bertram31.com

Hi, I'm new to the site. I am rebuilding an abused 28 bertram. It is a 1984 witch has a larger engine room [in height] and larger shafts [11/4"].
Does anyone know what diesels will fit into this boat. I was told the cummins remans / or the volvos pentas were a good fit. I am rebuilding the bulkheads and installing new engine stringers. I'm not sure if i will go gas or diesel , but i dont want to install the stringers if they will not accomadate a diesel. The volvo or cummins are said to cost about 13,000 each. Thanks gary.

I have twin Cummins 210's in my '83 B28 FBC.
I was not involved in the installation but the only alteration that appears to have been needed is a couple of risers in the engine hatches
to accomodate the coolant reservoir cap(s).

A quick search of yachtworld.com shows a smattering of diesels.

Yachtworld Listings

I paid nearly twice as much for diesel powered B28.
I felt I would benefit from the economy and safety during ownership and recover much of the cost at resale.
(If and when I decide to move up to a 31)

I replaced my cabin bulkheads and cockpit panels this spring and would be glad to help any way I can.
I tried to take helpful pictures along the way. Just drop me an email if you like.

i think the engines i was told about were cummins 190's whats the crusing speed with the 210's?

I will email you steve thanks for the offer.

I can tell you that Steyr 6 cylinder will fit in a 1980 28. Using the existing running gear which is 1 1/8 shafts. Came from factory with merc 233's and velvet 71c. Switching to a ZF gear with down angle neccesitates some minor mods to fit the tranny back through rear bulkhead. Also needed spacers to fit between ouput shaft and coupler. My height from engine bed to hatch at the aft end of compartment only 22 inches. Placing the engines all the way aft is the only way this engine would fit. If I had put longer shafts in then the forward placement of the engines would not have allowed the hatches to close. Pretty sure I have the small engine room configuration. Bruce is the authority here on the Steyr engines and I am sure he will drop a post.

These are high speed diesels which allows use of smaller diameter shaft. I am not sure if 1 1/4 is enough for a low speed and torque cummins. My gear ratio and prop thus far to specs are also unchanged. I am sure the other faithful will chime in on your question.

Wish I could give you true performance specs but the boat is not finished or in the water yet. I will say the engine and gear combo weighs 733 lbs per side. Much lighter than small blocks. Switching to diesel also means I do not have to cut the glass tank out of boat. Read thread on ethanol if you are not following me. Replacement fiberglass ethanol resistant tank is 3600 plus labor. Good luck and sounds like you have a lot to think about. My repower contemplation is over. Just need to button things up and see if the old girl still floats. Kevin

If you can live with 22 knots cruise and 25 knots on the top, the small Yanmar's are the way to go.They fit under the hatches and are thrifty at the pump.
Harry

I have the Yanmar 170'S in my 28 . It's not a rocket ship, 17 to 19 kts. at
2900 RPM is the speed I cruise at fully loaded for fishing. 3400 RPM'S is WOT.

Out here because of conditions I can't always cruise at that speed.

Bill Fuller has the 240'S in his 28. Maybe he'll chime in.

I'm very pleased with the 170"S.

If you have any questions PM or E-Mail me.

Aren't the Yanmar 240's and 170's the same size and weight? I seem to recal that the Yanmar literature more or less said that. Anyone?

Same size and same weight "I" think.

More CI displacement, diff. turbo and diff. injectors ?

Thanks for the replys.
This is helping make this major decison. This is a great site. Hopefully i will be able to help someone with information in the near future.

I had the 170s in my 28 and with full tower, generator and the full load, we were lucky to make 16 kts. We never paid attention to the rpms, only the pyrometers and while the fuel burn was very miserly, the boat was very underpowered. At WOT, the boat handled beautifully so while I would recommend the Yanmars, I would suggest you go for the 240s.

They are a direct replacement.

Interesting, this year I've noticed that my B28 (w/210's) rides and handles better the faster I go.

I'd love to have flo-scan so I find out if its more efficient to run faster with more hull out of the water.

I have a set of the 210's in my 31. Those engines perform the best 200 rpms off the top of 2650. Walter

For sure - Yanmar 240's and Cummins 4 bangers fit with, at most, minor modifications to the hatches.

Not sure how anyone got inline 6 Cummins in there.

Story I heard was that B28's with diesel from the factory have bigger boxes as do the later years.

Yanmar 240's- 2900 rpm (per the tachs) is 29 mph. 3400 is 34 mph. Flat water, no real load.

And here is the kicker - my tachs are roughly 160 low at wot. So its 34 mph at roughly 3270 rpm. T

Ernest, sounds like it's running better than you expected - great news. I would certainly have trouble keeping up with you on a long offshore run. I wondered, also, about how you cram 6BT's in a 28, but i saw one advertised in Boats & Harbors that claimed to have John Deere diesels, and the Deere doesn't make any small marine engines that I know of.

Ernest: What gears and props are you running with your 240's?
Eddy G.

Ran a little performance test this afternoon.

'83 B28 FBC w/ Cummins 6BTA 210's:

RPM's / Knots

800 / 6.0 (Idle)
1200 / 8.0
1800 / 15.5
2100 / 20.2
2300 / 21.6
2400 / 22.5
2700 / 26.5 (WOT)

(Knots x 1.15 = MPH)