The Thigh Burner

[double_entendre]

I think it was TWN who made a comment about inserting a power steering fluid cooler into the fuel return (to tank) line on the FJR to combat the heating of the tank. I thought that was a pretty cool idea and started looking into it today. My thought was that you could almost do it using an oil cooler like the BMW GS bikes had (have?) for oil cooling.

But I also turned up these threads and thought they were of interest.

https://forums.corvetteforum.com/showthread.php?t=1444874

Hmmm...a genuine actual built to task fuel cooler. I bet I could attach that in front of the radiator to one side so that it didn't interfere with the wheel or forks, eh?

https://forums.corvetteforum.com/showthread.php?t=1415268

Egads. As mentioned in the first thread, the fuel rails on a Vette get up to 165 degrees? No wonder the freaking gas tank gets so hot. "Hey, I know. I'm gonna fill this metal container with 165F gasoline and stick it between my legs :blink: to complement the 98.6F fire extinguisher I've already got there." :lol:

It looks like the pre-cooling efforts temps could be pretty absurd. A cooler might be the way to go.

I've rooted around to see if Earls has a web site, but can only find distributors of their stuff. Anyone know their web site?

Thoughts? Comments? Anyone already tried this line of thought?

Bob

Rancho Cucamonga, CA (Moving Saturday!!!!!!!!)

 

[twowheelnut]

I think it was TWN who made a comment about inserting a power steering fluid cooler into the fuel return (to tank) line on the FJR to combat the heating of the tank.

Nope, wasn't me. I have no heat issue with this bike. Too, the bike has an oil cooler. Thanks for thinking of me, though.

 

[double_entendre]

I think it was TWN who made a comment about inserting a power steering fluid cooler into the fuel return (to tank) line on the FJR to combat the heating of the tank.

Nope, wasn't me. I have no heat issue with this bike. Too, the bike has an oil cooler. Thanks for thinking of me, though.

Every night, baby. :wub:

But seriously, folks....

I did search a bit, but I'm just convinced that the search engine doesn't work really well and the post was recent enough (or something) that even Google can't find it. Ah well.

Anyway, I stick with my idea. Cool the fuel before returning it to the tank and that solves a big (to me) issue.

When I've got a garage, time & money I may just see if this is doable.

Bob

Rancho Cucamonga, CA (Moving Saturday!!!!!!!!!!!!)

 

[Geezer]

You already know this, but I have to say it anyway. Be very careful where you mount that cooler. You don't want a stone to puncture it while it's full of hot fuel.

And I'd be careful about using a cooler that was not designed for fuel. Probably OK if all parts are metal, but if there are other materials in it they may not hold up with pressurized fuel flowing through them.

 

[evil_henchman]

Here's a thought. Water cooled dirt bikes have all aluminum radiators and they come in 2 halves. One half is pretty small relative to the space in front of the FJR radiator. And there's a lot of really heavy duty guards available. Mine have stood up to all but the worst slam downs and I've never had a puncture. Might be just the ticket.

 

[double_entendre]

You already know this, but I have to say it anyway. Be very careful where you mount that cooler. You don't want a stone to puncture it while it's full of hot fuel.
And I'd be careful about using a cooler that was not designed for fuel. Probably OK if all parts are metal, but if there are other materials in it they may not hold up with pressurized fuel flowing through them.

Indeed, indeed. My thoughts were pretty much the same and the guy who originally posted about using a power steering cooler was worried about that too. Hot gasoline spraying onto a hot engine. Be very exciting. "Hello, State Farm?" :blink:

I'll have to contact Earls and see what they say, but I'm having a tough time finding their web site for some reason.

Bob

Rancho Cucamonga, CA (Viva HB!)

Here's a thought. Water cooled dirt bikes have all aluminum radiators and they come in 2 halves. One half is pretty small relative to the space in front of the FJR radiator. And there's a lot of really heavy duty guards available. Mine have stood up to all but the worst slam downs and I've never had a puncture. Might be just the ticket.

That or something like the radiator shield that I bought would work too. Probably want to use stainless steel braided lines or something like that as well, if not custom bent hard lines. Hmmm..

Bob

Rancho Cucamonga, CA (Get me outta here!!!!!)

