Help! My 318 is choking to death!!

[dwade]

I have a 1986 Dodge 250 Ram van. I’m going to be replacing intake manifold and carb on my 318. Also going to add headers and dual exhaust. Mostly to free up the engine for better fuel economy. This engine does have the lean burn system on it now from the factory. Can anyone give me some pointers on how to remove the lean burn and any smog junk I don’t need? Im going to also use MSD ignition. thank you!

 

[volaredon]

many threads on the lean burn delete. easy to do.

 

[dwade]

many threads on the lean burn delete. easy to do.

sorry I didn't think to look.

Thanks

 

[pishta]

Replace distributor and hack everything except the 4bb carb, 4bbl intake, 1 vacuum line from intake or carb to the distributor and maybe a 12v feed to the electric choke. You don't need anything else to run it.

 

[CRUZE 418]

When I put headers on my 360 Van, the fuel mileage went the other way.

 

[Ottmundr]

When I put headers on my 360 Van, the fuel mileage went the other way.

And how long did those tires last?

 

[CRUZE 418]

Quite awhile! Thought that the headers would give me more power for towing a small trailer, wrong. 276 gear ratio. Wish that I knew then what I know now about x&h pipes, and a few other things.

 

[Bewy]

MSD will lighten your wallet, nothing else. If you want better economy, use an Edel Perf intake [ or similar ]. The runner sizes in the Edel intakes are usually smaller in CSA than OEM because much has been learned about airflow since the original OEM intakes were designed.
Use an Edel 600 AFB or 650 AVS. The small primaries will give excellent economy, while the secondaries will be there when occasions require more power.

 

[gregcon]

The runner sizes in the Edel intakes are usually smaller in CSA than OEM because much has been learned about airflow since the original OEM intakes were designed.

That would be nice if it were true, but it's a very general blanket statement that can't be applied to all intakes. In a lot instances, aftermarket intakes have smaller runners for reasons not related to airflow.

 

[NCmtnDWELLER]

MSD will lighten your wallet, nothing else. If you want better economy, use an Edel Perf intake [ or similar ]. The runner sizes in the Edel intakes are usually smaller in CSA than OEM because much has been learned about airflow since the original OEM intakes were designed.
Use an Edel 600 AFB or 650 AVS. The small primaries will give excellent economy, while the secondaries will be there when occasions require more power.

Good point , we have a member who sales curved OEM distributors versus Off-shore MSD products .

 

[krazykuda]

I have a 1986 Dodge 250 Ram van. I’m going to be replacing intake manifold and carb on my 318. Also going to add headers and dual exhaust. Mostly to free up the engine for better fuel economy. This engine does have the lean burn system on it now from the factory. Can anyone give me some pointers on how to remove the lean burn and any smog junk I don’t need? Im going to also use MSD ignition. thank you!

Get an Edelbrock SP2P intake or Offenhauser dual port dual plane intake for that... They have good low end grunt and mid range up to 5000 RPM... Great intakes for trucks and vans for performance and economy...

 

[NCmtnDWELLER]

Get an Edelbrock SP2P intake or Offenhauser dual port dual plane intake for that... They have good low end grunt and mid range up to 5000 RPM... Great intakes for trucks and vans for performance and economy...

Great info , I installed a Isky towing cam and the dual port on my 76
Power Wagon 886 ambulance very impressive from just off idle to 3500 rpm .

 

[AJ/FormS]

When I put headers on my 360 Van, the fuel mileage went the other way.

I put TTIs on my smoggerteen winter motor with full 3" duals all the way to the back. It got fantastic mileage. But I did have to retune it from the 73logs it previously ran.
Headers can "over-scavenge", but I have a hard time understanding how, on a stock 360 with a dual-plane and factory 252 cam,lol. I mean it only has 30* of overlap, probably less than 28 of it effective. And the powerstroke is a very significant 119 degrees. So IDK why you @CRUZE 418 lost economy, no idea whatsoever.

