if you get a 440 motor, be sure, about the plugs,, rv motor takes rv 12yc not rj 12

[greg yoder]

bought a rebuild 440 and the plugs from my other 440 would not thread in the head, with one of my mopar buddies helping me, and getting him the head casting number, he figured it out, had a rv motor home motor, which has heavy duty heads and heavy duty cooling, and they take a differant spark plug, after 2 hrs, of searching this out, got the answer, and the beat goes on,, takes rv 12yc , champion, not rj 12 total differant thread,

 

[CBODY67]

In looking at those cyl heads, are the center exh ports together or separated?

In the 1990s, my machine shop operative got in a pair of Chrysler 440 heads, but they were different. The intake side looked to be normal Chrysler B/RB, but they had a LA-style combustion chamber (not the normal 906 chamber), angled plugs (tapered seat), but the main cosmetic difference was that the exh ports were all separate. The customer also brought in the Holley 4160 from the motor. The carb number matched a 1972 Chrysler 440 MHC application.

Due to some space issues, Accel built a special "shorty" spark plug for the MHC 440s.

Enjoy!
CBODY67

 

[commando1]

bought a rebuild 440 and the plugs from my other 440 would not thread in the head, with one of my mopar buddies helping me, and getting him the head casting number, he figured it out, had a rv motor home motor, which has heavy duty heads and heavy duty cooling, and they take a differant spark plug, after 2 hrs, of searching this out, got the answer, and the beat goes on,, takes rv 12yc , champion, not rj 12 total differant thread,

I've been telling the world the MH heads take the GM long reach plugs but nobody listens.

 

[furious70]

Odd that someone rebuilt one of those...

 

[CBODY67]

Probably a very well=seasoned block due to all of the hot/cold cycles and such. Other than the cyl heads, a normal 440 engine, basically. Bore =.030", put some Mahle thin-ring piston sets in it, with higher deck height plateau hone the cyl walls, and make power.

CBODY67

 

[Vaanth]

FYI...

Regular passenger car big block wedge engines (350, 361, 383, 400, 413, 426 wedge, and 440) all used 14mm, 3/8" reach, retracted (gasketed), 13/16" hex spark plugs.

Late 1970s 440-3 industrial/truck engines used a 14mm, .460" reach, tapered seat 5/8" hex spark plugs, originally equipped with OBL9Y (Chrysler # 4091938), or substitute RBL9Y, or RV9YC. These were used for additional cooling. The heads were the similar raw 4006452 casting as other 440 and 400 heads, but were machined differently for the smaller plugs.

361 and 413 heavy truck and industrial, and some marine, engines used a 14mm, 3/4" reach, retracted (gasketed), 13/16" hex spark plug without a projected tip (example, Champion N6). The plugs have a slight angle mount. These heads have the water inlets on the front for the large high mounted water pump and completely different exhaust ports than conventional big block wedge engines. Casting number is 2899943.

---

Regular 13/16" gasketed spark plug hole:

5/8" plug taper seat spark plug hole:

Industrial head:

 

[66furys]

I never cease to be amazed at what people know, and also the nutz things that the auto industry engineers did.

 

[fury fan]

I believe the tapered-seat was also used on a regular-style 440 head (meaning, uses regular B/RB exh manifolds and waterpump housing) on certain motorhome engines.
Perhaps a -2 series of engines? IIRC these heads would have the 'figure 8' cooling passage shape at the gasket area?

I suspect this is what @greg yoder is referring to, as it would be pretty unusual to mistake a 440-3 for a regular car-style 440.

Also - most of the sightings I've run across on -3 engines were 413s, produced into the mid-70s in HD truck (I have seen only a few 361s).
The 440s seemed to be installed in somewhat lighter-duty vehicles (like motorhomes).
I cannot recall ever seeing a 440-3 (I'm not denying they exist, though).

Just my memories of these uncommon things...