Harmonic Balancer replacement on a 4 cyl

[NetDoc]

I have been working hard on this 1968 Fibra and was going to launch it this weekend. Today, I was going to run a temp gauge when I noticed that the v-belt was upside down and on top of the upper pulley. Closer inspection revealed that lower pulley was way out of alignment with everything else. ARRRRRGH! I want to get my boat ONTO the water.

It appears that the front motor mount will have to be removed in order to have enough space to remove the pulley. In order to do this, I feel that the engine should be supported before I remove the mountings. I have a 2X6 and will be constructing a support beam from gunnel to gunnel using 2X4s to steady the 2X6 edgeways. I will be using an anchor chain to hold a come-a-long to provide the support I need to remove the front engine support. Anyone see a potential problem that I am overlooking? Is there an easier way to accomplish this?

FWIW, I will be replacing the water pump while I am in there. No need to tempt the fates with an old one.

 

[sqbtr]

Re: Harmonic Balancer replacement on a 4 cyl

Are you ever going to show is some pics of this hybrid you have?

No one can give you any honest answers till we see what you're workin on.

 

[Don S]

Re: Harmonic Balancer replacement on a 4 cyl

You have a Volvo drive, and a Mercruiser engine, and who knows what's between the two. It's probably Volvo, and if you raise the front of that engine more than a very small amount, you are going to damage something.
You have what is known around here as a "Junk Yard Dog" made from pieces and parts.
Doesn't mean it won't work and treat you right out on the water, just means there is no easy answer for anything.

 

[NetDoc]

Re: Harmonic Balancer replacement on a 4 cyl

The plan is to keep the front of the engine in stasis rather than move it up or down. I am more worried about the gunnels than I am the drive train. I'll post some pictures before I get started this am.

 

[NetDoc]

Re: Harmonic Balancer replacement on a 4 cyl

Separated Harmonic Balancer

Front view of Harmonic Balancer

Engine: starboard view

Front Engine Support: port view

Front Engine Support: front view​

 

[NetDoc]

Re: Harmonic Balancer replacement on a 4 cyl

Additional pictures from the bell housing (someone asked and they closed the thread they asked in)

Port View

Top View​

 

[NetDoc]

Re: Harmonic Balancer replacement on a 4 cyl

You have a Volvo drive, and a Mercruiser engine, and who knows what's between the two. It's probably Volvo, and if you raise the front of that engine more than a very small amount, you are going to damage something.
You have what is known around here as a "Junk Yard Dog" made from pieces and parts.
Doesn't mean it won't work and treat you right out on the water, just means there is no easy answer for anything.

After re-reading your advice, can you define "very small"? Also, it was my understanding that this is the original engine/outdrive set-up.

Finally, just where do I order a harmonic balancer for this beast?

Finally x2, is that a pressed on balancer? I don't really see a crank bolt on it, although I do see pull holes. Glad I still have my automotive tools. That being said, pulling the front motor mount will reveal more.

 

[Don S]

Re: Harmonic Balancer replacement on a 4 cyl

After re-reading your advice, can you define "very small"?

1/4 inch max.

Also, it was my understanding that this is the original engine/outdrive set-up.

Since Volvo never used the 140/3.0L engine until 1994, and never with the 200-290 style drives only with the SX drive, I would say it's not original.

is that a pressed on balancer? I don't really see a crank bolt on it, although I do see pull holes

Yes, it pressed on, and many of the 3.0L engines did not have bolts.

I'm going to look through some Mercruiser info and see if I can figure out what vintage that engine is. Then I can give you a link to the proper manual.

 

[NetDoc]

Re: Harmonic Balancer replacement on a 4 cyl

I have to go get ready for a memorial service for a fellow diver and ScubaBoardian: Tim aka netmage. But before I do that, I built the support beam I intend to use to support the engine. It's built from a 2X6X10' using the part I cut off (40") to support it over the hatch with a couple of 2X4X30" stabilizers. I am going to use a come-a-long attached by a chain wrapped around the beam. Very cheap and low tech, but since I will be just stabilizing the engine with no movement fore or aft, it should be sufficient. I'll probably start the rest Sunday afternoon or Monday morning. The local NAPA says they need the number off of the old balancer as they have no listing.

