Great question Zzz. Most snowmobiles today are efi and work great with pull starters, I'd think hand propping should work similarily well...

A1Skinner wrote:Great question Zzz. Most snowmobiles today are efi and work great with pull starters, I'd think hand propping should work similarily well...

I don't know if this really applies. It took sled manufactures quite a while to get it right. Maybe it has to do with the slowness of the revolution when hand propping that makes it difficult.

There are a couple of 540's for sale on the alaskalist with a lot of useful life left on them. I bet you could get one with the prop for a good price. I'd prefer a used good running engine that's just been pulled versus one that somebody says has been overhauled. If I was shopping again for an engine I'd think about getting one and fill it up with the cheapest oil to preserve it until you need it.

Contrary to belief you don't always have to buy a new engine, especially when test flying a new plane that you built. Why worry about breaking in a new engine when you're trying to learn your new plane and fix any discrepancies that come up.

whee wrote:

A1Skinner wrote:Great question Zzz. Most snowmobiles today are efi and work great with pull starters, I'd think hand propping should work similarily well...

I don't know if this really applies. It took sled manufactures quite a while to get it right. Maybe it has to do with the slowness of the revolution when hand propping that makes it difficult.

I guess if you're trying to hand prop the engine, it's because the battery is flat. I think EFI needs battery power to work?

Battson wrote:

whee wrote:I don't know if this really applies. It took sled manufactures quite a while to get it right. Maybe it has to do with the slowness of the revolution when hand propping that makes it difficult.

I guess if you're trying to hand prop the engine, it's because the battery is flat. I think EFI needs battery power to work?

I should not post when I'm tired. The battery-less EFI on snowmobiles is what took the manufactures a while to figure out, because they are designed without batteries is why I don't think we can compare them. With a dead battery you can't run the fuel pump so I doubt you could get it going by hand propping; I bet you could get one going that had a weak battery, enough power to get some fuel pressure but not enough to run the starter.

Hmmm. So the question is: does modern electronics and efficiency trump good old backcountry self-sufficiency? If you drain the battery while camping out in the middle of nowhere, do you setup the solar charger and read a few books? Maybe write one?

Z, I think the best solution is to just Pponk it

Zzz wrote:Hmmm. So the question is: does modern electronics and efficiency trump good old backcountry self-sufficiency? If you drain the battery while camping out in the middle of nowhere, do you setup the solar charger and read a few books? Maybe write one?

The EFI and Ignition does not take much juice (Really Small battery) Gel cell or one of the new dry type.
Have it charging all the time and the only time you can use it is in emergency mode!! Like when you are flying and your ALT/Gen quit or when you have left the master on over night ( No one here has done that!!) Pretty easy to install with 2 busses.
Just a thought!

Zzz wrote:If you drain the battery while camping out in the middle of nowhere, do you setup the solar charger and read a few books? Maybe write one?

Having had one battery gradually fail, I sometimes carry a small spare. Enough to run the pumps and give a chance to hand-prop. If there's a little life left in the main battery, I can jump-start too.

highroad wrote:I agree on the hot start not being an issue once you figure out your technique for the specific installation. The one change I would make to my Maule is to add FI.........

+1

I've flown approximately equal amount FI and carb. I would gladly go FI in my maule to get LOP operations and have never had a hot start issue once I learned the procedure for a particular engine.

Zzz, regarding Maule use of Lyc 540's.
O540 J1A5D 235hp 2400rpm no mogas but lightweight.
IO540 W1A5D and W1A5 235hp 2400rpm no mogas but lightweight and burns 1gph less than O540 J
O540 B4B5 235hp 2575 mogas capable but heavier than J and W and burns more 1gph than J
IO540 V4A5 260hp 2700rpm needs 91 octane but heavier than other engines used.
Higher legal rpm cost weight in crankcase, crank, pistons etc.
Higher rpm means shorter props to not exceed the desired best prop efficiency rpm.

I have prop started all of them.
O540 will prop start hot or cold.
IO540 only responds well when cold.

I think a lot of getting a good deal is just luck. I have a friend who heard about an FBO going broke and showed up with cash before the bankers and walked away with a factory overhaul IO-540 for $8K cash, cash, cash.

Keep your ear to the ground and talk to local mechanics and operators. Dave Aldred up at Scappoose recently scored an IO-320B1B (twin comanche) for $5K from a super secret source in Montana I think? It was an old rebuild that had sat on the shelf for 15 years. He took it apart to check it out and it still had the assembly lube in it. Gaskets, seals, and elbow grease and I think he said it's approaching 3000 hours in the training environment. You just have to keep patient and talk around. Dave is a good source of information about just damn near anything you want in your area. He could build you a nice motor maybe. Can't hurt to ask. What you see is what you get with him. Not a phony bone in the man anywhere.

I used to carry on a running conversation with old man Barrett. He's retired now and his son has the business. I wouldn't hesitate to give him a call. They may have the bones in stock. Same deal. Great rep and good to work with. They used to do all Lycoming's testing and development until they broke it off with Lycoming over various and sundry. Sometimes mechanics and minor subsidiaries of multi national corporations just don't get along. If you look on the cowl of airshow performer's airplanes, 98% of the time you'll see either Lycon or Barrett Performance. That doesn't mean that those places don't build ordinary engines though. Can't hurt to call.

