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Forum namePerformance/Engine
Topic subjecta 1/2 engine swap question (SOHC)
Topic URLhttps://forums.2gnt.com/dcboard.php?az=show_topic&forum=i5&topic_id=113708
113708, a 1/2 engine swap question (SOHC)
Posted by SPL_Eclipse, Sep-19-03 05:29 PM
this is a dumb qustion, but it just hit me that a lot of the neon guys actually prefer the SOHC version of the engine for various reason (mainly the torque and power curve for daily race..errr...driving). so heres my question: what would be involved in converting the stock 420a eclipse engine into its SOHC counterpart?

heres a thread in relation to this question, and it seems pretty simple, at least for the neon guys (ehhem, i now own a neon, BTW, lol), so i cant imagine that its any more complicated for us. (edit: when i say "us", im still refering to the fact that im an eclipse owner...its a bit hard to give that up, lol)

http://www.neons.org/forums/viewtopic.php?t=127035

any input?
113709, RE: a 1/2 engine swap question (SOHC)
Posted by TXrepresent, Sep-19-03 05:40 PM
You would have to get a new computer made for it. You might as well swap in the whole motor and wiring and computer from the neon. It would be easier that way.
113710, RE: a 1/2 engine swap question (SOHC)
Posted by SPL_Eclipse, Sep-19-03 05:53 PM
actually, according to that post you wouldnt. it is stated that the DOHC computer would run the SOHC fine. after all, we arent talking about a full engine swap here.
113711, RE: a 1/2 engine swap question (SOHC)
Posted by Squid, Sep-20-03 04:18 AM
I'd like to see a dyno plot of the SOHC Neon vs the DOHC Neon vs Eclipse.

But if you did want to bolt it up the exhaust and intake would be on opposite sides and rigging up the timing belt would be a real pain. The Neon guys can probably just use the tming belt setup from the SOHC but our engine mount location is diffrent and may not allow you to use the SOHC timing setup.

But in general DOHC heads flow better than SOHC heads. But the SOHC heads have less rotating mass. Why not just get a new set of cams.
113712, RE: a 1/2 engine swap question (SOHC)
Posted by MotoFool, Sep-20-03 10:36 AM
no point in it that would make exhast rear exit in the engine bay meaning alot of cutting....

Bill
113713, RE: a 1/2 engine swap question (SOHC)
Posted by SPL_Eclipse, Sep-20-03 04:42 PM
^^^ya, thats what i was looking for. i didnt *think* it would require too much work to switch the intake/exhast around, but i guess i was wrong, lol.

anywho, just another crazy idea down the drain.:P
113714, RE: a 1/2 engine swap question (SOHC)
Posted by Blmet, Sep-21-03 11:40 AM
you could use the dohc ecu, in fact alot of sohc neon owners switch over to the dohc ecu for a performance gain. Are the intake ports and exhaust ports shaped differently? Couldn't you just get a cam that switches the time the valves open to make the exhaust the intake and the intake the exhaust?
113715, RE: a 1/2 engine swap question (SOHC)
Posted by MotoFool, Sep-21-03 12:05 PM
easier to buy a neon head...

cause of the sensor on the cams

it could be done i dont see a point to it...

Bill
113716, RE: a 1/2 engine swap question (SOHC)
Posted by HadesOmega, Sep-24-03 08:32 PM
yeh I'd think you'd need to get some special cams so it would open the valves at the correct time if you'd want the head to flow in the direction ours is. But then again the head was made to flow the other way so maybe that'd be a bad idea.

one thing I like about sohc is that its easier to work on, like change timing belt and all that other head stuff. so simple :P maybe you could run it the way the neon is running it, isn't the head a lot skinnier than the dohc one? not sure O_o
113717, RE: a 1/2 engine swap question (SOHC)
Posted by chrysler kid, Sep-24-03 08:54 PM
>easier to buy a neon head...
>
>cause of the sensor on the cams
>
>it could be done i dont see a point to it...
>
>Bill

its easier / cheaper just to buy a sohc neon