Heat, dust and small engine Questions

[Sync]

Two years ago I ventured onto the playa with a mutant vehicle “Rat” based on a 50 cc GY6 scooter engine. It made it to Wednesday before the engine choked on the dust and seized. Got towed back to camp by a giant cat car. Lots of fun before that though. This year I’m building a bit bigger; making an almost full scale model of the Star Trek type 10 shuttle “Chaffee” with a coroplast body. Already in construction (Shopbots are amazing toys.) The base vehicle is a 150cc “King Cobra” dune buggy with a larger version of the GY6 engine that choked on the last mutant vehicle. To prevent further dust problems I’m going to put an extra dust filter on the engine that is an “oiled” filter. I have no experience with such things and was wondering if anyone can give me some advice on small motors and playa dust? Will an oiled filter just choke up sooner?
The second issue is heat. The body of the Shuttle is basically the largest faring of coroplast ever made, as far as I can tell. It encompasses the entire dune buggy, and although the GY6 engine has a fan of sorts, it has no water or oil cooling stock. I can have the undercarriage open, and some small vents, but I’m worried about overheating and airflow on these small GY6 engines. Anyone have advice or stories about small engines and heat on the playa? Not sure its an issue at 5mph, but have no experience. Thanks.

[Elliot]

From reading about GY6 engines on Wikipedia, I imagine they do not come with much of an air filter. You might do better by adapting a much larger air filter from a car or pickup.

Oil impregnated filters like the ubiquitous K&N brand work well on the highway. But I imagine they would need daily washing and reoiling on the Playa, whereas a plain paper filter can be blown reasonably clean with compressed air.

Something I am theorizing might work well on the Playa is an old-fashioned oil bath filter. These were used on cars as late as... I think the 1950s. The air flows thru a chamber with a pint or so of oil sloshing around in the bottom. The air flow is arranged so most of the dust is spun out and sticks in the oil.

Now.... This may not be realistic, but I have a Honda GL1000 Gold Wing shaft drive motorcycle for free to a worthy MV builder. This is water cooled. It needs the carburetors (four of them!) overhauled or replaced, or replaced with a single-carb conversion. I have reason to believe it is mechanically sound. This is hardly ideal MV material to my mind, but the price is right. It was given to me for the purpose of an MV, or something else fun like a giant margarita blender, so it is dedicated to that -- sooner or later.

[Sync]

Thank you. Alas, my meager skills would be unworthy of such a fine machine. Sure would like to see the margaritas it could make though. Larger paper filter is an idea worth considering.

[trilobyte]

I'm giving this a nudge over to the Preparation -> Transportation board, since that's a better fit for problem-solving/construction/preparation questions. Elliot's posted some great info, and hopefully some other playa vehicle designers can chime in with their tips and tricks for dealing with heat and dust issues. Good luck!

[moltensteelman]

I would think that a tractor centrifugal force pre-filter would be ideal. They use them for baja trucks and can be found at tractor wreaking yards or maintenance shops. Finding the right size might be a little tricky, but worth checking into.

[Sync]

So, after much research, mostly uneccessary, I found a coupple of things. The best air filters for the dust problem come from K&N filters. They replace the air boxes on most vehicles completely, and are well known in the ATV and racing industry. The filters get sprayed with oil to help collect particles. Amazingly, they appeaar to increase airflow and horsepower as well as being better than paper filters. In additon, there is a cloth sock that goes over the filter. That sock can be frequently removed and shaken out. The oiled filter alone would need to be washed out and re-oiled, probably several times, on the playa without the sock.

other fun facts; there are several air itakes on some motors, like the one for the cluch on this buggy, that also need a cloth filter to prevent dust from accumulating in the cluch. There also seems to be an extra proceedure for cleaning the chain that might be useful for bikes as well. Apparently racing dirt bikes have a chain cleaner and lube that leaves the chain 'dry', so that the lube oil on the chain doesn't attract dust and turn into mussy sandpaper. This might help some folks not have to replace bike chains post-burn.

All the mechanics I talked to said basically similar things. Playa dust will ruin wheel bearings and head-sets. But, the dammage is usually not critical unless left uncleanned once the machine is off-playa. Well oiled parts get slammed the most because the oil traps the dust, turning lubericant into sandpaper. Most critical part is not letting the engine breath the dust, or get into the crankcase oil wher it will wear on the rings and such until the motor is flushed completely.

[EspressoDude]

get a pyrometer with a sparkplug thermocouple washer. instant continuous reading of cylinder head temperature.

guess 200- 300 degrees ok; 600 won't last long. based on readings from air cooled turbocharged Corvair