GMPP Ram Jet 502 vs Merc HP500/525 EFI
08-29-2007, 08:42 PM
#31
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I have a buddy running a completely stock 502/502 with a Demon 850 and MSD ignition. He has run the hell out of it for 4 seasons with no problems at all. It turns 5800 rpm all day in a 23 foot Wellcraft Nova. The boat runs an honest 70mph. The old motor ran about 55 or so. I think the cam in the EFI motor is the same. I would not be afraid to run the ram jet out of the crate.
ZZ502 with a mild performance build and dyno results show 550HP and 600 lbs of torque.
Is it a Raylar, no. But, some find those motors beyond their finanical means. The ZZ502 platform fills that void with a reliable and powerful platform. I know of boaters who have used the ZZ502 with years of boating without any incident.
08-29-2007, 10:51 PM
#32
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Looks like these guys marinize the GMPP Ram Jet 502, http://www.flagshipengine.com
RamJet 502 at bottom, http://www.flagshipengine.com/catalog/cat_page25.htm
RamJet 502 at bottom, http://www.flagshipengine.com/catalog/cat_page25.htm
08-30-2007, 05:16 AM
#33
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I've run crate "auto" 502's 450 hp version in my boat for 5 years without a single problem.When i purchased i pulled a head to check head gaskets first,saw a GM part no.Went to my local Mercruiser dealer and ordered a set of 502 Mag head gaskets.Guess what same gasket.
08-30-2007, 09:30 AM
#34
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Looks like these guys marinize the GMPP Ram Jet 502, http://www.flagshipengine.com
RamJet 502 at bottom, http://www.flagshipengine.com/catalog/cat_page25.htm
RamJet 502 at bottom, http://www.flagshipengine.com/catalog/cat_page25.htm
08-30-2007, 10:31 AM
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The first engine(a 383) on that page they have, "Great for pulling skiers"
And right next to the the ZZ502 on that page is:
For those that want power and looks in your
boat, this one is for you. Turn key 502 hp Multi-
port fuel injection with 9.6 to 1compression ratio,
Aluminum oval port cyl. heads and 1 piece seal.
No Flywheel or Water Pump
Fresh water cooling should be used when
operating in salt water.
boat, this one is for you. Turn key 502 hp Multi-
port fuel injection with 9.6 to 1compression ratio,
Aluminum oval port cyl. heads and 1 piece seal.
No Flywheel or Water Pump
Fresh water cooling should be used when
operating in salt water.
