i bought a blown engine eclipse gs... a rod went through the block. i can find a neon engine a hell of a lot cheaper. Now i know it will fit and all because i am running a neon block with JE pistons in my car....but my question is, completly stock neon block with eclipse head. will the timing and everything be correct? i know its lower compression, but it would still run just fine right? thanks
doug

That's actually a really good question. I have my doubts, athough I'm not 100% sure. I have a suspision the crank is probably positioned differently which would throw off the sensors. I'd put my money on having to use a Neon head with a neon block/pistons/rods.

i know the crank works...i have a neon block with neon crank in my car...i just used eclipse pistons and rods. the throw from the crank would still be the same with neon pistons, just not enough compression....the crankshaft sensor is the same and the same oil/water pump. and whats the compression difference 9:1 to 9.6:1?? not much...hell, this could even be a cheap way to sort of build your car turbo..any other input? thanks

doug

DOHC pistons are the same, AFAIK.

SOHC pistons are flat and would be somewhere in the 10:1 range with a DOHC head.

That's right ... I forgot there are DOHC and SOHC neons. The neon block I used to build my motor was an SOHC. I remember the flat pistons that were in there.

And Doug - you're correct, the cranks are identical, I was just wondering if maybe the positioning of it and how the sensor read it were different on a Neon, as far as timing goes.

Originally posted by DarkOne
DOHC pistons are the same, AFAIK. SOHC pistons are flat and would be somewhere in the 10:1 range with a DOHC head.

This interested me as I just bought a Talon w/ screwed up head (and I have yet to find out what else enginewise). This is what I found, hope it helps :)

Q: Is there any parts interchangeability between the SOHC and DOHC motors?

A: "Putting DOHC pistons in an SOHC engine has been done. The two engines have essentially the same block and crank except for the PCV system in the '95 SOHCs. DOHC pistons raise the compression a little less than half a point. The DOHC engine actually has slightly less compression than the SOHC because it has 54cc of combustion chamber volume. The SOHC has about 48cc. Thats why the DOHC uses slightly domed pistons, to get the compression almost all the way back up.
If you are planning on putting a DOHC head on the SOHC block even after you change the pistons, you'd better plan on getting a DOHC donor motor for the project. Otherwise, it'll get real expensive quickly. You'll need the manifolds, throttle body, sensors, some timing belt drive components, and wiring harness to get it running. You'll also need a DOHC computer to get the right fuel and spark. SOHCs and DOHCs will run with the wrong computer, just not that well. The fuel and spark tables are totally different because the engines have different airflow characteristics."

I just got done doing this exact thing; I stole the DOHC engine out of a neon, stripped it down to the block, dropped my head on it, and dropped it into my car.

Now, for what it's worth, I could never get it to fire up on the stock ECU... I blame this on the guy who did the wiring job on my car before I bought it, however. Instead of messing with it, I just went ahead and got and wired up my megasquirt. And now she runs... sorta. See my post in the engine controller section. ^_^

Well I can tell you this. I dont know if the reasoning behind my rod "shattering" in my #3 cylinder had anything to do w/ it or not, but the rods were from a DOHC neon block. The block was from the eclipse, but the rods I bought from some guy on ebay that came out of a 95dohc. Maybe there was another reason behind it, I dont know. Just my input though. Why not just use the block, crank from the neon and get some eclipse rods to play it safe? and use your head of course

did someone say that the sohc has higher compression? i dont see why? I dont see where the rods would make any difference. the engine will still have the same compression as it did in a neon. the bottom half (block) should have no idea whats sitting on top. im going to try it, probably with a sohc because they are more readily available and cheaper...ill let you guys know how it works out.
doug

Think combustion chamber volume.