Swap Question?

whatsagm

Seaman
Joined
Feb 26, 2008
Messages
58
I just bought a very nice boat with a POS blown up 470 mercruiser. My question is how hard would it be to swap in a merc 140. I have a complete boat with the 140 so i have all the parts to do it. Or would it be easier to just fix the 470 and do the charging system upgrade.
 

TilliamWe

Banned
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Dec 21, 2004
Messages
6,579
Re: Swap Question?

Your problem is you would substituting 170hp and a lot of torque of a 224cid engine with 140hp and not nearly as much torque of a 181cid engine. That is not the best swap to make. It might be physically easier than putting in a V8, but you'll be left with an underpowered boat, most likely.
 

knied1

Cadet
Joined
Jun 27, 2007
Messages
22
Re: Swap Question?

The swap would be fairly easy, I swaped out a 3.0l with the 3.7L about 2 years ago. I was able to bring the boat and motor to work and use the overhead crane to lift and set the motors, that obviously made it alot easier. but it only took me about three hours, and im a newbee, this was the first motor swap i had ever done in a boat. The 224 does have alot of torque, I have an 88 Stingray SVC210, and the 224 pushes that boat with only 2 people up to 37 to 40 MPH depending on conditions. I actually wanted more low end torque, so this year i swapped the 2 bl carb for the 4 bl. that is supposed to bring the boat up to 190 hp.

If you do the swap, make sure you use the alignment tool for aligning the Gymball Bearing to the motor. I at first tried to do it by eye and with a tape measure, and it looked dead on. A buddy brought over his tool, thank God before i put the drive on, and i saw just how far off the motor was from alignment. Even as little as 1/64" out will mess up the Gymball bearing, and who knows what else, then you will be looking at an expensive repair.

Hope this helps
 

Don S

Honorary Moderator Emeritus
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Aug 31, 2004
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62,321
Re: Swap Question?

I swaped out a 3.0l with the 3.7L about 2 years ago.

Wrong way, He's wanting to go from a 3.7 TO the smaller 3.0L
 

knied1

Cadet
Joined
Jun 27, 2007
Messages
22
Re: Swap Question?

Don,

I realized that, but i was just simply trying to explain what swap i performed. Especially since im newer to the boating world, If he really wanted to do the swap, its not as big of a job, as it origionally appears to be. Also looking to give another opinion about the output of the 3.7l from someone who was in the same position as he was. The other point i was hoping to get accross was the importance of the alignment tool, and not to make the mistake that I almost made.

sorry if there is confustion,
 

Bondo

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Staff member
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Apr 17, 2002
Messages
70,465
Re: Swap Question?

with the 140 so i have all the parts to do it.

Ayuh,.... Sell it All, including everything but the drive for the 470,+ find a dead boat with a 4.3l V6.....
You'll even end up with a Spare outdrive,... Ratio wise...
I realized that, but

I followed what you were sayin',....
I figure you're Crazier than whatsagm,...
Loosing 50hp is 1 thing,... But going To a 470 is Insanity.... :rolleyes: :D

While the V6 swap is abit more work,... The pay-off is Well worth the effort....
 

stonyloam

Vice Admiral
Joined
Mar 13, 2009
Messages
5,827
Re: Swap Question?

Just curious, how did the 3.7 "blow up"? BTW when mine goes it will be replaced with a 4.3 as Mr. Bond-o suggests.
 

knied1

Cadet
Joined
Jun 27, 2007
Messages
22
Re: Swap Question?

Terry,
Im new to the boating world, but not the motor world, yes I have put some posts on motors, and left the questions somewhat generic, to find the little tricks that other people may have faced, and not have to figure them out my self. An interest in the 224, or 470 depending on what you want to call it, is the amount of torque that that little motor can put out.

There are 2 design issues that the motor does have. First is that the "stock" heat exchanger is ony a 3" and usually is the most comon reason for blowing the motor, the other issue is the charging system. Both can be fixed. First the heat exchanger, should be a 4" I see you are from western NY, Olson Brothers can help you find one if your interested. The charging system can also be fixed, with a alternator conversion kit.

By the way, with proper maintenance the design issues will never be a problem. They are only a problem if you ignore simple maintenance, or you purchased another persons laziness.

I have 2 motors, one with a bent rod,(recieved it that way) and one just fine, I am trying to find how to get the absolute most out of the motor, and then I will re-build them both. I am also going to change the rotation on the one in the garage, I know its a lot of work, and could find one that already rotating opposite, but that is one of the few things i havent done, and want to give it a try.(i know...i need a different hobby) I already started to tear it down, and am taking notes of the work to post for peoples ammusment. Eventually they will be sitting side by side, im just not sure if it will be in my current boat or a different one. I wont tie up this guys thread, and let him get the answers he is looking for, and im sorry for tieing up your post, i will not waste any more of your time.
 

stonyloam

Vice Admiral
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Mar 13, 2009
Messages
5,827
Re: Swap Question?

Just wondering if it was a overheating/head problem. As a 3.7 owner you can get to feeling a little paranoid here:D. Have a 4" exchanger, and have dealt with charging and water pump issues. Just saying that when and if it comes time to repower the 4.3 would be my choice. Actually the more folks say that this is a POS motor, the more I like it, but that's me.;)
 

knied1

Cadet
Joined
Jun 27, 2007
Messages
22
Re: Swap Question?

When re-powering, I don?t care if it?s a car, boat, snowmobile etc...... The best thing is to go with what YOU feel comfortable with; every motor in the world has a benefit, and a draw back. I know there are people who say this one is soo much better than that one, but think about it. If there was one perfect motor wouldn?t it be in everything? I made my choice after about 5-6 months of research, and just simply felt the 224 had more to work with. I would suggest that if you are looking to re-power, don?t just look at what one guy or another says is the best motor. Pick two or three that you are interested in, and then look for their problems. The one with the easiest problems for YOU to deal with, may be the best choice for YOU. A site like this one is actually just simply awsome for finding common problems with one setup or another. Look up my past, i joined in 2007, and didnt start posting until about a month and a half ago. Remember alot of research will save you 5 times the head ache in the future.
I?m finding it a little funny that only one replied to this guys thread until a ?Cadet? replied, and then all the experts came out.


whatsagm,

I completely understand the reason for your question,
You have a good running motor, and a non running motor, in this economy do you spend more to fix the more powerful one, or do a swap. The suggestion I can give is think about it, what do you really want to do with the boat and be honest with yourself and what might you want to do later on. If you are just a joy curser than, under powering your boat will not be an issue until it is time for you to sell. If you want to ski tube etc, than you might regret it. Another thing you can look into is....... do the swap; it is that easy, deal with what might be an underpowered boat, than look into either fixing the 224, Or picking something else that might suit your needs better. As long as you have a working boat, you can take all the time you need. Depending on your tools, and lift capacity, a swap should only take you a Saturday, and maybe a little bit of Sunday in the back yard.
 

whatsagm

Seaman
Joined
Feb 26, 2008
Messages
58
Re: Swap Question?

Sorry took me so long to get back to you guys. I bought this boat with a blown up motor. The moron that owned it before me dropped a screw down the spark plug hole and cracked the cylinder. I have decided to rebuild the 470 and upgrade the charging and cooling system. I'm a certied auto tech so for me this is not a hard task to do. Thank you for all of your replies.
 

Bondo

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Apr 17, 2002
Messages
70,465
Re: Swap Question?

If there was one perfect motor wouldn?t it be in everything?

Ayuh,... Do you mean like the fact that SBCs power about Every boat built in this day,+ age,..??..??
 
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