I have been looking for an economical fuel cooler and came across this http://www.ebay.com.au/itm/141561027331?_trksid=p2055119.m1438.l2648&ssPageName=STRK%3AMEBIDX%3AIT
Any thoughts or comments or has anybody seen one in the flesh.

hmm looks good ...although

these look like they are made for small volumes at high pressure ?

where as we may need high volumes at low pressure   I guess if the bolts could be drilled a bit bigger at the gland interface  to allow more fuel to flow unrestricted ...or less restricted might do the job ?

I had always thought a automatic gear box oil cooler with decent inlet - outlet pipes (6mm id  or better)  ...built for volume flow  would be the best design philosophy
but as you say, hard to find at a reasonable - economical price eh ?

That looks a little small to me.

This is the one I just bought and will be putting on my RT after I find some way to protect the fins.  Am thinking of installing in front of the timing chain cover.  At 5" x 12" it is pretty big, but should give me a lot of cool.

http://www.ebay.com/itm/131327447999?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT#shpCntId

Anybody knows what the flow of a K100 pump is? (I know that pressure is over 60psi)
I am looking to adapt a cooler on my bike too, but want to be sure that I will not restrict the flow (return line).
In my case, I would mount the cooler between the bike and the chair. This way it wont get heat transfer from the water cooler. Physical size of the cooler is not very important as I have plenty of room.

Crazy Frog wrote:Anybody knows what the flow of a K100 pump is?

45 liter/hour.

Inge K. wrote:

Crazy Frog wrote:Anybody knows what the flow of a K100 pump is?

45 liter/hour.

Thanks Inge

What I was thinking was using some barbed fittings instead of the banjo type fittings. I have tried to get info from the seller but all the enquiries go directly back to China and they just repeat what is in the listing which is why I asked here on the off chance that someone had maybe seen or used one.
Looks like I may just have to buy one to find out.  It certainly looks like it may do the job, I checked out some of the fuel coolers for go-karts but they look as if they wouldn't have the cooling capacity needed unless 6 in a row were used.
I am currently using an expensive and effective power steering oil cooler on the K1100 but I haven't been able to even get one the same size.

Are you liking the blue plastic coating as a stone protector? Rick?
I could not see any size of the cooler itself but would hope it as big as the banjo fittings

K75cster wrote:Are you liking the blue plastic coating as a stone protector? Rick?
I could not see any size of the cooler itself but would hope it as big as the banjo fittings

132mm x 76mm it is anodized but not sure if the banjo fittings are 10mm or 8mm as 8mm is very common in that pit bike and thumpster brands. Size is only an NPT tap away.

Why not wander down the min bike park and tell one of the kids with one on, that his bike sound off and you can have a look to see if its a simple fix, and study the hell out of it. Or buy one just for the sake of it. Quadbikes?

Update on my cooler.  The one in the posting above arrived and it is too big and the fins are too fragile, requiring  lot of work to fabricate protective grillwork.  I am returning it in favor of this one:



http://www.ebay.com/itm/201154322208?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

Will fit nicely below the radiator on my RT, needs no grillwork, and the fuel will have a residence time of approximately 40 seconds in it.

Let me know what you go with Rick...

I have been trying to hunt down a suitable unit for a while but its surprisingly difficult...

I ended up pulling the trigger on one, but when it arrived it was badly damaged. And im glad it was because it was very poor quality that didnt show in the ebay pics. Sent it back for a refund.

Hey, that new cooler on theBay looks great and very affordable.  PLEASE update with cooling results... summer us coming and my RT is all but unbearable on warm days.

Jim, I've gone summers with the lower fairings removed (ref. my avatar). Of course this means not the prettiest aesthetics but it is a ton cooler. 
A fuel cooler/heat sink will prob help w/fuel density, etc. but it won't cool the engine measurably.

I'm just shooting for a cooler tank.  Darn near burned my thighs on it a couple times last summer. 

The cooler looks pretty nice.  Getting the bracket made next week.  Looks like the cooler will fit quite nicely below the radiator on my K75RT.  

I calculated that the fuel is in the cooler in the airstream for about 40 seconds.  I'm hoping that I can get it to exit the cooler at near ambient(< 10F above). 

Will also allow me to reroute the return line.  It's bad enough that the pressure regulator is behind the radiator, but the return line runs back under the air box, and then forward to the tank right behind the radiator.  WTF?!  I think I can get from the cooler back to the tank with the cooled gas only exposed to radiator heat for 4-5 inches of hose.

Kyle10 wrote:Jim, I've gone summers with the lower fairings removed (ref. my avatar). Of course this means not the prettiest aesthetics but it is a ton cooler. 
A fuel cooler/heat sink will prob help w/fuel density, etc. but it won't cool the engine measurably.

Well, I've ordered one of these coolers using the link.  Same seller offers 10", 12" and 15" versions.  Measuring around my radiator area, the 10" looks like it gives the most possibilities.

I agree that it won't cool the engine.  That's not my goal.

