454 build criticism or opinions
Yesterday, 11:09 PM
#11
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Pro 1 320s have a good exh port.
585 is respectable. What RPM?
Today, 06:27 AM
#12
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Location: Mechanicsville Maryland
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Here's the cam I'm looking at.
The Brodix heads are on my 489 that's currently in my 272. I have Dart pro 1s that are fully ported going on that next couple weeks.
The drive is a early version Bravo 1
As for this boat, cruising rpm will likely be around 3800-4200 rpm with the intention of going fast whenever the want is there.
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Today, 01:22 PM
#16
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Eric Weingartner has a video on the Brodix 312s.
They would benefit from a very mild cleanup even in just the chamber lip off the seats.
That's a healthy cruise rpm 3800-4200. Less of an issue for the larger ports.
The cam looks to be in the ball park @223° int.
The GM forged Mag marine engines would peak at 5200rpm with 224° single pattern flat tappets with 0.510 lift. Longer exh duration would keep the hp up a bit after the peak.
They would benefit from a very mild cleanup even in just the chamber lip off the seats.
That's a healthy cruise rpm 3800-4200. Less of an issue for the larger ports.
The cam looks to be in the ball park @223° int.
The GM forged Mag marine engines would peak at 5200rpm with 224° single pattern flat tappets with 0.510 lift. Longer exh duration would keep the hp up a bit after the peak.
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Today, 01:33 PM
#17
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I've watched his videos and got the same info from him and cleaned up the chambers prior to putting them on my 489. If I remember correctly I believe he said that they were an identical head to the 088 casting with improved exhaust ports.
Today, 06:29 PM
#18
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That should be an interesting swap. I would love to hear if it actually is an improvement. Are you changing anything other than the heads ?
Today, 06:49 PM
#19
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I have a PP hurricane single plane intake, but I really want try it with the rpm air gap first. But here are the flow numbers done on a 4.300" bore. Thinking of adding 1.8 rockers to get my valve lift to .599" instead of .566 with the 1.7s.
