3.8 Mopar V6 question...

That would be the 3.9, which only had to last longer than a Dakota could rust out, so the bar was set pretty low.

The nicest thing anyone could ever say about the 3.7 POS is that it's still a lot better than the 3.9.

Something interesting: When Fiat merged with/bought Chrysler, they noted that there were either eight or eleven different V6s. Now there is one, the 3.6, and they use it in durn near everything. Even those new gigantic "RAM" (Fiat) delivery trucks.

Yeah, IMO, there's no point in buying a 3.9 to use in anything. Just buy a 5.2 or 5.9. It'll barely be any more expensive, it makes more power and it has a E36 M3load more aftermarket.

The nicest thing anyone could ever say about the 3.7 POS is that it's still a lot better than the 3.9.

I disagree totally with that. The 3.9 was very reliable. The 3.7 didn't offer meaningful benefits other than a better-looking stat block. It was larger, more complex, more failure prone, and didn't make any more power until you got to an rpm that noone drove it at. The 3.7 was the v6 they never should have bothered creating. I'm not defending the 3.9 carte blanche, either. They should have ditched both the 3.9 and 3.7 and went to using the 3.8 in trucks around the year 2000 instead of waiting until the JK, which was heavier than all the low-trim Dakotas and Rams they neglected to put the 3.8 in anyway.

I really think that back then, there was a stigma about using a 'car' or 'minivan' engine in a heavy truck-like vehicle. The 3.8 is more compact, lighter, simpler, and has proven to be more reliable than any other 6cyl Mopar was making at the same time. I would even put it past the 4.0 Jeep engine due to being similarly reliable but WAY less likely to pick up major blowby at high miles. Oh and about half the size/weight.

In reply to Vigo:

The 3.7 at least had the benefit of being a lot smoother, important in a cute-ute like the Liberty, and it didn't have the habit of shedding its exhaust manifolds that the 3.9 did.

I do agree, it was completely silly that they had so many different V6 engines of similar intent. So the Liberty has to have a "truck" engine because it's a TRUCK, but the minivans are just fine with the 3.8 or 3.3 even though people probably used those more as trucks than any Jeep, lots of Caravans and such towing boats and they did make commercial-vehicle versions of the minivans, too.

And then they finally ditched the old fours and put the 2.4 in the Wrangler! With the same silly front bedplate arrangement that the transverse models had, so you still need to unpeel both sides of the engine to get to the timing belt...

So if I'm hearing you guys correctly, you basically do the same things to a 3.9 as you would to a 318 V8 to perk it up a bit? Intake, exhaust, maybe a cam or porting if you want to spend the time/money on it?

Maybe talk a walk through summitracing.com or Jegs for a look at what kind of off-the-shelf hardware is available to perk up a 3.9. Camshafts seem to be pretty deep into the realm of either regrinds of stock items or specially assembled units from companies like Comp.

If you're okay with a lot of one-off or custom pieces, sure, the 3.9 is just another engine. But when the 318 has so much more support and potential...

So if I'm hearing you guys correctly, you basically do the same things to a 3.9 as you would to a 318 V8 to perk it up a bit?

Basically. In one sense the 3.9 is easier since it can use a v8 throttle body as an upgrade. The v8s are very throttle-body limited but getting substantially more flow in that area on a v8 is expensive/hard. On a v6 you just put a v8 throttle body on and you're doing ok.

There are off-the-shelf aftermarket cams for the 3.9. Regrinds may be cheaper but they aren't 'necessary'. Many people would say you get nearly as good of gains as a mild cam from just installing higher-ratio rocker arms, which is a completely external bolt-on that doesn't require taking the whole top and front of the engine apart and works within the stock powerband, so you don't have to unlock another 1000 rpm from the computer to see the gains.

The stock intake manifolds for the 3.9 and the 5.2/5.9 also flow like crap, even if you mod them. And I don't know if there's any upgrades in that department for the 3.9.

The 3.7 just like the 2.7 was never used properly. Both were built with features in place to implement more advanced features (variable valve timing, Multiple Cylinder Displacement, forced induction, etc) but instead of creating a lineup like Ford's Ecoboost Chrysler just sat in the power potential. A supercharged 3.7 with engine stop start and MCD gave nice Power/MPG ratio. The 2.7 with variable valve and intake timing was also nice.

Just so you know. The turbo 3.8L MCD with a fancy new head was all the way to the final step before production before being cancelled. It was getting close to 5.7 hemi numbers with an aggressive tune. Scared the marketing guys. Dummies. $$Millions wasted around the same time the diesel engine was cancelled after we started buying the mfg equipment. Two strikes. Both would have set Chrysler in a strong position with motors having been tuned for max MPG and great power. Opportunity crushed.