IRON DUKE 3.7 Liter 190 hp Fuel Consumption

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mnorton227

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I just bought a 1985 Four Winns Santara with a 190 hp 3.7 liter (224 Cu. In) merc outdrive. I was impressed with the power of the motor in a 3000 lb boat. I was told that this is the "Iron Duke" motor, but have seen a number of posts that say that the 3.0 liter is the "Iron Duke".

Does any body know which is which?
Any Info on reliability?
How about Fuel Consumption at 4000 rpms in gallons per hour?

Would love to here your feedback.

Thanks
 
superbenk

superbenk

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Re: IRON DUKE 3.7 Liter 190 hp Fuel Consumption

I've seen the name "Iron Duke" thrown around a lot for the GM 3.0L, but I'm not sure that's 100% accurate. If anything I'd expect the similarities end at the block. I'm sure someone with more history knowledge can chime in with better info.

As for fuel consumption, my 3.0L gets ~3-4 MPG at 4000 RPM (very rough estimate). At 25MPH, that's 6-8 GPH (again, very roughly).
 
Don S

Don S

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Re: IRON DUKE 3.7 Liter 190 hp Fuel Consumption

I just bought a 1985 Four Winns Santara with a 190 hp 3.7 liter (224 Cu. In) merc outdrive.
I was told that this is the "Iron Duke" motor,
Click to expand...

It's definitely not the "Iron Duke", since it has an aluminum block Designed by Mercruiser, and a Ford 460 head.
GM had the iron duke, not even sure it was the Merc 2.5, but it sure wasn't 3.0L either.
 
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TilliamWe

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Re: IRON DUKE 3.7 Liter 190 hp Fuel Consumption

mnorton227 said:
I just bought a 1985 Four Winns Santara with a 190 hp 3.7 liter (224 Cu. In) merc outdrive. ...
Any Info on reliability?
Click to expand...

I am sorry to hear that.
Reliability is BAD if you don't know how to maintain it. And even then, it's spotty.

As the link shows, the Iron Duke is a Pontiac 151 Cu In engine. What you have is most definatley not iron, nor a Duke! hehehe
 
RogersJetboat454

RogersJetboat454

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Re: IRON DUKE 3.7 Liter 190 hp Fuel Consumption

TilliamWe said:
What you have is most definatley not iron, nor a Duke! hehehe
Click to expand...

Aluminum Deuce is more like it.... :D

Pretty sure the Merc 2.5 was a variant of the 3.0L. The "Iron Duke" known as the "Tech 4" or cross-flow was mainly a transversely mounted engine, although they did stuff them in S-10 trucks/blazers, Camaros, and Grumman LLV postal trucks. You could time there 0-60 in minutes instead of seconds....
 
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