Horsepower?

bcstringer

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Dec 18, 2009
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I've looked all over the Internet and in my shop manuals and nothing listed as to what horsepowers match with what the engine is. My certificate of title has to be wrong, it states 145 hp, but I have a 1987 OMC Cobra 5.0L (Chevy 305 V-8). Anyone have reference chart or something for OMC's various horsepowers?
 

jimmbo

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In 1985 it was rated as 230hp with a 4 barrel carb. However that may have been a crankshaft rating. By 87 they may have been rating them at the prop
 

Tnstratofam

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My 1988 5.7 liter (350) with a 4 barrel is rated at 230hp, but it could be rated at the prop. I don't know for sure.
 
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Scott Danforth

Grumpy Vintage Moderator still playing with boats
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Assume you have 205hp. Anything above that is a bonus
 

HT32BSX115

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I've looked all over the Internet and in my shop manuals and nothing listed as to what horsepowers match with what the engine is. My certificate of title has to be wrong, it states 145 hp, but I have a 1987 OMC Cobra 5.0L (Chevy 305 V-8). Anyone have reference chart or something for OMC's various horsepowers?
Howdy,

Welcome aboard!

145 hp is probably low for a 5.0L V-8 (4.3L V-6's are frequently rated at 190hp...) yours is probably someplace around 200-230.......crankshaft HP will always be higher than propshaft HP by 10% or so..... But why would you care?

The actual numbers are pretty much meaningless unless you can put your engine on a dyno....and then they're still pretty much meaningless......
 

Silvertip

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Sep 22, 2003
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In 1978 the 305 was indeed rated at 145 SAE net HP in my then brand new GMC van. Perhaps someone at the DMV used some GM specs to arrive at that number. I once owned a Vega Wheel camper which was a tandem axle pop up camper. Guess what -- it was titled as a Chevrolet. And we pay these people.
 
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