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37C fuel tank size

Manny

.
Oct 5, 2006
977
Hunter 82? 37 Cutter Wherever the wind takes me
In some documentation I see stated that the 37C had a 60 gallon tank, in others I see 45 gallons. Can anyone tell me what is correct? Or did it vary by year ,or by what the customer specified?
I can't tell what the size is on mine so that is why I am curious.
 
Feb 21, 2013
1,476
Hunter 46 Point Richmond, CA
The documentation for your sailboat on this site below says 44 gallons but does not specify if US or Imperial gallons.


This internet site says 60 US or 50 Imperial gallons: Hunter 37 - Wikipedia

To confirm measure the outside dimension (hopefully rectangular) and calculate the volume + width x length x height x 7.48 x 0.95 = capacity in US gallons. If you cannot do that, then gauge the tank, fill it up and then prorate the total capacity to the volume you filled. Install a depth gauge. Worst case run the tank nearly empty then fill her up to confirm the volume. Maybe the forum has another idea OR a Hunter 37 cutter knows their fuel tank capacity based on their measurement.
 
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Jan 22, 2008
1,518
Hunter 34 Alameda CA
Good luck with that one. My H34 has a tag on the fuel tank that indicates 25 gallons. There is no fuel gauge. We've run that thing completely dry a couple of times and after filling it up clear to the top of the hose, it's never taken on more than 21 gallons. Maybe it is 25 gallons at absolute zero when diesel is contracted to the max. You'll just have to figure out how much you can put into it.
 
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May 24, 2004
6,435
CC 30 South Florida
My H34 has a tag on the fuel tank that indicates 25 gallons. There is no fuel gauge. it's never taken on more than 21 gallons. Maybe it is 25 gallons at absolute zero when diesel is contracted to the max.
Allan I know you are aware of this but may help explain it for others. Tank capacity is rated with the tank totally empty. The usable fuel capacity is the amount of fuel that can be used before the pick up tube starts sucking air. This varies with the condition of the seas as the amount of boat motion may dictate when it starts sucking air. For this reason prudence dictates that a reserve of around 20% of the total size be calculated to determine the usable fuel capacity. In the 25 gallon tank the usable capacity of fuel should be capped at 20 gallons to account for that portion that cannot be accessed plus a couple of gallons for emergency use. Having an hour meter and having calculated the burn rate of the engine in Gallons per Hour (GPH) will allow a sailor to determine at any point the approximate amount of fuel he has on board and what portion is usable.
 
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Jun 8, 2004
892
C&C Frigate 36 St. Margaret's Bay, Nova Scoti
If you remove the cushion and the plywood panel under it in the aft cabin, the entire top of the diesel tank is revealed. Somewhere on the top of the tank is a builder's tag. From my less-than-reliable memory, the tank on my H37C was built by Florida Marine Tanks and was 38 US gallons (nominal capacity).
 
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Mikem

.
Dec 20, 2009
709
Hunter 466 Bremerton
Just topped off my daughter’s 1984 37c. The gage read under 1/4 full and we put in 36 gallons. That seems to confirm the 44 gallon capacity listed in the specs.
 
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Likes: sail sfbay
Jun 8, 2004
892
C&C Frigate 36 St. Margaret's Bay, Nova Scoti
Just topped off my daughter’s 1984 37c. The gage read under 1/4 full and we put in 36 gallons. That seems to confirm the 44 gallon capacity listed in the specs.
Somewhere in the forum archives there is a thread about the actual tank volumes for water and diesel... Because the tank is V-shaped at the bottom (where the float-gauge is installed), '1/4 tank' on the gauge means only a couple of gallons of usable diesel left. 1/2 full showing is more like a quarter tank in reality. I'm sticking by 38 gallons...;)

On my old H37C, I emptied the tank, cut a clean-out hatch near the gauge, cleaned the interior and refilled. As I added successive 5 gal jerry jugs of diesel, I noted the reading on the gauge and made up a table so I could accurately estimate the fuel remaining from any gauge reading. Unfortunately the table went with the boat when she was lost.

On another note, I found it was really easy to 'burp' a bit of fuel out the air vent on the stern. On my boat, the vent line was routed from near the top of the tank, down into the bilge and under the shelf that holds the hot water heater, and back up to the vent on the transom, thus trapping a bit of diesel at the bottom if I over-filled or if I sailed on port tack with a full tank. The solution is to re-route the vent line so that it leads "straight uphill" from the tank to the vent.
 