But I can tell you this; that the 76/77 van 360s had the lousiest 2bbl carb tune, ever installed on a Chrysler, and even if you got the carb sorted, she would have wanted cruise timing into the mid 50s at 2400 or better rpm, AND, because the engine was so prone to detonation, that would have been impossible to achieve. I worked several hours apiece on some of those getting them sorted and it was no picnic. And on one of them, the owner had already spent a lotta money with other mechanics, to no avail. That's when he finally heard of me lol, the guy who only works on Mopars.lol.
Well; that's because I only know Mopars,lol. I could work on your Ford or Chevy, but if I ef it up you guys talk amongst yourselves, and hang me. So go find yourselves someone else to crucify. I Only know Mopars (and Honda motorcycles), so that's what I work on lol. And if you're not happy, I give you a 10-day money-back guarantee. which no -one has ever collected on.
But there was this early 70s Ford LTD with an FMX that totally cured me from ever working on FMXs ever again,lol.
So anyway; CRUZE 418, if you had one of those, you got my sympathy,lol.
The funny thing is; I inherited one of those from my Mom when she passed away, and it ran just dandy-fine.

 

[Bewy]

Gregcon,
Can you read? [ Post 8 ] I didn't claim smaller CSA runners applied to all intakes, I only mentioned Edel intakes. Long after the Japs & Europeans worked out that large CSA intake runners were losers, the US finally got it.
Edel learned new things from research & testing, such as using a trapezoidal [ look it up ] shape through runner bends to maintain uniform velocity throughout the runner.

 

[dwade]

Get an Edelbrock SP2P intake or Offenhauser dual port dual plane intake for that... They have good low end grunt and mid range up to 5000 RPM... Great intakes for trucks and vans for performance and economy...

Yes I was planning on the edelbrock sp2p with a “matching” spread bore carb.

 

[dwade]

Great info , I installed a Isky towing cam and the dual port on my 76
Power Wagon 886 ambulance very impressive from just off idle to 3500 rpm .

What kind of millage were you getting?

 

[Bewy]

Yes, the Edel SP2P would be a good mileage intake. Also, the Holley Z manifold.
There done though by about 4500 rpm.

 

[dwade]

Yes, the Edel SP2P would be a good mileage intake. Also, the Holley Z manifold.
There done though by about 4500 rpm.

I never heard of the Holley Z intake. I will check it out. I was thinking about matching whatever intake I get with a spread bore edelbrock or the Holley street Demon.

 

[rumblefish360]

I never heard of the Holley Z intake. I will check it out. I was thinking about matching whatever intake I get with a spread bore edelbrock or the Holley street Demon.

AKA Holley Street Dominator. The “Z” series is easily identifiable by the “9th” runner at the rear of the intake to connect cylinders 7&8 to help balance the engines air & fuel intake charge.

It’s a low level single plane intake that lost power vs other dual plane intakes in the same arena of performance it was listed and touted for. It will out HP up top in the rpm range vs the dual planes.

I would not use this intake for mileage purposes.
Now that Edelbrock SP2P was well liked for its mileage gains. For ease, ether a factory 4bbl or a Edelbrock performer will do well and there easy to get.

@Bewy While I normally agree with the MSD statement, he is ditching the lean burn system. It’s not a bad ignition replacement idea. The trick here (U.S.) is finding a vendor that has the OE style ignition box that will last AND provide a nicely upgraded spark.

So far, IMO, FBO is the best bet.
(4secondsflat.com)

If you loose mileage with headers, there’s a problem, and I don’t think it’s the headers!

 

[AJ/FormS]

If you loose mileage with headers, there’s a problem, and I don’t think it’s the headers!

Like and agree.
Probably in the combo or overlap.
The headers can put a heck of a pull on the nearly-closed-throttle, low-speed circuit, thru the overlap cycle; especially with a small-plenum, and most especially with a small-plenum,dual-plane, intake. As can 11/1 compression with nearly un-measureable LeakDown.
I had to lean the heck out of the low-speed circuit, of my dedicated hiway carb.
@rumblefish360 , you have nearly the same combo as do I, namely; 223/230/110 cammed 360, and I'll bet you are/or will be, finding that out.
That 223 cam has the potential to make phenomenal fuel mileage AND excellent street-power, but it takes a support combo to eke it out of her; it won't happen with 3.91s,lol. But she will make good fuel-mileage down at 2100 or even a bit lower.
I put some valve springs on mine, and she happily ran to 7000 or more, and she went 106 in the quarter@ 12.9, like that, with a really lousy 60ft.
I liked that cam a lot, and was very sad when it began dropping lobes. Had I known in 2004, what I know now, I would have gone straight to a solid-lifter cam for a replacement; daymn my lazy-azz.

