25Bertram.com

[krazyfisher]

hi
I have a b20 with a 470 and am looking at changing the power plant.
What options are there?
and how hard are those options?

thinking maybe a v6 220hp???? would like fuel injection but trying to keep the $$$$ down.

what are power plants that work the best?

all and any help would be great.

thanks

[walterk]

The boat came with a straight 6 165 hp. Mercruiser makes a 3.0 4 cyl 135 hp (at the prop) that fits with room to spare. Volvo makes a similar 3.0 that is fuel injected but has a catalytic converter as per 2010 DEC/EPA rules. V-6's will provide more horsepower but are tighter fits. No matter what you choose, if it's a gasser, you'll need to change the tank. If you choose diesel, the tank can stay. Volvo has a D-3 straight 5 that's a beautiful fit and will give great performance, but it won't be cheap. I'm sure others will chime in. Good luck!

[krazyfisher]

mine is an australian built bertram. it came standard with the 470 and the tank a 200l fibreglass.
I really dont want to drop HP and would like a bit more.
there was an option for the 888 mercruiser 188hp v8. they fit but they are too bum heavy.

[Axelz]

The D3 would be fantastic and there is a new 220 hp out that replaces the old 190 hp, but as mentioned, very expensive. I think that most bang for the buck would be the merc 383 stroker. Zerocavity put a 383 in his rebuilt B20, do a search on photobucket and you will find a few pics on the installation, looks very clean. A bravo three leg would do the trick making the boat much more easy to handle at low speeds since deep vees tender to drift around a bit with one prop.

I had a bravo three diesel leg on my old 25er (with yanmar 315hp) and compared to how the boat was with the old bravo one it was a big difference.
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25 Moppie -66 Babyblue Yanmar 315 hp Bravo 3 x diesel SOLD

26 Moppie -83 2x165 crusader SOLD

[pacific marlin]

Axels,Hi

I'm curious to know what speed you got with the Yanmar 315,

as I'm repowering a 25 Express with the same motor,

Regards Ian.

[Axelz]

Hi, I reached 42 GPS knots WOT(48,6 MPH) fully trimmed with very little diesel and alone in the boat. On the other hand it was no problem reaching 38 knots with 4 people and almost filled up (160 litres) but I think that the hulls limit is around 40 knots, doesnt really have the go fast lines. The torque is massive on that engine and is perfect for a single repower, very economical at cruisin speeds around 27-30 knots.
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25 Moppie -66 Babyblue Yanmar 315 hp Bravo 3 x diesel SOLD

26 Moppie -83 2x165 crusader SOLD

[two up]

Krazy.

I have fitted mine with a Volvo 4.3Gxi and duoprop leg. This combo did make it slightly bum heavy so I have repositioned the batteries into the cab under the floor. Now just about perfectly balanced. I dont think you want to go with a 3 litre unless you intend to keep the boat as light as possible. I have boatboxes. stainless targa/ canopy frame all the gear for gamefishing and 3 people, full gas, it pulls about 38 knots.
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20 Bahi Mar one of the best boats ever built.

[krazyfisher]

thanks i will have a look at the volvo

[krazyfisher]

well looked at the D3 $57,000 AUD...........

took the boat for a run yesterday and after 3nm it was over 3/4 on the temp. checked this morning and the fresh water coolant is down may 2 cups... I will check it out this week.

is it worht rebuilding the 470 if its the head/block?

I have the type I / 470 drive what matches up to that other than a 470??

long term I wanted a complete 4.3 v6 package with the bravo drive, but now is not the time to spend $20-25,000 aud....one wage, wife ,kid etc etc.

any thoughts welcomed

thanks

[JohnD]

I'd say work with what you've got until you can afford what you want.

In my B35 I nursed Gas motors for 7years before I made the switch to diesel. In my B20, I'm going to keep the 165 and roll with that. I found a good used take-out for $1000 and plan on a new exhaust manafold & hoses before installing. That should give me some good reliable service.

So, fix what you've got if you can or look for a good take-out and work at making it reliable. That will keep you going until you can free up the funds for a brand-new package. Who knows you may decide to move up to a bigger boat anyway...

br,
JohnD

[krazyfisher]

when had a play with it yesterday the exhaust elbow was all but completly block so I replaced it changed the water pump. just need to give it a run and see how it goes.

[krazyfisher]

well just an update after the elbow change... it run as good as new.. the whole boat felt better. I know it cant but it just did

thanks

[JohnD]

Great News!! Keep her going a little while longer. Rember the best thing for a boat is to be used