bertram 28 repower

You know, there are just way too many variables and too many options.

The majority of the time, the gas engines die an early death from the raw water manifolds not being changed every 5 years and they ingest saltwater. I've also seen gas engines go 3,000 hours if really maintained and not abused. It also depends on the condition of the existing engines and your intended use on whether they should be rebuilt or replaced with new ones.

Going with new engines, you're going to gain HP and speed in the same engine size/footprint, and technology (fuel injected) etc., but at a great cost.

If the engines haven't ingested saltwater, and haven't had a catastrophic failure (such as a major overheat cracking a head, or thrown rod), they can be rebuilt pretty reasonably in comparison to replacing. Quality of the rebuild relies solely on the parts being used and the rebuilder and can be all over the map. Also, if the engines are NOT freshwater cooled, I would go with a new short block. As the block passages can be thin on an old raw water cooled motor.

A new short block is a good medium, you have your cylinder heads rebuilt, intake installed etc etc.....However a bare long block might be a good way to go.....However, again it depends on the condition of all of the accessories and everything else.

Personally before I spent the money to repower with gas at $35k, I'd spend a little bit more and go with rebuilt diesels. Otherwise I'd rebuild.....if feasible

But your best option depends on your individual situation. Secondly, you couldn't give me a 28' Bertram. They're a well built boat and ride ok, but they NEVER stop rocking even at the dock in calm water.

Yes, you can convert the boat to fresh water cooling..... I don't know the exact cost, but you need a heat exchanger, expansion tank, and various other parts.

I ran one that was converted to 185hp Yanmars, it ran well but cruised at only 20 knots and then would slow down to 17 knots, then speed back up and really relied on trim tabs and was slightly underpowered. 220 hp Yanmars would be ideal. The name of the boat was "permanent wave" and the name fit the boat extremely well.

I've been happy with my Bertram 28 with the small blocks. It cruises 22 knots ... WOT is 27 knots.

When I repower/rebuild I will go with stroker 383 small blocks looking for at least 350 hp.

We use the boat mainly for tubing with the kids and having an "extra" boat. It doesn't see much use but I do like the boat.

If the Yanmar 4LHA diesels were available, they seem to be the ultimate choice for this boat. I don't use it enough to go through that kind of a reconfiguration.

You should be able to get that kind of power easily out of the newer vortech motors in nearly stock form without having to stroke a set of 350's. Either way will get you there. Or a set of 383's with dart cast iron heads with a tiny bit of porting, a marine cam from crane and a decent intake manifold should do the trick

Hi,
Interesting to read the reccomendations, I have just completed (Dec11) an engine conversion on my 28 and after a good look around used the Yanmar 4LHA-DTP'S 200hp, i am thrilled with the preformance with cruising at 18/20knots using only 20/22 litres per hr total for the two engines, at commissioning we topped out at 31knts with about 200l fuel and 3 people on board, we also put in new shafts, struts & props,
I looked at the 240hp but felt that give my cruise speed that the extra hp would be wasted and i would only use more diesel for no gain,

Actually they run very nice with the larger motors and use the same GPM as what you have now at the same speed......and less at cruise speed because you gain a lot more speed with that extra 80hp...... 240's cruise them around 28 knots......

We had the smaller 4LHA's on our last 28. Ran like sewing machines. We put about 300 hours a year on them for 3 years. Speed was not an issue for us - its a rare day off Sydney when you can cruise at more than 22 knots. 28's have their faults, but i loved that it (hull and motors) could be relied upon to to get you home when you wished you had pulled the lures in before the front hit.