I agree with what's already been siad for the most part. The pistons are different and would need to be changed. However I will argue slightly only the differences in compression ratio. The DOHC actually runs a lower stock CR than the SOHC. I don't have the actual numbers here at the moment but I think it's something like; 8.3:1 DOHC, 8.6:1 SOHC I will verify this later today. I always assumed the DOHC had higher compression due to it's needing premium gas, but this is due to the more agressive ignition timing and not a higher compression ratio. I also know the two heads have different combustion chamber volumes which further changes the CR if you mismatch the pistons.

 

ok, so my numbers were a little off. Compression ratios are as follows: DOHC 9.6:1, SOHC 9.8:1 (As stated in my '97 FSM). Still haven't tracked down the CC volumes though.

 

Thats right everything is the same in the bottom end except for the pistons. You will need the PCM, wiring harness, pistons and head.

 

I have found the Piston are different and the Crank Bearings are different - the SOHC engine bottom Bearing ( the bearings come in two parts) The top side of the bearing fits perfect! the bottom side bearing is notched on the wrong side! Same for the Journal Bearing two - the top side fits perfect - and the bottom side does not fit - If I have time tonight after work - I will try to take a couple of quick snapshots and will post them

Greg

 

I would go with the DOHC, the bigger the better. I'm not sure what's exactly involved but if you have the time anything is possible. I want to do the 2.4 SRT-4 turbo engine swap in my 98 R/T.

 

pictures would be great Greg, I want to have as much info compiled as humanly possible by the time i start buying parts and tearing stuff down.
-Cheers

 

Greetings Builtfourspeed,

I have already locked up the Garage for the night - but tomorrow night I will post pictures of the difference on the Crank and Rod bearings as well as the pistons on the SOHC and the DOHC. Everything else has been bolting right up perfectly!

Greg

 

I have just finished putting the engine back in the Car - I still have to hook up all the Belts, Electronics, Fuel Lines and Injectors - should be up and running around tomorrow

I will create a new thread tomorrow and post the difference on the SOHC and the DOHC parts.

Greg

 

Do it up all nice and neat and I will sticky it to the top of the page. Also PM Amanda a copy for the Do it Yourself area.

 

About 6 months ago, the head gasket went out on my '97 SOHC and I started looking at options. About a year earlier, I had bought a '96 Avenger for $100. The car had been completely thrashed, but it still had a good engine. Ran well but transmission was shot. The idea was to take the engine out and do something with it, but not really sure what.

After the head gasket blew, I started looking up information about the engines to see what could be done. I'm currently in the process of swapping the DOHC head from the Avenger into the Neon. After I started having engine problems, I didn't really trust the neon anymore, so I'm completely replacing the block, head and everything electrical. I know that the exhaust exits on the front of the Avenger instead of the rear of the neon and will cause a bit of a routing problem, but it should still be doable.

To my knowledge, the Avenger / Eclipse has no advantage over the DOHC Neon engine, as it produces 10HP less power. I'm not into the project to make a high performance maching, but simply to see that it can be done and to have something that few have tried. I know that the head itself will fit. My only concern is if the intake manifold will fit or not.