Date: Thu, 15 Jan 1998 15:18:04 -0800 Subject: COZY: Subaru 2.5 convert to cozy pg1(long) From: alwick@juno.com (ok How) As promised, here is first page of details of conversion of 2.5 ltr soob engine to Cozy. I'll just send 1 page each month or so until fully documented. Sorry to those not interested, but I think this can really help those similarly inclined. 1-12-98 Installation of Subaru 2.5 liter Legacy engine to Cozy MkIV Description of engine: The 2.5 liter engine has been used in Subaru Legacy vehicles starting in 1996. It’s been a successful engine for Subaru as evident by it’s spread to vehicles other that Outback in 1997 and 98. It’s a 4 cylinder, horizontally opposed, fuel injected, 4 stroke, water cooled engine. It is rated at 165 hp and fuel consumption of 7gph is expected (all water cooled, multi-valve, fuel injected engines way more fuel efficient). The Legacy engine is attractive for the cozy application due to it’s compact shape (horiz. opposed cyl.) and reputation for longevity at high rpms. Step 1, Engine Purchase: I’m very fortunate to live in a part of the country where the Subaru vehicles are very popular. Two very reputable (there is a rare statement) used Subaru suppliers are within 7 miles of my residence. Both happen to advertise in Kit Planes. I learned of their reputations both first hand and talking to some of their customers. I bought the engine from Foster Auto Parts. I bought a number of other components from Mountain Tech Subaru. I paid $2500 for the engine complete, which is about twice what a 2.2 liter would be. There aren’t very many of the 2.5 liter engines available yet. I’m sure the price will be less for others in the future. Inspection of Engine: I was able to go look at the damaged vehicle and listen to the engine run prior to purchase. The vehicle had been hit at drivers door, and didn’t roll over. Once the battery was jumped, the engine fired right up. One lifter was clicking away, as expected from an engine that obviously hadn’t run for a couple of months. After couple minutes, the lifter noise went away. I was able to see that the vehicle really did have only 16k miles on it. As far as the engine condition, this was a no brainer. I did have the opportunity to view another 2.5 liter engine at the same place. Since it had a manual tranny and was a 97 engine (vs. 96) I was very interested. However, it was in a vehicle that had rolled over, and the engine wouldn’t start. It was getting no spark to plugs. They tried a different computer, igniter, and could not solve problem. Since it was a rollover, I was a little concerned of damage due to oil draining into cylinder, and causing rod damage when next started. Probably a fairly low risk, but the wrecking yard mechanic had seen such things in the past. Keys: Be more wary if vehicle was rollover. Have someone listen to engine run before purchase if possible. What engine components do you need? Everything. Foster Auto Parts did an excellent job. No broken wires. Nothing torched off. They knew it was for an airplane and knew exactly what was needed. I ended up with engine, ac, multiple wiring harnesses, the engine control module (ECU computer), the igniter (mounts to firewall), starter, fuel pump, fuel sending units, exhaust system. The only items missing are flywheel (as this engine had an automatic) and radiator. I will purchase a manual tranny bell housing (for starter mount) and flywheel from Mountain Tech Subaru. I intend to have air-conditioning in my Cozy, so the ac components which use the new non-freon refrigerant were welcome. Keys: Buy from reputable place that knows what components you need. Have them throw in a flywheel, manual tranny bell housing, and starter. Make sure exhaust (and oxygen sensors) included. Include fuel pump, igniter, ECU, Mass air flow sensor, wiring harnesses. -al From: "Johnson, Phillip" Subject: COZY: Subaru Conversion by AL Wick Date: Tue, 20 Jan 1998 13:52:40 -0500 In a post sometime last week Al Wick gave his recount on purchasing a Subaru auto engine and advised against engines from a role over accident for what I believe to be invalid reasons. The Subaru, and I guess most modern automobiles, are equipped with a roll over switch which deactivates the engine and fuel system in the event of a roll over. The switch must be reset before the engine may be restarted. His experience at the wreckers yard suggests that the roll over switch had been activated which is why the engine was impossible to start even when the ECU's were changed. This switch prevents damage to the engine in the event of a roll over. On a second note, automobiles using automatic transmissions often use a different cam(s), or have different ECU programming to benefit higher RPM operation. An engine designed for use with a regular transmission will likely have as good or better torque characteristics for aircraft auto conversions and is probably a better buy for that reason. ---------------------------------------------------------------------- Phillip Johnson Tel (613) 253 2229 (H) Ottawa, (613) 599 3289 ext. 441 or 232 Ontario, Cozy MKIV RG #30 Canada. Subaru EG33 ----------------------------------------------------------------------- Date: Thu, 22 Jan 1998 18:49:20 -0800 Subject: COZY: Subaru 2.5 convert to Cozy pg 2 (long) From: alwick@juno.com (ok How) Potential failures: General: Any custom installation of anything is highly prone to failures. Addressed below are some of the more likely problems expected. This report is biased. It includes my method of installation, and little else. There are a lot of discussions regarding alternate approaches. Such as custom computer, fuel injection, radiators, psru, etc. Fuel: So far, the only redundant items I have are two fuel pickups (1 heavily filtered, 1 gascolator filtered only) and two fuel pumps. I added a fuel tank in the area above the main gear (behind the rear seat back). Not much space there available, this tank is only 2.5 gallons. This was necessary since the Subaru fuel system dumps unused fuel back into the fuel tank. Watch out! The method you use to handle this returned fuel is a common problem to these installations. The fuel is returning from high pressure to much lower pressure. It will tend to develop bubbles, which will cause fuel pump to cavitate, resulting in engine fuel starvation. It is necessary to return fuel to a pool of cool fuel to allow the temperature to drop and the bubbles to dissipate. I will have to monitor closely to determine if this 2.5 gallon middle tank is adequate. Inside the middle fuel tank I used the Subaru fuel inlet filter for 1 pump inlet, and left the other pump inlet unfiltered. My main pump will be highly filtered, while the backup pump will have gascolator filter only. More on this later as I complete testing. Keys: Most failures are related to fuel starvation. Returning fuel is a significant concern if you use the stock fuel injection sys. Cooling: 1) Most aircraft installations have cooling problems. The Subaru Legacy engines are more prone than most due to a strong tendency to develop air pockets. These air pockets don’t just go away. They do cause overheating. I’ll add the details on how to identify and solve this problem later. 2) There is a very simple, proven method of cooling the Cozy. Mount 1 radiator on each side of the bottom engine cowl (compliments of Nigel Field). Air scoops added under the wing divert air into horizontally mounted radiators and are very effective. I enjoy experimenting, and have not chosen to use this tried and true method of cooling. I’ve elected to place radiators inside the wing baggage area. I suspect I have only a 70% chance of this method working, but if it does, I will have a very low drag method of cooling. The magic of glass is the ability to easily change to other alternatives. If my method doesn’t work, I can easily adopt the above mentioned approach. I will provide more details if my approach works, but at this point I would definitely not recommend it. Keys: You will have an air bubble in your system that will cause overheating. If you improvise cooling installation you will have problems to overcome. There are a number of cooling specifics not addressed here. Changes: Most failures are the result of change. How am I altering the stock engine installation? The more characteristics I change, the more likely I will have a failure. I recommend keeping engine changes to a minimum. Those items you do change, should be looked at thoroughly again and again looking for potential failure modes. Looked at by people other than yourself. Key: All failure will be the result of changes I have made to the system. -al From: Lee Devlin Subject: Re: COZY: Subaru 2.5 convert to Cozy pg 2 (long) Date: Fri, 23 Jan 98 15:20:50 MST al writes: > I enjoy experimenting, and have > not chosen to use this tried and true method of cooling. I’ve elected to > place radiators inside the wing baggage area. I suspect I have only a 70% > chance of this method working, but if it does, I will have a very low > drag method of cooling. The magic of glass is the ability to easily > change to other alternatives. If my method doesn’t work, I can easily > adopt the above mentioned approach. I will provide more details if my > approach works, but at this point I would definitely not recommend it. Are you suggesting that you put the radiators in the passenger compartment, i.e., in the wing baggage areas? If so, you will need some serious external airflow over the radiators unless you want to cook yourself and your passengers. Internal combustion engines produce about 2/3 of their energy in heat and of that about 1/2 is removed with the cooling system. If you are generating 150 HP (conservatively) then you'll burn about 9 gallons an hour even with an amazingly efficient auto engine. Three of these gallons will be used to heat your cockpit. That's about 400,000 BTU/hr of heat which is about 20 times as much as you need for cabin heat even on the coldest of days. More importantly, a radiator without airflow just doesn't provide adequate cooling and you'll likely have difficulty with coolant temperatures. You'd also lose precious baggage space (in-flight reachable, no less) a commidity already in short supply in EZ's. I don't like to discourage people from experimenting but unless I'm misunderstanding your approach, you may want to consider something a little more tried and true in the critical area of engine cooling. Lee Devlin LongEZ 36MX Cozy MkIV Ch. 11