Instead, I think this will really help keep the gas tank, fuel and fuel pump cooler.   I'm going to re-route the fuel return line... get rid of the vertical part that's right behind the radiator on my K100 RT, and route the fuel return through this cooler.  In the summer, I really am burning the insides of my thighs on the gas tank, even with blue-jean pants.

For $25.92 delivered, it looks really really good.  Heck, an oil filter is $20 at my local BMW shop.  I view this as a cheap experiment.

I'll post photos and comments about how this all works out.

Point-Seven-five wrote:I'm just shooting for a cooler tank.  Darn near burned my thighs on it a couple times last summer. 

The cooler looks pretty nice.  Getting the bracket made next week.  Looks like the cooler will fit quite nicely below the radiator on my K75RT.  

I calculated that the fuel is in the cooler in the airstream for about 40 seconds.  I'm hoping that I can get it to exit the cooler at near ambient(< 10F above). 

Will also allow me to reroute the return line.  It's bad enough that the pressure regulator is behind the radiator, but the return line runs back under the air box, and then forward to the tank right behind the radiator.  WTF?!  I think I can get from the cooler back to the tank with the cooled gas only exposed to radiator heat for 4-5 inches of hose.

Hey, let me know how your routing works out.  Pictures and comments if you can.  Thanks!

Will do.  Have to get the bracket made.

Point-Seven-five wrote:I'm just shooting for a cooler tank.  Darn near burned my thighs on it a couple times last summer. 

The cooler looks pretty nice.  Getting the bracket made next week.  Looks like the cooler will fit quite nicely below the radiator on my K75RT.  

I did get a burn on my thigh from the New England get-together last year. I bought a traditional auto trans oil cooler for the same reason, but haven't had a chance to install it. The one suggested in this thread might be an easier option, so I may buy one of them instead. Clarifying: the one point seven five mentioned in post 11.

Burn on thigh and some rain on my return run in the section that was slow enough that the RT fairing/screen couldn't help much (unlike at normal highway speeds) were my only small disappointments in an otherwise great weekend at Smithy's place. 

Bill

The cooler I have on the K1100 and Charlie has on his K100 is about 150mm x 80mm and 16-18mm thick. Charlie got lucky and got one at a swap meet but I paid full price.
Its years since I bought mine and it has no brand that I can find and the local auto shop no longer employs the guy that spent a long time finding it for me so I don't know what it is to get another.
They work very well, so much so that in winter the tank doesn't even get warm so I miss out on that aspect.
I believe it was made for a very small auto trans or a power steering fluid cooler. I've been hunting all over the net but no luck so far, I have come across a few that would do the job but they are bulky.

RicK G wrote:
They work very well, so much so that in winter the tank doesn't even get warm so I miss out on that aspect.

Do they have winter in Queensland?


This is the one I bought earlier but haven't mounted yet.
http://www.ebay.com/itm/251192452340?_trksid=p2059210.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

Bill

Looks a little too small to really do anything.  With the flow rate of the fuel in the system, residence time in the cooler is probably under a second.  Not much heat transfer going to happen in that short a time.  If you strung 4 or 5 of them together, maybe, but at $28 a pop, there has to be a more cost effective approach.

I looked at that go kart cooler some time ago and decided it was too small so made one about 3 times the length but it still was not worth having as the fuel moved through too quickly and so not much cooling was done.
I can get coolers that are 3 times the size of what I have on the K1100 but they cover almost all the radiator which makes it harder for the engine cooling.
At the moment I have many other more pressing things to repair so this will take a seat well to the back.

.75
Any updates? 
Been looking into this as well. All kind of poss. solutions, from simple finned inline 'tubes' to mini radiators, eg oil coolers.

Kyle, I took the template for the mount to a fabricator yesterday.  Waiting for it right now.  Hope to have it by this weekend. 

Still at least a week away from a mount up as I'm going to have to pull the radiator grille, engine bars, lowers, and who knows what else to get things mounted. 

Will take pictures.

I ordered the same cooler as yours and I am waiting for it.
My big advantage is that I will be able to install it on the sidecar mount. If that works well, I will buy one for the solo bike too.
The funny thing is that I don't have a lot of heat problems with the solo bike but few times on the one with the sidecar, the gas was boiling to the point that I couldn't open the gas tank and the foam gasket got teared apart. (I have a complete used gas tank on its way).

I am not intending to modify the path of the return line. In stead, I will first try to put a hose coupler on the line and route it to the cooler. Then from the output of the cooler it will go back to the tank.
At least, if I have any problems, I can quickly revert to the original fuel line system.

I have all kind of modifications or maintenance to do on the bike, but with the exceptional winter that we have, I spend all my time shoveling snow and I have not done anything on the K100 yet.

The sidecar is stored under my deck and it's now seized under a heavy coat of ice. (The bike itself is in my basement)
The two other K bikes are in the shed, but I figure that it will be mid June before the lawn can absorb all the water generated by the melting ice to be able to get them on the stret.
Will I ride this year? God knows....

