360 marine cranks?

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RevboxRyan

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School me on 360 marine cranks. Pretty sure the dart sport I bought came with 2 of them being as they both have repaired water jackets and the rebuilt one will not fire at all. Yes I have spark fuel and air. I've swapped and done this countless times this one will not fire one bit changed everything that could be wrong besides crank pistons and rods. Any way to tell externally?

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RevboxRyan said:
School me on 360 marine cranks. Pretty sure the dart sport I bought came with 2 of them being as they both have repaired water jackets and the rebuilt one will not fire at all. Yes I have spark fuel and air. I've swapped and done this countless times this one will not fire one bit changed everything that could be wrong besides crank pistons and rods. Any way to tell externally?

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Is it possible that it came out of a twin engine boat and it runs backwards
 
Moparpuller said:
Is it possible that it came out of a twin engine boat and it runs backwards
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Yeah are the cranks physically different? Timing chain and cam I've changed thinking was bad cam or timing chain since I have multiples around. I've never had anything like this before.
 
Following along here and when you say Marine crank I have to wonder, is that crank special to run at a higher RPM? Sorry for getting off topic...
 
if it is the reverse driven side, I thought I read somewhere that the area where the rear main seal rides is different. stock cam?
 
abdywgn said:
if it is the reverse driven side, I thought I read somewhere that the area where the rear main seal rides is different. stock cam?
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It had a stock replacement cam previous owner rebuilt then I put an old crane energizer cam in I have and different timing chain. Has compression fuel and spark. Wont even fire or sneeze like if I was 180 off. And when I hold throttle open it sounds like one or 2 cylinder push air back out like valve events and pistons are out of cycle with each other.
 
Diagonal knurling grooves for the rear main seal in a marine crank MAY be cut in the opposite direction. Not all we’re reverse rotation though. I wonder if they would have used the heavy duty cranks cast by GM at the Flint Michigan foundry. They are marked differently (CFD, I think?) and have higher casting quality than the Chrysler cranks.
 
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The thing to get an engine to run reverse is the cam and some cases cam drive, distributor, water pump and accessories like generator. Chev trucks used to have a BB TRUCK setup that was normal rotation engine, but the cam rotated backwards because of a 2-gear drive.

Reverse Mopars should have a big tall thrust device under the distributor to take care of that as the drive gear tries to ride up. Normally Mopar reverse marine engines use a timing chain but a revers ground cam. Only thing to worry about on the crank is IF the striations on the crank oil seal area go wrong way.

This here is 440, but SB used the same type of device

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