Fuel return to tanks [Archive] - TheDieselGarage.com

: Fuel return to tanks


flips
12-13-2009, 02:35 PM
I have no issues, just curious. How much fuel in GPH does a mechanical cat return to the tank,:thinking as compared to a C15 :thinking and an Acert

:thinking

ynot
12-13-2009, 03:04 PM
I have no issues, just curious. How much fuel in GPH does a mechanical cat return (20GPH+/-) to the tank,:thinking as compared to a C15 :thinking and an Acert (Both 80GPH++)

:thinking

:happymugs

Jfaulkner
12-13-2009, 03:55 PM
That explains why my fuel tanks are always warm.:happymugs

ktw900
12-13-2009, 04:05 PM
good question flips,i been wonderin that to.i figured the new ones returned alot more but wow thats alot.

CumminsISXpower
12-13-2009, 04:30 PM
Which explains why newer engines are not as prone to jelling in the winter months as the old..:buddies

bmoeller
12-13-2009, 04:49 PM
Which explains why newer engines are not as prone to jelling in the winter months as the old..:buddies

As long as the fuel pressure stays up. Shimming the pump spring has helped a LOT. 102 now, vs 90 makes a difference. So far so good at -4*. Virtually NEVER been an issue on the old E7 and EM6 Mack engines we have. Once or twice maybe. Last winter was hell with my C15. Had to run a LOT of Howes. Had to use a gallon every time I fueled up, and put in 175 gallons (and running a pair of 135 gal tanks).

How many gph on a ISX? The fuel pressure is ~290, IIRC?

CumminsISXpower
12-13-2009, 09:30 PM
65++GPH,so plenty to heat the tanks if it has been running long enough,dont here of too many problems,if ya do here about them its a careless mistake. Make sure that the lift pump is strong,and that the psi reg/drainback valves are clean of debri 25psi and 320psi/also im sure somebody has hacked it off by now but the fuel inlet screen.Oh fuel psi specs.........it take at least a 100psi IFSM rail to fire idle is 225 to 290 psi... :wave

bmoeller
12-15-2009, 03:49 AM
Never had the ISX gel yet. :) The PSI on ours is a very steady 290. :D Only time it isn't, it's needing a new fuel filter.

french277
12-15-2009, 04:08 AM
Je travaille sur peu de générateurs avec le moteur de taille simauir comme vous décrivez ici.,
Le système mech pour la classe de 14 à 16 litres le retour de carburant note typiquement environ 80 litres par heure.

Pour verison électronique ils vont beaucoup plus haut flowage ils useally exécuté à environ 300 ou plus litres par heure.

Donc vous pouvez voir grand diffrence et vous ferez a remarqué que les réservoirs à carburant sont chauds de cela.


I work on few generators with simauir size engine as you describe here.,

The mech system for 14 to 16 liter class the fuel return rate typically about 80 liter per hour

For electronic verison they go much higher flowage they useally run in about 300 or more liter per hour.

So you can see the big diffrence and you will noticed the fuel tanks are warm from that.


Merci,Marc

droy
12-20-2009, 03:47 AM
Please pardon the hijack, but would like to put a couple of questions out that are along the same topic;

(1) What would be the minimum size fuel line to use on a C 15?

(2) Best location for a fuel cooler?
Would like to install a one on my truck, I understand that some Petes have coolers under the sleeper, using the return line; I have seen some industrial engines (I THINK the model #s were 3542?, looked very similar to a C 15), powering generators, brand new @ local Cat dealer- these had a cooler mounted on the radiator brace, almost sure they used the supply line somewhere between filters and supply pump. (Meant to go back and study them in more detail, but never did).
I was given a hydraulic oil cooler approx. 15"x18", inlet & outlet look to be at least 3/4", thinking of mounting it either in front of radiator, or under sleeper.
Live in Louisiana, but do run northern states, so would I need to disable it during the winter months?

(3) Quite a few truck O/O in my area have been replacing the stock fuel / water separator with Cat # 8H-7204 (called a primary filter group). It is a canister type filter housing, with a permanent screen inside, unscrewing the large bolt on top lets you access the screen for cleaning. Supposedly this is not as restrictive as the stock spin on separator (Cat #2568753). After ordering one, I was concerned to see that the inlet and outlet was 3/8" NPT; Fellows already using this gizmo said to simply drill & tap out to 1/2" NPT, (looks easily done).
Due to it's compact size, and lack of petcock at the bottom, has me wondering if:
(A) Is it really a water trap?
(B) After opening the line size to 1/2"NPT, will it actually be less restrictive than the stocker?

french277
12-20-2009, 08:55 AM
Pour la provision de carburant j'aime garder quoi que ce soit de plus grand que 1/2 ID la ligne utilisera normalement la moitié de la ligne de pouce verison pour le retour gardent au moins 3/8 et vous exécuterez la ligne de retour au refroidisseur de carburant il y a peu d'emplacement vous pouvez le monter.

