3.8 Mopar V6 question...

Anyone got a quick 'n dirty build suggestion for one?

Scrap it?

That's pretty quick, and dirty.

The only time I ever had one open, the crank had a chunk missing out of one of the counterweights about half the side of an egg. It didn't look like a deliberate casting feature, it just looked like Chrysler took some used kitty litter and repurposed it for casting sand. That's all I ever needed to see to seal the deal on that engine as a zero-performance platform.

On the "say nice or don't say anything at all" tip, a 3.8 would bolt right in to replace a 3.3 that bew the rocker stands off of its heads. I know someone who did that in an Intrepid. It took the Intrepid from slow, to marginally less slow but with 100% more check engine light!

It's a okay engine for use in it's intended purpose but there's nothing really there for performance use.

Supercharger and Turbocharger kits, headders, typical bolt-ons, and tuners exist for the variant used in Wranglers.

It's an extremely reliable engine. I would consider it one of the most reliable domestic engines ever.

There was no performance aftermarket for it at all until they put it in Wranglers. Now there is some overpriced stuff out there, and finally a RWD manual to bolt it to.

Biggest thing is cam and intake manifold. The heads have been good since day 1 in 1990, but they've been updated twice that i can think of and gotten better each time.

You have to run standalone and manual on them if you really want performance. Megasquirt works on them. The auto transmissions have their own computer so even if you make the engine make power higher up the trans won't let it shift any higher than stock, thus the need for a manual.

The valvetrain in them is good for 7500+ out of the box. They put the 3.3 in Shelby Can-Am cars before they ever released them to the public (~1989) and they were making 250+hp @6800 rpm. They had higher compression, cam, headers, and a higher-rpm-biased intake manifold. Nearly stock heads and valvetrain. That was the earliest 'worst' heads and the smaller displacement 3.3. 30 years later, if you couldn't make 250+ hp on a 3.8 i would certainly blame the operator and not the Chrysler design.....

Biggest issue with them is that they were tied to berkeleying horrible transmissions...

Vigo wrote: There was no performance aftermarket for it at all until they put it in Wranglers. Now there is some overpriced stuff out there, and finally a RWD manual to bolt it to.

Didn't they have a five speed for the Dakota? Tell me more about the Wrangler transmission....?

Vigo wrote: Now there is some overpriced stuff out there, and finally a RWD manual to bolt it to.

I was under the impression that it shared the bellhousing pattern with the 3.0 and therefore a whole lot of Mitsubishi transmissions could bolt to it. No go?

stroker wrote:

Vigo wrote: There was no performance aftermarket for it at all until they put it in Wranglers. Now there is some overpriced stuff out there, and finally a RWD manual to bolt it to.

Didn't they have a five speed for the Dakota? Tell me more about the Wrangler transmission....?

Yeah, they had manual trans Dakotas. But they never put the 3.8 in the Dakota (it was the older 3.9 V6 and then later the 3.7).

Dakotas never got the 3.8 (which is stupid, but dont get me started, im the only one who cares), and the 3.8 doesnt share bellhousing with any Mitsu engines.

It DOES share bellhousing with the Chrysler 2.7, 3.2, 3.3, 3.5, and 4.0 v6 engines.

I would like to know if it shares with the new 3.6 Pentastar v6 but i am not sure of it yet.

Vigo wrote: It DOES share bellhousing with the Chrysler 2.7, 3.2, 3.3, 3.5, and 4.0 v6 engines.

and I'm assuming none of those had a North/South transmission available?

stroker wrote:

Vigo wrote: It DOES share bellhousing with the Chrysler 2.7, 3.2, 3.3, 3.5, and 4.0 v6 engines.

and I'm assuming none of those had a North/South transmission available?

The 4.0 V6 did, but I think they were only slushboxes. NSG370 6 speed out of a 07 - 11 Wrangler is the only game in town for a RWD manual for those motors, I think. And most of those transmissions will be set up for 4wd.

There are a LOT of 2.7 and 3.5l Chargers out there.

and I'm assuming none of those had a North/South transmission available?

At least 3. A 4spd chrysler auto, a 5spd MB auto, and a 6spd MB manual box (the nsg370) It's true that the majority of manual Wranglers are 4wd, but they also used that trans in RWD Liberty, Nitro, and Crossfire apps.

Assuming the new 3.6 uses the same bellhousing, there's also the new 8spd auto, but i don't know anything about swappability of the electronics on those.

let's make sure I'm asking about the right engine. The 3.8 is a 318 with two cylinders lopped off, right?

No, that's the 3.9. Had one in a D150. It was definitely an engine.

let's make sure I'm asking about the right engine. The 3.8 is a 318 with two cylinders lopped off, right?

Oh, wow. LOL. That's the 3.9 alright.

Well, the answer to that is easier. Take anything you can do to a stock-block, stock-head Magnum 318, multiply by 0.75, and there is your answer.

It's a perfectly good engine. As long as you don't need aftermarket block/crank/heads it is the same as building a Magnum 318 except it is pricier per hp and you always end up with spares you didn't really want when ordering parts.

Quick and dirty build is it's already interference so mill those heads, shorten the runners in the intake (theres a handy dandy access plate on bottom to allow this!), knock out any plenum divider in the intake, put a bigger V8 throttle body on it, cam if you're willing to and higher-ratio rocker arms if you aren't, headers, exhaust, MP ecu or tune, and rev it closer to 6k (stock upshift is 4800).

If it's automatic, convert it to a 5spd.

This thread became relevant to my interests when i realized that no one will pay me anything for my 1996 chrysler t&c...

So the verdict is that no manual will bolt to it either? damn.

Vigo wrote: If it's automatic, convert it to a 5spd.

What five speed manuals are available for it? I was under the impression the truck 5-speeds were fragile and geared too low...

stroker wrote:

Vigo wrote: If it's automatic, convert it to a 5spd.

What five speed manuals are available for it? I was under the impression the truck 5-speeds were fragile and geared too low...

Geared too low is totally fixable with taller rear end gears as long as the gear spacing is decent. An AX-15 is decently strong and shifts well. The Getrag 238 6 speed from the mid 2000s Dakotas works behind the 3.9 or any other small block based Mopar (3.9, 5.2, 5.9, 3.7, 4.7, 5.7, 6.1, 6.4) and it's pretty strong (has been used in Wranglers with SRT motors). There's an NSG370 variant that'll bolt up as well.

http://www.novak-adapt.com/knowledge/transmissions/manual/nsg370 (wrangler tranmission that bolts up to the 3.8). 4.4:1 first gear. seems a bit low?

hmm, paired with say a 3.53 in a ford 8.8 rear pumpkin would give somewhat decent final speed/acceleration. (80 mph, 2900 rpm in 6th; 33,56,85,117,146,174 mphat 6500 rpm with a 26.68" tire).

hmm, paired with say a 3.53 in a ford 8.8 rear pumpkin would give somewhat decent final speed/acceleration. (80 mph, 2900 rpm in 6th; 33,56,85,117,146,174 mphat 6500 rpm with a 26.68" tire).

That all sounds pretty good to me.

Gimme an idea of what a decent junkyard engine would cost...?

In reply to stroker:

Wait. First you ask about building a Dodge 3.8 V6, which made me think you had one. Now you're asking what it costs to get one?

Just what kind of situation are you in here exactly?

In reply to pres589:

Bench racing, sort of. No engine in hand, I was just noodling what I thought was the pushrod V6 based on the 318.