| Author | Message | ||
     Hugh Thomas New member Username: Arrowiii Post Number: 1 Registered: 02-2009 |
am finishing an express S90, and need some help. I have a Lycoming I0540-K1G5 Engine. Does anybody have pictures of their firewall? What oil cooler and placement do people use? I am interested in using the dual heat muffs through the firewall interested in different mixing boxes, which is the best route to the cabin? The engine has a firewall to front air intake, do people use a NACA air intake on the side? What are people using for the fuel selector switch? I have so many questions hope you all don't get tired of me asking. Hugh(arrowiii(at)2fast net) | ||
| Charles M. Robinson New member Username: F15epilot Post Number: 61 Registered: 02-2004 |
Hugh, I've got several pictures of my firewall of my Auriga, which should be similar to your S90. Shoot me an email and I'll respond directly. There are some already posted here, as well. Just do a search of my posts. I still fight higher (than I'd like) oil temps. I've a C4B5 version, with an oversized oil cooler. I'm scavenging air off the back of the bafflings, which is not as efficient as I believe I can get. Oil coolers (like water coolers on auto conversions) are a two-fold problem. Getting air 'in' to the cooler is part one; getting it out the other side and back into the freestream is the other. Arguably, since the latter is 'low' pressure air, it's the harder part. I'm going to re-route my cooler so that the exhaust is a set of louvers on the bottom of my cowling, and use a NACA scoop to pick up the air from the side. That's my summer project. If you do a Google or Yahoo on experimental radiator placement, you'll find some good articles on radiator placement. Those relate directly to oil coolers, too. My air intake (again, search on my posts) is right below the spinner. I use a foam K&N filter, which holds up better in rain than a paper version. Not sure on the routing of your K1G5, but it sounds like you need to get the air to do a 180 to enter the intake? Others have used NACA scoops. An option would be to use the same type of air intake as my previous builder did (I got the project after that was done); just route the air flow from that intake via a duct to your air intake manifold. Finally, note that the worst airflow entry point into the cowling is right behind the prop by the spinner. Again, some good posts on pressure distributions around cowlings can be found on-line by searching for radiator ideas. The one I found (will go looking for that site reference) shows that the pressure distribution adjacent the spinner is actually 'away' from the plane, not into the two holes. Unfortunately, our planes came designed with those two holes for cooling air. The trick, you'll find, is how you get the air back OUT of the cowling, which will affect both your CHT and EGT. For that reason, you should have a good, multi-channel engine monitor that reads individual CHT and EGT per cylinder--that lets you monitor all the jugs in case you have a 'hot' spot. Will search for the info on radiator placement and get back to you. Chuck | ||
| Reinhard Metz New member Username: Reinhard_metz Post Number: 89 Registered: 03-2003 |
For what it's worth, I don't understand the notion that the "pressure distribution adjacent the spinner is actually 'away' from the plane, not into the two holes". I have two pieces of evidence that that can't be true 1) My engine cooling, using the original Wheeler cowl, is excellent - run 310 to 330 degree CHTs under full range of ambient temps, 390 or so max in a hot day long climb.(IO360) 2) I have my inside ventillation air picked up in a pair of scoops at the top of the two inlets, back about 4", and junctured to the firewall feed-throughs with a pair of mating duct couplers, (done to avoid the side NACA ducts), and the vent air is a veritable "torrent", which in cruise I always throttle way back to keep from being blasted. What I believe is known to be correct is that round inlets are more efficient than the cute Wheeler ones, but I suspect it's not huge... Reinhard Metz | ||
| Charles M. Robinson New member Username: F15epilot Post Number: 62 Registered: 02-2004 |
Reinhard, Here is a link to a group of great articles on cooling systems. They are primarily for radiators, yet the principles are the same for oil coolers. You are correct in that air is 'in' to the holes...at the bottom. Here is the wind tunnel diagram showing what I was talking about and a link to the articles (Cooling--in 4 parts). http://www.ch601.org/resources/cooling_systems1.htm http://www.ch601.org/resources/cooling_systems2.htm http://www.ch601.org/resources/cooling_systems3.htm http://www.ch601.org/resources/cooling_systems4.htm Chuck  | ||
| Steve Christensen New member Username: Stevec Post Number: 14 Registered: 12-2002 |
