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350 meg not performing up to par ?

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350 meg not performing up to par ?

Old 07-11-2019, 07:02 PM
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Huh. ..A chebby small block Always wondered if they were good motor boat engines.

Should I remove my BBC's and replace w/ sbc's??
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Old 07-11-2019, 08:51 PM
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Came across this marine 355 build, The engine is rated at 430 HP @ 5500 RPM. Peak torque is 470 ft/lbs @ 4500 RPM:

Building a Chevrolet 355 CID performance marine engine

Air Flow Research 180cc SBC Eliminator Street Cylinder Heads (AFR Part # 0919)
Comp Xtreme Marine hydraulic roller retrofit kit (Comp # 12-417-8, Grind Number XM 270HR)
Comp Cams Magnum aluminum roller rockers
Holley 600 CFM Marine four barrel carburetor
Edelbrock RPM Air-Gap intake manifold.
TRW .030" over flat top forged pistons


I know this is crankshaft HP but is it just me or does 430 HP seem a tad high for this?
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Old 07-11-2019, 10:49 PM
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That's from Westech dyno. which reads high compared to all others. Depending on compression 375-400hp more likely.

That's 320+/- hp hp O'connor Marine.
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Old 07-11-2019, 10:49 PM
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Originally Posted by mountainmadness View Post
Huh. ..A chebby small block Always wondered if they were good motor boat engines.

Should I remove my BBC's and replace w/ sbc's??
You willing to tell O'connor Marine how fast your single small block/Alpha drive boat was ?
And I do remember you happened to AFR heads on it too. As matter of not lying fact.
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Old 07-12-2019, 02:51 AM
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Stock 350 mag, alpha drive, 58 mph gps
mildly tuned sbc, alpha drive 88-90 mph gps

And did it with 15 yr old technology, no dynos, no magic computers, straight up old school backyard hillbilly junkyard parts.

And yes sir some small port old afr heads
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Old 07-12-2019, 06:57 AM
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So, according to the person who called me a liar...........
30mph / 5mph per 100hp added = 600HP you added.

So, 260hp base + 600 = 860 at prop.
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Old 07-12-2019, 08:00 AM
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You guys fight about motors all you want... I want to know where Mountain Mutt got the Alpha drive that handles 860 hp !!!!!
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Old 07-12-2019, 11:14 AM
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Originally Posted by phragle View Post
You guys fight about motors all you want... I want to know where Mountain Mutt got the Alpha drive that handles 860 hp !!!!!
That's the point.

However he did have , by my guess, 600HP or a little bit more, and the Alpha SS survived for a bit...then it crunched.

Now that I produced a HP guess again, maybe someone will come on and call me a liar again.
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Old 07-12-2019, 11:18 AM
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I wonder how an Alpha SS on my Pantera would run?
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Old 07-12-2019, 06:53 PM
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Originally Posted by SB View Post
That's the point.

However he did have , by my guess, 600HP or a little bit more, and the Alpha SS survived for a bit...then it crunched.

Now that I produced a HP guess again, maybe someone will come on and call me a liar again.
Funny how your guess and mine were within 20 hp of each other. Lol



By the way. Your a phucking liar.... Feel better now 😁
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