Can someone explain what this plate is?

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19DodgeDemon72

1972 Demon Resto-Mod
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So, as you can see there's a plate with it seems to be 2x mounts on the front of this 340. I'm very intrigued to what this is and what it's for. Thanks for any help!

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tree'd by y'all while i was looking for examples of a marine engine mount.

some kind of motor plate, for sure. but specific application unknown.
(mopar marine manual doesn't indicated anything and show's standard mount bosses being used)
 
Yup. It's a motor mounting plate. You better check to make sure that's not a reverse rotation motor.
 
Omgosh I'm so confused. Haha
I'll get the block numbers here in a few minutes and see if that helps. Here is a top down picture.

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nice. looks like somebody's little hot rod motor with a bunch of mix-n-match parts! what'd it initially come out of?

the #'s will tell the origin. doesn't look marine, so that's a bit of relief!
 
Dana67Dart said:
If it is, won't a cam change fix that?
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Nope. It will need a crankshaft, too. The hash marks for the rear main seal are in the opposite direction from a clockwise running automotive engine. The rear main seal will leak badly in a clockwise application.
 
You "might" could get by with polishing the hash marks off. These modern seals do a good job, but I don't know.
 
Dana67Dart said:
If it is, won't a cam change fix that?
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i think there's more to it than that. i wanna say the rear main cap/seal is a whole situation in an unto itself. i believe the cranks are their own beast as well.

edit: dammnit. tree'd by RRR again
 
junkyardhero said:
i think there's more to it than that. i wanna say the rear main cap/seal is a whole situation in an unto itself. i believe the cranks are their own beast as well.

edit: dammnit. tree'd by RRR again
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My bad.
 
RustyRatRod said:
My bad.
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nah, you had the info at the front of your brain. i knew the crank was different, you knew how it was different. that's some high end granular knowledge. it's cool stuff like that, that make this place tick.
 
junkyardhero said:
nah, you had the info at the front of your brain. i knew the crank was different, you knew how it was different. that's some high end granular knowledge. it's cool stuff like that, that make this place tick.
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Well, if you say I have high end knowledge, I take your word for it. LOL
 
Doesn't look marine- (beside the fact I've never seen a four speed boat) marine engines had a somewhat different manifold with the carb flange cut at a pretty severe angle, cast oil pans (iron or aluminum depending on the year), a cast iron timing cover, and the early style iron water pump right up through the end of production in the mid 80s. Not to mention the marine exhaust manifolds.
Pic of manifold:
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Reverse engines are easy to spot- in addition to what was already mentioned, they had a thick bearing plate under the distributor (to keep the intermediate shaft from pounding the distributor due to the reverse rotation) and to allow fitment of a B engine distributor to allow the advance mech. to work in RR, and a strange looking oil pump- again, due to the rev. rotation.
The OP's motor plate actually looks like a manufactured piece hijacked from a stationary industrial motor application, saw a similar looking setup years ago on an irrigation pump. I'd pay close attention to the timing cover, it may have been thinner than standard in order to keep everything lined up- water and fuel pumps, pulleys and alternator; not to mention allowing the balancer to seat all the way on.
 
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Lets have a look at the engine side of the flywheel and the front side of the harmonic balancer, what I see is a "cast" crankshaft, other things have been modified maybe they got the balance addressed too.
 
If you have the timing cover that came off of the motor, look and see if it has a stepped section at the bottom. If they didn't mill it down the thickness of that plate, and step it in at the bottom of that plate, it would have been hard to seal up. Probably would have leaked a little even if they did....lol.
 

junkyardhero said:
nice. looks like somebody's little hot rod motor with a bunch of mix-n-match parts! what'd it initially come out of?

the #'s will tell the origin. doesn't look marine, so that's a bit of relief!
Click to expand...
That's what I'm thinking too. I'm trying to upload more pictures and it keeps timing out on me. Dang it
 
I'd say that motor needs a smidge more than a cam and a crank :poke:
 
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