I've only been flying since August, but so far my experience seems to be similar to Reinhard's. No problem cooling the engine on a day in the mid 90 degrees. The scoop on the lower left cowl inlet provides a huge blast of fresh air. The right side provides the heated air. If I start out around 0 degrees, I'm not turning the heat down till about 30 minutes into the flight. I've got an IO540 C4B5 engine. Steve Christensen  | ||
| Charles M. Robinson New member Username: F15epilot Post Number: 62 Registered: 02-2004 |
Steve, Is that a Q-Tip prop on your bird? I have a C4B5 with Q-Tip; the DAR initially didn't catch the fact that, from his research, that particular combination had not been done. My 25-hour flight profile turned into a 40-hour profile, accordingly. I have round-hole inlets on my cowling with a square inlet for the air filter. What scoop are you referring to? I'm guessing it's a duct inside the left cowling inlet? I thought about trying that, too, but it would go past the exhaust. I'm going with the NACA scoop on the side of the cowling, instead. Also, did you seal off the bottom of your cowling since you don't have the nose strut fairing? I haven't done that, and I'm guessing that the high-pressure flow along the bottom is slowing the airflow through the whole cowl a bit. That's the fun...experimenting 'til you get it just right. Chuck | ||
| Steve Christensen New member Username: Stevec Post Number: 14 Registered: 12-2002 |
Chuck, You sure got that right - to be able to fly and build a flying machine, I don't know how life can get better than that! I believe my prop is a Q-tip prop. It is what they call the scimitar construction. The number is HC-C3YR-1RF/F7590. Hartzell built this for the Lopresti speed mods for the Cammanche 260. So it is STC'd for the IO-540 and the O-540. Notice the flippers near the hub, they are there to force extra preasure into the engine intake to increase horsepower slightly. The cabin air scoops - the cowl inlet openings for engine cooling, on the lower surface closest to the spinner (on a horizontal line that goes right through the center line of the prop) there is a scoop on each side that measures approx 7/8" high by 1 3/4" wide. One side is for cabin fresh air and one is for cabin heated air. I'll see if I can find a close up pic. I do have a nose strut fairing. I made the exaust pipe holes flush and then added adjustable cowl flaps to be sure to have enough cooling airflow at slow speeds. Thought I had better pics. Here are 3 pics to get idea. Keep having fun, Steve    | ||
| Charles M. Robinson New member Username: F15epilot Post Number: 63 Registered: 02-2004 |
Steve, Thanks for the closeups. I like the cowl flaps...might have to work those in. And the flippers to force air into the duct...interesting. I don't have those, just the bent ends of the Hartzell prop; which occasionally gets me the, "how did you do it...nose gear collapse?" question when people see me working on my plane. Need to get my nose gear fairing on the bird, too. So many fun things to do...so little time. Cheers, Chuck | ||
| Steve Christensen New member Username: Stevec Post Number: 15 Registered: 12-2002 |
Chuck, Sorry to hear about the nose gear mishap. No doubt makes for a fair amount of effort to bring to its previous form. Keep at it you will be flying soon. Have a good day, Steve | ||
| Shawn kelley New member Username: Skelley Post Number: 25 Registered: 01-2004 |
O.K. everyone here what I know. After working on three Express all with C4B5 engine in them, two with the orginal Wheeler inlets and one with the round S-90 inlets I have found that you need to have the outlet air at least 1.5 times the size of the inlet air by volume. My oil cooler is mounted on the back buffle by cylinder #6 and runs a average of 176 to 186f even on a 100+ days cylinder stay at 330 but I control that mostly. with the mixture. As for fresh air intake I get mine for two NACA scoops on the sides for the fuselage right above the joint and about 8" from the firewall, and I get a hurricane when I open them up. If you need more info please email me at sechadog@epud.net | ||
| Charles M. Robinson New member Username: F15epilot Post Number: 64 Registered: 02-2004 |
Shawn, Thanks...I definitely need to up the outlet size. Think I'll do that via simple cowl flaps, and of course, the nose gear fairing. Steve...no mishap with my nose strut. The bent ends of the prop just leads people to believe that's what happened. Kind of comical. I hear some guys with Q-Tips have come back to the airfields to find well-meaning A&P's had grounded their birds. Of course, the fact that the paint on the 'bent' tips is fresh seems to go right by them! Time to plan some cowling work. Chuck | ||
| Shawn kelley New member Username: Skelley Post Number: 26 Registered: 01-2004 |
Chuck I can send you some pics of my cowling if you like email me at sechadog@epud.net Shawn |