I've got a 1998 Plymouth Neon ACR (DOHC 2.0L) that I'll be refurbishing shortly. The intention was to keep the engine close to stock, but I ended up finding a junked out 420A DSM at the local U-pick with a fully ported & built cylinder head. This cylinder head had BC valve springs and titanium retainers, stainless 1-piece valves, ARP head studs, and BC Stage 2 N/A cams. This is a great, reliable setup for mild N/A cars, but it's not cheap to purchase new. I walked away with everything plus the valve cover for around $70 USD. The Mitsubishi 420A Mitsubishi and Dodge Neon ECC engines are very, very close but they have the head ports flipped. Some people put 420A intake cams into the Neon exhaust cam slot (which is the same position on the head) to maybe gain a bit of free power. Effectively, I'd like to cannibalize the 420A head for its parts, sell the bare 420A head, use the parts to build up a Neon head, deck it 0.030", and slap it on my ACR.
On paper, the BC0167 Stage 2 N/A cam for 420A would be a great fit for the Neon head. In a 420A application, the intake and exhaust both have a 210* duration at 0.050", but with 0.354" lift on the intake and 0.386" lift on the exhaust. In a Neon application, the hotter cam would work the intake side. The issue(s) are that the dowel pins are not in the right place on the cams for use in a Neon, and a machine shop will have to drill new dowel pin holes to put them in the right spot. Manageable, but a big invoice in this case would defeat the purpose.
I asked BC tech support if they'd be willing to volunteer the information on proper dowel clocking to save me a few bucks on the machine shop figuring it out, but they came back with something I wasn't expecting: "The opening and closing ramps are reversed so you would need to regrind the cams properly". Huh? Is this really at thing? Do intake and exhaust cams really have ramps that are so different that swapping them would have an adverse affect on operation, or are they just trying to sell a cam regrind?
I ran an exhaust cam on the intake side of a KA24de. I moved the dowel pin. Can't honestly I saw much of a bump.
Those are rocker arm engines, right?
I have a feeling the rocker pivots are on different "sides" of the cam. Because of the geometry involved, the opening and closing ramps of a cam for a rocker arm have to be shaped differently, and this will be different depending on which side of the cam the rocker pivot is, leading the cam or trailing the cam.
As far as dowel pins go, those are just so the timing marks on the pulleys line up. You can make your own marks and ignore the OE ones. You're talking about decking the head .030", so you will need adjustable cam pulleys anyway to keep the cam timing from being way off.
Former Camshaft engineer from Chrysler that did work on the neon engine. In general, I think that camshaft ramp rates are important for functioning of the engine.
Imagine the spring rate of the valve. Now assume it is has a spring rate that is not high enough to keep the rocker/follower in touch with the camshaft lobe during the closing phase. So now you risk the camshaft rocker/follower hammering near a single spot thousands of times a minute or chattering down the backside ramp of the lobe. I think the best case is the camshaft is soft enough to build up a nice deep dent. That way you don't shatter the rocker/follower or you don't lose the keepers and drop a valve. Not pleasant.
While the heads are swappable for moving the turbo to the front of the car, I don't think I remember many people just swapping the internals of the head....but that is now 18+ year old information from my brain. The slick move was to find the Mexico Domestic Market turbo Stratus parts. But they are like finding mermaids unless you have someone near Mexico City where they were the standard highway patrol car around there. All of the JA (stratus/cirrus) and 2.0L manufacturing equipment and some IP rights were sold to a Russian auto maker.
So it matters, but you imply you will use the higher rate springs from the salvaged head. So if you are just playing with the car you can go forth and see what happens!
Also and aside.
I have found that over the years more and more information online has become confused between the Diamond Star (read mitsubishi) 2 door version stratus and the Chrysler made 4 door Stratus. Engine information between the 4 cylinder mitsubishi motor used in the 2 door cars is sometimes intermingled with information about the chrysler engineered and manufactured 2.0L engine. Some sites even try to claim they were engineered together because they include information from a third engine, the tritec motors.
People even make up names for the motors. Internal to Chrysler back then we didn't name the 2.0L or the 2.7/3.3/3.8/3.5. I think marketing tried a powertech name on some of the truck motors but internally we just called them the 3.7L/4.7L. And when the Tritec program did start they created a code for the old 2.0L to help management understand reports on all the engines but outside those reports we didn't really use that code. So now that forums and blogs try to give them names or engine codes(like A20 or 588 etc) it makes me very suspect of anything else they write.
Sadly that information has started to bleed into the online Neon engine information as well. At one point 2 years ago, maybe 3 now, someone changed the neon wikipedia to say it only came with the mitsubishi V6...
. It got fixed but man it is interesting how confused the internet is about the late 90s early 2000s Chrysler engines.