 

[double_entendre]

Bingo. Might have found a part here:

https://www.jegs.com/webapp/wcs/stores/serv...ategoryId=10291

Bob

Rancho Cucamonga, CA (104 degrees today. Bloody hell.)

 

[HaulinAshe]

https://www.jegs.com/webapp/wcs/stores/serv...ategoryId=10291

Any idea what the physical dimensions are of that unit?

 

[double_entendre]

https://www.jegs.com/webapp/wcs/stores/serv...ategoryId=10291
Any idea what the physical dimensions are of that unit?

I found this: https://www.perma-cool.com/Catalog/Cat_page15.html (see the middle of the page). Seems to me that there's no way you could fit the 1200/1210 unit on the bike, but the other two would probably fit.

I can't quite tell from the pics, but it looks like they have either hose clamp or threaded fittings and I'm sure we'd want to go with the threaded and stainless steel hose. And probably wrap the hose with plastic to provide an additional layer of protection.

This is getting downright interesting. :detective2:

Bob

Rancho Cucamonga, CA (Movers show up Saturday!)

 

[nusman68]

-it was Radman that had the idea of the cooler, in case you were still wondering...

the idea looks sound; to pull it off from an engineering standpoint is another; but I'm sure it's feasible. Think I'll be looking for mounting points....

Might raise a few eyebrows in the service dept., though:

Service manager: "What the hell happened here Bubba?"

Bubba: (lit cig still in his hand) "I don't know, I wuz working on this here FJR, got the fairings pulled off, went to unhook this oil cooler and it went up like kindlin"! :dribble:

Yeah, yeah, I know....not all service depts. are that bad!

 

[Capt. Bob]

[i can't quite tell from the pics, but it looks like they have either hose clamp or threaded fittings and I'm sure we'd want to go with the threaded and stainless steel hose. And probably wrap the hose with plastic to provide an additional layer of protection.

This is getting downright interesting. :detective2:

Bob

Rancho Cucamonga, CA (Movers show up Saturday!)

On my 66 Chevelle (in my drag racing days) I ran a "cool can". Copper tubing inside of a coffee can size vessel that was then packed with dry ice. Cool the fuel, make it denser, pack more in and go much faster. In your app. you're trying to just cool the fuel. Don't know where you would mount it. Maybe on the back like some do for the aux. fuel cell. Back there you could mount a large "cooler" and fill it with standard ice each time you stopped for a break. Extreme idea to say the least but probably fairly safe. Heat would have to bother me very much to do this mod.

Just a thought, though probably not much of one. Must be the heat.

 

[murf]

The fuel cooler probably would help by cooling off the returning fuel. However, I'd venture the majority of the heat transmitted to the tank comes from the heat rejected by the engine. The 06's seemed to have solved the problem by putting in a heat shield and moving air through the space between the tank and shield.

 

[3dogs]

It is hard to tell if the 06 keeps its tank cool due to just the heat shield. The 06 design does not return fuel from the fuel rail to the tank as the eariler models do so no heat is carried by the fuel into the tank.

 

[double_entendre]

-it was Radman that had the idea of the cooler, in case you were still wondering...the idea looks sound; to pull it off from an engineering standpoint is another; but I'm sure it's feasible. Think I'll be looking for mounting points....

Might raise a few eyebrows in the service dept., though:

Service manager: "What the hell happened here Bubba?"

Bubba: (lit cig still in his hand) "I don't know, I wuz working on this here FJR, got the fairings pulled off, went to unhook this oil cooler and it went up like kindlin"! :dribble:

Yeah, yeah, I know....not all service depts. are that bad!

:lol: :lol:

I'm sooooooo glad I do my own work. Thanks for the Monday morning laugh!

Bob

Huntington Beach, CA

 

[double_entendre]

[i can't quite tell from the pics, but it looks like they have either hose clamp or threaded fittings and I'm sure we'd want to go with the threaded and stainless steel hose. And probably wrap the hose with plastic to provide an additional layer of protection.


 



This is getting downright interesting.
:detective2:
 



Bob



Rancho Cucamonga, CA (Movers show up Saturday!)