Engine Support Beam ​

 

[Don S]

Re: Harmonic Balancer replacement on a 4 cyl

I don't find anything with that type front mount, or thermostat housing in Merc, One thing that may have happened, and could be why it's said to be original, it Volvo in the early years did sell drives and transom shields to boat manufacturers who then installed their own engines. Glastron was one that did it with Ford engines, never seen it done with a 140, but that doesn't mean it didn't happen.
Other than the accessories being different, the block is still a GM 3.0L engine. Here is a link to a Mercruiser manual that may at least help you with that engine.
http://www.4shared.com/document/hh5Z9V47/Service_Manual_10.html

 

[NetDoc]

Re: Harmonic Balancer replacement on a 4 cyl

I don't find anything with that type front mount, or thermostat housing in Merc, One thing that may have happened, and could be why it's said to be original, it Volvo in the early years did sell drives and transom shields to boat manufacturers who then installed their own engines. Glastron was one that did it with Ford engines, never seen it done with a 140, but that doesn't mean it didn't happen.
Other than the accessories being different, the block is still a GM 3.0L engine. Here is a link to a Mercruiser manual that may at least help you with that engine.
http://www.4shared.com/document/hh5Z9V47/Service_Manual_10.html

Thanks Don... information always makes the job easier.

I think that the boat gunnels should support this weight. Any comments on that?

 

[Maclin]

Re: Harmonic Balancer replacement on a 4 cyl

From a mechanical engineering perspective, I would want to tie the bottom stands together so they would not have any chance of doing the splits and sliding out off the top of the gunnels. Something connected across the span from the top of each side's corners maybe. I know it is for a static load, but things can get bumped.

 

[NetDoc]

Re: Harmonic Balancer replacement on a 4 cyl

The beam worked perfectly. Not much spreading, but then its only a four banger!

I got a marine grade pump with a bronze impeller and I started to do the work. It only took about a half an hour once I got my tools together. Here are some pics:

Front Engine Mount/Support removed

You can see the bearing race coming apart

Harmonic Balancer Puller (Snap On)

The offending Harmonic Balancer and Water Pump​

I am glad I went ahead and got the pump. The old one was not marine grade and had seized. I am certain that it was the reason the harmonic balancer came apart. I have not found the harmonic balancer yet. I saw one for over $200 on the internet, but I would like a more reasonable one, if possible.

I noticed that the engine did not seem level before I removed the front mount. It looked a lot better after I raised it just a bit. There is an adjusting mechanism and I think I will play with that once I go back with the pulley. Also, I was amazed to see that the engine support screwed directly into the stringer. The two outer came out clean, but the middle one is stripped and gooey looking. I could run a strip of SS bar stock 5/16"X2" and the appropriate length across the stringer and attach it to the stringer epoxying the holes closed. Then I could drill and tap holes for the front mount.

 

[Don S]

Re: Harmonic Balancer replacement on a 4 cyl

Level doesn't mean squat. Depending on transom angle, level could be way off.
You adjust it to the alignment points on the flywheel housing and the transom shield.

 

[NetDoc]

Re: Harmonic Balancer replacement on a 4 cyl

Thanks for the input, but I don't quite understand that picture. I don't see those shims on my unit. Also, that applies to the rear... is there no adjustment technique for the front?

 

[Don S]

Re: Harmonic Balancer replacement on a 4 cyl

As old as your setup is and not being all Volvo, it's impossible to say what the adjustment method should be, or where to look. The picture I posted works on 270's and newer Volvos, but what you have is not all Volvo. Maybe someone else knows what you have, I sure don't.

 

[NetDoc]

Re: Harmonic Balancer replacement on a 4 cyl

Yeah, I am getting that! The front mount has a clear "OMC" cast into it.

After some research, here is what I think I need:

OMC: 55045T
or
GMC: GM0382628E

I think a harmonic balancer from a 68 Nova II with an L4 2.5L 120 (151) engine will work as well, though the timing mark won't be right. I have found nothing yet.

 

[NetDoc]

Re: Harmonic Balancer replacement on a 4 cyl

For those that have been following me on this, she needs some cleaning, new paint on the floor (January), windshields and a harmonic balancer! Still, here are some before and current pics:

Before

Now

Before

Now

Before

Now​

 

[NetDoc]

Re: Harmonic Balancer replacement on a 4 cyl

It appears that the harmonic balancer has been located by the NAPA store next door for about $150 and is on its way. Yay!

 

[NetDoc]

Re: Harmonic Balancer replacement on a 4 cyl

I think that I do want to run some bar stock under the motor mount. The motor is obviously tilted down (40+ years of sag?) and the outdrive looks stressed. While the mount is adjustable up and down, I like the idea of solid stainless steel or brass under the mount. That way, I can clean up the rot with epoxy, and anchor into the stringer at different locations. I was worried about the metal/fiberglass interface, but that's already being done with the mount. SS is way stronger (overkill) and brass is far easier to machine. Thoughts on either? I'll still have to raise the engine another 1/4" or more after I install it. What am I missing here?