Fram Ultra XG2 (OG) C&P (9,584km)

[BlueOvalFitter]

The current (modern) HEMI's don't really have hemispherical chambers, they are somewhat closer to pent roof. They had to add quench areas in the chambers because a hemispherical chamber has very poor manners at low engine speeds, resulting in incomplete combustion and really not fun to drive (low on power, poor response...etc).

This is why the "street" HEMI engines, like Ford's BOSS 429, had quench areas added to the sides of the chambers, to improve drivability and give the engine good street manners.

The modern HEMI has always needed "help" in running clean, that's why they have dual ignition (16 spark plugs). because the chamber design just doesn't lend itself, even with quench areas, to clean and complete combustion at lower engine speeds, the dual ignition, which is phased, fires twice in order to try and clean that up. It's actually an extremely old technique used on big bore engines (I've seen 30's vintage stuff with it).

So, the 6.4L, which has a 4.09" bore (the 5.7L has a 3.92" bore) will suffer a bit more from these characteristics. It's also higher compression (10.9:1) and tuned for performance so it will fuel dilute. You put all that together and you have an engine that's going to generate more carbonaceous material than your average small bore high efficiency 4-pot or even a small bore engine like a Modular. The fuel dilution means that some of that is invariably going to end up in the sump.

Of course the HEMI isn't alone in being "dirty". The LSx engine family was hit with the same TSB from AMSOIL for avoiding extended drains with the EaO filters because they can apparently do the same thing. Of course they don't need dual ignition to pass emissions requirements, so I expect they aren't quite as bad.

Whole article on the heads here:

Inside The G3 Hemi Cylinder Head - Car Craft Magazine

We take a very close look inside the G3 Hemi cylinder head. Get the details only at carcraft.com or the October 2012 issue of Car Craft Magazine.

www.motortrend.com

But some pictures:

The early (non-VCT) 5.7L:

This is the Eagle chamber (modern 5.7L, my wife's truck):

You can see the considerable quench areas on each side, making it less round. The top picture with the head gasket really shows this well.


This is the 6.4L Apache chamber:

More round (more hemispherical), less quench area. Means it is going to be dirtier running at low speeds. It also has absolutely huge valves for a stock engine, 2.14" intake, 1.65" exhaust (as noted in the article).

BTW, thanks for that tutorial on the Hemi.
You seem to know your way around engines. Do you build/race them as well? It has been 2011 since I built an engine.

 

[OVERKILL]

BTW, thanks for that tutorial on the Hemi.
You seem to know your way around engines. Do you build/race them as well? It has been 2011 since I built an engine.

You are quite welcome!

Just a shadetree, grew up around and wrenched on boats (my grandfather had a small fleet), tractors, snowmobiles and ATV's. Had a natural inclination for it. He was a big Ford guy, had a 427 SOHC in a Thunderbird at one point, a pile of Lincolns...etc.

I've assisted in the tear-down and build up of a few 350 SBC's with a buddy of mine (his dad had an S-10, he and I put together three engines for it, IIRC) but most of my experience is with SBF's. I've got a fair bit of experience with the EEC-IV era 302's, as I was a fox body enthusiast for quite a while (still am, but don't own one anymore) and there's a lot of community there, so we'd be turning wrenches on each other's rides frequently. Three different engine swaps and builds with another friend, both carb and EFI. A few difference H/C/I swaps...etc.

That's part of the reason we bought the '95 Supra you've probably seen me post in the boat section. Has a nice EEC-IV 351W in it, which I'm super familiar with.

 

[BlueOvalFitter]

You are quite welcome!

Just a shadetree, grew up around and wrenched on boats (my grandfather had a small fleet), tractors, snowmobiles and ATV's. Had a natural inclination for it. He was a big Ford guy, had a 427 SOHC in a Thunderbird at one point, a pile of Lincolns...etc.

I've assisted in the tear-down and build up of a few 350 SBC's with a buddy of mine (his dad had an S-10, he and I put together three engines for it, IIRC) but most of my experience is with SBF's. I've got a fair bit of experience with the EEC-IV era 302's, as I was a fox body enthusiast for quite a while (still am, but don't own one anymore) and there's a lot of community there, so we'd be turning wrenches on each other's rides frequently. Three different engine swaps and builds with another friend, both carb and EFI. A few difference H/C/I swaps...etc.

That's part of the reason we bought the '95 Supra you've probably seen me post in the boat section. Has a nice EEC-IV 351W in it, which I'm super familiar with.

That is so cool. It's almost a carbon copy of me.
My dad raced/built engines all while starting up his heavy equipment business (sold it after 47 years). I have been around it since I can remember (5 years old). It took me a few years into my 30's to FINALLY realize EFI was so much better than a carburetor.
My brother is the original owner of a 1979 Indy 500 Pace Car Mustang. It has 32K and change, original miles on it. He keeps it under wraps in his friends conditioned car warehouse.

 

[bullwinkle]

I get it, but resent the six month regardless of mileage requirement. My Hellcat is stored in the winter months so I end up doing a 600 mile oc in the spring to meet the warranty requirement. I’ll do a cut and post in about a month. Should be about 2,000 miles.

Extra Guard in the winter, a better filter in the summer (OG Ultra, RP, Amsoil)!

 

[jkasch]

Extra Guard in the winter, a better filter in the summer (OG Ultra, RP, Amsoil)!

That would save a few $, but I'm using the MS-12633 certified PU 0w-40 and oem filter for warranty. I know that by law, I can use any filter and oil in the correct grade, but I don't want to have to hire a lawyer to fight a potential idiot service manager. I purchase the oil at my dealer too because their price is competitive.

 

[OLEJOE]

Just did an OCI on my 2022 Ram with the 6.4l at 768 miles and the MO-339 had some metal specs in it along with some different colors of RTV. I went back with the PUP 0W40 and an Ultra XG2. I would have posted the pic of the filter but it was torn up pretty bad dismantling it. Had to just about crush it with a strap wrench to get it off.