3.8L Dodge Dynasty

[Vigo]

Some Can-Am pics from my photobucket:


They obviously had custom pistons and rods.

I dont know how to identify the crank as 3.5-based. I have a 3.5 sitting in the dirt in my backyard but i am lazy about it. It was supposed to get mocked up in the old dynasty engine bay before i scrapped it but i got impatient.


They definitely did something here but it's still pretty far from the stock gasket marks at the entry.

I dont think they did anything here.

Those dont look like stock 3.3 valvesprings.. all i had to do was look. lol


This looks stock to me.

So, my educated guess is that all the 3.3/3.8 valvetrain needs for 7000 rpm is valvesprings, maybe.

[bakes]

you got some specs on the intake and exhaust valve sizes

[Vigo]

Im sure they are out there for the can-am somewhere, but id have to look. I can put calipers on the 3.3 heads i have outside, maybe later tonight.

I can also take a picture of the stock chamber, we should be able to tell from that if the can-am valves were the same or bigger.

[thedon809]

I think I have some newer 3.3/3.8 heads here at the shop. Last three of the part # is 183.

[Reaper1]

That crank is 100% cast. Isn't the 3.5 crank forged and that was the whole stink about using it? Seeing this, it looks like the forged crank info for the Can-Am engines was a myth. That sucks. The main caps look like standard cast iron units using stock bolts. I've not inspected the inside of a 3.3 that closely, but it looks to me like those parts are stock.

The porting on the intake, and not the exhaust was possibly to balance out the flow. Remember those engines had what looked to be like really good headers on them that probably scavenged well.

[Vigo]

I dont have an engine (out) to look at to verify those about what stock caps look like, but the picture with the pistons and caps sitting by themselves sure looks like non-stock caps and bolts. Since the picture of the crank in the motor shows stock caps and bolts, i dont know what to say about what can-am motors originally came with. I need to do actual research now. I do know some people upgraded things on their own afterwards so its possible some of the stuff i posted is not 'can-am'. I should not post things without context info.. i need to do more reading.

[Force Fed Mopar]

Pretty sure the 3.5 is a completely different engine from the 3.3/3.8, and therefore the cranks won't interchange. First things that come to mind is belt-driven SOHC vs chain-driven OHV, and different oil pump setups.

[Vigo]

Yes, that is the exact reason why the 3.5 crank is not a bolt-in (different crank snouts due to the differing timing setups). They are not COMPLETELY different motors.. the 3.5 uses the 3.3 stroke, 3.8 bore, same deck height, bore centers, etc. I think the oil pans and oil pan gaskets are interchangeable. They're very closely related on the bottom end.

But, i dont plan to use any 3.5 parts for this Dynasty other than the autostick TCM that came out of my 97 Intrepid.

[Force Fed Mopar]

Yeah I don't see any reason to run a 3.5 crank when you can just swap in a 3.8 Or a 4.0 from a Pacifica...

[Vigo]

Yeah, there's so few people that run into the crank's limits on any given motor, its usually just mental masturbation to even talk about it. I'll be the first to admit i will probably never find that line with this 3.8.

[black86glhs]

The torque from the 3.8 alone will wake that die-nasty up, YO!

Seriously, it will feel more like driving a real big car and not the little big cars they are. Like the difference between a 4.9 caddy vs. a 4.6 caddy.

[Reaper1]

Pretty sure the 3.5 is a completely different engine from the 3.3/3.8, and therefore the cranks won't interchange. First things that come to mind is belt-driven SOHC vs chain-driven OHV, and different oil pump setups.

Yes, that is the exact reason why the 3.5 crank is not a bolt-in (different crank snouts due to the differing timing setups). They are not COMPLETELY different motors.. the 3.5 uses the 3.3 stroke, 3.8 bore, same deck height, bore centers, etc. I think the oil pans and oil pan gaskets are interchangeable. They're very closely related on the bottom end.

But, i dont plan to use any 3.5 parts for this Dynasty other than the autostick TCM that came out of my 97 Intrepid.

I could swear that somewhere along the line I've heard of the 3.5 crank being used in a 3.3. If you have access to a machine shop, almost anything is possible, and if you have access to prototype raw forgings....well...how much can you afford becomes the main question.

The 3.5 was based on the block architecture of the 3.3/3.8 engines. They are technically in the same familiy of engines. Yes, there are some major differences, but the basic stuff, as has been already pointed out, is all the same.

Yeah I don't see any reason to run a 3.5 crank when you can just swap in a 3.8 Or a 4.0 from a Pacifica...

I didn't believe it until I saw it, but the 3.5 and the 4.0 used in the Pacifica are NOT Chrysler engines. They are Mercedes engines. I've seen both taken apart to different degrees and they look nothing like the Chrysler engines of the same size.

[thedon809]

Wut. They are Chrysler engines. The 4.0 is a stroked 3.5l. The only Chryslers that use a merc engine is the grand Cherokee with the diesel and arguably crossfire but that is a Mercedes to begin with.

[Vigo]

Yeah, not sure where you're getting that but the 3.5 and 4.0 are both chrysler designs that have roots all the way back in the 1990 3.3.

I think there was a guy on dodgeintrepid.net who either tried or succeeded in putting a 3.5 crank in a 3.3 (or actually 3.8?) motor with some mods. Everything i ever learned on that website is of dubious accuracy because its been so long and my memory is terrible. hehe

[Reaper1]

I saw a 4.0 torn down to the heads and it didn't look anything like the 3.5's from Intrepids and such. I just looked at AllPar and it states the engines are related, but I also remember seeing Mercedes on the electronics and peripherals.

