[valiant67]

I'd consider upgrading the whole powertrain to a 5.9 magnum and OD transmission. For simplicity a 93-95 van would be the best donor.

 

[seuadr]

I'd consider upgrading the whole powertrain to a 5.9 magnum and OD transmission. For simplicity a 93-95 van would be the best donor.

i'd thought about that - but it was not clear to me how straight forward it would be. i haven't found a writeup by anyone yet that discusses a full swap, just the trans and/or heads. i'm concerned about clearance for the exhaust and location/transfer of all of the electronics. i suppose at least the tank should be easy to find a spot for..

is the body so similar from 1970 to 2003 that i could maybe just fully transplant the dash, etc?

 

[Dave Z]

i'd thought about that - but it was not clear to me how straight forward it would be. i haven't found a writeup by anyone yet that discusses a full swap, just the trans and/or heads. i'm concerned about clearance for the exhaust and location/transfer of all of the electronics. i suppose at least the tank should be easy to find a spot for..

is the body so similar from 1970 to 2003 that i could maybe just fully transplant the dash, etc?

While I can't be very specific there is a b-van history at allpar which notes technical changes from year to year, though some issues you listed may not be listed: Dodge B-series vans, Ram Van, and Ram Wagon

 

[seuadr]

what do you think about the 3.9 magnum instead?

 

[valiant67]

The 3.9 in the vans was usually paired with the old 3 speed automatic instead of the 4 speed (OD) automatic.
It also seems the heavier vans (3500 by that time) were almost always V8 powered. The 5.9 was good for about 2 MPG on average better over the 5.2 V8.

 

[pbrutsche]

what do you think about the 3.9 magnum instead?

I suggest not. It's a LA-based V6 with less power and torque than the late '70s LA 318 you have now. A early '90s port-injection LA 318 (aka 5.2 magnum) or LA 360 (aka 5.9 magnum), with the corresponding transmission, should be a straightforward swap.

Either way I would go for a A518 transmission.

 

[seuadr]

The 3.9 in the vans was usually paired with the old 3 speed automatic instead of the 4 speed (OD) automatic.
It also seems the heavier vans (3500 by that time) were almost always V8 powered. The 5.9 was good for about 2 MPG on average better over the 5.2 V8.

huh, interesting. i would have expected better efficiency from the 5.2L motor, all other things equal.

I suggest not. It's a LA-based V6 with less power and torque than the late '70s LA 318 you have now. A early '90s port-injection LA 318 (aka 5.2 magnum) or LA 360 (aka 5.9 magnum), with the corresponding transmission, should be a straightforward swap.

Either way I would go for a A518 transmission.

yeah, definitely going with the A518. I saw a company that had a stand alone harness for the NAG1 and thought about investigating that, but, i don't think the "bang" would be worth the "buck"

honestly, if i were to fantasize about it, I'd go with the pentastar 3.6L and NAG 1, but i imagine it would be a serious undertaking for what would likely be relatively modest returns

 

[pbrutsche]

huh, interesting. i would have expected better efficiency from the 5.2L motor, all other things equal.


yeah, definitely going with the A518. I saw a company that had a stand alone harness for the NAG1 and thought about investigating that, but, i don't think the "bang" would be worth the "buck"

honestly, if i were to fantasize about it, I'd go with the pentastar 3.6L and NAG 1, but i imagine it would be a serious undertaking for what would likely be relatively modest returns

The 360 makes a lot more power than the 318 and is going to be less stressed with a heavy vehicle, like a 3/4 ton truck or B-series van. The engine doesn't need to work as hard and consumes less fuel.

It's the same concept as a modern Pentastar V6-powered truck getting the same (or worse) fuel economy as the 5.7L, especially when it has a load on it.

As far as the Pentastar goes, I don't think that particular configuration is worth it. There is so much more custom work that needs to be done compared to anything else. Doing a 5.7L Hemi+NAG1 would be cheaper and better supported, just because it's a well-understood restomod setup.

I think your money would be better put into a A518 and doing a LA 360 of some sort, even if you are putting an aftermarket TBI or port injection system on a pre-Magnum carbureted engine.

 

[seuadr]

I think your money would be better put into a A518 and doing a LA 360 of some sort, even if you are putting an aftermarket TBI or port injection system on a pre-Magnum carbureted engine.

i'm definitely going to be going with the A518 - not sure about swapping anything beyond that, i guess it will depend heavily on the results i get and condition of the current 318 (doesn't run, for all i know it's blown and then a 360 becomes a no brainer)

that said, i bet i could get my hands on a 360 LA pretty cheap...

 

[Dave Z]

It's easier to find 318s than 360s, from what I hear... demand and all. But yes, I just looked up EPA estimates on the Charger SE for a quick story ( 1975 Dodge Charger SE: Comfy but slow cruiser ) and found that the 360 was the most efficient engine by around 2 mpg. The 318 was second, I think, then the big 400.

 

[ImperialCrown]

360 has the 2.02" intake valves. The Magnum is a good breather (for 1990's technology). EFI is smart fuel management.
Skip the exhaust headers, they won't gain you very much over the stock manifolds (and could harm low-end torque for a slight gain of high-end torque). The stock exhaust manifolds may not be pretty, but are 'tuned' for good efficiency.