Le refroidisseur pétrolier hydraulique travaillera aussi je sais que certains ont bas tempture la valve de contournement dans là donc si trop froid il contournera juste jusqu'à ce qu'il réchauffe alors il s'ouvrira.

Comme loin pour le filtre je ne suis pas vraiment famuir avec cela un donc un de notre membre fera chorus des détails, mais la voie vous décrivant si aucune vanne de vidange ci-dessous alors ce n'est une eau seperator du tout


For fuel supply I like to keep anything bigger than 1/2 ID line normally will be using half inch line verison for return keep at least 3/8 and you will run the return line to the fuel cooler there are few location you can mount it.

hydraulic oil cooler will work as well I know some have low tempture bypass valve in there so if too cold it will just bypass until it get warm then it will open up.

As far for the filter I am not really famuir with that one so one of our member will chime in with the details but the way you describing if no drain valve below then it is not a water seperator at all

Merci.
Marc

John_G
12-20-2009, 02:49 PM
Actually, returning more fuel t othe tank makes a truck MORE prone to gelling!

There are a number of reason for this:
- The more you return, the more you draw. Higher draw rates place more strain on the filters and pumps. If you burn 10 gallons an hour (6 MPG @ 60 MPH) why pull nearly 100 to the engine? That's a LOT of work to pump that much extra fuel especially when it's cold.
- The more fuel you return, especially warm or hot fuel from the cylinder head, the more MOISTURE you will condense in the tank. By show of hands, who thinks water in your fuel tank is good? NOT ME!
- Moisture in the tanks will crystilize and plug the filters, the fuel may be flowable, but even at 30*F the water is FROZEN and blocking the filter. NOT GOOD!
- The hotter the fuel the LESS power you make. Density is related to temperature, the colder the fuel the more dense and the more power you make. That's why they use fuel coolers in racing!

CumminsISXpower
12-20-2009, 03:37 PM
I dont agree with that. However I will agree with the fact that anything hot going into cold will make condensation[water] but, anyone you ask will tell you that the more warm fuel you return to the tanks,the more you draw, the more fuel you move is less prone to jelling. I would rather run all winter with hot fuel and below average performance with a quart of water in the bottom of my tank that can be drained out,then be on the side of the road,or a wrecker coming after me! I have been doin this quite awhile and I have seen many locations for fuel coolers.Depending on the OEM,I have seen them under cab/bunk,under trans,vertical in frame rail,side of radiator,in front of radiator,or however anyone wanted to mount it. I have seen a few issues with cooler where people have installed them on the suction[draw] side of the system,which works until a leak or seap,then sucking air and not good from there! We had a gentleman who converted a big a/c condensor into a fuel cooler,that sat in front of the air to air,and was obviously catching alot of air,in the heat of summer he was averaging 72 to 78 deg fuel temps! He ran a Scaterpillar C-15 and was getting awesome fuel economy and performance,just goes to show what you can do with some time!!;)

John_G
12-20-2009, 04:22 PM
Think of it this way, if you need 12 gallons an hour from a 100 gallon tank, all you *need* to get that is a 1/4" line. Remember, you have 60 minutes to get that fuel. If you need 100 gallons, well you'll need a LOT larger line -16 or so. Why? The more draw, the more restriction.

Remember, the filters are the same area no matter the fuel draw and the more fuel you try to put thru a filter in an hour the more pressure drop there is. The greater the pressure drop the more easily the ice crystals form and you are "gelled".

The problem with higher returns is mostly from ice crystals, not the ability of the fuel to flow. Remeber that diesel, even #2 ULSD will EASILY flow at 25*F, but ice will block the filter!

CumminsISXpower
12-20-2009, 05:06 PM
So what your trying to say is you could feed any large cube engines these days with a 1/4 or 1/2 fuel line???? Its not all psi,it flow too! I will continue to run how I,and others have for a long time with no issues Thanks!!!!This ULSD crap is whats killing us anyways!! Lets go back to letting some coal roll!!:bang

black_dog106
12-20-2009, 05:42 PM
So what your trying to say is you could feed any large cube engines these days with a 1/4 or 1/2 fuel line???? Its not all psi,it flow too! I will continue to run how I,and others have for a long time with no issues Thanks!!!!This ULSD crap is whats killing us anyways!! Lets go back to letting some coal roll!!:bang

:whs

bullhauler89
12-20-2009, 06:36 PM
I guess I have more trouble with the filters waxing up more then anything, and the fact that i quit using howes helped alot, anyone ever set a bottle of howes in a snow drift about -10 it will turn to mush. Anymore I try to stop at places where I can blend my own fuel bad on economy but better than sitting on the side of the road freezing your arse off...