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Mikem

.
Dec 20, 2009
709
Hunter 466 Bremerton
Somewhere in the forum archives there is a thread about the actual tank volumes for water and diesel... Because the tank is V-shaped at the bottom (where the float-gauge is installed), '1/4 tank' on the gauge means only a couple of gallons of usable diesel left. 1/2 full showing is more like a quarter tank in reality. I'm sticking by 38 gallons...;)

On my old H37C, I emptied the tank, cut a clean-out hatch near the gauge, cleaned the interior and refilled. As I added successive 5 gal jerry jugs of diesel, I noted the reading on the gauge and made up a table so I could accurately estimate the fuel remaining from any gauge reading. Unfortunately the table went with the boat when she was lost.

On another note, I found it was really easy to 'burp' a bit of fuel out the air vent on the stern. On my boat, the vent line was routed from near the top of the tank, down into the bilge and under the shelf that holds the hot water heater, and back up to the vent on the transom, thus trapping a bit of diesel at the bottom if I over-filled or if I sailed on port tack with a full tank. The solution is to re-route the vent line so that it leads "straight uphill" from the tank to the vent.
Jim, you make an excellent point. The actual capacity of the tank may in fact bear no resemblance to actual usable fuel. In my daughter’s case I can only assume that it is a 44 gallon tank based on the “gage” reading and the 36 gallons we put in it. All we really know for 100% certainty is that having burned 36 gallons it did not run out of fuel. My son put 46 gallons in his 2000 H410 listed with a 50 gallon capacity. Follow the aviator maxim that the fuel you left behind does you no good.
 

Manny

.
Oct 5, 2006
977
Hunter 82? 37 Cutter Wherever the wind takes me
Thanks to everyone. I have a feeling 45 +/- is about right. While I have no idea if the fuel gauge is reading properly I had put in 15 gallons recently and noticed it moved from a little under 1/2 a tank to a little bit over 3/4 tank. I was asking because I am planning on going for long trip soon and was trying to figure out if I will need extra fuel or not. I have a rough idea of what the engine burns per hour but would also like to get that to a really accurate number if possible.
 

Blaise

.
Jan 22, 2008
359
Hunter 37-cutter Bradenton
On Midnight Sun, hull #42, the fuel tank is 42 gallons and the water tanks are 50 gallons each.
Blaise
 
May 24, 2004
6,435
CC 30 South Florida
Other than pumping fuel out of the tank and filling it back up I cannot think of an easier way to determine the tank's capacity. My other question would be, do you have a need for a 60 gallon tank or will 45 gallons do? Consider that out of those 45 gallons no more than 40 gallons should be usable capacity and that the recommended 20% reserve will leave with a prudent usable capacity of around 36 gallons. With the 3 cyl. engine that burns under 1 gallon per hour you will have about at least 36 hours of motoring. If these capacities meet your needs then call it a 45 gallon tank and operate it accordingly. Somehow having a 60 gallon tank in a 37' Hunter does not sound realistic to me. To figure out your engine burn rate, you do not need to know the size of the tank just figure how much fuel is burned for the amount of time the engine is ran between fills. Doing the calculations every time the tank is topped off will render a more refined burn rate number. Much more accurate than the fuel gauge.
 
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Jun 8, 2004
892
C&C Frigate 36 St. Margaret's Bay, Nova Scoti
I'm not interested in getting into a ruckus about H37C tankage - heck I don't even own the boat anymore - but I refer you to a site by another former owner who completely tore his 37 apart and rebuilt it (his website has probably never been seen by most of the newer owners): Rainbow Chaser. Gene Gruender worked on all the tanks and found the fabricator's tags on each tank: The water tanks are 45 US gallons each - not 50 gallons as Hunter stated - and the diesel tank is 38 US gallons, not the 44 gallons that Hunter listed. I highly recommend that any new H37C owners thoroughly read Gene's site and also José Guidera's website about his restoration of S/V Bonheur.
 
Oct 2, 2019
1
Hunter 37 Cutter Philadelphia
While we are talking about the diesel tank, I recently had to cut mine out and replace it. Attached is a drawing of the replacement tank I had fabricated. It is able to fit through the door to the aft cabin without any modifications.
 

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Sep 29, 2016
58
Hunter 37C Havelock
Mine is an 82 37C there is a tag on the fuel tank that says it was made by Florida Marine Tanks and it is 38 gallons. Yours should have one also unless someone removed it. ABYC standard required it and it was required to say the material it was made from, the capacity, that it was rated for fuel and what it was pressure tested to.