Info on Mercruiser 0A494867 170Hp engine.

Joined
Mar 27, 2010
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There are a couple of known issues with the 470 engine. I have the last version the 3.7LX which was last made in '89. They have a large bore and torque along with very good fuel economy.

Here is a thread on one of the issues: https://forums.iboats.com/threads/1986-mercruiser-470-coolant-leak-through-weep-hole.673343/


Here... read this article on the job:

These engines don't like to get hot. With the block being made of aluminum and the cast iron head, with different expansion rates, it almost always results in a blown head gasket. With everything working as it should, my engine runs at 160° all day long. Have a good temp gauge on the helm. The earlier versions had 3" diameter heat exchangers which had issues cooling enough and were later replaced with a 4" diameter version.

Also the charging system is expensive to replace if it fails. The factory set up is a stator that produces current which is located under what looks like the harmonic balancer. There is also a voltage regulator that is water cooled near the heat exchanger. The VR is prone to failure and usually causes high voltage readings when failed. 15+ volts. The best fix is to replace it with a belt driven alternator, there are aftermarket kits available, none by Mercruiser. The kits are bolt in and made for this engine, easy conversion if you have to.
 

Duranma62

Cadet
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Jul 28, 2021
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Good morning everyone. Is there a car engine I can put on this boat that will work? Any thoughts?
 
Joined
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3,008
Good morning everyone. Is there a car engine I can put on this boat that will work? Any thoughts?
Sure there are many, but it won't be a direct swap. Mercruiser also used Chevy and Ford engines but they were mostly V6 or V8 Engines. Your engine only has one front engine mount, the V engines will have two. The 4.3 Chevy would be the best swap to go to, they use the same gear ratio in the outdrive that you have now. If you go to a V8 you'd have to swap the drive. You could swap to another inline engine but I think the 3.0 and 165 were both older engines that what you have. And you'd be loosing torque.

Are you having problems with this motor?
 

glennj3

Petty Officer 1st Class
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Sep 6, 2011
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What type of engine did you replace it with? How hard was to install and alternator conversion kit?
I think you were asking me? I replaced it with a used same engine. My mechanic found this conversion kit. It is very simple & works like a charm! The belts turn on the old stator. It was not expensive!
 

Duranma62

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Jul 28, 2021
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Thank you everyone for your replies. I think I am going to give this engine a chance. Where to start? I think since it has been sitting for a long time, I should start with the fuel assembly. Drain the thank, change the fuel.pump. Then tackle the electrical. Plugs, wires, points, distributor cap, and rotor. What are your thought? Like I said, the engine turns over when I hook up the battery and turn the key, but it won't start.
 
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Mar 27, 2010
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Don't replace the fuel pump yet. They very rarely go.
I agree on the full tune up.

If it doesn't have a fuel water separator, you should add one in between the tank and fuel pump. Once you get the tune up done and you confirm you have spark. You can run the engine off a portable gas container and some fuel hose instead of the boat's gas tank, just to get it running.

Yes, get that old gas out of the tank, start fresh. It's probably going to need a carb rebuild unless it was ran out of gas when it was stored.
 

Bt Doctur

Supreme Mariner
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Aug 29, 2004
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19,345
you people need to read up on stator charging systems.
The stator generates AC voltage and the rectifierchanges that to DC voltage
 

Bt Doctur

Supreme Mariner
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Aug 29, 2004
Messages
19,345
produces a square wave dc to mimic the ac sine wave
the 4,3 on average is 175-200 hp , You will have to make new front motor mounts and/or stringers. Wiring should be plug and play at the harness side. Drive gear ratio should stay the same.
 

Duranma62

Cadet
Joined
Jul 28, 2021
Messages
24
produces a square wave dc to mimic the ac sine wave
the 4,3 on average is 175-200 hp , You will have to make new front motor mounts and/or stringers. Wiring should be plug and play at the harness side. Drive gear ratio should stay the same.
Hi,
Where did you find a manual for this engine? I ordered one from Amazon but it didn't cover this engine very much.
 
Joined
Mar 27, 2010
Messages
3,008
Hi,
Where did you find a manual for this engine? I ordered one from Amazon but it didn't cover this engine very much.
The factory service manual covers more than a Clymer or Seloc manual. He may have the paper version I don't know.... Years ago the PDF versions were available here but were shut down due to copyright. Boatinfo.no has them also but no longer work as you need Flashplayer to open it and it's no longer supported.
You can try here, just a quick search:

You would need Mercruiser manual # 6 for your drive and manual # 8 for your engine.
 
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