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Maka · 18-03-2018, 04:28

Let me get this right. Your Perkins 4108 is 52 years old, and you want to replace it with a different brand engine ?
Unless you need less or more HP, why abandon a proven reliable work horse? Why not a rebuilt or new Perkins 4108?

fish53 · 18-03-2018, 04:36

I'd keep the Perkins parts are extremely common and relatively cheap and they're easy to work on, they all leak however. I have a 4-108 in the garage with a BW 72 2.45 to 1 that I'd sell for less than the sales tax on a Beta.

Maka · 18-03-2018, 04:45

Fish
Where is your garage located ?
Im interested in your 4108 for sale.

stormalong · 18-03-2018, 10:18

Quote:

Originally Posted by Maka

Let me get this right. Your Perkins 4108 is 52 years old, and you want to replace it with a different brand engine ?
Unless you need less or more HP, why abandon a proven reliable work horse? Why not a rebuilt or new Perkins 4108?

Let's see. Smoother running, less pollution, less oily mess under the engine. Parts available worldwide from Kubota. No unexpected rebuild costs that could drive the cost of the rebuild close to the cost of a new engine.

The 4-108 went out of production in 1992. There are no "new" 4-108s.

Why would't you want to replace it?

Woodland Hills · 18-03-2018, 11:10

Because the Perkins is not a computerized engine and if the Zombie Apocalypse is preceded by an EMP, you will still be able to charge your batteries at anchor and move the boat.

stormalong · 18-03-2018, 11:25

Quote:

Originally Posted by Woodland Hills

Because the Perkins is not a computerized engine and if the Zombie Apocalypse is preceded by an EMP, you will still be able to charge your batteries at anchor and move the boat.

Neither is the Kubota V2203 (Beta marine BV2203). One of the reasons I chose Beta over VW marine.

Sometimes newer is just plain better. Not always but true in this case.

peter57 · 19-03-2018, 07:40

Quote:

Originally Posted by Wainui

So running a 26000 lb boat with a Beta 50 at 2200 rpm which is 42 hp @ 1 gallon ph is Too much for a Walters Vdrive?
I’ve read that ideal size of engine is 1hp per 500lbs.
Many thanks for all your replies.

42 hp is over 2 gallons per hour (specific fuel usage)

sailor_ed · 19-03-2018, 08:44

Just some anecdotal info. My Gulfstar 41 loaded displaces about 30,000lbs (I have a lot of stuff! Full time liveaboard). With my Beta 50 @~18 to 20,000 rpm I make 6kts and burn about 1 gal/hr. With my 4-108 I burned just over . 75gal/hr at cruising conditions which were in the same ballpark. (I don't remember exactly). With the Beta I can push to 7.5 kts when warranted which I was not comfortable doing with the Perkins (noise, vibration and my own psychological limitations! :-)

In *theory* the Perkins could develop 47hp so it seems to me the Beta 50 is not really much of a step up in that regard.

exMaggieDrum · 19-03-2018, 08:51

This thread caught my eye since I have a 4-108 Perkins (ca. 1980), a BW velvet drive (1:1), and a Walters V-drive (2:1). The Perkins does leak oil but not a gusher. It is noisy and vibrates a lot. I am changing to a screw on engine fuel filter because I hate the mess of the standard canister filter which is on the other side of the engine from my access. But it seems to be a solid engine with a solid set of transmissions. I plan to keep it.

But it is interesting to see what others are doing in case I am faced with replacing it. I have always heard good things about the Betas so they would be on the list. I would have no hesitation considering a higher HP motor.

My previous boat was a Whitby 42 with a 80 hp Ford Lehman, definitely a bigger motor. It used 1.1 gph to push me at 7 knots after I changed the pitch on my Max-Prop. When I got the boat it used 1.4 gph for the same speed. So I am not sure going up from 42 hp to 50 hp will guarantee 2 gph just because of the hp change. It all depends on the engine design, the prop, the boat design, and the way you use the boat from what I know and experienced.

Aksailor14 · 19-03-2018, 09:30

I replaced a BMC diesel with a Beta 37.5 utilizing the 1978 Velvet drive in my Esprit37, works like a champ! Velvet drive parts ans service are readily available even in Alaska.

Wainui · 19-03-2018, 10:15

According to the Beta specs 2200 rpm is 43 hp @ 4 liters per hour.

http://www.betamarinenc.com/wp-conte...A-50-Graph.pdf

peter57 · 20-03-2018, 07:32

Quote:

Originally Posted by Wainui

According to the Beta specs 2200 rpm is 43 hp @ 4 liters per hour.

http://www.betamarinenc.com/wp-conte...A-50-Graph.pdf

At what load? You also have losses in two gearboxes

A rule of thumb 5hp/ litre, this can be stretched and shrank of course.

You have a Max prop that is pitch adjustable so you should easy find an economical cruising speed around a knot off hull speed with that good looking boat.

The prop will easy take more pitch after the 4108 and should get your 4L/h but using way less hp back in the higher torque curve and have plenty in reserve without overloading.

Cheers.

sailor_ed · 20-03-2018, 09:03

I am curious as to where the "rule of thumb" value of 5hp/liter comes from. Is this well known to yachties ?

kmacdonald · 20-03-2018, 09:54

Quote:

Originally Posted by Wainui

According to the Beta specs 2200 rpm is 43 hp @ 4 liters per hour.

http://www.betamarinenc.com/wp-conte...A-50-Graph.pdf

That's impossible. A very efficient turbo diesel burns about 1 gallon per hour for every 20 HP. A small naturally aspirated mechanical diesel burns about 1 gallon per hour for every 18 HP. The Beta chart shows max HP at 2200 rpm. The fuel burn at 2200 rpm doesn't give the engine load. Could be no load at all for all we know. The chart says "fuel consumption based on theoretical prop loading" not max output.