I have been looking for all sorts of info since I have decided to go with the 2.4 swap in my GLH. Reading a bit here and there and by moments overwhelmed(understatement).
I found an article and decided to share it with you guys. Lots of simple info and can be used for references.
It comes from Engine Builders magazine website.
Hope it helps.
Article was to long and I had to post it in two parts. If an administrator wants to join them together would be great.
Chrysler replaced its old SOHC four cylinders with an all-new family of SOHC and DOHC engines in 1995. There were 2.0L SOHC and DOHC versions, along with a 2.4L DOHC that was installed in the FWD cars and minivans. Add seven different head castings that came with and without EGR and A.I.R. and throw in 14 different cams and you have a recipe for disaster, if you’re not careful. So, let’s take a look and see if we can make some sense out of all the changes Chrysler made from ’95 up through ’06, before the 2.4L engine was replaced by another all new family of “world class” four-cylinders.
BLOCKS
There are six distinctly different castings including four FWD blocks and two RWD blocks. And, the latest FWD block may or may not be machined for a turbo application.
1995-2000:
The original casting was a 4621443 block that had a 4621445 bedplate. It was used up through 2000.
2001:
The hole for the oil pressure sender on the passenger side was moved back about 6? in 2001 so it was much closer to the bell housing. It’s a 4621443AB casting.
2002: The oil drainback hole in the head was enlarged in ’02 so there was another “bulge” added to the block on the driver’s side, between the third and fourth cylinders. It’s an all new casting that has 4781655AA on the driver’s side.
2003-2006:
There was another all new FWD block in ’03 that incorporated several more changes, but the most noticeable one was the change in the location of the hole for the crank sensor; it was moved from the front of the block on the passenger side to the back of the block on the driver’s side in order to accommodate the new, bolt-on “target ring” for the crank sensor.
There were some other changes made to accommodate the turbo motor, too, including a boss on the passenger side that can be drilled for the oil return from the turbo and an additional oil galley inside the block that’s machined for the four “oil squirters” that are used to help cool the pistons on the turbo motors. Look for a 4781632AA/AB casting.
2003-2004 RWD:
Chrysler installed the 2.4L motor in both the RWD Jeep Wrangler and Liberty beginning in 2003. The RWD block is a unique casting (53010502AA) that doesn’t have the “ear” that sticks out from the front of the block down by the pan rail on the passenger side of the FWD blocks.
These blocks have “RWD” cast on the passenger side so they’re easy to spot. The Catch-22 is that this block was used for both the Wrangler and Liberty in ’03, but only for the Wrangler in ’04 because the Wrangler platform continued to use the old style computer and crankshaft (without “NGC”) through ’04 even though the Liberty got the “NGC” computer along with a new block and crank in ’04.
2004-2005 RWD:
The RWD block was revised in 2004 to accommodate the bolt-on “target ring” with more notches that was used with the new “NGC” computer so the hole for the sensor was moved over to the driver’s side and back toward the bell housing, just like it was on all the ’03 cars. The revised 53010502AB casting was used for the Liberty in ’04 and ’05 and the Wrangler in ’05 and ’06.
CRANKS
There have been two cast cranks used in the 2.4L from beginning to end, one that has the sensor wheel machined directly on the second counterweight and one with a bolt-on “target ring.”
The 4621916 casting was used from 1995 through 2002 for all the FWD applications and for some RWD applications in 2003 and 2004. It can be identified by the “sensor ring” with 18 windows that is machined right on the second counterweight. This crank was used for the platforms that came “without NGC,” meaning they had the old style computer, so it was used for all the FWD applications until ’03 when they were changed over to the “next generation controller” (with NGC). It was used for both the Liberty and the Wrangler in ’03 and for the Wrangler in ’04, because the RWD platforms weren’t changed over to “NGC” until ’04 and ’05.
2003-2006:
The 4781590AA crank has a “target ring” with 32 windows bolted on the back of the rear counterweight. This crank must be used with any platform that has “NGC” including all FWD applications beginning in 2003, the Liberty in ’04 and the Wrangler in ’05.
According to the parts book, Chrysler used a different crank for the early turbo motors, but both of the new turbo short blocks we bought while researching these engines had the 4781590AA casting, so Chrysler has apparently decided that the regular cast crank is strong enough for the turbo motors, too. However, there may be a turbo crank with a different casting number out there, so don’t be surprised if you stumble on one in a core.
RODS
There have been only two rods used for the 2.4L engines, one that’s made of powdered metal and one that’s a steel forging.
All of the naturally aspirated engines came with a press-fit, powdered metal rod that measures 4.46? from edge-to-edge between the big and little ends. These rods are easy to recognize because they don’t have a balance pad on either end, but don’t mix them up with the 2.0L rods that look the same, because they’re too short for the 2.4L.
The turbo motors all have a forged rod that’s bushed for a full-floating pin. There isn’t an actual forging number on it, but our sample had “m” and 23/151 on the cap. These rods also have oil squirt holes that spray oil on the walls to help “reduce piston noise at start up and improve scuff resistance.”
