Fuel cooler for EFI engines

HorizonblueDK

Petty Officer 1st Class
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May 27, 2010
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355
Someday I will build an EFI V8 for my 18 footer. I sometimes wonder if it is really necessary to have a fuel cooler, if I made a return line to the tank.

This is how I would make the system, sorry for the foreign language, but I think you get the understanding anyway.

BuffertankEFI.jpg

The reason for having a buffer tank, is to avoid fuel starvation, when the level is low and slushing around in the tank.

So, would a fuel cooler be necessary here ?
 

Bt Doctur

Supreme Mariner
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Aug 29, 2004
Messages
19,346
Re: Fuel cooler for EFI engines

My understanding of fuel coolers was to cool the fuel .We used cool -cans in the race cars. Why not just use one of these after the pump but before the rail , your basic trans cooler for inboards, fitting are threaded .
HEXMER9TRACOOL_zps7f0aeee4.jpg
 

HorizonblueDK

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Messages
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Re: Fuel cooler for EFI engines

I would like to keep the engine installation as simple/clean as possible. When looking at a friends Volvo Penta 4.3 with TBI, there are hoses and pipes and boxes everywhere, rubbing against the engine paint. Doesn't look nice.

His engine doesn't have a return line to the tank, which means that a small amount of fuel is circling on top of the (hot) engine. If such a system doesn't have a fuel cooler, there would probably be vapor locks on a hot day.

When the fuel is circling back to the tank and buffertank, I suspect that it doesn't get hot enough to create problems. The buffertank can be placed in a room in the bilge.

The returnline system may not appear simple, but I can place the parts away from the engine and thereby have a cleaner engine installation.
 

Walt T

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Mar 16, 2002
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1,369
Re: Fuel cooler for EFI engines

If it's TBI it has to have a return line. I'm sure some of the guys here will correct me if I'm wrong but I always thought TBI had it.
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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50,289
Re: Fuel cooler for EFI engines

fuel coolers were added to prevent vapor lock. in fact, most gensets also have both a pre-cooler and a post cooler as well.

trust me, if the OEM could get away without a fuel cooler, they would.
 

Bondo

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71,095
Re: Fuel cooler for EFI engines

If it's TBI it has to have a return line. I'm sure some of the guys here will correct me if I'm wrong but I always thought TBI had it.

Ayuh,..... I've Never seen a return to tank line in Any boat,... Efi, or Mpi,...

The fuel canister at the motor cancels the need for a Pressurized fuel line runnin' all over the boat,...
A Leak, would fill the bilge with Gasoline,....
 

HorizonblueDK

Petty Officer 1st Class
Joined
May 27, 2010
Messages
355
Re: Fuel cooler for EFI engines

The fuel canister at the motor cancels the need for a Pressurized fuel line runnin' all over the boat,...
A Leak, would fill the bilge with Gasoline,....

Good point.

I would just like to get rid of that fuel cell. It's expensive and has caused a lot of problems on Volvo engines, so I read on this forum and other sites.

Building a system in the boat, with a returnline should off course be done with the best materials and the smartest solutions. Only rubberhose where it is necessary.
 

Fun Times

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9,126
Re: Fuel cooler for EFI engines

One of the main reasons engine manufacturers need to have their own independent fuel systems that is not connectet to the "Boat" is due to the engine needs to be able to run independently as much as possible from the boat. They don't really want to get to in depth into the fuel system on the boat side as that could be a legal liability plus they are not really sure the type of boat the engine is going to go in so one design fits all.

As Scott said, if they did not have to do a fuel system like that they would rather not.

Mastercraft boats is the only recreational boat that i know of that went outside the box and put a fuel pump with return inside the fuel tank. They had their problems as well.

The older high performance boats that have a VST tank on the engine have been having good success with running a return to the tank to prevent vapor lock. It's a good idea to do if you can.;)
 
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