Beginner question on 377 v 496
09-16-2019, 09:28 AM
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Beginner question on 377 v 496
Have a regular 377 in a 247 islander weighs 4,000lbs. The reg 496 weighs 400 more lbs and offers a .7 better power to weight ratio. Is that worth the extra weight? How big a difference in top speed/boat performance does .7 make. Again, new to this, please just helpful advice.
09-16-2019, 10:19 AM
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Have a regular 377 in a 247 islander weighs 4,000lbs. The reg 496 weighs 400 more lbs and offers a .7 better power to weight ratio. Is that worth the extra weight? How big a difference in top speed/boat performance does .7 make. Again, new to this, please just helpful advice.
09-16-2019, 10:37 AM
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I'm not sure where you got the 400 lb weight difference. I think it's closer to 100-150 lbs. regardless, I believe too many people over think the weight issue and under think the torque advantage of the big block. It will generally make more torque at a given rpm compared to the small block. I love small blocks but the big block will almost always have an advantage in the marine environment.
09-16-2019, 01:55 PM
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I’d put in the bbc without a second thought. If you’re in fresh water find one with aluminum heads, manifold and exhaust and you’ll be pretty darn close to a sbc.
I swapped out a lot of cast iron for aluminum on my 272 Islander with the 502 and still looking for a prop with enough bow lift to compensate for the weight loss.
I swapped out a lot of cast iron for aluminum on my 272 Islander with the 502 and still looking for a prop with enough bow lift to compensate for the weight loss.
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09-17-2019, 07:01 AM
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Doing a quick google check sbc is 575 and bbc 685....
and there is no substituent for cubic inches accept for cubic dollars
the bbc is already one step above a sbc to start with....
and there is no substituent for cubic inches accept for cubic dollars
the bbc is already one step above a sbc to start with....
09-17-2019, 07:28 AM
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09-17-2019, 08:21 AM
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[QUOTE=flashgordon;4706720]Doing a quick google check sbc is 575 and bbc 685....
and there is no substituent for cubic inches accept for cubic dollars
the bbc is already one step above a sbc to start with....[/QUOTE
You are absolutely correct, something isn’t right! That is what has made me start thinking engine swap. As I’ve had it out, first I got an emission fault and engine went into guardian mode. O2 sensor was fouled. Replaced it, took it back out, got a Fuel System Fault and engine went into Guardian mode. Its currently in the shop again.
and there is no substituent for cubic inches accept for cubic dollars
the bbc is already one step above a sbc to start with....[/QUOTE
You are absolutely correct, something isn’t right! That is what has made me start thinking engine swap. As I’ve had it out, first I got an emission fault and engine went into guardian mode. O2 sensor was fouled. Replaced it, took it back out, got a Fuel System Fault and engine went into Guardian mode. Its currently in the shop again.
