Offshoreonly.com - Blown 502MPI Makes 1000 HP?

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Quote:

Originally Posted by HPJunkie (Post 2216345)

Hey smitty, Hows it runnin? Good I hope. I have a question for ya. I have been logging with an LM1 and I get a lot of lean spikes on the graph. I mean a lot. someone said those are misses showing up as oxygen and therefore lean. I get them at all speeds. It makes it kinda hard to read the true mixture. I am wondering about my plug gap. I have an MSD and the plugs are set at .035. NGK -7 plugs new wires cap and rotor as well. I cant hear a miss, The boat ran 92 with 3 people and gas and cooler saturday. Would a bigger gap maybe help? I read an article in HOtboat this weekend about a blown sanger or something they took out of storage after 17 years cleaned it up and set the plugs at 045 and ran it? I was initally thinking 030. Any thoughts from you or others would be good! Thanks greg

I have ran .040 using msd but would stick with .035 even with the msd if your running 10 lbs of boost or more,if your running less I would open them up to .040 and see what happens,you might even go to .045. Smitty

Quote:

Originally Posted by articfriends (Post 2217786)

I have always used the -20 cc blower pistons which yield around 8.25-1 compression,I'm sure I could make more base power but I like being able to run the extra 1 or 2 lbs more boost on the same 93 octane gas.

I know Articfriends know this but for others
You will have more max HP with lower compression & more boost on the same octane gas. The only problem is the procharger does not build max boost off idle such as a screw supercharger would. So with lower compression the motor does not have all the power down low. Good part with this is the load on the outdrive is lower at low rpm's