Re power

A few 54 Bertram's were successfully repowered with MTU Detroit Diesel Series 60 (14 liter) engines rated at 825 hp. They cruised at a 20 - 22 knots.

Another option would be a Volvo Penta D13 at 900 hp. They are usually conservatively rated.

But your most versatile option would be a CAT C18, rated anywhere from 873hp to 1150 hp.

Something to be said for displacement, hard to beat 18 liters. You can get all three serviced in SoCal.

Would the 13 L Cat C12-9 be too small? It is a bit lighter than the C18 and a lot less weight than the DDs. Or how about a Cummins K38? Stop over and talk to Tony Athens, he would have a lot of good info and has done several Bert repowers..

I don't think the C12's would have enough torque. Honestly I would stay at 1000 hp and not downsize to 800hp. That hull runs so much better at 25+ knots than it does at 20. Also, you can always run them slower if you want to cruise slower and it's easier on the motor. I'd definately go with C18's, that would be my primary choice. Much easier and cheaper maintanence schedule than the Man's. But I think 1100 Common Rails would be my second choice..... Cummins QSM's wouldn't be a bad choice either..... but I think CAT would be most preferred with resale and the C18's are a bulletproof 10,000 hour motor, 75 gph for both at cruise. I think their torque curve would be the best suited and you might get lucky and not have to change props only re-pitch them and you'll probably gain 4-5 knots over the 12v92's. I'd stay away from Volvo's as you just never see them in SF, also the C18's raise fish.....The Series 60 DD's just don't have enough torque for this application IMO.

Actually there is a late 90's 54' Bertram over in Texas listed on YW that has rebuilt Cat 3412's in her in the high 300's. That would be a good way to go for what sounds to be a turn key boat.

Some more food for thought regarding weights (dry - each):

CAT C12 - 2589 lbs.
Cummins QSM 11 - 2620 lbs.
Volvo Penta D13 - 3439 lbs.
MTU DD Series 60 - 3600 lbs.
CAT C18 - about 4000 lbs.
DD 12V92TA - 6410 lbs.

The C12 & QSM 11's are better suited to repowering a Bertram 46, while the D13 and Series 60 will get you a 20 - 22 knot boat. I have seen a Bertram 50 SF repowered with Volvo Penta D12's rated at 800 hp, and it did quite well.

But if you want to be able to run 25 knots+ cruise in a Bertram 54, then you would be looking at the CAT C18.

Since these are all 2300 rpm engines, it is more a matter of hp than torque, and the 18 liter Cats have the advantage.

Other food for thought. The Mid 2000's 57' Bertram was essentially the 54' hull stretched, and probably a bit lighter, but would cruise over 30 knots with 1350hp MAN's.

The 54 has some limits in terms of potential speed, as do most mono-hedron moderate deep-vee hulls. The extra waterline for the 57 is a definite advantage.

There was a 54 in CA, "Country King", that probably underwent the most extensive refit ever, even upgrading from MAN 1100's to 1350's with 3 years after being finished, and the performance gains where not as expected.

I agree, and the 54' Bertram hull is only so much. The 57' gains a pretty flat additional 3' of running surface in the transom to help with speed over the 54'. The Strikers were the same way, welding a 1' trim tab across the transom at the right angle on those had them pick up 4-5 knots.

I know of a 45' Hatteras SF they did a cockpit extension on to about 53', the boat was called the Shark, They also threw 1100 MANs in it and that thing flew after the extension and cruised at 34-37 knots.....

But for the OP, I'd put C18 1000 hp in the boat.......and I think that would be the ideal engine for it......and closely match his existing parameters......shaft's/struts/props and he'd probably cruise 25-26 knots....at 75 GPH......or go with the 1150hp and run them easier and have the power/speed if you need it.......but the 1000hp C 18's are rated for 10,000 hrs and I forget how much fuel used and are near bulletproof with parts availability worldwide.....as well as a great engine display/ throttle-controls combination.......

Why would you send him to Cummins dealer/mechanics when he is talking CAT engines - they don't even have their own haul out facilities?

If you read his response you would see that he is talking about a CAT 3406E. What does Cummins have in 800hp+ that works in a 54 Bertram at 20+ knots cruise?

[/QUOTE]...and where would I find haulout facilites owned by Quinn or Hawthorne?[/QUOTE]

I am sure he can buy from whatever CAT source and get the work done at a reputable yard - Shelter Island Boatyard in SD, Gambol in LB or one of the pricier NB guys. Bid it out to whoever is hungriest.

Spending that kind of money, I would want deeper pockets from my installation resource for warranty/support, rather than an "independent". But if it was for a Bertram 31, I would reconsider.

The 3406E became the C18 Caterpillar (with some minor changes of course). I would go with 4 cycle for many reasons. Not sure on the budget though, talk to some people that have done it before.....As far as I know, getting the old ones and new ones in shouldn't be that big of a deal, take out the cockpit window and the floor hatches in the salon......One of our members has done it a couple of times on his.

Hi,

If the OP is on a tight budget the 3406E would be very well worth considering even if he has to buy a couple of old cores out of trucks to get the best reman core deal.

The 3406 ain't the newest thing from CAT but they are certainly a good tough workhorse with a very well proven track record.