Later model 3.8 swap in an "A" body

[dodge freak]

I did the 3.9 V6 in my 66 dart wagon and it is a lot harder to do then the 5.2 the v6 eng mount in the center of the eng and 5.2 are in the same location as the rest of the v8 motors and with the the overdrives you still have to cut the floor for the o/d and the v6 with 3.23 don't work worth a **** I had to go with the 3.55 and with I got abot 22 mpg and in my 64 Dart with the 5.2 i get 23 to 24 mpg with 3.91 in it and I think both cars weigh about the same both cars had a/c. I did all the wiring my self and if I had to do another one I would do the V8.

I wished I had the link but I did see online an reprint of a story in 1967 in Car Life mag about getting the best mpg and high speeds. The talk was 80--90 mph speeds would be happening on the new interstate freeways just being built so GM built a car for max mpg and high speeds.

They claim the 455 ci were the best engines to use cause they could be gear down-slow down the most yet still have the power to run at high speeds.

2.45 gear they used with the switch pitch converter--lock ups and OD trans were not thought about--1967 recall The looser converter would be used for quick take off/ I believe they got around 20 mpg at 60 mph and around 14 at 90 , they were quite pleased since most cars got 14-15 not driven over 60 mph

 

[krazykuda]

Over 20 mpg is going to be tough to pull off and still drive quickly. Got a 2008 Gm car with the 3.5 and I get only 21 mpg on it. Now I got a lead foot around town and go 80 to 90 on the highway if traffic is light.

If you were to do 55 mph all day, sure the mpg would improve.

I have a 94 Buick century with a 3.1 L that gets 29 MPG on the highway, a 99 Grand Prix GTP with the 3.8 L supercharged that gets 25 MPG highway, and a 05 Impala with the 3.8 L supercharged that gets 25/24 MPG highway around 75 MPH.

I think some of your "economy" problems are in your driving habits. No offense intended. :burnout:

 

[RustyRatRod]

A much better modern alternative would be the 4.0 Jeep engine.

 

[dodge freak]

I have a 94 Buick century with a 3.1 L that gets 29 MPG on the highway, a 99 Grand Prix GTP with the 3.8 L supercharged that gets 25 MPG highway, and a 05 Impala with the 3.8 L supercharged that gets 25/24 MPG highway around 75 MPH.

I think some of your "economy" problems are in your driving habits. No offense intended. :burnout:

I'm sure it is, 21 mpg I can handle--wish my 340 got 21 but then I drive that one quicker accelerating. We got different roads here, I-696 you go 80 and people are passing you. I go to other places and traffic moves slower. When I went to Canada I don't know what my mpg were cause I switched the speedo to km but gas last me much longer, I drove much slower as well

But fwd drive is more efficient I believe. If I swap the 3.5 in to my 340 78 Magnum and drove the same way, it likely get me only 17--18 mpg

And if my 340 had the same gear ratios as the 3.5 engine has, it likely go from 11 mpg to 15-16 mpg.

The only engines I think would give much much better mpg and still have power are these new turbo 4 bangers just coming out. And how long are those 4 bangers going to last ?

Yeah I would hold off a bit, maybe next spring, maybe longer

The 4 bangers would be the lightest as well, so better handling, braking besides better mpg.

Yep, once Caddy gets a 300 hp 4 cylinder engine, then I might look in to it. Be nice if gas could just go back under $3 again

 

[krazykuda]

We got different roads here, I-696 you go 80 and people are passing you. I go to other places and traffic moves slower. When I went to Canada I don't know what my mpg were cause I switched the speedo to km but gas last me much longer, I drove much slower as well

I'm very familiar with I-696. I used to live in Madison Heights and work in Farmington Hills in college. Not many places for the FUZZ to hide.

Not like I-75 south. They hide where I-96 joins near Mexican Villiage and nab you hiding on the 96 merge lanes. Or between exits 35 - 37 on I-75 where the speed changes. I've seen 5 people pulled over in that 2 - 3 mile stretch AT ONE TIME. Speed trap. :rambo:

At least in Detroit rush hour, you can usually go 45 mph minimum in the bottlenecks. Chicago rush hour, you are riding the brakes for miles! And no service drives to get off on and reroute. :-({|=

 

[Joe Dokes]

Just bought my wife a mini-van with the 3.6L V-6. Awesome engine. 282 HP, 0-60 in a 4000LB minivan 8.0 seconds.

Personally I wouldn't mess around with ANY other V-6.

Regards,

Joe Dokes

 

[res1vw21]

According to Larry Shephard, the stock 360 cam was the best to use for fuel economy (252 dur and .410 lift I believe). throw in a set of Rhoades lifters and a good dual plane intake and 600 -625 cfm vacuum secondary carb. Keep in mind if you switch to 340/360 heads you will lower compression. I used a set of 10.5 compression forged pistons with 360 heads and got final compression of 9.2 in my 17.75 econo engine. also go for a low gear like 2.76. also try lock up trans/converter.