 

[dwade]

Like and agree.
Probably in the combo or overlap.
The headers can put a heck of a pull on the nearly-closed-throttle, low-speed circuit, thru the overlap cycle; especially with a small-plenum, and most especially with a small-plenum,dual-plane, intake. As can 11/1 compression with nearly un-measureable LeakDown.
I had to lean the heck out of the low-speed circuit, of my dedicated hiway carb.
@rumblefish360 , you have nearly the same combo as do I, namely; 223/230/110 cammed 360, and I'll bet you are/or will be, finding that out.
That 223 cam has the potential to make phenomenal fuel mileage AND excellent street-power, but it takes a support combo to eke it out of her; it won't happen with 3.91s,lol. But she will make good fuel-mileage down at 2100 or even a bit lower.
I put some valve springs on mine, and she happily ran to 7000 or more, and she went 106 in the quarter@ 12.9, like that, with a really lousy 60ft.
I liked that cam a lot, and was very sad when it began dropping lobes. Had I known in 2004, what I know now, I would have gone straight to a solid-lifter cam for a replacement; daymn my lazy-azz.

Im curious to know what the stock cam in my 1986, 318 2 barrel is? Im wondering if it cam with the same cam as the 4 barrel 318?
The engine has 105k and doesn't blow any smoke. After I remove all the smog spaghetti mess I was thinking of trying to squeeze the best gas millage i can get. New intake, carb, ignition system and headers. What headers would you recomend? Im going to go Catless into free flowing semi-quiet mufflers with crossover.

 

[rumblefish360]

Your in box is full...

I was running a 600 Edelbrock. I didn’t play with the carb much.
355 gears w/26 inch tires.
I was about to make a move to tune a 750 Edelbrock.

Like and agree.
Probably in the combo or overlap.
The headers can put a heck of a pull on the nearly-closed-throttle, low-speed circuit, thru the overlap cycle; especially with a small-plenum, and most especially with a small-plenum,dual-plane, intake. As can 11/1 compression with nearly un-measureable LeakDown.
I had to lean the heck out of the low-speed circuit, of my dedicated hiway carb.
@rumblefish360 , you have nearly the same combo as do I, namely; 223/230/110 cammed 360, and I'll bet you are/or will be, finding that out.
That 223 cam has the potential to make phenomenal fuel mileage AND excellent street-power, but it takes a support combo to eke it out of her; it won't happen with 3.91s,lol. But she will make good fuel-mileage down at 2100 or even a bit lower.
I put some valve springs on mine, and she happily ran to 7000 or more, and she went 106 in the quarter@ 12.9, like that, with a really lousy 60ft.
I liked that cam a lot, and was very sad when it began dropping lobes. Had I known in 2004, what I know now, I would have gone straight to a solid-lifter cam for a replacement; daymn my lazy-azz.

 

[AJ/FormS]

Your in box is full...

I was running a 600 Edelbrock. I didn’t play with the carb much.
355 gears w/26 inch tires.
I was about to make a move to tune a 750 Edelbrock.

Room made

 

[Nat]

AKA Holley Street Dominator. The “Z” series is easily identifiable by the “9th” runner at the rear of the intake to connect cylinders 7&8 to help balance the engines air & fuel intake charge.

It’s a low level single plane intake that lost power vs other dual plane intakes in the same arena of performance it was listed and touted for. It will out HP up top in the rpm range vs the dual planes.

I would not use this intake for mileage purposes.
Now that Edelbrock SP2P was well liked for its mileage gains. For ease, ether a factory 4bbl or a Edelbrock performer will do well and there easy to get.

@Bewy While I normally agree with the MSD statement, he is ditching the lean burn system. It’s not a bad ignition replacement idea. The trick here (U.S.) is finding a vendor that has the OE style ignition box that will last AND provide a nicely upgraded spark.

So far, IMO, FBO is the best bet.
(4secondsflat.com)

If you loose mileage with headers, there’s a problem, and I don’t think it’s the headers!

I'M USING THE FBO box on all my cars i like the rev limiter built in and it gives a decent spark