Aaron

you could always add a removable fuel cell to you car. Build it from fiberglass, shape it like the inside of your trunk. when you're not flying, store it empty in your garage. That way you could always be sure to have full tanks. If I were to use your system, then I know I'd forget to fill up the car on the way to the airport.

-*UOTE]How's your Cozy going? and what motor are you intending on using? Well, I'm firmly in the Mazda Camp, as a matter of fact the engine is about all I have for my cozy I realize I'm a bit backwards here, but here's my reasoning. I'm going to work on the engine for a bit longer, see about getting the bugs out of that system, then I'll start on the plane later this year. I'm delaying the plane a bit until I'm absolutely certain it's what I want to do- This way if I change my mind, I can build a Kit-car instead In the next few weeks I should start rebuilding what I call "Candidate motor #1" a 1988 Non-turbo rotary. Once all of it's systems are working well, I might try to get my hands on a newer turbo model, like the new renesis which weighs 60lbs less than the engine I'm currently playing with. Good luck with the turbodiesel!

If you assume 26F as the ambient temp, the non-intercooled temps are 104 and 214, respectively. An engine could certainly run with a 104F temp, but the power increase from an intercooler (If the intercooler can hit, say 50F) is still around 11% I, for one, an glad I never skydove over NZ. That's frickin COLD! Here in Houston I remember it being in the 35-50F range year round, falling from 15-17,000ft, depending on how close the jet stream was. Of course I was a little pre-occupied at the time... The Merlin engines did use a two-stage supercharger, I think with intercooling between, but keep in mind that compressor technology has come a long way since the late 30's when that system was designed. Compressor rotational speeds were limited by the bearings, and no one could do the calculations on a supersonic compressor wheel. That sounds like a manual wastegate- do people do that? why? An automatic wastegate could keep the inlet pressure at whatever setting you dial in, no matter what the altitude, no extra switch for the pilot to forget.

Lead's only a problem if you have a catalytic converter or an oxygen sensor. Since we don't need an emissions inspection, and Tracy's EFI doesn't use an oxygen sensor, no worries. I'd imagine that lead actually makes rotaries more reliable (less housing wear) but then I'd be imagining things again

Sure you could just stick the intercooler in the cowl. It still will have some drag to it, if it has any airflow at all. I still haven't seen a Cozy in person yet(I hope there's one at the regional fly-in in May!), so I'm only going from what photo's I can find on the web, but why not build an internal duct to direct and smooth that airflow to the required areas (air filter, radiators if any, intercooler). Ducting the flow will result in more efficient cooling and much less drag, compared to the non-ducted case. Now, since I didn't have any numbers the the upper half of my post, here's a worked example as to why you would want to intercool Say we have a 70% efficient compressor, and we're at 10,000 feet. The inlet air is 50F. If you compress just enough to bring the pressure to sea level, the compressor outlet will be at 132F. If you compress to 22.7 psi absolute (8 psi gauge) your inlet will be at 246F!!! If you use an intercooler in these situations, your temps can be lowered to around 72F and 126F respectively. This means you don't have to back out your timing to reduce risk of knocking (detonation) Now on to the power recovery aspects: We can assume that power is directly proportional to air density if everything else is constant. For the normalization case (14.7 psi absolute) intercooling gives a 11% increase in air density, so an 11% increase in power. For the 22.7 psia case, it's 20% more power, but in truth that number is hard to gauge, because the ignition would have to back out the timing with an intake at 246F (making even less power)

Regarding Drag reduction over increased cooling Thatis one very popular philosophy, and for good readon: "Every lb of thrust saved by drag reduction is a pound of thrust gained." But let me make a few points to the contrary: 1)If you are going to turbo at any appreciable pressure ratio, then you should intercool, period. Not for increased power, but for increased reliability (less chance of detonation) 2)We're talking about a plane that needs an airbrake to get it to drop out of the sky- this ain't no dirty Cessna. How much drag are you saving? (no offense to Cessna pilots nor to the denizens of Wichita, KS intended)

It was rumored he was putting in a turbine and that 13B is for sale. I've seen your site, thanks , I even have hardcopies of it

I can't wait to see the engine he's rumored to be putting in now If it's anything like tha allison C20 Turbine, that means up to 450Hp in a 200lb package. Of course he's got a little over 1 hour of fuel at full power...

With all due respect to Richter and his efforts, I'm not sure I'd follow the same path (using a BOV and closing the wastegate) Heres why: 1)Your working the turbo harder than you need to. 2)No redundancy- if the BOV fails, overboost is likely and then detonation will occur. 3)because your compressing everything then blowing some off, the temperature of the charge is higher. 4)with no wastegate, all exhaust is forced through the turbine, creating turbo heat issues and making the engine less efficient (higher pressure drop in the exhaust section) For my design, an internal wastegate turbo will be used with the wastegate as the primary pressure regulator. A BOV set at max boost will also be used as a safety measure.

