What the hell... I won't be bidding. Here's what caught my eye. Doesn't it
look pretty good for the money?

Don

http://cgi.ebay.com/ebaymotors/ws/eB...MEWA%3AIT&rd=1

On Thu, 13 Oct 2005 15:04:10 GMT, "Old Boat Goat"
wrote:

Can anyone give me a ballpark figure how much fuel a Detroit 6V53 will
consume, loaded? Trying to estimate fuel consumption of twin 6V53s pushing a
45' hard chine, V-bottom cruiser, 29 gross tons.

TIA

Don


Hmmmm let's see:
thrust times speed = power required.
power divided by efficiency = fuel consumption rate

We're almost there at the answer....now tell me:
what thrust? depends on the prop size and RPMs
What speed?
What drag?

That's all we need now! :-)

Brian W

"Brian Whatcott" wrote in message
...
On Thu, 13 Oct 2005 15:04:10 GMT, "Old Boat Goat"
wrote:

Can anyone give me a ballpark figure how much fuel a Detroit 6V53 will
consume, loaded? Trying to estimate fuel consumption of twin 6V53s pushing
a
45' hard chine, V-bottom cruiser, 29 gross tons.

TIA

Don


Hmmmm let's see:
thrust times speed = power required.
power divided by efficiency = fuel consumption rate

We're almost there at the answer....now tell me:
what thrust? depends on the prop size and RPMs
What speed?
What drag?

That's all we need now! :-)

Brian W

Well I figure there has to be one or two guys around here with twin 6V53s,
or even a single, in their boats, that already know their engines burn 6
gph, 8 gph, 10 gph or whatever. That's all I was asking for. That's accurate
enough for me. Steve (see above) gave me more than expected and did so
without being patronizing.

Don

"Old Boat Goat" wrote in
news:JGB3f.177623$1i.158134@pd7tw2no:

http://cgi.ebay.com/ebaymotors/ws/eB...item=458152236
2&rd=1&sspagename=STRK%3AMEWA%3AIT&rd=1



Wow....700 gallons at $4/gallon. I'm impressed...(c;

Probably make a nice dock condo if you could put it somewhere under
$400/month.

--
Larry

On Thu, 13 Oct 2005 23:00:57 GMT, "Old Boat Goat"
wrote:

What the hell... I won't be bidding. Here's what caught my eye. Doesn't it
look pretty good for the money?

Don

http://cgi.ebay.com/ebaymotors/ws/eB...MEWA%3AIT&rd=1




40+ feet of mahogany planks on oak framed hull - looks like a mobile
wood store!

Brian W

If you cut your speed back to no more than about 1.1 x SQRT(LWL), about
7 kts, you can probably get your consumption well below 1 gph. I have
a 30 ton 49 footer with twin 671s. At 1000 RPM we get 7 kts at about
..7 gph, at 1300 RPM 8.5 kts at 1 gph.

Don,
These are '69 engines, non turbo, with 45 injectors unless modified. If you
kept her speed to about 7 knots and with a relatively clean bottom, you
might realize 6 gallons each per hour.
Steve

"Old Boat Goat" wrote in message
news:ZEQ3f.185936$1i.39408@pd7tw2no...

"Brian Whatcott" wrote in message
...
On Thu, 13 Oct 2005 15:04:10 GMT, "Old Boat Goat"
wrote:

Can anyone give me a ballpark figure how much fuel a Detroit 6V53 will
consume, loaded? Trying to estimate fuel consumption of twin 6V53s
pushing a
45' hard chine, V-bottom cruiser, 29 gross tons.

TIA

Don


Hmmmm let's see:
thrust times speed = power required.
power divided by efficiency = fuel consumption rate

We're almost there at the answer....now tell me:
what thrust? depends on the prop size and RPMs
What speed?
What drag?

That's all we need now! :-)

Brian W

Well I figure there has to be one or two guys around here with twin 6V53s,
or even a single, in their boats, that already know their engines burn 6
gph, 8 gph, 10 gph or whatever. That's all I was asking for. That's
accurate enough for me. Steve (see above) gave me more than expected and
did so without being patronizing.

Don

Thanks Brian. I was expecting a much lower fuel consumpiton figure than
either what you or Steve calculated. More in the range of what Wayne gave me
here

"If you cut your speed back to no more than about 1.1 x SQRT(LWL), about 7
kts, you can probably get your consumption well below 1 gph. I have a 30
ton 49 footer with twin 671s. At 1000 RPM we get 7 kts at about .7 gph, at
1300 RPM 8.5 kts at 1 gph."

I've heard commercial fisherman up here (B.C. Canada) brag about the
economy of their 6-53s in 35' - 40' trollers. Heavy built, beamy,
displacement hull workboats. 2 - 3 gph is what I recall guys telling me but
I sometimes can't believe what I remember. It's been 25 years since I was
involved in that fishery.

It's all a moot point since the boat in question has now sold. Still, It
would have been a neat, relatively cheap adventure for this old seadog.
Might have had some good times and sold the boat at profit a few years on.
You wouldn't believe what a "dock condo" rents for in Victoria harbour right
now.

Don





I didn't mean to pastronize - I like to help!
But accuracy is not at stake. It's all the variables.

How about this approach - for any diesel,
say 0.4 lb of fuel per HP hour
So an honest 100 HP costs 40 lb/hr = 7 gal/hr
an honest 200 HP costs 14 gal/hr

A 100HP drives different hulls at different speeds. Naturally.


Brian Whatcott Altus OK

On Sat, 15 Oct 2005 21:24:33 GMT, "Don"
wrote:

Thanks Brian. I was expecting a much lower fuel consumpiton figure than
either what you or Steve calculated. More in the range of what Wayne gave me
here

"If you cut your speed back to no more than about 1.1 x SQRT(LWL), about 7
kts, you can probably get your consumption well below 1 gph. I have a 30
ton 49 footer with twin 671s. At 1000 RPM we get 7 kts at about .7 gph, at
1300 RPM 8.5 kts at 1 gph."

Don

If using 100 HP takes 7 gal/hr, then 0.7 gal/hr means you throttle
down to 10 HP tops. Nothing magic there. And yes I know, it is
pleasant to dream that if you held your mouth just right, you could be
at the helm of a mighty sea boat again! My dreams tend to focus on
airplanes these days - the only toy I do not presently own but do
covet.

Brian W

If using 100 HP takes 7 gal/hr, then 0.7 gal/hr means you throttle
down to 10 HP tops. Nothing magic there. And yes I know, it is
pleasant to dream that if you held your mouth just right, you could be
at the helm of a mighty sea boat again! My dreams tend to focus on
airplanes these days - the only toy I do not presently own but do
covet.

Brian W

Had one of those too. Sold it at a low (and broke) point in my life.
Starduster II, a lovely biplane, 190 HP, CS prop. Wish I still had it but...
It's still around the area and I could have it I really wanted it but... at
this time in my life, the annual meds. are a concern.

Good luck. Get one if you can, you (and your kids) will never regret
it. You can always sell an airplane. Not so a boat.

Don