On my 66 Chevelle (in my drag racing days) I ran a "cool can". Copper tubing inside of a coffee can size vessel that was then packed with dry ice. Cool the fuel, make it denser, pack more in and go much faster. In your app. you're trying to just cool the fuel. Don't know where you would mount it. Maybe on the back like some do for the aux. fuel cell. Back there you could mount a large "cooler" and fill it with standard ice each time you stopped for a break. Extreme idea to say the least but probably fairly safe. Heat would have to bother me very much to do this mod.
 
Just a thought, though probably not much of one. Must be the heat.


(Quotes weren't working for some reason, so I just indented; I'm sure most of you are smart enough to figure it out.)

Meant to reply to this a while ago and been absolutely buried for quite a while at work & home both.

Love that cool can idea, but it doesn't sound too practical for long-distance (i.e., > 0.25 mile) usage. :lol:

My original thought was to mount the cooler in front of the radiator and trim the stone guard to fit it and protect it from rocks and whatnot.

For me the heat is a big deal, in part because my left shoulder is all screwed up from my first motorcycle wreck (stuffed my 1983 GS450 into an Armco guardrail and landed on it) and so when I'm riding I'm using my legs against the tank and back muscles to support my body, keeping as much weight off of my wrists as possible. Doing that also keeps weight off of my shoulder and that keeps it from hurting. If I spend much time with weight on that shoulder it gets to hurting pretty bad.

Problem is that clamping my legs against the tank as part of my body support can damn near burn the insides of my thighs.

What Mama Yama ought to do is offer a retrofit kit for the pre-06 models to eliminate the fuel return line that dumps hot gas into the tank. :glare:

Failing that, just call me the Bob Villa of FJRs.

Bob

Huntington Beach, CA :yahoo: :yahoo: :yahoo:

P.S. Thanks to Radman for the idea!

 

[tripletango]

[i can't quite tell from the pics, but it looks like they have either hose clamp or threaded fittings and I'm sure we'd want to go with the threaded and stainless steel hose. And probably wrap the hose with plastic to provide an additional layer of protection.


 



This is getting downright interesting.
:detective2:
 



Bob



Rancho Cucamonga, CA (Movers show up Saturday!)

On my 66 Chevelle (in my drag racing days) I ran a "cool can". Copper tubing inside of a coffee can size vessel that was then packed with dry ice. Cool the fuel, make it denser, pack more in and go much faster. In your app. you're trying to just cool the fuel. Don't know where you would mount it. Maybe on the back like some do for the aux. fuel cell. Back there you could mount a large "cooler" and fill it with standard ice each time you stopped for a break. Extreme idea to say the least but probably fairly safe. Heat would have to bother me very much to do this mod.
 
Just a thought, though probably not much of one. Must be the heat.

(Quotes weren't working for some reason, so I just indented; I'm sure most of you are smart enough to figure it out.)

Meant to reply to this a while ago and been absolutely buried for quite a while at work & home both.

Love that cool can idea, but it doesn't sound too practical for long-distance (i.e., > 0.25 mile) usage. :lol:

My original thought was to mount the cooler in front of the radiator and trim the stone guard to fit it and protect it from rocks and whatnot.

For me the heat is a big deal, in part because my left shoulder is all screwed up from my first motorcycle wreck (stuffed my 1983 GS450 into an Armco guardrail and landed on it) and so when I'm riding I'm using my legs against the tank and back muscles to support my body, keeping as much weight off of my wrists as possible. Doing that also keeps weight off of my shoulder and that keeps it from hurting. If I spend much time with weight on that shoulder it gets to hurting pretty bad.

Problem is that clamping my legs against the tank as part of my body support can damn near burn the insides of my thighs.

What Mama Yama ought to do is offer a retrofit kit for the pre-06 models to eliminate the fuel return line that dumps hot gas into the tank. :glare:

Failing that, just call me the Bob Villa of FJRs.

Bob

Huntington Beach, CA :yahoo: :yahoo: :yahoo:

P.S. Thanks to Radman for the idea!

Fuel cooling is not the answer. Messing with the design of the bike yeilds nothing but liability and safety issues and really creates more problems than it solves. It is a well designed bike with a few quirks.

I reckon the best way if you can take care of it and more cheaply is with the bagster tank cover?