My dad had a 76 Charger back in the day and It got 20 MPG stock! I've never been able to break 20 MPG yet. If a stock 360 Charger can do it, it is possible. One of these days...

My setup was idling at 24" mercury with stock 318 heads, and would overheat over 80° outside. Problem was too much compression. Put on 360 heads and got 22.5" mercury at idle. Was able to use a 20.5 power valve and vacuum guage to keep power valve from opening whenever possible. Could still accelerate well at 12" mercury to stay "econo".

Just a few tips to help you.

Whats a converter?:banghead: I have the OD aluminum case 4spd.:burnout: I might be able to pull a 3.21-3.23 rear gear but most likely will need to switch to a roller cam to do so. I think I am turning 2100rpm (not sure how accurate the tach is)

I will look into the 360 cam though thanks for the suggestion,

I was planning on shooting for right about 9.25 comp to just with a set of 302 heads for the better burn. (I wish I had a set of 308 heads but alas I don't and this is a budget build)

I am already getting 20mpg just looking for more :thumrigh:

 

[BillGrissom]

I have the 3.8L in our T&C minivan. It is a basic 2-valve push-rod engine, but much better than the V-6 Magnum engines it replaced. I wondered about a V-6 Magnum too after seeing one in a large RAM van at the junkyard recently. Allpar says they were designed as a quickie specifically to fit the Dakota by chopping 2 cylinders off a V-8 Magnum. They vibrated terribly and Chrysler soon figured a way to squeeze a V-8 into the Dakota and dump them (maybe leftovers went to vans).

I too wonder about retrofitting a 4 cyl to an A-body. The 2.4L in our 1996 Voyager minivan has almost as much power as the V-6 of that year (3.3/3.5L I recall), probably because a more modern DOHC distributorless design. I don't know if there was a RWD tranny for it, but I do see 904 trannys for 4 cyl Jeeps on ebay (USPS). The bolt pattern looks like my 2.4L, so maybe a bolt up. My guess is the 2.4L would be too tall, since when I took the heads off I was surprised how far down the top of the block was. I suspect that will be a problem with any OHC engine. Even with push-rods, Chrysler had to slant their long stroke six.

 

[dodge freak]

I'm very familiar with I-696. I used to live in Madison Heights and work in Farmington Hills in college. Not many places for the FUZZ to hide.

Not like I-75 south. They hide where I-96 joins near Mexican Villiage and nab you hiding on the 96 merge lanes. Or between exits 35 - 37 on I-75 where the speed changes. I've seen 5 people pulled over in that 2 - 3 mile stretch AT ONE TIME. Speed trap. :rambo:

At least in Detroit rush hour, you can usually go 45 mph minimum in the bottlenecks. Chicago rush hour, you are riding the brakes for miles! And no service drives to get off on and reroute. :-({|=

That cause people have jobs in Chicago, lol

Yeah the cops can be funny, some places they are a rare sight, other places it looks like their home turf, gotta remember where you are at--and amuse they are always there on every on ramp.

Wastes gas to slow down to 72, speed back up to 80, slow back down to 72 but what can you do, lol again

If you could get 40 plus mpg @ a steady 65 mph, that be really cool, it be slower but so much cheaper to get to far away places--like Chicago for the weekend. If 55 mpg cars-engines are really going to be here in 10 years they might be worth looking in to.

Mopar A bodies have the leg up on the B bodies cause they are lighter and would respond better to a 4 cylinder. Suv's and pick ups are going to have to get better mpg also, so there be rear wheel drive engines-trans available.

If I ever do the switch I' going to try to keep an open mind and look for the best setup, regardless what brand it is. Far as I care old Mopar is long dead, only name is left, same with the other brands. Heck I might even get a Ford engine, lol, least they didn't pull the bankruptcy BS--look how much GM is now earning, they didn't have to file bankruptcy, they just did, to cut expenses-wages across the board so now they can earn 8 billion in 3 months

 

[KosmicKuda]

Just bought my wife a mini-van with the 3.6L V-6. Awesome engine. 282 HP, 0-60 in a 4000LB minivan 8.0 seconds.
Regards,
Joe Dokes

Yep. The 3.6 Pentastar was again just voted one of the 10 best CURRENT engines out there. They're throwing them in everything and over one million are on the road already.

 

[dodge freak]

Yep. The 3.6 Pentastar was again just voted one of the 10 best CURRENT engines out there. They're throwing them in everything and over one million are on the road already.

That means they are going to be littering all over ebay before long so prices will be cheap :glasses7:

I would take the trans with the engine and make it all fit, lol The drive shaft would need some custom work but its doable

Hardest part for me would be the wiring, hopefully its done decent and easy to swap out