Thank you for the input. The valve spring kit in the head is the BC0160 setup, which is listed as correct for the 420A (95-99 2.0L non-turbo DSM) and the Chrysler 2.0L/2.4L, including the SRT-4 if used with a single keeper setup. I believe the springs themselves also work in the 4G63 and others. The valves in the head match the stock size for the Neon 2.0L (34mm & 30.5mm?) and are also reported to fit both applications on BC parts listings. The rocker arms on them were the stock replacement style (95-99 Neon & DSM), same with the lifters with the small bleed hole, but I'm using 2.7L rockers and PT Cruiser 2.4L lifters, as the recipe goes.
The BC1100 springs included in the BC0160 kit spec out at 84lbs seat pressure @ 1.550" and 235lbs @ 1.000", which is plenty for a cammed Neon with a 'proper' setup. Since you confirm that the ramps do differ and there are adverse outcomes possible, the rational move seems to be to buy new Crower Neon cams and sell these cams to someone who needs them.
At one point 2 years ago, maybe 3 now, someone changed the neon wikipedia to say it only came with the mitsubishi V6.... It got fixed but man it is interesting how confused the internet is about the late 90s early 2000s Chrysler engines.
I need to file the idea of a 6g72 Neon under awesome troll build I don't have time for.
MadScientistMatt said:
At one point 2 years ago, maybe 3 now, someone changed the neon wikipedia to say it only came with the mitsubishi V6.... It got fixed but man it is interesting how confused the internet is about the late 90s early 2000s Chrysler engines.
I need to file the idea of a 6g72 Neon under awesome troll build I don't have time for.
I have seen pics of the 3.0 Caravan engine in a Neon, with the top of the plenum milled flat so an Eaton supercharger could be bolted to it.
Oddly enough, not this particular one.
I forgot to add - the direction and rotation of the camshafts does not change between these - when swapping the camshaft roles, the opening ramp of the intake cam becomes the opening ramp of the exhaust cam, and vice-versa. So in essence, the question should've been whether the opening ramps are different between an intake and exhaust cam.
On the subject, are lots of V6 Neons running around. We have the one of the cheapest/most frugal ownership groups out there, V6s are cheap and plentiful, and are fair game.
I have no familiarity with these particular engines, but on some modern DOHC roller rocker setups the cams essentially operate in reverse to each other because of how they're situated in relation to the valve and rocker.
Also, in these designs the shape of the lobe is very different between the opening and closing ramps. Some, if not all, now, have inverse radii on the opening ramp, which can cause all kinds of interesting problems when you run them backwards. It also takes more specialized equipment to grind these profiles, which a lot of shops don't even know about. Look at all the problems and broken parts people were having with performance cams on the early GM eco engines, and it was for these very reasons.
There's a fairly major GM eco performance supplier right now that sells a performance ground intake cam and tells their customers swap the OE intake cam in to the exhaust side. I did the early development on these and told them NOT to do this for the reasons mentioned. They went ahead and did it anyway. And I guarantee that cam they're selling is not ground properly.
Where in Canada are you? If you're close I can look at the cams
In reply to CanadianCD9A :
if both cams rotate in the same direction as installed, then i vote for full send, as the opening and closing ramps will be on the correct sides of the cams. also, you got it all cheap enough that who cares if you break something? do it for science, man!
In reply to AngryCorvair (Forum Supporter) :
Only if the rocker pivots are leading or trailing in both cases. The relationship between lobe lift and valve lift changes quite a bit depending on where the rocker pivot is, and on the opening and closing ramp.
which, in retrospect, is WHY you use a 420a exhaust cam on a Neon intake. The rockers will be operating the same.
JBinMD
New Reader
4/3/23 5:30 p.m.
CanadianCD9A said:
I forgot to add - the direction and rotation of the camshafts does not change between these - when swapping the camshaft roles, the opening ramp of the intake cam becomes the opening ramp of the exhaust cam, and vice-versa. So in essence, the question should've been whether the opening ramps are different between an intake and exhaust cam.
On the subject, are lots of V6 Neons running around. We have the one of the cheapest/most frugal ownership groups out there, V6s are cheap and plentiful, and are fair game.
Honda D-series has entered the chat.
JBinMD said:
CanadianCD9A said:
I forgot to add - the direction and rotation of the camshafts does not change between these - when swapping the camshaft roles, the opening ramp of the intake cam becomes the opening ramp of the exhaust cam, and vice-versa. So in essence, the question should've been whether the opening ramps are different between an intake and exhaust cam.
On the subject, are lots of V6 Neons running around. We have the one of the cheapest/most frugal ownership groups out there, V6s are cheap and plentiful, and are fair game.
Honda D-series has entered the chat.
Well yeah, when the cost of entry is as high as an older Civic, one tends to not have much left over for things 
