Inliners International Forums General Discussion Engines 4 cyl. engine

I've got a 120 hp mercury inboard engine that looks like a chevy engine. Cast iron head,block,cam in the block and valves in the head. It came out of a 1970 boat that the hull rotted out. Is this the "iron duke" engine? If so, what is it worth as I need the room inside. The manifolds are on the left side if your standing at the rear of the engine. Starter,fuel pump and dist. are on the right side. Any help is appreicated. David

Yeah, that sounds like an iron duke. Those are getting harder to find as the years go on, but they are not in great demand either. They used to be a popular racing engine, but there are several aftermarket copies that are made of aluminum and make a whole lot more power.

You may get a better idea of how much it's worth by going to another website and asking there. Try this one or search for similar outfits and racing organizations:
www.bmara.com

There are still lots of dirt track racers out there that are limited in funds and rules to using iron motors, so you may be able to find somebody in Texas that wants it.

You could also just post it for sale in the classifieds here on this site.

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David
newbie #4153

Dave, I've been working with these engines for years. They have the same block as the '62 thru '70 Chevy II four-bangers, which is 2/3s of a 230 six. They are NOT an Iron Duke, although the later Iron Duke was derived from the old Chevy II engine. Iron dukes are 151 cubic inches and Chevy II engines are 153 cubic inches. The 120 HP Mercruiser engines have the same head as the Chevy II engines. They have a variety of carbs on them, including two Carter single barrel carbs. The 140 HP versions are bored out to 181 cubic inches, have a different head with better breathing and also have a variety of carbs on them. The 181 is the most desireable to anyone building a light hot rod, or lakester. I had a souped-up 120 Mercruiser engine in a Chevette and it was a snappy performer. I presently have a 153 Chevy II engine from a '70 Nova in my Model A. Where do you live? I'm in central PA. I might be interested in the engine, or parts from it, if you're not too far away. If you're interested in selling it, or just want to talk about these engines, e-mail me at drh@digital-link.net

Dennis, that's funny about the name Iron Duke. The first time I heard it was in 1969, long before the "metric Iron Duke" came out. I was thinking about the early model, which was an option for my '63 pickup, and which you call the Chevy II engine, when I answered the post. Just guess it's a case of which words mean what, huh?

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David
newbie #4153

FYI... as far as marine engines. Years ago I had a 153 chevy in my boat. It was OMC not mercurser. The intake was on the left as David decribes. It was 120 HP with dual 1 bbl carter RBS's I think.

Just my 2cents

Clyde,

I've never seen OMC/chevy four-banger engines, just Mercruisers, but they are sweet little engines and I guess anyone could use 'em for small boat power. I'd like to know more about the OMC applications.

David wrote:
"Clyde,
I've never seen OMC/chevy four-banger engines, just Mercruisers, but they are sweet little engines and I guess anyone could use 'em for small boat power. I'd like to know more about the OMC applications."

This is the nearly the same engine as the Mercruiser. GM built the 153 cid for automotive, marine and industrial applications. It is (was) sold to marine and industrial customers without an intake or exhaust manifold. GM quit using it for cars and light trucks around 1970. The engine then evolved to the 181 cid (3.0 liter) in the mid-1980's. It is the same basic block but the bore and stroke is changed...from a 3.875" x 3.25" to a 4.0" x 3.6" stroke. In 1989, the rear 2-piece seal went to a one-piece seal similar to a GM V-8 engine. In 1998-99, the head design was changed to make more power. A throttle-body injection system is an option too.

The performance version "Iron Duke" is actually the GM-Pontiac Superduty-4 race engine. It shares a few characteristics with the 153 and 181 but is closer in appearance to the GM "R" street engine installed into the rear-drive Chevy Monza and Pontiac Fiero.

GM discontinued the Superduty-4 engine but an improved version is now made by Kansas Racing Products. It is much stronger than the 153-181, the OEM "R" engine and the old Superduty-4. The new block is more versatile as it accepts most V-8 small block cylinder heads...GM, Ford or Mopar.

Regards,
Gerry Dedonis
Kansas Racing Products Inc. http://www.kansasracingproducts.com


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