Finally, call Mattituck and see what they say. Cant' hurt.

I wouldn't put ECI cylinders in my airplane though. Just me. Factory or Superior.

Oh, one final thing. The big bucks are in parts. Shop rates at certified engine shops are less than your local Dodge Dealer.

The best way to setup up a electronic ignition and injection system is with a dual battery setup. The batteries are isolated with a automatic charging relay and master switch. One battery acts normal as the main battery and the second as a backup. After start the alternator charges the main battery. When full the charging relay closes and the alternator now charges the standby battery until full. The Master battery switch has 3 positions, OFF, ON and Combine Batteries. In normal operations you run the master in ON. If the alternator fails or the alternator/main battery fail, switch to the combine batteries position and the standby battery provides enough power to land.

If the master is accidentally left ON it will drain the main battery only, switch to the combine batteries position and you have power to start the engine and fly away. The alternator will then immediately start charging the main battery until full.

This is a fool proof setup with good redundancy.

You can definitely hand prop fuel injected engines with a dead battery. You do need a primer to make it really workable. But if it is primed before the battery is dead (and not flooded) you can still hand prop 'em.

Well, I'm still wandering in the fog of engine research. Thanks to all who've replied this far. Jeremy, your model breakdown for the Maules was helpful.

As for carbureted vs injected, I'm still wavering. I'm on the injected side of the fence now, mostly because one of the arguments for is smoothness. I assume that's because the charge that enters each cylinder can be tuned?

As far as spec'ing the actual engine model, I had someone recently tell me that only wide deck could use roller tappets. Does that sound right? Is wide deck a characteristic of only the cylinder? Or the case as well? It doesn't seem indicated by any of the model codes so I assume only the former.

Battson, I know you had to lengthen your cowling for some reason on your 540. Remind me why that was?

I've had several people recommend that I find a mid time 540 that's the model I want and just run it's time to overhaul. If you were building a brand new aircraft would you do that? I guess not having to run WFO during phase 1 flight testing might be nice, that's about the only upside apart from it being cheaper. Where does a mid time 540 exist other than as the result of a wreck?

The engine "kits" that comprise a new experimental engine are few. I guess there's what? Lycoming factory, ECI, and Superior?

Yada yada yada

I used a C235 Mac prop, which has a two-fold effect. It's got a longer flange distance built-in (between blade CL and flange), and also it's spinner has the blades right at the back of the dome. Both those factors meant the nose bowl had to be further forward. That suited me, because it gave more room for my induction to hide inside the cowl.
The background info is - the length of the cowl is usually determined by the prop and it's spinner. You need to have that and the engine, before you can start on the cowling. One or two guys have used a spacer, like firstbearhawk to make room for his induction, but generally you set the nose bowl in place to match the spinner, leaving a 1/4" or 3/8" gap.

What about smoothness has you swaying, Z?
Are you thinking vibration profile, or are you thinking balanced fuel flow and therefore ability to run smoothly at different power settings?

Battson wrote:Are you thinking vibration profile, or are you thinking balanced fuel flow and therefore ability to run smoothly at different power settings?

I guess I would say both. Doesn't the latter manifest as the former? I've always considered the dynamic prop balance to be something that's done last once you decide on a favorite cruise RPM, but it's just frosting to the inherent smoothness and low vibration that are accomplished by everything else. What makes an engine vibrate?

Edit: Having re-read the question...
There are many things which cause an engine to vibrate, http://en.wikipedia.org/wiki/Engine_balance#Flat_six_engines. The balance of the combustion events is one of them, but I don't know whether it's a big one or not.

It seems to me that an engine with excellent cylinder mixture characteristics could still run rough at certain vibration frequencies because of the modal interaction of the engine/prop, or any number of other things internal to the engine. A well designed and manufactured engine seems to be the solution there, but I guess we're stuck with what we have on offer.

If it's got a sweet MT 3 blade acting like a huge flywheel, so much the better. But you might get more short-strip performance out of a 2 blade which vibrates around a lot more...? Ahhh, the decisions! Enjoy them.

Our 185 with an IO520-D (300 hp for TO, 285 hp continuous) has an electric fuel pump AND a manual primer. If the battery fails, you can use the manual primer and hand prop the engine. I know a couple of guys with thousands of hours of Alaska time that have had to do this, both on 180's and 185's. I'm really kind of hoping I don't ever have to - we've got a 3-bladed prop that runs really smooth, but would be a bear to hand-prop I think...

As far as EFI goes I don't have any experience with any on Lycomings however the mechanical injection is pretty simple. You can hand prop them but you need enough battery to run the boost pump to prime it. Either way you go, a Lycoming is always going to cost more than a Continental even in the airboat world. As far as fuel efficiency the injection is the way to go. Engine smoothness comes from your prop, a two blade is always going to have more shake than a 3, no matter if its on a O-540 235hp or IO-540 260hp. The most expensive part is the crank and cases. If you can find those 3 things at a reasonable cost, the rest isn't as bad. To do roller tappetts, the case has to be machined for the tappetts. Standard cam followers are around 50$ a piece and roller tappetts were around 375$ a piece as of a year ago. IMHO I don't think a roller engine is worth the extra expense, very little benefit for the cost.