Replacing A4 With a Yanmar 8HP Diesel

[Muscongus]

When I do this, should I also add some form of vibration pads under the engine mounts?

By the way, in replacing everything - engine, transmission, shaft, prop, fuel tank, hoses, wiring, gauges, exhaust - you know, everything.

While I've never done this before I'm a glutton for punishment and have a bit of mechanical sense to me.

Any advice would be greatly appreciated.

Thanks,

Dan

[roverhi]

The Yanmar motor mounts are huge soft rubber affairs. Not a problem with vibration on my 3GM. If they use those mounts on your engine, shouldn't be a problem. The Yanmar mounts are horribly expensive and not so long lasting however. The Yanmar mounts themselves had delaminated with under 400 hours run time though quite a few years. Changed to after market mounts when I reinstalled the engine to get more room among other things.

[Muscongus]

The boat that I took the yanmar out of didn't have any vibration pads. Thought that was a bit odd, but, wasn't sure. Three Catalina that I've just picked up is the first boat that I've had with an inboard.

While I've got the old A4 out, I'm going to redo the sound proofing. There are openings to the sail locker - think I should build some sort of door there?

[CAELESTIS]

If you want quiet and have the room, you should look at a gas/water separation muffler. Soundown - peace and quiet for architectural, marine, & industrial applications

Soundown also makes engine room sound insulation.

[Eclipsed]

Hi, what are you going to do with the A4 engine that you removed? I might be interested in buying it if the price is right. PM me if--?

[Muscongus]

Originally Posted by CAELESTIS

If you want quiet and have the room, you should look at a gas/water separation muffler. Soundown - peace and quiet for architectural, marine, & industrial applications

Soundown also makes engine room sound insulation.

I've got a bubbler that came with the yanmar. That looks like the same kind of thing as that muffler. Not sure, though. The bubbler is a stainless tank that the exhaust routes through. it ends up with water in it. I thought it was about cooling the exhaust, but, maybe it also helps to quiet things down.

[foggysail]

Originally Posted by Muscongus

When I do this, should I also add some form of vibration pads under the engine mounts?

By the way, in replacing everything - engine, transmission, shaft, prop, fuel tank, hoses, wiring, gauges, exhaust - you know, everything.

While I've never done this before I'm a glutton for punishment and have a bit of mechanical sense to me.

Any advice would be greatly appreciated.

Thanks,

Dan

Dan--

If that engine has a horizontal piston, you will be sorry!!! I had a Yanma 12HP in my sailboat, what a PIG! I had to redesign the entire motor mount structure to keep the life lines from resonating and when they did so, they swung up and down at an unbelievable rate.

Again, if it has a horizontal piston learn more about it before you install it. Worst of all, the pig cannot even be converted to a decent anchor!

[CAELESTIS]

Originally Posted by Muscongus

I've got a bubbler that came with the yanmar. That looks like the same kind of thing as that muffler. Not sure, though. The bubbler is a stainless tank that the exhaust routes through. it ends up with water in it. I thought it was about cooling the exhaust, but, maybe it also helps to quiet things down.

Not the same thing. That is the standard water lift muffler. The separation muffler drops the sound another 20db and is secondary to the waterlift. These are commonly used with gensets.

[Muscongus]

Another concern is the angle of the shaft. I'm thinking that there will be a difference between the two motors.

Is there a flexible coupling or something that can make that variation no big issue?

[Muscongus]

I've got the shaft and prop (and stuffing box for that matter) from the Hunter 27 that the yanmar was in. I tried to take everything so that the problems would be minimized.