 

[radman]

While any method of cooling the fuel would have a direct benefit for both motor and pilot, any device that routed fuel outside the protection of the frame would be dangerous as hell should a crash occur. My idea was to use a Ford power steering cooler, found by the thousands on older (70's) LTD's, Grand Marquis etc, we used a lot of them as engine oil coolers on Enduro cars we built to run at local circle track events to make money to support my Late Model car. They were cheap, tough, and plentiful, but were set up for hose and clamp connection only, which would work on the Feej return line, but still would add two leak-prone fuel line connections. Also, there are very few spots to locate it even if crash worthiness is not a consideration-it's useless without airflow around it. Another thought is to just use steel tubing and make a long loop of it, also in the return line, which is how GM cools PS fluid on many of their front drivers. Would be easier to find a fairly safe location for it, around the outer front edge of the radiator would be ideal, and easy to fabricate. But in any case, safety must be Job 1, any leak would likely prove to be catastrophic.

 

[jestal]

It will be interesting to see the results of anyone trying this but I will go down on record saying that cooling the fuel returned to the tank is pointless.

Work on the air flow. The heat on you is coming from the hot air flowing over the top of the engine/bottom of the tank.

There is an interesting phenomenon with fuel in a tank like that. It just does not get as hot as you think it might. To understand this, first think about water boiling at 212 F and will stay at 212 (boiling away) no matter how high you turn the burner up. More heat makes the water boil faster but it does not get hotter than 212 F. If you put a thermocouple or other temperature monitoring device into the fuel in the tank you will see it warm up slightly and then stablize at a temperature....probably around 130 F. It will stay there no matter how much hot fuel is poured into the tank because the fuel starts to "boil" off the light ends and it will stay at that temperature until all the light ends are boiled off. Basically what happens is that the fuel is starting to be distilled and it will stay at the "boiling" point of the lightest of the light ends (around 130F) until they are gone.....much like the water stays at 212 F no matter how much heat is applied or how long the heat is applied.

The tank skin temperature might go higher due to the hot air being blown over it but that is not going to be corrected by cooling the fuel...you need to stop the hot air flow.

I have seen many situations where the amount of heat introduced into the fuel tank of vehicles was reduced dramatically by adding coolers and/or heat shields but the actual bulk fuel temperature inside the tank was hardly changed at all...I mean only one or two degrees F from running with or without a heat shield. The amount of vapor generated by the tank was affected considerably (boiling less of the light ends off due to less heat input) but the actual liquid fuel temp hardly changed at all. If you are worried about vapor generation, cool the fuel. If you are trying to make the tank cooler, cooling the fuel is not going to do much at all.

Making fuel "cooler" does not make it more dense to make more power. Sorry, another old wives tale bites the dust. "Cool cans" were put onto fuel lines for carbureted hot rods to cool the fuel before it enters the carb so that it does not have the tendency to flash into vapor. Carbs don't handle vapor real well and excess vapor caused by hot, volitile fuel dropping pressure suddenly across the needle and seat in a carb is what caused the power loss. So, cooling the fuel helps that situation. That engine might run better with a cool can but it runs better because the carb is working correctly not because the fuel is denser and thus putting more fuel into the engine. The engine will only run correctly or be optimized for a specific air/fuel ratio....say 12.5:1 for best power. If the fuel is suddenly made "more dense" it would make it richer and then the engine would loose power because it would be over rich. If it ran better because of denser fuel then the carb was too lean to begin with and correcting the carb settings/jetting would have been more appropriate than making the fuel denser.

In some fuel system plumbing cool cans were used ahead of the mechanical fuel pump to prevent vapor lock of the fuel pump. As the mechanical pump sucked on the fuel line any high volitility fuel would flash into vapor more easily and the pump would lock up on the vapor. So...it runs better with the cool can because the fuel pump can now pump...not because of "denser fuel".

The guys on that Corvette forum well meaning but misinformed. A fuel cooler is simply not needed nor required. Rare cases might exist where cooler fuel might help vapor lock symptoms with an intank pump or something but not for the situations described.

If you want to cool off the FJR take the time to pull the radiator and seal up the panel behind the radiator to stop the hot air from the rad and from over the exhaust pipes from being routed up over the top of the engine onto you.

