Dean So your saying if there is no water or low water flow/pressure in the innercooler say under boost wfo that the blower can create enough heat to melt the innercooler core causing it to fail. Like a blow torch on the top of it??



If so? That would make me want to put a waterpressure alarm on the innercooler to save the innercooler/motor.

Thanks
Rob:D

You guys must both be smoking the same stuff.... I can understand fuel burning under the intercooler and melting the fins or core.... but I'd need a couple of hits of acid to begin believing in "blower cavitation". Maybe I should start selling perpetual motion machines on OSO..... Seems some people here can suspend the laws of thermodynamics. :eek:

Hey guys, I posted this on another site, but this will give you some insite on what goes on. It's not a lack of water, overly high discharge temps, etc.:

It takes over 2000 deg F to melt cupronickel intercoolers. This has happened on both roots and screw type superchargers, but happens to the screw more often. This happens when there is sometype of engine misfire (or an open flame through the intake tract such as intake valve being open during combustion) and a flame comes up into the intake and lights the fuel coming from the sc. The reason the screw compressor makes it worse is that it's coming out at a high velocity in a concentrated area, and typically it's mixed with enough air to help it light. This air and fuel is compressed together and typically has a pretty close air to fuel ratio that it burns realitively easy. A roots displaces air in many random area's (except for the triangle port style blowers), and the air/fuel is not compressed or mixed very well together, making it harder to light. When you light the air fuel charge coming out of the compressor, it's like a blow torch. Whats amazing is that the engines still run, not good, but in some applications, you can't feel the motor miss a bit until it's melted and the water comes.

Now what everybody misses is that the engine has to continue to run to burn the intercooler. A back fire, a misfire, etc. for a short burst will not burn or melt the cupronickel cores. Aluminum is possible, but not cupronickel. It has to sustain 2000 deg F for a minimum of 5 seconds before it starts to fatigue. Backfires, misfires, if severe enough, cause the motor to die and therefore the fuel injection or carburation stops adding fuel, and the fire can't burn anymore so you'll have a flash fire that quickly subsides. Water in the intercooler HAS NOTHING to do with burning the core, again, they can take 2000deg F.

It's not the discharge temp of the SC, although the hotter the temp, the more likelyhood of the fuel being lit. The cases, rotors, etc. are aluminum and melt at over half the temp of cupronickel. If the discharge temp was hot enough to melt, the rotors and case would be liquid metal!

Some of the things I've seen do this, and it's most common and very high hp, massive camshafted engines. One application had a steel braided fuel line run about 1" over the coil. Over time, this got closer and closer until it touched, whether somebody was working on the boat, or whatever. Once that happenned, boat was cruising in a poker run and it begin to misfire was the coil wire arc'd with the steel braided line. It showed no signs before and the motor didn't die until it was flooded with water.

If there wasn't fuel in the intercooler or coming out of the SC, it would be nearly impossible to ever hurt a cupronickel core.

Thanks,
Dustin Whipple

Were the only one that makes a true cupronickel intercooler. Superchiller is effective, but it's aluminum. The TBS is also very effective, but also aluminum. KE made some cupronickel core for the TBS but it's no where near as effective. Cupronickel itself is not the best cooling, whats the trick is the patented technology to braze copper and cupronickel together, which takes almost 2400deg F. Copper is one of the metals for cooling. So if you had pure cupronickel, it's worse than aluminum. Then you have to go to contruction, bar plate is much stronger than extruded tube. How it's welded, billet vs. tubing, louvered fins vs. straghit, 24fpi vs. 16, etc.

We make what I feel is the best intercooler on the market, but it's also the most expensive, and has gone up nearly 20% because the copper price has gone up over 100% in the past few years.

Thanks,
Dustin

Dustin,
If you remember, we spoke at length about what caused the core that I had to melt. I know that the customer put the motor on the limiter, but the SS braided fuel line was very close the coil. Never knew for sure what caused it. I put bigger gears in the drives and moved the fuel line and it never happened again. I have built several quadrotors since and kept those two things in mind and never had a problem.
I was thinking the same thing about the discharge temp being high enough to melt the core. Wouldn't it melt the case and rotors and intake manifold first???
Thanks for clearing it up. Talk to you soon. Eddie

:rolleyes: :rolleyes:

Ohhh... I thought it was blower cavitation........ :rolleyes:

Classify it as reversion MR.know it all:rolleyes:

Eddie, yup, the cast aluminum rotor housing, the billet aluminum rotors, the billet aluminum IC housing, etc. would all melt if the discharge temp was anywhere near that area.

Thanks,
Dustin

Yes, I am all over the internet like the plague!

This is what your buddy Roger at PSI stated
although he indicated that the carbs running dry is what gave ya the igniting backfire.
He was not at all impressed with the "turtle" fix the big
engine boys in michigan were doing to fix the problem.

Good post Dustin!
Thanks

I'm not an expert, but wouldn't one of those small sensors mounted in the area just above the intercooler that would detect heat or fire be useful in this application? Thinking about the type of sensor that they use for burners that are supposed to light and if they don't the sensor doesn't get tripped it shuts off the fuel to the furnace? It could be tied into the ignition circuit or the fuel delivery circuit if your using electric fuel pumps.

PS-Gerry, got one 540 done with your heads, runs nice, thanks.

Perry