detroit 6v53 power on hatteras

[scubajohn]

i would like to know if the 653 is a good sorce of power for a hatteras 40 ft
they are in the boat so iwould like to keep them.

what would the cruise be and what about fuel consuption they are rated 210 hp each

any help would be great thanks john

[Ike]

The Coast Guard has used the 6V53 engines in their 41 foot utility boats for many years with great success. Someone else will have to tell cruise and fuel consumption. I managed a CG industrial facility where we overhauled engines and the 6V's went at least a 1000 hours (that's ten years for the average boater) under really hard use (Used and abused is more like it) between overhauls. Of course the Coast guard can put that many hours on an engine in less than couple of years. They were very rugged and reliable

[FAST FRED]

what about fuel consuption they are rated 210 hp each

An antique design (1936) that is Very reliable and would definatly be worth keeping.

These engines NEED to be loaded at 60% or more to be efficent, less than 60% does not reduce the fuel burn by much.

A Gal an hour will give 16 hp if properly set up, so running at 125hp or so will cost about 8 gph per engine.

New engines with electric injection , turbos and intercoolers MAY get 22 to 24 hp from the same gallon of diesel.

But paying for the swop would require hunderds , or thousands of hours of operation , just to brake even.

Keep what you have , but DO remember Detroits use 40wt CF-2 lube oil , and multigrade will kill them DEAD!

FAST FRED

[scubajohn]

thanks for the info guys i feel better about them now and a big thanks on the oil does this aplly to all diesles or just detroits anyone have a guess on speed 41 ft hat fishing boat

[stevel]

Originally Posted by scubajohn

thanks for the info guys i feel better about them now and a big thanks on the oil does this aplly to all diesles or just detroits anyone have a guess on speed 41 ft hat fishing boat

This applies to 2-stroke diesels. Something about being in a 2-stroke diesel makes multi-viscosity oils want to shed polymers. My dad wouldn't listen to that advice, ran Rotella (a fine product for it's intended use) in his 8v71 and ended up ventilating the block with a connecting rod.

My single 6v53 runs great in a 26' personnel boat, and gets the same fuel consumption numbers that have already been mentioned.

[Corpus Skipper]

From my experience, an older (heavy) 40' Hat with 6-53s should run about 19-21 kt. wide open with a moderate load, and cruise 15-17 kt, at about 16-18 gph total, 25 gph total at wot.

[williewiskers]

"From my experience, an older (heavy) 40' Hat with 6-53s should run about 19-21 kt. wide open with a moderate load, and cruise 15-17 kt, at about 16-18 gph total, 25 gph total at wot."


I have an OLD (1961) Uniflite 42' and 6v53n engines and Im having a hard time matching props to my boat. Based on your experience with your 40' Hat, what props were you using to get the numbers referenced in the cited post?

I have run it through all the calculators and called prop shops, but the answer isnt clear.

Loaded weight= 52000#
waterline length= 39'
length= 42' (45' LOA w/ pulpit and platform)
shaft dia= 1.75"
shaft material= naval brass (some corrosion)
two engines= 216 HP S.A.E. HP each (210 at shaft)

borg warner velvet drive transmissions assumed to be 2.10:1
(@ 2.10 ratio the max SAE HP is 250 with safety factor of 2 and naval brass shafts @ 1.75")
(@ 2.57 ratio the max SAE HP is only 205 with same shafts)

1.91 ratio trans's wouldnt be an appropriate ratio and the 2.57 is too much for the shaft, so I assume 2.10:1.



On the whole internet, you are the only one who seems to have something close to what I have that actually seems to know something about it.


Thanks for your reply

Chris
Lincoln Harbor
Weehawken, NJ
Hudson River

[gonzo]

Those old Detroits will leak oil. It is an ongoing problem with them. The solution is to install a drip pan under to prevent the oil from spreading throughout the boat.

[stevel]

They are just marking their territory.

Originally Posted by gonzo

Those old Detroits will leak oil. It is an ongoing problem with them. The solution is to install a drip pan under to prevent the oil from spreading throughout the boat.

[gonzo]

That's one way to make yourself feel good about the oily territory surrounding a DD

[FAST FRED]

The old truckers motto

"
IF Detroit Diesel made bricks ,
they would be green,
And LEAK OIL!

FF

[bentleyboats]

I love the comments about this wonderful motor. I've had the privilege of working on quite a few of these. Using single viscosity oil is a must. Ventilating a block, that's a good one.

I think 210 hp is a little light for the Hat. The 42' Oceans and 40 Tollys use 300-400hp. Now the Hat may be a semi displacement boat, I don't remember off hand. Prop design is at best a trial and error effort.

This is going to be fun. I'm repowering a 30 Tolly Sport Cruiser with either 300hp Cats or a 300+ Detroit. 6b Cummins are also a consideration. The real issue is that this thing is v drive.

I agree with the 60% thing, but are we talking natural asp here? The turbos have to be run up to get best efficiency. Naturals don't seem to care.

Every time I hear some know it all knock a Detroit at a boat show, I want to throttle them, or beat them about the face and neck. Obviously they know nothing about Detroits. I can fix oil leaks, a little atf in the fuel every so often keeps the injectors clean. Running multi grade oil gives off horrible blue smoke on fire up cold. I can see that a mile away.

I enjoyed the comments. If I can be of help, let me know.

[351EFI]

An old trucker friend of mine described the Detroits as "Green Leakers" and went on to state that "The only thing they do well is convert diesel fuel into noise".

That was a bit harsh, and I'm sure that there may be a small amount of truth in it, but the fact remains that there have been thousands of these engines, in all sorts of applications that have given years of trouble free service. On the rugged West Coast of British Columbia, it is said that they are the closest thing to being a "logger proof" engine that has ever been built. Anyone who has spent time in logging camps can appreciate this.

Sure, they are an antiquated design, not particularly easy on fuel, and can be a bit hard to live with if not adequately silenced, but they are rugged, relatively cheap to fix, and parts are available almost everywhere.

If I were in your situation I'd keep them.