Changfa Kubota radiator delete!?

[XYZER]

I have been putting together a small generator from parts I have acquired. The engine is a Kubota EA500-N.

I built a new frame and installed a Leece Neevel to charge batteries at our off grid ranch.

I thought I had all of the bugs worked out....oil leaks...bad seals but wouldn't you know it all of my test running a getting all just right before I was going to commit it to the wilderness and I have developed what appears to be a leak in the radiator. I am not sure if it is the radiator itself or the seal where it mounts to the engine block. I took it off and it appears someone else has also from the new silicone on the radiator where it mounted to the block. No soldiering has been done on radiator. I know many guys toss the radiator. I will do the same if this one is dead. Before I do that and all of the work involved I am looking for suggestions on how to check this style radiator. The coolant appeared to be coming from the tubes but in reality it was everywhere. It is well built. Any suggestions on how to find a bad tube?

Now if it can't be fixed what is the proper way to make a plate so an external radiator can be added?   

[SteveU.]

Hi Mr XYZER
Make up a 3/8 inch plate that would bolt onto the cylinder case opening. Centered over where others will recommend you put your inlet/outlet holes IF you change over to remote cooling; for now drill a hole to pull through a tubeless tire valve stem assembly. Bolt this plate instead for nwr onto the radiator base - sealed of course. Also seal your fill cap or the filler neck somehow. Rubber hose clamped and turned back on itself, ect. ( Sorry man I have an expensive professional inflatable bladder adapter with the built-in inflator nipple for this). Then with a hand pump or bicycle tire pump put a bit pressure to it. NOT much only a couple of PSI! Your choice now whether to use the water tank check for bubbles method or the spray bottle with dish soapy water method to check of leaks.
Setting up to test will put you part way to converting.
Regards
SteveU.

[Ronmar]

Dave
   Do you have a low pressure air regulator?  The way I test cooling systems is to attach the LP regulator to the drain pipe on the radiator filler neck.  If it has a conventional radiator cap, it is set to open and release coolant pressure, and also has a one way return valve to let coolant back in.  LP air can easilly enter the system thru this overflow port.  I have my LP regulator outputting into a "T" fitting with a hose barb and a gauge on the remaining 2 fittings.  Fill the cooling system completely full, connect up the air and slowly turn the pressure up.  3-5 PSI usually shows most leaks, but do not exceed the pressure rating for the radiator cap, which is the pressure the system should be able to withstand.  You are feeding pressure into the outlet/overflow port.  Since there is no place for excess pressure to escape, you must not exceed maximum system pressure

Once you see water leaking/flowing, you can use a bit of air from a blowgun to blow things dry to help determine the exact source. A really bright light source helps here also. The good thing about testing this way is that you are testing ALL the seals hoses ect.  Sadly since this is a dense tube bundle, if a tube is leaking, you may have difficulty determining exactly which tube it is.  You should however be able to quite easilly determine if it is the tube bundle or the union between radiator and crankcase that is leaking...   

Good luck.

[XYZER]

Steve,
Great idea for the test/delete plate. I know not to exceed the cap preassure and can ge a low preasure regulator. I figured I would have to make a plate for testing but being able to use it as a delete plate also is a big plus! Where is the best place for the coolant ports? Is one extended longer than the other? The plate I will be working on ASAP. Looking for recomondations for coolant line configuration in the plate.

Thanks Guys!

Dave

[Ronmar]

The extended side is placed so that the long pipe goes down in alongside the cylinder to reach as deep as possible into the case.  My 1100 came with a alternate cooling kit in it's spare parts kit.  It includes a plate and two bulkhead pipe fittings, one longer than the other. If I get a chance I will pull it out and take a pic or vid for you this afternoon...

Another option, if you have a coolant drain would be to convert it into a coolant return.  I seem to recall reading about someone going that route

[XYZER]

Ronmar,
Thanks! A picture as usual would be a big help. I figured one needed to be longer and I am assuming that would be the cold return and the hot would be on the opposite side of the cylinder head. I am still going to make a plate and see about fixing the radiator. I think one of the tubes is leaking due to the paint on the radiator being gone in that area. I also see a slight crack in the upper tank area. I am going to get a piece of 1/2" plate and relieve the center area as the tubes stick out past the mounting surface. I am going to take it to a radiator guy and see if he want's to take a stab at it. The cost may also make me need to do it but if I can't make it work I'll have the plate for a backup.

[playdiesel]

Dave, I posted a bit on your post over on the "other" page.
Butch

[Ronmar]

Here is a pic of the kit that came with my S1100...

http://i270.photobucket.com/albums/jj85/rmarlett/75152143.jpg

[XYZER]

Ronmar,
Thanks for the picture! I am in the process of making a steel plate that will seal the end of the radiator and if I can't fix it I will set it up like the delete kit. I will probably take it to a radiator shop and see what they think. The may have to dissamble it down to the tubes as I think the upper tank is the culprit. I can solider but a good radiator guy has a knack.......maybe. The old timers are getting hard to find anymore. They just replace the radiator anymore.

[Ronmar]

Yep, since those dense tube bundle heat exchanger/radiator cores are typically dip soldered, they are almost impossible to repair unless you can see and reach the crack/leak.

[admin]

seeing how you have two alternators running while the engine is running, why not drive a small bosch auxiliary heater pump?

they move enough water to cool at least 15hp, maybe more

you can simply pump water into the bottom drain on the cylinder block and return it out the top via the t/stat, with a small hole in
it of course.

those little bosch pumps are about as bullet proof as anything and allow the engine to drive a heavier load without overheating than is possible
with siphon cooling in my experience.  the system can then have a 7lb radiator cap and an overflow bottle just like a real engine.

using a pump allows more freedom in radiator/exchanger placement as well.

fwiw
bob g

[XYZER]

Guys,
After looking over the original radiator I have decided it will not be worth the fix. Even if I get it fixed it will be temporary at best. It is a complicated arrangement of a spot welded steel frame and the radiator. I am going to make a plate and want to keep the thing as simple as possible. Thermo siphon is my first preference. I will probably do with a Metro radiator because I have a fan and shroud from left over from one of my Listeroid projects. Question? I was thinking of installing a thermostat.....any feedback? I don't see any negatives do you? As mentioned earlier tapping for a sending unit for the fan also.....can the sending unit handle the fan or does a relay need to be used?...... I would use the drain in the head as part of the thermo siphon but I believe it is too small to allow a good flow. A pump would aid this issue for sure but I am frustrated at how this project is going and need to get it functioning soon and keep it simple. It will not be in a continuous unattended use application.   I think this fix is easier than fixing the radiator.....I hope!....any pitfalls?
Dave

[SteveU.]

Yes DaveX.
You will need to use a power relay for the wattage of the radiator fan motor.
Pick something automotive parts store common for both the thermal sensor switch and relay/plug. Common ones in the $15-20. range. many of these off of low production vehicles maybe "free" "cheap" as used take-off's but $30-50. new as low volume stocked, or even special order.
Been there - done that. Grrr. Damn VW stuff.
Regards
SteveU.

[veggie]

These adjustable snap disc temp switches are great for fan control.
Amp capability should be fine for most any fan on a system like yours.
I think I paid $25 for mine. I use this type on the Listeroid and the Changfa.

Nice project.

cheers,
veggie