Lifespan of Volvo MD7A?

[Kittiwake]

AFter 30 yrs and about 4200 hrs, Kittiwake's MD7A has given up the ghost, at least compression-wise. Have decided to repower her with a Beta 14. What kind of lifespan have you had with your MD7A?

1. If anyone needs parts for MD7A, I have some new that have never been used, and will list them in the buy/sell portion of the message board.

2. I'm interested in any photos, experience with repowering their CD 28 with a Beta 14. Andy Denmark has been helpful, as always, looking for as much info as I can possibly find.

Thanks,

Peace and Fair Winds, Bill Watson (kittiwakecd28nospace@msn.com)))

[Neil Gordon]

Since 1977... So far, so good.

[Jack.Ducas]

Hi Bill,
I have a 1982 CD30 with the MD7a. It's now got low compression in one cylinder but once warm it starts and runs pretty well. Had the boat for about 12/13 years and have maintained it yearly. What type of parts are you going to list? Very interested in hearing what you have and what you're looking to get for them. Where are you located?
thanks much!

[John Ring]

I put a Beta 14 in my CD28 a few years ago, went in pretty easy. The stock Beta mount package sits right on the old Volvo beds, just need to block her up an even 2" and maybe angle the aft ones in just a bit.

The Beta is about half the weight of the MD7A and much easier to handle. The glow plugs make her start fast, even on cold days, and she's a LOT quieter and smoother than the old Volvo. The fresh water cooling is nice too, allowing the motor to operate at a warmer more efficient temperature. Another nice feature is the Beta is shorter, so you gain room around the stuffing box. I used the new space to put in a PSS shaft seal. Of course, you'll need a longer shaft, and a new prop that turns the other direction. You'll also need to design & install a new exhaust system. The Beta exhaust manifold is on the port side and doesn't have a built in muffler like the MD7A. May as well swap out the cutless bearing while your back there.

John Ring
CD28 #241 Tantalus

[Kittiwake]

Jack - the part that is new is the mechanical fuel pump. The injector pump has 419 hrs on it since it was rebuilt, and is probably the only part that should be worthwhile. The alternator is 4 years old, and was hard to find and was expensive. Also have a Volvo oil filter and fuel filter that are new, along with a alternator belt. Haven't come up with a price, so if you're interested, send me an email (kittiwakecdnospce28@msn.com - remove the nospace) and we can come up something.

John - thanks for the photos and info about the installation. Looks real good and your experiences are certainly along the lines that I've heard from Andy Denmark about the Beta 14. Noticed that you have the flexible coupling, so far everyone except Beta that I've talked to has suggested that I should not install it, with such a short shaft and protected prop. Any thoughts?

Peace and Fair Winds, Bill

[John Ring]

...John - thanks for the photos and info about the installation. Looks real good and your experiences are certainly along the lines that I've heard from Andy Denmark about the Beta 14. Noticed that you have the flexible coupling, so far everyone except Beta that I've talked to has suggested that I should not install it, with such a short shaft and protected prop. Any thoughts?

Peace and Fair Winds, Bill

Thanks Bill.

I see the flexible coupling much the same as a rubber motor mount - another opportunity to provide a degree of shock/vibration absorption between moving mechanical parts. I don't see how it can do any harm, other than maybe electrically isolating the shaft/prop, but this is easily fixed with a grounding brush on the shaft leading to ground. Or, a copper strap/wire jumping over the flexible coupling.

A few other Beta options to consider are the deep oil pan, the high rise exhaust manifold (required really), a Speed Seal cover for the raw water pump (now that it's up front), a coolant overflow tank, and the optional Iskra 70 amp alternator package that comes with the wider drive belt and wider pulley wheels to keep the belt from slipping under load. As there is plenty of space to put a Beta 14 in a CD28, I voted for all of the above. With a good prop, 14 hp is plenty for a CD28.

John

[Kittiwake]

John
Thanks again - I had thought about the coolant overflow tank, and will get the speedseal (it was real useful on the Volvo). Beta recommends the shallow sump (I thought it was for space issues) and the high exhaust riser. I'll keep thinking and getting info about the flexible coupling. Did have a discussion with Beta about grounding the prop and shaft.
Peace and Fair Winds, Bill

[John Ring]

John
Thanks again - I had thought about the coolant overflow tank, and will get the speedseal (it was real useful on the Volvo). Beta recommends the shallow sump (I thought it was for space issues) and the high exhaust riser. I'll keep thinking and getting info about the flexible coupling. Did have a discussion with Beta about grounding the prop and shaft.
Peace and Fair Winds, Bill

No problem Bill.

Where we have to block the motor up 2" there is plenty of room underneath for a deep oil pan. My Beta does lose a little coolant over time, so I'm putting in a coolant overflow tank, mounted fwd in the port cockpit locker. This will let me check the fuel gauge and coolant level at the same time. Also, it's a good idea to put a vented loop into the raw water exhaust hose between the heat exchanger and the exhaust too. I tucked my vented loop way up high into the bridge deck space just over the exhaust manifold.

Good luck, and if you have questions along the way feel free to toss me a note.

John Ring
CD28 #241 Tantalus