For your application air/air would be ideal. I would suggest an all aluminum tig welded unit, such as made by Garrett or Spearco. These units don't vary much from manufacturer to manufacturer, but do make sure to buy from an established, proven manufacturer, as there are some fly-by-night outfits who slap these together with poor workmanship. Looking through Garrett's tables, an intercooler which would work well for you would be about 12x12x4.5 inches, and weight about 14.4 lbs (Garrett part # 703522-6001) Garret sizes these based on the following assumptions: Compressor outlet Temp:250F Pressure ratio=2 ambient cooling temp: 75F available cooling air pressure drop: 1 inch H2O Under these assumptions the 12x12x4.5 intercooler should be able to cool the charge air for a 275HP engine by 120 degrees F, with only a .17 psi pressure drop on the charge side. You'll note all of these assumptions are conservative in your case, so this might actually be more intercooler than you need, but as long as the pressure drop, weight and drag are low, more isn't a bad thing. source of info : www.turbobygarret.com

Most of the turbo systems I've seen have either an integral wastegate in the turbine housing or have one installed elsewhere to control boost, are you saying that the aircraft systems you're used to don't? two words: Yii-Kes. Good points about detonation,etc. the Continental he's turbocharging is already a turbo model, runs a 7.5:1 compression ratio, and is set up for mild turbocharging (it looks like a pressure ratio of 1.1-1.5, based on engine HP). As I understand it the big thing for dust is getting rid of the 35 year old turbocharger and slapping in a new one, hopefully comparably sized. Do I have that right, dust? Dust, the other option you might consider is a turbo rebuild kit. That'll run you much less cash than a new turbo, get you good as new results, and would be much easier.

I'm not trying to be overly critical of anyone, were just discussing the pro's and con's here. I hope my posts didn't come across as condescending, they aren't meant to be.

So, 2 small turbo's, the compressor outlets linked together before the intercooler and throttle? This is very much like the Biturbo V6 in Marbleturtle's car, except his routes the compressor outlet to the intercoolers first (1 on each side) then into a Y-pipe combining the flows, then into the throttle. A few thoughts on this thought experiment: 1)the Non-turbo Continental makes 195 HP, the turbo 360-A makes 210. This implies a very low pressure ratio: At sea level the pressure ratio is around 1.1, at 10,000 feet it would be 1.5 2)Even though it's a 360 CID engine, the max speed is 2800 rpms. The non-turbo airflow for this engine is around 250 cfm, turbo'd that would be 400 cfm, so even for a single turbo you're in the "sweet spot" where most turbo's are designed. 3)Reliability-If a big single turbo fails, the engine makes reduced power. There's a chance you could have an oil leak, a coolant leak, or both; with two turbos this chance is doubled. So I would say this is all negative, there's no redundancy advantage to having 2 turbo's at all. 4)Ease of fabrication-I'm not 100% sure, but it's likely the motor he gets already will have an exhaust manifold hooked up to a turbo (probably why the TSIO-360 weighted in at 60 lbs heavier than it's non-turbo twin) So that's one less part that needs to be fabricated. I dunno, I don't see any compelling reasons to make thing complicated, it's bad enough putting all them pistons and valves and weak crankshafts in front of a propeller

Why twin turbo's? I missed that conversation. In auto use, some maufacturers use twin turbos to eliminate turbo lag, such as the 3rd gen RX-7. people who modify RX-7's (Farrel et al.) usually dump this system and go back to a single big turbo system. Why? doubling the turbos quadruples the design headaches. For an aircraft, I can't see why you'd use twin turbo, is it possible you mean "Bi-Turbo" where one turbo feeds each bank of cylinders? This is done on many cars, especially Audi's series of V6 and V8 biturbos, but controlling them can be problematic. Here's an example: Wastegate adjustment. If you use turbo's with internal wastegates, they must be perfectly synchronized. If not, one bank will see slightly higher pressures, producing more power, and the uneven pulses can shatter the crank. You have twice as many intercoolers, twice as many hose clamps that can break. If the TSIO-360 is already a turbo motor, then it should have manifolds already made for it's turbo, the only wrinkle is finding a modern unit that fits, or making an adapter. Making an adapter is far easier than making a whole manifold. Large, why twin turbo?

I thought I'd create a new thread for this so we don't go to 5 pages on that thread If you can get the displacement, and operating speed, along with the power you're looking for (and the power developed in the NA version), then I'll be happy to make some suggestions as to turbo size, and walk you through the calcs so we all have a better understanding of turbo sizing. As always before you go buy a turbo, you should call the application engineers at Garrett with all this info in hand so they can make a reccomendation for you. They do this for a living, for me it's just a hobby.