[thedon809]

4.0l as in 08 pacifica
DESCRIPTION SPECIFICATION
Type 60° SOHC V-6 24-Valve
Displacement 4.0L
Firing Order 1-2-3-4-5-6
Compression Ratio 10.2:1
Lead Cylinder #1 Right Bank
Metric Standard
Displacement 4.0L Liters 244 cu. in.
Bore 96.0 mm 3.780 in.
Stroke 91.0 mm 3.583 in.

VALVES
DESCRIPTION SPECIFICATIONS
Metric Standard
Face Angle (From Horizontial) 44.5°-45°
Head Diameter-Intake 36.37-36.63 mm 1.4319-14421 in.
Head Diameter-Exhaust 28.87-29.13 mm 1.1366-1.1469 in.
Length-Intake (Overall) 114.41-114.99 mm 4.5043-4.5272 in.
Length-Exhaust (Overall) 126.17-126.75 mm 4.9673-4.9902 in.
Stem Diameter-Intake 6.935-6.953 mm 0.2730-0.2737 in.
Stem Diameter-Exhaust 6.906-6.924 mm 0.2719-0.2726 in.
Stem-to-Guide Clearance-Intake 0.022-0.065 mm 0.0009-0.0026 in.
Stem-to-Guide Clearance-Intake (MAX.) Rocking Method 0.29 mm 0.0114 in.
Stem-to-Guide Clearance-Exhaust 0.051-0.094 mm 0.002-0.0037 in.
Stem-to-Guide Clearance-Exhaust (MAX.) Rocking Method 0.370 mm 0.0146 in.
Valve Lift-Intake (Zero Lash) 9.00 mm 0.3543 in.
Valve Lift-Exhaust (Zero Lash) 7.00 mm 0.2756 in.
Valve Margin-Intake 0.835-1.165 mm 0.0329-0.0459 in.
Valve Margin-Exhaust 1.44-1.77 mm 0.0567-0.0697 in.
Valve Stem Tip Height-Intake 42.366-43.655 mm 1.6680-1.7187 in.
Valve Stem Tip Height-Exhaust 45.205-46.486 mm 1.780-1.8305 in.


3.5l as in 04 intrepid
DESCRIPTION SPECIFICATION
Type 60° SOHC V-6 24-Valve
Displacement 3.5 Liters
(214 Cubic Inches)
Bore and Stroke 96.0 x 81.0 mm
(3.780 x 3.189 in.)
Compression Ratio 9.9:1
Lead Cylinder #1 Right Bank
Firing Order 1-2-3-4-5-6

Valves
Face Angle 44.5–45°
Head Diameter—Intake 36.37–36.63 mm (1.4319–1.4421 in.)
Head Diameter—Exhaust 28.87–29.13 mm (1.1366–1.1469 in.)
Length—Intake (Overall) 114.41–114.99 mm (4.5043–4.5272 in.)
Length—Exhaust (Overall) 125.67–126.25 mm (4.9476–4.9705 in.)
Stem Diameter—Intake 6.935–6.953 mm (0.2730–0.2737 in.)
Stem Diameter—Exhaust 6.906–6.924 mm (0.2719–0.2726 in.)
Stem-to-Guide Clearance—Intake 0.022–0.065 mm (0.0009–0.0026 in.)
—(Max.) Rocking Method 0.29 mm (0.0114 in.)
Stem-to-Guide Clearance—Exhaust 0.051–0.094 mm (0.002–0.0037 in.)
—(Max.) Rocking Method 0.370 mm (0.0146 in.)
Valve Lift—Intake (Zero Lash) 8.55 mm (0.3367 in.)
Valve Lift—Exhaust (Zero Lash) 6.53 mm (0.2571 in.)
Valve Margin - Intake: 0.835–1.165 mm (0.0329–0.0459 in.)
Valve Margin - Exhaust: 1.44–1.77 mm (0.0567–0.0697 in.)
Valve Stem Tip Height—Intake 42.366–43.655 mm (1.6680–1.7187 in.)
Valve Stem Tip Height—Exhaust 44.705–45.986 mm (1.760–1.8105 in.)

[Vigo]

Good news: found a 91 3.8 computer in the yard today while i was just looking around. Didnt take any tools with me so im going back tomorrow to get it. I was worried that the knock sensor on my car was a 90-only thing, but the 91 3.8 car has it too, which makes me happy.

Hopefully this will give me proper 3.8 power and less pinging. Still waiting to get some wiring i plan to use for the FIC so this will happen a lot faster in the interim.

[Reaper1]

If you have the CCD bus connected between the 3.8 SBEC and the TCU, the TCU will send out a "torque reduction request" to the SBEC under WOT shifting. I don't *think* the bus is used for anything else that year going to the TCU as it *should* still have the SDS.

[Vigo]

Yeah, 90 still has the SDS/VSS in the extension housing.

Im not sure at what point torque management came into existence. Ive had quite a few 604 vehicles and some had it and some didnt. I dont think this 90 or my 93 had it. I dont think the 94 donor van had it. I havent owned a 95 604 vehicle, but my old 96 Avenger had it and my 97 intrepid had it. I only have an incomplete smattering of TCM pinouts but my educated guess is that torque management debuted in 95 which coincided with the cloud car and 2g dsm application debuts.

The TCM diagrams i have after 95 (i have 96, 97, 98, and '00) all show torque management being on a dedicated line on pin #10 of the TCM going straight to the engine controller. Years before that have #10 as a blank. The CCD bus is on pins #4 & 43 throughout all the diagrams i have.

One of the mod i did to my old Avenger was put a switch in that line to be able to turn off Torque Management.

[Reaper1]

The FSM I read was a maroon manual (1990), and it described the torque management like it only happened exactly when the upshift would occur, nothing more...and it was only on the 3.8. Thing is, I thought the 3.8 didn't come out until '91 or '92?