fuel consumption

[Stan Ditcham]

Hi all,
I recently purchased a 3607 carver with 2 x 350 hp engines.
I have not used the boat yet as i bought it winter stored 300 miles away and will fit it out and sail it home in spring.
the fuel tanks hold 250 gals us,
travelling at about 8-9 knots what kind of fuel consumption should i expect? (hourly?)
Does anyone know where i can buy a main replacement hatch .Size 19.5 in X 19.5 in.cutout size. New or used?
Does anyone know the size of the thru hull fittings located just above water line. We have 2 ac's .?
Thanks for any assistance.

[bud37]

Welcome to the forum....

[SkyeToo]

here is some data for that boat and engine combo which I use as a rough guide
CARVER FUEL CONSUMPTION

At .7 nmpg (be sure to take that extra step to nm or calculate speed in mph) at

16 kts (roughly 2800 RPM) that's 11.2 gph (43 liters/hour)

$4 per gal. $44.80 per hour x 8 hour day= $358.40

$1.4 / liter * 43 = $60 CDN/ hour @ 16knots (APPROX $44 USD/hour)

POOR mileage is around 12 knots – below plane, above hull speed

WORST – flat out ($100/hour at least)

[km1125]

I think those tanks are 240 Gallons, or 120 per side. Not much of a difference but if you're filling them up or running them down that extra 10 might. The fuel pickups and gauge sensors are at the rear of the tanks, so as you get up on plane you'll see the fuel level increase as the fuel tilts towards the back of the tank. That's great when you're up on plane but when you drop down to idle again and that fuel goes back to level it could be a cause for concern if you are really low. If you ever get in that situation, then turn BOTH engines to just one tank and run that one dry, then switch to the other tank.

8-9 knots is pushing the hull speed a bit. 8-9 MPH is probably best for fuel consumption. I don't think I'd expect more than 2MPG or about 4-6 GPH (both engines)

When you say "main replacement hatch" are you talking about the one above the V-berth? That is the same size and style as the one in the aft cabin. Those were made by Grey Enterprises, who was later bought out by Bomar and then Pompanette. They won't have the originals anymore but should have something that fits the hole.

Here is a thread where another member was discussing these hatches:
viewtopic.php?f=30&t=5185&p=39229&hilit=pompanette#p39229

For the through-hulls, are you just referring to the ones for the A/C units? You should have at least 5 others... two for bilge pumps, one for the aft sink, one for aft shower sump and one combo that does the galley sink and fwd shower sump.

Also, there is the hose size and the cutout diameter. You can have fittings for the same 3/4" hose, but two totally different cutout diameters, so be careful if you're just trying to buy replacement parts.

[g36]

Here's a good website with various engines you can select yours and see apx fuel burn at various rpms.....https://www.boat-fuel-economy.com/crusa ... us-gallons

[SkyeToo]

g36 - thanks for this meter. One should note that is for 1 engine, not 2.
very useful!

SkyeToo

[bud37]

Qr Bbpost g36 - thanks for this meter. One should note that is for 1 engine, not 2.
very useful!

SkyeToo

There is a twin engine choice on that calculator....choose merc then home and at the top you will see choices for different engine size/hp ratings...I would consider the hp more than the specific engine Cubic inch size as fuel burn is related to the used HP.....it is all ballpark anyway in relation to overall engine health and the quality of the build....no two are the same.

[Winegrapewill]

I recently installed fuel flow meters on my 1989 3607 with twin 350hp/454's. Best fuel nmpg is very near 1600 rpm, which is around 7.5 kts on a medium loaded boat with full fuel and water. Works out to about 1.2 nmpg. Put is up on plane and it goes to about .5 nmpg from 15 to about 20 knots (rpm to about 3700). The engines run really good that fast, but the whole in the wallet is a bit much. If you have tide, it always helps to go with (it has jumped my nmpg as high as 1.8, and down to 1 against)

Good luck, they are great boats.

[km1125]

Qr Bbpost I recently installed fuel flow meters on my 1989 3607 with twin 350hp/454's. Best fuel nmpg is very near 1600 rpm, which is around 7.5 kts on a medium loaded boat with full fuel and water. Works out to about 1.2 nmpg. Put is up on plane and it goes to about .5 nmpg from 15 to about 20 knots (rpm to about 3700). The engines run really good that fast, but the whole in the wallet is a bit much. If you have tide, it always helps to go with (it has jumped my nmpg as high as 1.8, and down to 1 against)

Good luck, they are great boats.

Those numbers sound a little bit low, but not by a huge amount. How's your ignition timing? Do you have electronic ignition or points? Are you still running carbs or do you have fuel injection?

[Winegrapewill]

Timing was checked and both at 12 deg btdc. 2 deg high but no pinging, no overheat. I'm gonna leave it. Running Quadrajets tuned with a vacuum gauge for idle mixture, 20 hg at idle. Distributors are electronic Prestolite. I usualy keep full water tank and full fuel so I'm not light. That might explain it.