Fuel return cooler

[MLee]

10 years ago there were post that inquired about putting on a return line fuel cooler to help reduce the temperature in the fuel tank, so the engine could use a bit cooler fuel. There was alot of debate about this but did anyone ever do it?

My truck seams to run alot better with cool fuel, when first started and also when fresh fuel (add) has cooled the mix some. Feels like a bit more power has been added etc.

Whats your thoughts? Did it work?

 

[Sticks]

The biggest advantage I can see from adding a fuel cooler is to assist in cooling the VP44 - which does not apply to your truck.

The cooler fuel is a tad more dense - ergo more fuel delivered on the injection - more power. Negligible differences between hot and cool.

 

[MLee]

The biggest advantage I can see from adding a fuel cooler is to assist in cooling the VP44 - which does not apply to your truck.

The cooler fuel is a tad more dense - ergo more fuel delivered on the injection - more power.

So as you have stated in the quote there might be some advantage to this install. By the seat of your pants it seem that there is a bit better performance and pulling the load up the hills untill the heat rises in the tank.

Thanks for your input.

 

[Sticks]

So as you have stated in the quote there might be some advantage to this install. By the seat of your pants it seem that there is a bit better performance and pulling the load up the hills untill the heat rises in the tank.
Thanks for your input.

What, you work for FOX News? What I stated is theoretical. IF there are any HP differences between operating temp fuel and cold fuel, it is going to be very minor, if readable. A lot of other factors come into play when you are talking about cold fuel in a coldish engine [READ - engine at operating temps, rest of the engine compartment not heat soaked yet] seeming to have more power. The same theory applies to having more power and boost on cold humid days - hence the water/meth injection that a lot of us have done.

If you do this, remember to remove/bypass/cover it up come winter.

One could also argue that you get better performance with hot fuel - earlier ignition ~ advanced timing, better atomization ~ complete burn, potentially higher exhaust temps/expansion ~ more turbo response.

 

[fox]

I remember reading an article years ago, I think by a Pittsburg diesel shop, that test show better power and performance with diesel at 80 degree fuel temps. This was done over many millions of miles in the test.
I think it also showed that best performance was at 800 EGT.
Just numbers to tune for, but with all the electronics now I would guess the stats have changed.

 

[Sticks]

I remember reading an article years ago, I think by a Pittsburg diesel shop, that test show better power and performance with diesel at 80 degree fuel temps. This was done over many millions of miles in the test.
I think it also showed that best performance was at 800 EGT.
Just numbers to tune for, but with all the electronics now I would guess the stats have changed.

That would be an interesting read.

 

[MLee]

I remember reading an article years ago, I think by a Pittsburg diesel shop, that test show better power and performance with diesel at 80 degree fuel temps. This was done over many millions of miles in the test.

I think it also showed that best performance was at 800 EGT.

Just numbers to tune for, but with all the electronics now I would guess the stats have changed.

So how did they cool the fuel to 80*? and keep it there. I can understand the 800* EGT.

Sticks, why did the drag racers in the early day of drag racing, and maybe they still do, use a COOL can for there fuel? to get more power and more denser fuel delivery. They did not use a radiator to keep the engine cool cause of the 1/4 mile run. It was weight reduction, and not needed. NO I don't work for FOX NEWS and your statement did not look like THEORETICAL to me. Just your idea for the VP44. So why do you have the water/Meth set up on your engine? to cool the fuel delivery maybe?

Same idea, different way of delivery and principle.

Having done the search on the idea and seeing that no one had given it a try, thought I'd post for an answer.

 

[GReed]

IIRC, one of the guys doing the test on cooling return fuel tested the temp of the fuel and it was about 149 degrees. There was talk about asphaltene falling out of the fuel at a lower temp. 120 degrees maybe? JEG'S and maybe Summit have an inline log style fuel or transmission cooler that should plumb into the return line fairly easy. I don't remember if they tested the fuel temp both ways from the tank to see if any difference was made.

 

[Sticks]

... So why do you have the water/Meth set up on your engine? to cool the fuel delivery maybe?

No. Water/Meth injection cools the intake air making it more dense. Higher compression pressures, better fuel burn. I can run straight water and get some performance increase with lower EGT's, but not much (the methanol helps for rapid evaporation). I can run straight methanol and get really good performance increase, and higher EGT's (I'd be adding another fuel basically).

For my truck, and the way it is setup, a 75/25 to 65/35 (water/methanol) is ideal depending on altitude and ambient temps. Roughly 70hp (based on dyno results) and 250* lower on the EGT's on a sustained run (driving up a grade at a fixed speed). I do not use it below 35*, I get a bit of a knock from the engine which may or may not be fine, I'll opt out to be safe.