We've had 15+ feet of snow this winter.  The first 7 feet melted in a little over one week during a warm spell in December.  Don't worry, a few days with highs in the 40's-50's and it will be all gone and the drying can commence.  It's only mid March, and you'll be on the road before May gets here.  The snow mountains that were over 20 feet high in parking lots just a week ago are already down to only 12-15 feet high and shrinking.

Routing looks fairly straightforward on my 75.  With the cooler located horizontally in front of the timing chain cover below the radiator, I can bring the return line to it keeping it all below the radiator.  From the cooler back to the tank appears pretty easy as well.  The line would run from the cooler right up to the tank spigot right behind the radiator cowl but out of the air flow through the radiator.  The short distance where it may be in that airflow shouldn't be too hard to insulate.

The fact that the fuel pump puts out so much flow is good to help the cooling process.  As the tank level drops, the turnover rate of the remaining fuel keeps increasing.  At half tank the tank volume goes through the cooler about every 15-20 minutes with a cooler residence of approx. 40 seconds.  I expect that fuel returning to the tank won't be more than 5 degrees F above ambient. 

Last, the way I am planning to mount the cooler should make it easy to add a heat shield between it and the engine, should the need arise.

RicK G wrote:I looked at that go kart cooler some time ago and decided it was too small so made one about 3 times the length but it still was not worth having as the fuel moved through too quickly and so not much cooling was done.

Should it matter how long the fuel is in the cooler if it just returns to the fuel tank that it came from?  As fuel goes through the cooler it is immediately replaced by more fuel from the same tank, getting cooled.  A larger cooler with more cooling surface, sure, but flow rate in a closed system shouldn't matter.  Or is my logic flawed?

Darrin

In theory you are right but if the fuel is moving quickly against the cooler alloy then heat transfer isn't as good as if the fuel is moving slowly.
This is the reason I want to get the same type I have as on the K1100 because it has many small galleries that are long due to an S shaped system that is stamped into the metal before assembly.

Actually, the fluid needs to move fast enough to be turbulent for the best heat transfer.  The design  problem is providing enough distance to allow enough residence time at a turbulent flow rate to remove the desired amount of heat.

Slower is not always better.

Point-Seven-five wrote:Actually, the fluid needs to move fast enough to be turbulent for the best heat transfer.  The design  problem is providing enough distance to allow enough residence time at a turbulent flow rate to remove the desired amount of heat.

Slower is not always better.

Wow!  Received my cooler via UPS today.  VERY nicely made.  Can't beat the price.

Now: for mounting brackets.  Anxious to see what Point-Seven-Five (real name?) has come up with.

good luck jim ...stick with it ,,the results when working right are pretty good

cheers

Champing at the bit for the mount.  Bike is disassembled and ready to do the fitting.  Hope they have it tomorrow so I can start putting things back together on the weekend.  Won't have it together right away because I am taking the opportunity to do some repair work and paint on left side lower fairing. 

Working on fairing indoors.  -14C in the garage this morning.  Not pleasant wrenching weather.  OZ and Kiwi land sound so nice right now.  At least the snow is melting.  Might be gone in a couple more weeks.

Will be posting pictures and comments.

Update:

The cooler bracket arrived this afternoon and I have commenced the cooler installation.   So far I have got the bracket bolted up to the lower radiator mount and have figured out where the cooler mount holes have to go.  I have a few pictures and will be drawing up plans for the bracket so anyone can copy it.

So far, it looks like the idea is going to work, at least on a K75.   Might need some tweaking on a K100 because the engine is longer.  Only problem is that the cooler sits a little close to the bottom of the radiator grille.  I will modify the dimensions of the bracket to correct this.

Quitting for the night.  Will be getting a new drill bit, fuel line, hose clamps, and some hardware tomorrow.

if you can ....investigate nut serts    this is what you might use if drilling into the radiator mounts ( aluminium )  whilst the 1.6 - 1.8mm aluminium will hold a thread for a 4 mm bolt for a while it will strip out over time , and maintenance .

the nutsert will clamp to the aluminium and provide a wider spread of strength to the whole affair ...the threaded section of the nutsert will allow for minor slipups with torguing up the bolts so as to not strip out .

beg or borrow an insertion tool for the job ....you might only ever have to do it once

I have converted most of my threads through the surrounding frame to nutserts recently where the likely hood for removal regularly is apparent . and it works well .

Actually Charlie, I am using 6mm x 25mm bolts with fender washers regular nuts and lockwashers to replace the original flathead screws and body nuts.

I found it to be a lot easier to just push a bolt through and spin the nut on from the front, and I don't have to drill anything.

Have you decided on a cooler for the chooky Rick?

Curious to know what you'll be using.

Yeah I will be curious too.
I was told about a small cooler that a local guy saw but haven't got to checking them out yet. Apparently it was made like the Davies Craig auto trans coolers but about 50mm x 200mm and 20mm thick so it could be good.

Update:  After 4000+ miles I can say that my cooler is working very nicely.  Fuel tank temperature rise when riding in temperatures up to 80F is negligible to imperceptible.  Be aware that I also have installed insulation under the tank, and that may be helping as well. 

In any event, for the price of less than $70 the results are very satisfactory.