392 in Challenger

[t hamm]

Is putting a 392 hemi into a 74 Challenger a difficult or worthwhile project?

[PRO]

Hard to say but I know a guy who put one in a dart and believe it or not the older hemis are wider at the exhaust mating surface than the 426,although a challenger has more engine bay than a dart it would a measurement Id check before going any further.The 392 was the bad mo'fo for many years,and its dimensionally related to the small block so it shouldnt pose alot of mounting questions,hope this helps............PRO........

[Larry S.]

T Hamm, I can tell you everything you need to know (see my signature line). Email me at heminut392@yahoo.com .

[tallzag]

That would be a very cool swap, but they weigh a ton!

[DAHEMIKOTA]

The old Hemi's were actualy a true hemi as the new style hemi's had the exhaust valves angled to allow the body to be dropped onto the "K" member in production. The valves were tilted 3 degrees in toward the center of the engine. Thus the old hemi was more efficiant than the new one. But as tallzag said it weighs a ton. (850 lbs) The crankshaft is also 1" longer . You would have to use a trans adaptor to mount it to a new style torquflite. The starter was mounted lower on the old engine also. It would be an interesting prodject.

[Larry S.]

Originally posted by DAHEMIKOTA
But as tallzag said it weighs a ton. (850 lbs) .

Actually, Bob Walker at PowerPlay Hemi (who knows these engines about as well as anyone around) has them rated at 737 lbs., and that includes the starter, generator, stock cast iron waterpump, and stock cast iron intake and exhaust manifolds. There's quite a bit of weight to loose by going to an aluminum intake, Chevy waterpump with adapters, alternator, and mini-starter! By way of comparison, Bob has the Chevy bigblock rated at 693 lbs.

[DAHEMIKOTA]

Silly me, I always thought they weighed more than the 440 wedge. I know the smaller Hemi that was refered to as the "baby Hemi" was about the size an "A" block . That may weigh About 737 lbs. It had smaller heads and block than the 331,354 and392 Hemi. Maybe I am wrong, I've only been working on them things for 49 years.

[528HemiDart]

That will be neat to see that swap, always nice to have a hemi... tell me what happens..

[Larry S.]

Dahemikota, Tex Smiths Chrysler Hemi Engine Manual lists the 354 at 737 lbs., and the 392 at 767 lbs. The Chrysler hemi ( the biggest of the early hemi engines) has the same bore spacing as the LA series engines, so the block is basically the same length as a 318. It is also an unskirted block, as opposed to the B/RB engines skirted block, which would be some weight savings. Most of the extra weight of the 392 is in the heads, which weigh 75 lbs. each. During the 49 years you've worked on them, have you actually put a 392 and a 440 on a scale and weighed them? I would really be interested in knowing the actual weight difference of the two.

[jelsr]

Just a FYI post, Moparts on the web has weights as follows
B's 620lbs
RB's 670lbs
331 Hemi 745lbs
426 street Hemi 765lbs
BB chevy 685lbs

[Larry S.]

Hmmm, I can't imagine how raising the deck height would add 50 lbs. between the B and RB engines. That seems excessive to me!

[DAHEMIKOTA]

Without gen, starter, dry weight 767#. Weighed with starter,generator, cast iron bell housing, flywheel and clutch 850#. I have weighed quite a few of them. Actually hung them from a scale although it did not break it down to grams. 440 with the clutch and bell housing 750#. 426 street hemi with iron heads 843#. The 392 bare block weighs in at 180#. 318/360 LA block 165#. 440 bare block 205#. Hemi block is slightly more because of oil returns for the heads and the cross bolted mains. My personal rides I have built with hemi engines are 1952 Plymouth 392, 1957 Ford 392, 1957 Studebaker 392, and present 1970 Gremlin 528 hemi. I did many more for other people. I am sure all the engines must have weighed differantly because of intakes, headers, starters, flywheels and such. Good bye.......

[jelsr]

Larry S,
The 3/4" deck height doesn't stop there, the crank is bigger, the connecting rods and pushrods are longer, and the intake is about 1" wider to name a few. It adds up.
DAHEMIKOTA,
Thats a light 440, I've never had a B or RB that was under 220LB.

[Larry S.]

Originally posted by DAHEMIKOTA
Without gen, starter, dry weight 767#. Weighed with starter,generator, cast iron bell housing, flywheel and clutch 850#. I have weighed quite a few of them. Actually hung them from a scale although it did not break it down to grams. 440 with the clutch and bell housing 750#. 426 street hemi with iron heads 843#. The 392 bare block weighs in at 180#. 318/360 LA block 165#. 440 bare block 205#. .......

Hey, thanks for sharing that info. I'm definately going to copy it for future reference.