Page 1 of 1
2.0 SOHC magnum vs 2.0 DOHC
Posted: Fri Sep 17, 2010 1:18 pm
by Guard1an
hey guys i have a 2000 neon 2.0 with a spun rod bearing on the #3 rod. And I have the opputunity to get a RT engine (2.0 magnum motor SOHC) or a 2.0 DOHC,
question is which is the best bang for the buck ??
what makes a magnum motor a magnum motor besides the sick aluminium intake manifold ??
and will both of them bolt to the stock ATX ??,
I am sorry if this has been asked before i just got back from the boneyard and just wanted to post this real quick so i can head back and wait for a response ( wife will check and let me know)
-Mike
Posted: Fri Sep 17, 2010 1:29 pm
by gtxtreme19
They will both bolt up fine, if you have a 2000 and the motor is03 or newer you wont be able to use it without megasquirt or something.
The magnum motors have a different head, intake and exhaust manifold
Re: 2.0 SOHC magnum vs 2.0 DOHC
Posted: Fri Sep 17, 2010 1:30 pm
by stdlystdmufn
what makes a magnum motor a magnum motor besides the sick aluminium intake manifold ?? (the mag engine also has a better head, header, camshaft, PCM w/advanced spark, and muffler)
and will both of them bolt to the stock ATX ?? (yes they will)
Posted: Fri Sep 17, 2010 2:31 pm
by Guard1an
you guys rule, thank you for the quick replys, so i will need the head, cam, intake and exhaust manifold, and pcm, anything else ??
-Mike
Posted: Fri Sep 17, 2010 4:44 pm
by occasional demons
The block.
If you can get the 2.0 DOHC, there are more options available, and you do not have to worry about it being NGC, unless you have export PT Cruisers sitting in your JY.
With the DOHC, you will also need all the bolt on stuff, (Manifolds, PCM etc. ) But you will need to do some rewiring to make a DOHC PCM work in your 2gn.
--------------------------------------------------------------------------------------
Edit: The DOHC can run off the SOHC pcm. But I would use the R/T pcm, since your options are there. That would be interesting, as IDK if anyone is using an R/T pcm to run a DOHC.
--------------------------------------------------------------------------------------
The Magnum, if you can get the engine bay harness, by all means do. With the PCM, you will have a plug and play working IM. No WOT/RPM switches, wiring and relays to mess with.
The SOHC is easier, but the DOHC leaves more room for creativity, but takes more effort/brain power.
Posted: Fri Sep 17, 2010 7:12 pm
by Guard1an
well the place wants to charge $580 for a complete motor plus a $50 core fee, i will be hitting up the boneyard in the morning, the R/T is an iffy took a really nasty hit to the front right, motor is gonna be a mofo to get out, the DOHC car is pretty decent from what i saw, so i will drop the pan and pray theres no metal chunks. also aren't the blocks different from SOHC and DOHC 2.0's ??
for the magnum how easy would it be to run a standard (non magnum) harness what mods need to be done to make the butterflys work ?? or are they even needed ??
when you say the options are better for a DOHC, what options are available ?? isn't the DOHC 2.0 parts interchangeable with mitsubishi 2.0's ??
how is the DOHC able to run on the SOHC computer ??
Are the mounts the same ?? oh the DOHC is in a Dodge Avenger not a neon,sorry should have clarified that
-Mike
Posted: Sat Sep 18, 2010 12:58 pm
by Guard1an
bump, haven't made it to the boneyard yet, trying to figure out which i should get, the 2.0 DOHC head will fit the 2.0 SOHC block right ?? i know i will need all the DOHC stuff, timing belt, cams, cam gears, valve cover anything else ??
-Mike
Posted: Sat Sep 18, 2010 1:30 pm
by gtxtreme19
Why not Just take the whole Dohc motor?
Posted: Sat Sep 18, 2010 1:39 pm
by Guard1an
cause its almost $600, and i am not sure if the bottom end is good in it, and i am still debating which will be the most beneficial in the end 2.0 magnum or 2.0 SOHC, i will probably head that way here in a bit, will let ya'll know how it turns out, btw as long as its pre-'03 will any 2.0 DOHC work in a '00 neon ?? doesn't matter if it came from an avenger or not ??
-Mike
Posted: Sat Sep 18, 2010 1:50 pm
by stdlystdmufn
making the btterflies work is prety easy, even easier if you just hook it to an RPM switch.
Posted: Sat Sep 18, 2010 7:53 pm
by occasional demons
Guard1an wrote:. also aren't the blocks different from SOHC and DOHC 2.0's ??
Blocks are the same, but the pistons are different.
isn't the DOHC 2.0 parts interchangeable with mitsubishi 2.0's ??
No
how is the DOHC able to run on the SOHC computer ??
Turn the cam magnet.
Are the mounts the same ?? oh the DOHC is in a Dodge Avenger not a neon,sorry should have clarified that
If the exhaust is in the front, then you would have a hell of a project. The bottom end is the same, but I believe the heads are reversed for the diamond star cars.
