Tollycraft vs. Hatteras vs. DeFever

A high strung short lived early attempt to make a high hp (for it’s era) marine diesel in a smaller package. Something that didn’t exist at that time.

In those days nobody cared about getting only 3000 hours of life out of them. You could rebuild them cheap and you couldn’t swing a dead cat without hitting someone who worked on them. That’s not the case today.

Availability issues with antiquated parts and very few old timers left who will even work on them.

Some here will disagree but my opinion is that it’s over for Detroit’s unless you already own them, and know them, and love them. Then by all means keep them running and keep on keeping on. But buying a boat today? No.

Not for the kind of cruising you said you wanted to do. Bahamas? Loop? Up and down the Eastern Seaboard? Nope.

Maybe a floating condo and the occasional weekend overnight outing. But not the kind of cruising you described. Sorry.

In the mid 1970’s I had a 36’ sportfisher with a pair of 6v53 naturals. A whopping 210hp each. And I have the hearing loss to prove it.

It doesn't work that way, as long as you don't exceed hull speed you'll only use about 36hp or so to push tgd boat, I'm spitballing here but at hull probably in the range of 4gph.
My two 6-71s (450hp x 2) burn a combined 3.75gph at 7.75kts.

I've never seen a 453 with a turbocharger but still run two naturals in rough terrain cranes on a daily bases. I've owned them since the mid eighties and neither has had a head removed. I did have a 653 turbo that was a trouble free engine for many years but it was bad about cracking the fuel lines at the injectors early on.

I dunno how to do the computations, but...

I'd guess it takes minimal horsepower to get to and maintain 8 kts.

Lots more horsepower to get above 10, even more above that to reach 12. Maybe not the full 660, though.

If the boat was built when the QSC option was 500 hp, if the builder was committed to Cummins power, and if the builder thought 550 might be best for occasional need in real-world applications, maybe the QSM was the next best option.

You only have to feed the engine as much as you want to. IOW, if you're only using 100-hp most of the time, you're only burning 100-hp worth of fuel during those runs. There's probably a slight penalty for more horsepower than you'd routinely use... but I bet it's not really all that much in the grand scheme of things. (Somebody else here might be able to provide real factoids about stuff like that.)

Example: We have twin 900-hp engines. 1800-hp total. When we run within our normal comfort zone, "trawler" speed, we're burning between 6-8 GPH total (both engines). Can't (and don't) do that all the time, of course...​

Charleston toe Rehoboth is an easy trip. I'd say if you like that boat best for all it's other features, and if the price is OK for your budget, you could be boating by this time next week. Without regard to whether the engine is maybe larger than strictly necessary.

Easy for me to spend your money, though.

-Chris

BTW, Ross, that "one owner" part would likely be a plus, in my mind.

-Chris

100% THIS. For the age boats you are looking at I'd be more concerned about maintenance records and knowing the boat was frequently run. I also would not completely write off Volvo. They have made some very solid engines over the years.

We could have considered a 459, but there never was one for sale while we were shopping.

If it's got Zeus pod drives, you may want to read up on those. I don't remember if those were being built during Brunswick's Cummins/Mercruiser Diesel phase...

-Chris