[SBMN39]

Did some digging on the boards, either I'm not using the search function right, or this hasn't been discussed recently.

I've been doing some online research about the 6G72 engine, and how it evolved in other cars after the Lebaron ceased production in '95.

One of the most interesting improvements to the 3.0 was the 24 valve version, still with just SOHC, but with 4 valves per cylinder. This motor could be found in the Stratus, for example. Serpentine belt and peripherals are on the same side as the Lebaron (though I can't find a picture of the belt path and the peripheral arrangement). Radiator hose is on the other side of the intake, but I don't see that being a huge issue. Heads don't look any wider than the 2v heads.

Has this been done yet? What difficulties might be involved (besides needing the newer engine's computer and all electronic ignition)? Would the transmission in the Lebaron match up?

http://gtcarlot.com/engines/Dodge/Stratus/2004/3.0+Liter+SOHC+24-Valve+V6/50084603.html

Here's an example I found on google images.

I would think if it can be done without excessive fuss or body modifications, it might be worth the stock 54 bhp gain, but I'm not sure.

 

[valiant67]

Lots of people have talked about it over the years but I am not aware of anyone successfully completing such a project.

 

[dana44]

I would think swapping the whole engine would be a better start in a project like this, as I believe there are other changes besides just the heads themselves, such as water passages in the block, I think I remember a stronger bottom end, piston tops different to maintain valve clearance and compression, and of course the electronics package as you mentioned. Otherwise I think it is a direct bolt-in as far as transaxle goes. I believe it would be a pretty cool installation.

 

[SBMN39]

I would think swapping the whole engine would be a better start in a project like this, as I believe there are other changes besides just the heads themselves, such as water passages in the block, I think I remember a stronger bottom end, piston tops different to maintain valve clearance and compression, and of course the electronics package as you mentioned. Otherwise I think it is a direct bolt-in as far as transaxle goes. I believe it would be a pretty cool installation.

Sorry for not clarifying, that was essentially my question...can the entire engine (long block) be swapped without too much trouble...I wouldn't try and mate the heads off the newer engine onto the old block.

 

[dana44]

Oh, sorry, thought you were talking about just the heads. As I said, the whole engine should be able to swap, I think the mounting points and transmission bolt pattern is the same between the two engines.

 

[SBMN39]

Oh, sorry, thought you were talking about just the heads. As I said, the whole engine should be able to swap, I think the mounting points and transmission bolt pattern is the same between the two engines.

Couple of pictures of the single cam 24V heads. Aside from the obvious, spark plug channels relocated to the top of the heads near the injectors (in the top photo they are stuffed with paper), they look to be roughly the same dimensions are the 12v heads. Which may mean the entire long block assembly will fit nicely. Interesting to note the motor mounts are the same, dana44.

 

[dana44]

How do the pistons look between the two engines? Also, something I note on all the heads with quench areas, see the brown that shows where the sharp edge of the combustion chamber is? If you take at least a file and round those sharp edges not only will the combustion chamber burn better, more power is to be had from the flame front as it increases its burn capability, meaning more efficient burn, too. Also means you could run higher compression with cheaper gas because the ping spots in the combustion chamber is gone.

 

[SBMN39]

How do the pistons look between the two engines? Also, something I note on all the heads with quench areas, see the brown that shows where the sharp edge of the combustion chamber is? If you take at least a file and round those sharp edges not only will the combustion chamber burn better, more power is to be had from the flame front as it increases its burn capability, meaning more efficient burn, too. Also means you could run higher compression with cheaper gas because the ping spots in the combustion chamber is gone.

That's a good question, it would almost be worth having the Haynes manual on the Stratus just to see the comparative photos.

The real question I have is, can the stock transmission in the 93-95 Lebaron handle the horsepower increase? I've had bad luck with that transmission before.

 

[valiant67]

Here are the problems, even assuming the engine bolts in place of the old one.
The old Chrysler engine controls won't work with the new motor, so you'd have to use the new (Mitsubishi) engine controls. Then those controls won't be compatible with the transmission computer (which requires feedback from the engine system and the transmission would need beefed up most likely). So then you probably need to swap the somewhat fragile A604 for either a 5 speed manual or the non-computer controlled 3 speed automatic. But then, you still have the body computer which not going to play well either.