Electronics would be he hard part of any newer powertrain transplant.
Drain & refill the diff with a good synthetic hypoid 75W-90 to lower viscous drag?

The aerodynamic flag-style mirror was the best aerodynamic gain followed by a sheetmetal bellypan, when a car magazine did some van modifications for a report a few years ago.

It will never be particularly fast or economical. My dad had a 1979 PB200 with 5.2L & 4-on-the-floor (OD). It managed 23 mpg (highway) on trips with a family of 6.

 

[valiant67]

I need to clarify my 5.2/5.9 comment.
For the old carbureted vehicles the 5.9 (360) could get better MPG than the 5.2 (318) in heavy vehicles.
For the Magnum series engines in the heavier vehicles, the 2.5 and 5.9 were rated basically the same MPGs.

 

[seuadr]

The aerodynamic flag-style mirror was the best aerodynamic gain followed by a sheetmetal bellypan, when a car magazine did some van modifications for a report a few years ago.

It will never be particularly fast or economical. My dad had a 1979 PB200 with 5.2L & 4-on-the-floor (OD). It managed 23 mpg (highway) on trips with a family of 6.

Yeah there is a fair amount of opportunity for aero, on another forum we are investigating that.

As far as mileage, i would be THRILLED 8f i could hit 20!

 

[seuadr]

So ya'll got the wheels turning on a 5.2 or 5.9 magnum and trans swap and i've collected the following information so far:

- i need a 360 oil pan either way i guess?
- if i get a pre 96 magnum van nearly everything is a direct swap over for gauges etc. just get a donor and move everything
- the early magnum efi kinda sucked and i should consider either going back carb or doing an aftermarket EFI
- sounds like i have to trim some steel on the driver's side down by the magnus header, but just a little
- sounds like i want to add a timing chain tensioner while i'm in there - there are aftermarket sources?
- sounds like the mechanical fan clearance can be a pain - i planned on going electric anyhow.


couple things i'm not 100% clear on
- some talk about using the LA accessory components and covers, others talk about using the magnum ones and grinding some stuff to fit? not clear if there is a clearly better path?
- i've seen mention of the water pump from the LA but haven't read why that is important. perhaps clearance?
- if i don't have a saginaw style power steering pump i'll have to get some custom lines - but, i'm guessing i can find a saginaw style pump if i comb some junkyards. sounds like a federal pump could also bolt on correctly.
- as long as i'm using the engine AND trans, i don't have to worry about flexplate/balance (internal vs external) but i'm not clear on if i can use the same linkage or not, but sounds like i could possibly swap to a cable linkage?
- one of the threads mentioned the following: Magnum cam snout extender, or - preferably - roller cam from 89-91 LA 318 w/long snout.

i sure i'm missing more?

 

[valiant67]

Magnum EFI was basically the same throughout. Are you sure the site wasn’t confusing the 1980’s TBI (still on an LA motor) with the true MPFI Magnums? These TBI engines were the first with the OD automatics.
LA was 3.9 and 318 through 1991, 360 through 1992.
Magnum started on 3.9 and 5.2 in1992 and for 5.9 in 1993.
The only real difference is that in 1996 and later they were OBDII, which is a little more complex to swap but maybe easier to hook a scan tool up.

 

[seuadr]

Magnum EFI was basically the same throughout. Are you sure the site wast confusing the 1980’s TBI (still on an LA motor) with the true Magnums?

i am sure of NOTHING 🤣

i've done so much reading on things the last few days that i'm willing to commit to nothing more than the names dodge,318 and magnum

 

[seuadr]

The only real difference is that in 1996 and later they were OBDII, which is a little more complex to swap but maybe easier to hook a scan tool up.

that is good info to think about actually - cause an OBD2 port would mean that if i ended up with a RE instead of an RH i could hook up a tuner that could adjust shift points and stuff for economy.


i had a 5 star tune for my F350 focused on towing efficiency and it really did help with not getting stuck around where lockup would normally happen and holding gears a little longer, etc.

looks like 5 star only does fords, but, i'm sure that there are others out there.

 

[68RT]

Reason the 318 does not get the mileage is when the engine is under a higher load, the air-fuel ratio drops to protect the engine. Being that the van is heavy, the 318 works harder and sits longer in the richer mode.

 

[seuadr]

Reason the 318 does not get the mileage is when the engine is under a higher load, the air-fuel ratio drops to protect the engine. Being that the van is heavy, the 318 works harder and sits longer in the richer mode.

that makes sense. weight wise, i'm not sure where i am going to end up, it looks like the B300 curb weight was ~4900, but, i expect that the fully kitted camper was a lot more (i haven't had any luck finding specific numbers)

with the steel body removed and replaced with fiberglass and aluminum skin,in addition to being gutted i would expect a weight savings, but, who knows how much. i'm picking it up sunday so should know a lot more soon, especially if i can hit a scale on the way back.

i plan on aiming for a lot less shag, wood paneling and lighter furniture/fixtures but i'd bet i'll still be north of 6k before camper fluids.