 

[double_entendre]

It will be interesting to see the results of anyone trying this but I will go down on record saying that cooling the fuel returned to the tank is pointless.
Work on the air flow. The heat on you is coming from the hot air flowing over the top of the engine/bottom of the tank.

True maybe? If my legs are clamped against the tank and they're burned where they were touching the tank, isn't the issue the tank or the contents thereof as much as the hot air under the tank that's heating it?

There is an interesting phenomenon with fuel in a tank like that. It just does not get as hot as you think it might. To understand this, first think about water boiling at 212 F and will stay at 212 (boiling away) no matter how high you turn the burner up. More heat makes the water boil faster but it does not get hotter than 212 F. If you put a thermocouple or other temperature monitoring device into the fuel in the tank you will see it warm up slightly and then stablize at a temperature....probably around 130 F. It will stay there no matter how much hot fuel is poured into the tank because the fuel starts to "boil" off the light ends and it will stay at that temperature until all the light ends are boiled off. Basically what happens is that the fuel is starting to be distilled and it will stay at the "boiling" point of the lightest of the light ends (around 130F) until they are gone.....much like the water stays at 212 F no matter how much heat is applied or how long the heat is applied.

That's believable, but 130F is still pretty toasty. How hot does water have to be to burn you? According to a few sites I found, the whiners will tell you to not set your hot water heater over 125F. So if the tank contents are 130, that's toasty.

The tank skin temperature might go higher due to the hot air being blown over it but that is not going to be corrected by cooling the fuel...you need to stop the hot air flow.

I wonder if a two-pronged approach doesn't solve the issue. If the issue is from hot air being directed under the tank and also hot contents in the tank, addressing one but not the other might mitigate the issue, but not completely solve it.

I have seen many situations where the amount of heat introduced into the fuel tank of vehicles was reduced dramatically by adding coolers and/or heat shields but the actual bulk fuel temperature inside the tank was hardly changed at all...I mean only one or two degrees F from running with or without a heat shield. The amount of vapor generated by the tank was affected considerably (boiling less of the light ends off due to less heat input) but the actual liquid fuel temp hardly changed at all. If you are worried about vapor generation, cool the fuel. If you are trying to make the tank cooler, cooling the fuel is not going to do much at all.

Maybe I have someone cut the tank and insert an internal tank with an air space between the two layers. :lol:

Making fuel "cooler" does not make it more dense to make more power. Sorry, another old wives tale bites the dust. "Cool cans" were put onto fuel lines for carbureted hot rods to cool the fuel before it enters the carb so that it does not have the tendency to flash into vapor. Carbs don't handle vapor real well and excess vapor caused by hot, volitile fuel dropping pressure suddenly across the needle and seat in a carb is what caused the power loss. So, cooling the fuel helps that situation. That engine might run better with a cool can but it runs better because the carb is working correctly not because the fuel is denser and thus putting more fuel into the engine. The engine will only run correctly or be optimized for a specific air/fuel ratio....say 12.5:1 for best power. If the fuel is suddenly made "more dense" it would make it richer and then the engine would loose power because it would be over rich. If it ran better because of denser fuel then the carb was too lean to begin with and correcting the carb settings/jetting would have been more appropriate than making the fuel denser.
In some fuel system plumbing cool cans were used ahead of the mechanical fuel pump to prevent vapor lock of the fuel pump. As the mechanical pump sucked on the fuel line any high volitility fuel would flash into vapor more easily and the pump would lock up on the vapor. So...it runs better with the cool can because the fuel pump can now pump...not because of "denser fuel".

The guys on that Corvette forum well meaning but misinformed. A fuel cooler is simply not needed nor required. Rare cases might exist where cooler fuel might help vapor lock symptoms with an intank pump or something but not for the situations described.

Neat stuff. More than I ever knew about the topic, though I'd heard of vapor lock I had no idea what caused it.

If you want to cool off the FJR take the time to pull the radiator and seal up the panel behind the radiator to stop the hot air from the rad and from over the exhaust pipes from being routed up over the top of the engine onto you.

The only spot where the hot air on me gets annoying is my left shin, and it seems to me that some of the folks who have done air redirection have had the overall engine temp go up because the air flow was reduced. True?

Thanks a ton Jestal for all the time you put into this. I sincerely appreciate your thoughts and suggestions.

Bob

Huntington Beach, CA