 

[SBMN39]

Here are the problems, even assuming the engine bolts in place of the old one.
The old Chrysler engine controls won't work with the new motor, so you'd have to use the new (Mitsubishi) engine controls. Then those controls won't be compatible with the transmission computer (which requires feedback from the engine system and the transmission would need beefed up most likely). So then you probably need to swap the somewhat fragile A604 for either a 5 speed manual or the non-computer controlled 3 speed automatic. But then, you still have the body computer which not going to play well either.

Wonder how rare the 5 speed is to find, much less install. I know they put a 5 speed in a very few 93-95 V6 Lebarons if you custom ordered them that way. Think I read that somewhere on Allpar.

So you think the later model MItsubishi 24V V6 from the Stratus would be electronically incompatible with the older stock transmission mated up to the original Mitsubishi 12V V6. Not something I would have considered.

 

[valiant67]

While the 5 speed was somewhat rare behind the V6 in the Lebaron it was more common in the Daytona, Sundance (Duster) and Shadow.

There is no way the Chrysler transmission computer would work with the Mitsubishi engine controls so that effectively rules out an A604 4 speed auto with the swap. You may also find that the body computer in the LeBaron won't work without the proper engine computer so you'd have to rewire the features the BCM controls.

 

[SBMN39]

While the 5 speed was somewhat rare behind the V6 in the Lebaron it was more common in the Daytona, Sundance (Duster) and Shadow.

There is no way the Chrysler transmission computer would work with the Mitsubishi engine controls so that effectively rules out an A604 4 speed auto with the swap. You may also find that the body computer in the LeBaron won't work without the proper engine computer so you'd have to rewire the features the BCM controls.

What about the automatic transmission from the Stratus to go with the later model engine? Too hard to adapt to the Lebaron?

 

[Hard Hat]

I have a 94 Lebaron and this question was brought up in my Sebring club ( CSCC.net) one of our members has successfully transplanted a 3.5L mitsubishi engine to a sebring convertible (that usually houses a 2.5L 24 valve) and he looked at the specs and it is possible to swap out the 3.0 (being the same block) with any number of Mitsubishi cars (including the Stratus) 3.0, 3.5 and 3.8 will bolt up...as for the computer...this would have to be dealt with sensor by sensor due to the changeover to OBD2 in 1996. it is possible though and he has been trying to get me to drop one in my 94...Maybe someday!

As for the transmission...they are virtually trhe same transmission 41TE... my 94 was recently rebuilt and is now up to 1999 standards...

 

[ImperialCrown]

There are 2 different Stratus and Sebring models. The FJ/ST coupes were DiamondStar (Mitsubishi, including FJ24S: Eagle Talon/Mitsubishi Eclipse) and the ST's had the 24 valve V6's. The JA sedans and JX convertibles were domestic (Sterling Heights) and like the FJ had the 2.5L until 2000. The 2.7L domestic (JR) was used in the sedans starting in 2001. The ST used the 3.0L. The coupes and domestics were 2 completely different cars.
The Stealth and 3000 were availible with the 3.0L DOHC and turbo models.
The Mitsubishi Cyclone engine family are all similar:

http://en.wikipedia.org/wiki/Mitsubishi_6G7_engine

The manual transaxles can differ. The domestic 3.0L/5-speed was used in the P-body, A-body, J-body as well. The ST used a Mitsubishi 5-speed. They are all hard to find. You would want a donor car with the clutch, shifter, misc. hardware and electronics to do the conversion.
The domestic automatics are the 41TE, but I see the F4A33-1 on some Mitsubishi DiamondStars/Imports.

 

[Larry38]

We made this swap in our race car Dodge Daytona. 12 valve sohc to a 24 valve sohc. To keep it simple we are using the computer from the original 3.0 12 valve sohc. Car runs great very responsive. We are currently racing with an automatic transmission. We just installed the 5 spd for this up coming race at Lucas Oil Raceway Park in Indianapolis. We do not think we are getting the full 200hp by using the original computer and injectors. Video of our last race, we are the #38 red, white and Blue dodge daytona. 3 Daytonas in this race. #60 was fast qualifier 3.0 12 valve v-6 5 spd.

 

[92LeBaron]

I have a '92 LeBaron convertible with the 3.0v6 (automatic). I would really like to swap out the motor for something a tad stronger/newer & nothing crazy expensive. Suggestions or should this just stay in the fantasy realm?

 

[ImperialCrown]

I believe that @Jerry Simcik did a 3.0L, 24-valve, DiamondStar/Stick-Shift conversion to his JX convertible.
I think that the electronics are the biggest difference. You would want to have the skills and tools to do this major operation.