PISTONS
The pistons for these engines are pretty straightforward. There are two versions for the naturally aspirated motors and there’s one turbo piston. The original piston had a “dome” on it, but both of the later ones have a dome that’s shaped more like a “ski ramp” on the crown. They all sit pretty low in the cylinder at TDC, but the turbo sits way down in the bore.
1995-2000:
The original, naturally aspirated piston had a “dome” with a flat spot on it.
2001-2006:
The original piston was modified slightly in ’01. The dome was converted into more of a “ski-ramp” design without the flat spot on top. This added about 2cc to the crown so the compression ratio went up slightly.
2003-2006 Turbo:
All of the turbo motors have a coated, cast piston in them. According to the SAE paper on the turbo engine, Chrysler was satisfied that the cast piston would be adequate as long as they cooled it from the bottom with the “oil squirters.” It has a full-floating pin, it’s coated with Mahle’s Grafal™ material and the upper ring groove is hard anodized to prevent microwelding of the top ring. It has an 8.0:1 compression ratio, so it sits way down in the hole at TDC. It has the “ski ramp” crown on top “because it contributes to improved WOT spark and idle stability,” according to Chrysler.
HEADS
Chrysler has used several heads on the 2.4L along with some additional variations, depending on the application.
1995-2000:
The first head that was used from ’95 through ’02 was a 4667086 casting, but we catalog the two different part numbers because of the cam change in ’98.
2001:
The original head was replaced by the 4667086AB casting in 2001. It had smaller exhaust valves, smaller, rectangular exhaust ports, two more bolts (10 total) for the exhaust manifold plus one more for the intake manifold and one more for the rocker cover. There was also a pronounced bulge added to the head on the driver’s side, between the third and fourth chambers.
2002:
The oil return hole in the “bulge” on the driver’s side was enlarged in 2002, so the casting number was revised again; it’s a 4667086AC or AC-J now. All of the ’02 cars and minivans with this head appear to have had EGR, so we drill the hole in all of them, but we include the Chrysler EGR block off plate (p/n 4591803AA) and gasket (p/n 4861535AA) along with the engine just in case there’s an ’02 application that came without EGR.
2003 w/o Turbo:
None of the ’03s had EGR, according to our research, so we use the 4667086AC-J castings without EGR for all ’03 applications or build the engine with an EGR head and install the block off plate on it.
2003 w/ Turbo:
The turbo engine was available in the SRT4 Neon and supposedly in the PT Cruiser according to the AAIA list of VIN codes, but there’s nothing listed in the Chrysler parts book for a ’03 PT Cruiser with a turbo, so we don’t think it really exists. In either case, the turbo motors would have had the 4667086AC-J casting that came with special exhaust valves and no EGR in ’03.
2004-2006 w/o Turbo, With Federal Emissions:
There was another new head introduced in ’04. It had a recessed area right above the exhaust manifold that created a plenum for the A.I.R. system that was used on the Stratus and Sebrings with “California emissions.” All of these castings had four cast bosses that could be drilled for A.I.R., but they weren’t drilled for the engines that came with “federal emissions.” Some of these heads were drilled for EGR and some weren’t, depending on the year and the application.
Our research says that the 2004-’06 Minivans and the 2005-’06 PT Cruisers, both with and without turbo, came with EGR and the rest didn’t, but I wouldn’t care to bet the farm on it, so we recommend drilling all of these heads for EGR and including the block off plate and gasket along with the engine in order to avoid any possible problems.
Chrysler has superceded the ’02 and ’03 heads with the later 4667086AG-D casting so it can be used backward, but there’s one extra bolt hole on the passenger’s side of the AG-D head that may or may not be used for some applications, so we don’t recommend installing the ’02 or ’03 heads on any of the later engines.
2004-2006 Turbo:
The 4667086AG-D casting was used on the PT/Turbo from ’03 through ’06. The A.I.R. holes were never drilled for this application. We believe that the turbo motors came without EGR in ’04, but it appears that they had EGR in ’05 and ’06, so it’s best to drill them all for EGR and include the plate and gasket for the ones that came without EGR. Don’t forget that the turbo heads are unique because they have special exhaust valves.
2004-2006 Turbo:
The 4667086AG-D casting was used on the PT/Turbo from ’03 through ’06. The A.I.R. holes were never drilled for this application. We believe that the turbo motors came without EGR in ’04, but it appears that they had EGR in ’05 and ’06, so it’s best to drill them all for EGR and include the plate and gasket for the ones that came without EGR. Don’t forget that the turbo heads are unique because they have special exhaust valves.
2004-2006:
The FWD Stratus/Sebring cars with VIN “J” and “California emissions” had the 4667086AG-D casting with the four A.I.R. holes drilled. We were surprised to see that the new head we bought specifically for this application didn’t have EGR, but we have to assume that these cars were built without EGR since the head came without the EGR hole.
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