A few tests the Garrett GT series AUTOMOTIVE turbochargers go through: (www.turbobygarrett.com) A 1000 hour on engine durability test. A 500 hour cyclic Gas stand - According to Garrett a "Beat the crap out of the turbo" test A 200 hour Thermal cycle test-Every 10 minutes cycling the turbo from low temperature to cherry red. Marble, it seems to me the reason you feel an automotive turbo won't work is this: All the automotive turbos you've had experience with were designed to make full boost at low engine speed. This generates lots of heat at higher operating speeds. The properly sized turbo for an aircraft engine would in general have a larger turbine housing, so full boost occurs only at full engine rpms. Proper design and sizing of the turbine will prevent heat concerns. Again the key is matching the turbo size to the application.

http://www.ntsb.gov/ntsb/brief.asp?ev_id=20001208X09045&key=1 the pilot's diversion of attention from the operation of the airplane and his inadvertent application of right rudder that resulted in the loss of airplane control while attempting to manipulate the fuel selector handle. Also, the Board determined that the pilot's inadequate preflight planning and preparation, specifically his failure to refuel the airplane, was causal. The Board determined that the builder's decision to locate the unmarked fuel selector handle in a hard-to-access position, unmarked fuel quantity sight gauges, inadequate transition training by the pilot, and his lack of total experience in this type of airplane were factors in the accident.

I just reviewed the thread and apparently I can't read very well. I do still beleive that the turbo's in use in cars are the same animal used in diesel engines and in aircraft use as well. A prime example is the TA04 and T04 turbo systems. Both made by Garrett, they are both the same size, have the same clearances, etc. The TA04 is used in aircraft and the T04 is used in diesel and autos. I'll try to get some definitive info on these two turbos to confirm they are identical, except for certification. Greg Richter was using a T04 to the best of my knowledge, a turbo quite common in automotive circles. Why does beleive that aero turbos operate at higher temps? The EGTs of airplane, autos, and diesel engines are in the same range. Compression ratios are in the same range (or lower in the case of a normalization turbo), turbine speeds are the same. So I don't understand why the turbo be hotter in an airplane? Is it the constant use idea? What about diesels, which are also constant use? Sorry for all the questions, I too am in search of knowledge.

The turbo systems for cars are not limited by the turbo's capacity- the limit is the engine itself, and the vagaries of auto use, such as non-constant speed use, throttles slamming shut, turbo lag, etc. Making a general statement that turbos can't handle constant power doesn't make sense. What about turbine engines? can turbines not handle constant power? Diesel or Gasoline makes no difference, much of the time they use the same model of turbo. You do have a good point though, in that auto-conversion can't just take what works in a car and slap a prop on it. The operating conditions for a plane are very different and require larger turbos in general, than would be acceptable in an automotive use.

But by any chance did he work for GM or ford during the 70's? Many American automakers still believe "there is no replacement for displacement" but it's simply not true anymore. Turbos are an excellent way of recovering otherwise wasted energy, modern turbos can be used continuously, and there's nothing cheap about a properly designed turbo system.

It's strange, almost everyone I've told about building a plane, in particular this type of plane, mentions Denver. do you guys get the same reactions> In skydiving we call the unenlightened masses "Whuffo's", because they usually ask "Whuffo you jump out o' dem planes?". Is there a similar term when talking about experimental aviation? Personally I get asked "Whuffo you want to build an airplane?" quite often.

Almost any wastegate (even "non-adjustable" OEM types) can be adjusted to 0 boost simply by lengthening the actuator rod. Shortening slightly fron there gives you mild boost Another way is to put a pressure regulator between the manifold and wastegate such as the "Dial a boost" product. This could give you cockpit control of the boost. Wether its worth all the effort for normalization, it's hard to say. For those looking to turbo-read Corky bell's book-very good, steps you through the process of selecting a custom turbo setup

"An Eccentric Crank"

Blow Off Valves (the "Pop-off" you reference) are used only to vent throttle-off transient boost spikes. In an airplane, you won't have these transients unless you shut the throttle very quickly. To control steady-state boost a wastegate can be used, these are adjustable.

Neglected the effect of air density in calculating the air requirements- for a 300 HP engine at 10,000 feet, the cooling air needed is nearly 20,000 cfm, giving a duct inlet of 2.5 sq feet @ 90 mph inlet velocity. EDIT: arrgh, forgot to account for the temp at altitude. If the inlet air is at 10000 feet (10.2 psia) and 50F the area requirements work ouy to 1.11 sq feet (8820 cubic feet/min) this is for the 300HP case. How big is the Naca Inlet on the Cozy anyway?