I need 420a cylinder head information

I would like any information possible regarding Chryslers 420a DOHC cylinder heads, 2.0L, 2.4L, Avenger all model years. I am trying to determine which head will be correct for a swap we are considering.

Thanks John

Well, the DOHC heads will swap between any 2.0 and 2.4 - part numbers are identical across all applications. So that means Cloud Cars, Neons, PTs, etc are all viable donors. Word is that the 2000+ m/y (post-PT) head flows a little better than the previous version. The cam followers are better, too, and don't suffer from oil starvation as much as the previous ones do. The cam followers are a direct swap into any DOHC head and in fact I believe they superseded the old part number.

What do you need to know? Are you running the Exhaust manifold "forwards" (NonTurbo DSM)or backwards? (Neon, PT, Cirrus/Stratus). A few years ago, the hot setup was a PT 2.4 head, which had a slightly different port location/shape and flowed a bit better than the 2.0 Neon head on the exhaust side. It's been a few years since I thought about this: I could be wrong. The 2.4 and 2.0 heads are essentially interchangable, turbo models have inconel alloy exhaust valves, IIRC.

Nathan

edit: Doh! Treed!

Actually the 420A designation refers to the Mitsubishi version. The Chrysler version should properly be refered to as the D4RE or ECC. They are remarkably similar. but the Mitsu spins in the opposite direction ( exhaust in front, intake on rear, etc.).

Is there a flow difference between "standard" and "Avenger" heads? (I know they go "opposite ways")

What I am considering is a junkyard build 2.4L with the Avenger head (for a front mount turbo) using a cast eBay 420a turbo manifold and a T3 with a front mount intercooler.

Everything is basically the same(chop the water neck off of a neon intake and the bolt holes line up) except backwards.

Detroit Neon Owners Site Admin said: 95-00 2.0/2.4 DOHC heads are all the same and have the small oil return. 01-early 02 2.4 DOHC heads have smaller exhaust valves, square exhaust ports and different intake manifold bolt patter and have the small oil return. 02+ 2.4 DOHC heads have smaller exhaust valves, square exhaust ports and a different intake manifold bolt pattern and a large oil return. you need to find out what size oil return your block has so you can determine what year range you can run. if your block has the smaller oil return than a 2.0 head is what you want since it has the larger exhaust valves, if you have the large return you can either weld it up and redrill it to the smaller size and run the 2.0 head or run the newer style head w/ smaller exhaust valves

I'm told that the smaller valved "PT head (01-02)" that fits the smaller oil return neon head actually flows better as a result of the port configuration. I've reworked "old" intake manifolds (Neon) to fit the 02+ heads. Some have welded up the large return on the HEAD in order to use the newer casting on the old style block. (again, to take advantage of the different exhaust port configuration)

neons.org has more info than you can shake a stick at, and they (used to?) take accuracy quite seriously. It's been a few years, so my info might be out of date.

Nathan

Forgot about them as well, Thanks Nathan.

No worries.... I have to say I'm looking forward to seeing the results! Will you be using SRT-4 rods and pistons? They're available cheap, and are strong enough for sane people. (400ish whp)

Nathan

Still considering, but since I have more access to cheap Neon/Cloud/Avenger bits than Northstar bits right now it looks more likely the 2.4L will be used.

Not to stray to far from the topic... but..ever have one of those moments when something you'd swear would work.... but... in the end you find out it won't? I had one of those moments a few years back when I found that Mopar made two different versions of the same DOHC head. One, a mirror image of the other, for the 2.4L 4 cylinder engine. And I thought "Y'know, that just like a DOHC V8 setup". So, IF they COULD be bolted to a block, what block would that be? Well... after looking at the bore spacing of several different blocks, I found that they could ALMOST work on a Triumph Stag V8. ALMOST.... It turned out the bore spacing of Stag blocks is not symmetric...

But hey, it almost worked!

Greg

Greg55_99 wrote: when I found that Mopar made two different versions of the same DOHC head. One, a mirror image of the other, Greg

Please refer to my earlier post. They are not the same engine. But they are. Depends on where you want the intake/exhaust to be /.