I would try and get the van's emissions, carburetion, and ignition system as close as possible to what came from the factory. Use the factory one-barrel caruretor, factory computer controls, etc...At least then the system should work with a catalytic converter (in theory). Otherwise I predict you will end up with a clogged catalytic within a year.

If you want to read more about my adventures with my brother's van, do a search on this website for posts by me using "my brother's van" as the search words.

If you are really interested, I still have the AIR pump, bracket, and belt for the motor. It is yours for the cost of shipping, but I suspect that shipping this item halfway around the world would not be an inexpensive proposition.

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Casually looking for a Clifford hyperpak intake for cheap.

"pretty much all of the emissions equipment"

What does this entail, btw? My van has ESA (and associated sensors), purge canister, EGR, cat and smog pump, and that's it (no feedback carb--never had one), and is a few years newer.

Do you have an ESA or electronic ignition?

Is the purge canister removed, or just disconnected?

Is the EGR valve removed, or just disconnected? (I'll assume the EGR amplifier is gone).

What carb does it have?

Is there a vacuum diagram under the hood showing what it should have?

Depending on the answers, bringing it to original design (or design intent) may not be as big a deal as it may seem (although it's alot of vacuum tubing. I replaced all of mine and I think it took about 80 feet of 4 different sizes combined).

Well, the opinion is consistent and overwhelming: I should go for my (um ... missing) option 4 - no cat and no air.

Many thanks to you all for the advice. This /6 is my first serious venture into home mechanicing and I wouldn't be where I am without this forum. It was a pure fluke that I ended up buying a /6, but now love the fact that I'm its custodian. It's been a fascinating and very rewarding two years. I intend to write it all up and post it here - if that's an appropriate thing to do?

Now to find a non-cat exhaust and re-read the forum on 2.25" vs 2.5".

R.

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'86 Dodge Ram B250 Dayvan, 225, Mopar ECU EI conversion w/ Pertronix Flamethrower.

Ok, here goes, this is how I inherited it from the PO:
- As above, the air pump and all its pipework gone.
- Cannister disconnected.
- EGR disconnected.
- Hot air feed for the thermostatic air cleaner removed.
- Vacuum to the computer disconnected! Mind you, when I tested the vacuum can it was shot anyway.
- PCV of dubius state.
- In addition the Holley 1945 carb was ... errm ... "tired" and had a manual choke kludged.

So far I have done the following:
- NOS Holley 1945 with new electronically assisted auto choke (thanks Dan).
- Cannister reconnected through a transparent fuel filter.
- EGR disabled via reversal. A friend has machined a nice plate to use instead, but fitting it is low priority at the moment.
- Computer replaced with an MP electronic ignition kit using all new LT wiring via a relay off the ignition master (what a difference that made). I swapped the coil to a Blaster2 with this too. I'm still working on tuning the timing.
- PCV replaced of course. As have all the vacuum tubes - just to be safe.
- I have the parts for the hot air feed to the air cleaner and it's on the to-do list.
- I've replaced both manifolds too, but that's another story for the full write up.
Yes. And I have the FSM of course. Oh, and a Haynes manual for oil changes

Regards,
Richard.

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'86 Dodge Ram B250 Dayvan, 225, Mopar ECU EI conversion w/ Pertronix Flamethrower.

yeah...

in that case, give up on the cat idea.

I like option 4, just a simple 2.25" system and muffler, no air pipe, air pump or cat.

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Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

Hi, I have a1982 Dodge , d150 pickup, which I bought 2 weeks ago. All the smog equipment
has been removed . It has a new exhaust system with a glass pack muffler. The carb has been replaced with one from a'78 model. It gets 18 mpg around town and 22 on the road . trans is a 833 od . The air injection tube has been bunged up.
Having put up with crappy drivability from various cars before EFI its a relief to have this old jewel run so well.

There is no smog inspection in this part of Arizona , due to low population density and maybe the fact that the wind is always blowing , either to Las Vegas or to Phoenix, so any smog we make is immeadeatly exported to somewhere else.

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Rick G