Converting marine to automotive

magster65

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Sep 1, 2002
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Has any one had any experience converting a marine 354 hemi to street use?
hemiathome.jpg
 

magster65

Commander
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Sep 1, 2002
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Re: Converting marine to automotive

In case anyone's interested I got some info today;
* this engine is a right hand rotation... needs new cam
* marine cooling different... need to tap the outer bosses on the heads and have a crossover/thermostat kit
* crank different... snout needs to be welded and machined for timing chain (marine is all gear drive for the pumps/trans)
* bolt ons... starter, distributor, timing cover, water pump, pulleys, intake... all not compatible.
Most of that stuff would get replaced anyways...
Good stuff... marine rockers are adjustable... rods are 'heavy duty'... likely high nickel block (not confirmed though)

The only thing that concerns me is the crank. Instead of welding and machining I'd rather get an automotive unit.
Anyone have a 354 hemi crank sitting around their kitchen? :joyous:

I didn't know but apparently all early hemi cranks are forged.
 
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dan t.

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Feb 28, 2008
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1,137
Re: Converting marine to automotive

Wow that should be in a museum, all I can say is try it, you might find the spark advance curve is a little lazy.One thing you need to do is put hardened seats in the exhaust valves those old heads dont like unleaded fuel.
 

magster65

Commander
Joined
Sep 1, 2002
Messages
2,573
Re: Converting marine to automotive

Wow that should be in a museum, all I can say is try it, you might find the spark advance curve is a little lazy.One thing you need to do is put hardened seats in the exhaust valves those old heads dont like unleaded fuel.

Yes agreed there's a full disassembly/rebuild/check on the whole thing including the heads.
It was in a friends 30' 1956 or 57 Grenfell. It put that big old tank up on plane no problem.
It's a fairly rare engine... hemi's have sex appeal! lol
That sucker is going to be supercharged in a old hot rod one day.
 
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