-Mike
Posted: Sat Sep 18, 2010 10:17 pm
by Guard1an
hell good or hell bad ?? what are the differences between the pistons ?? yes the exhaust is in the front, with the intake close to the fire wall, how do i turn the cam magnet ?? like i have said i can get a short block for $75+$25 core from the one place, and the head from the rape you place,
-Mike
Posted: Sun Sep 19, 2010 12:20 pm
by occasional demons
With the reversed head, IDK if the magnet needs turned or not.
Most ppl that even bother with that head in a neon do it to put a turbo in the front. And I don't know of any examples to link you to, I have only seen it discussed.
IDK if anyone has even bothered to do a N/A Eclipse style head in a neon. You are looking at full custom exhaust, prolly IM, etc. There is really very little info here on that. There might be more on the other org.
viewtopic.php?t=51702
viewtopic.php?t=49516
Posted: Sun Sep 19, 2010 2:17 pm
by Guard1an
well i started working on the DOHC avenger first, got the heatshield off and bam, first ah shit, exhaust mani is cracked bad (its a stock cast iron mani) at the merger point of the runner, second ah shit was the cam lobes intake side of #3 & #4 the lobes on both cams were all smooth, and had a great wear pattern for roller cams, but on those last 2 there where what i consider hot spots you know how the wear pattern produces a nice shiny ring around the cam lobe ?? it does and these 2 had that, except there was a dull "hot/scuff" spot right at the nose of the cam lobe
my concern is if there might be deeper damage internally, oh and it was missing a cam gear which i could get off any number of 2.4L's surrounding her haha. are the 2.4 cams different than the 2.0 in terms of performance ?? i will need to go back this weekend to finish working on the head to get it off, along with the intake, gonna take some dimensions and see if *hopefully fingers crossed that it will work*
is the magnet you speak of (on the reversed head) on the exhaust cam on the back of the head (right side) ?? thats another reason i reallllllllllllly like that head the exhaust is in the perfect location for turbo mounting, and SRT piping for the turbo inlet might work for the intake, given its location, i will try and get back today and finish pulling the head if i can, i noticed a lot of vaccuum canisters ( the car has cruise) and egr crap, do i need to get all that stuff to make this head work (not the cruise) ??
heres a pic of the '02 RT now you see why this is a pain to even attempt to pull parts lol, but i did manage to grab the exhaust for $28 and the PCM for $35+$15 core, i told them it was an airbag module haha
-Mike
Posted: Sun Sep 19, 2010 2:37 pm
by Guard1an
and whats the difference between SOHC and DOHC 2.0 pistons ??
-Mike
Posted: Sun Sep 19, 2010 10:06 pm
by occasional demons
Guard1an wrote:and whats the difference between SOHC and DOHC 2.0 pistons ??
-Mike
Compression ratio.
IIRC, DOHC pistons will raise the C.R. in a SOHC engine about .5
Putting a DOHC head on a SOHC bottom end will lower it .5
I think the DOHC C.R. is about 9.6:1 The SOHC is 9.8:1 (Pre NGC)
The combustion chambers obviously are also different volumes thus why the pistons make a difference with a SOHC head and the DOHC head with SOHC pistons.
The cam magnet should be on the intake cam regardless of which head. 2.0 cams are the better option for a little more power.
Edit:
On that head the cam near the firewall is the intake cam. The cam that is closest to the particular manifold is the corresponding cam. It would be a pretty interesting head, if it was the other way.
Posted: Sun Sep 19, 2010 11:06 pm
by Guard1an
do you happen to have a pic of said magnet ?? I guess i was looking at the cam position sensor on the exhaust cam then, good news to hear about the dropping of compression, lower compression, better boost

also can anyone tell me what exactly the differences are between a stock and RT PCM ?? i have the number written down:
bottom PN P05033087AB 0503
module SN T28EH01520KD8 20 53 21
on the front: module pn P05034130AD
4130AD
and casted into the case below that is this
04745860
64490
21
Posted: Sun Sep 19, 2010 11:32 pm
by occasional demons
There should be a VIN number. 8th digit should be an "F".
The sticker on the cover face is the correct info. The VIN should also be there.
5034130AD MODULE POWERTRAIN CO $939.00
Prolly correct as an R/T pcm, as that is the same PN as mine.
Having the VIN run at your local dealer will tell you what options the car has/had. If it has SKIM, it will in most cases, need to be reflashed to your car. I somehow have gotten away with not doing that. I may be the only person with a SKIM pcm in a non SKIM car.
R/T pcm just has a more aggressive fuel and spark curve. It will only use it as needed tho. Putting an R/T pcm into a regular neon will not affect the fuel mileage or octane requirements if it is driven normally.
But it will make better use of bolt ons, and with those, higher octane fuel. With all the oem stuff, I actually got better mileage with 87 octane over 93.
It also has a nice boost in spark and/or fuel at 4900 rpm under hard acceleration. I do not have the head or IM installed, and it still acts like there is something kicking in at 4900 rpm. But only at WOT.