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454 Fuel Consumption and Performance

H

herdbull

New member
"I posted a question about a e

"I posted a question about a engine that was lying down on me a couple weeks back. Everyone who replied said "ignition ballast resister". Everyone was correct. Thank you so much!

I was so impressed, i want to ask two more questions.

1. I know there is no silver bullet in improving performance. However, if you were me and you wanted a little more speed out of the boat to help her reach her full potential and then maybe a little extra, what would you try? I have heard putting on larger performance flame arrestors would help. Then another mechanic told me to save my money.

2. Independant of the first question, if I was more worried about improving fuel economy, what would you try? I realize 454 big block crusaders weren't made for fuel efficiency, but I also think every little bit helps. I have been told (again) performance flame arrestor, delco electronic distrubutors to replace centrifigal advance distributors currently in place, leave oil low in the dip stick, and increase the size of my exhaust discharge piping. Any thoughts or advice out there.

I love this website. Thanks for sharing.

Jim"
 
"I'll take a shot at this,

"I'll take a shot at this, and am sure you will get lots more informed tidbits from others as well.

1. More power; You need: more air flow, more fuel flow, less exhaust restriction. Overall, more flow. You can get this in various ways with a non-turbo engine; bigger carb, more rpms (with less reliability), more lift/overlap cam, more compression ratio (with higher octane fuel). All this assumes you want more TOP END power. Low end torque is counter to several of these tricks.

2. More economy; primary is a leaned out mixture, and that is a bit of dangerous ground without instrumentation help. Some may say lower rpm (more prop pitch); this will reduce windage losses, and may reduce pumping losses as well. I think these are rather secondary in a boat, although play well in a car, or other, under utilized displacement application. Low oil, news to me, and highly suspect. Bigger flame arrestor, NO, assuming you are running optimum mixture. Electronic distributors, I think not. More reliable, maybe, but not less fuel.."
 
"Jim, It appears to me you ans

"Jim, It appears to me you answered your own question. There is no silver bullet. Keep your bottom and running gear clean. If you don't have to, don't fill your tanks full. Take off anything you don't need to decrease weight. As far as the oil issue I think you mean thinner oil not low level oil right?"
 
"short on time so here's a

"short on time so here's a quick dump from memory:

1) get a floscan or equivalent - w/o it you won't know what you did. Make sure proper tune up is done.

2) keep detailed records - log book, tuning notebook, something so you don't reply on memory.

3) propscan the props - it will make the whole rig run better.

4) run only on the primaries - they are most efficient

5) tune the secondary system so it is OFF when the air valve is shut. You can tighten up the air valve to keep it closed a bit longer. if the accelerator ports drip, lower the float.

Biggest improvement on my came from two things:
lower secondary hangers & softer primary piston. I 'screwed up' in that i made both changes at one time.

Reduction from 16 gph to 12 gph at 3K cruise. There's more to get but like Dave said, a lean mixture in a boat is very unforgiving."
 
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