4-place Builders with Continentals

[whee]

I don't have a drawing of the "N" but I think your right on the "K"

The N and K use the same induction.

Why not just buy the O470 mount from Avipro? That is what I'm going to do if I end up using a 470 series engine that will fit that mount.

[Mark Moyle]

Pics of the 520. Will be adding upper engine mounts. Cowl is Mooney Acclaim


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[Robert440]

Thanks for the pics. Your set up looks good. As far as buying the Avipro mount goes, I'm not so sure it will work because I have the older military O470-4 that originally came in the T-34A. It uses the E225 style dry sump case.

[Mark Moyle]

I bought a used Avipro 470 mount... Was close. Cut it apart...used some of it. Built a stand for the engine that bolted to the oil pan. Then shimmed to align. Used a rotary laser...


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[whee]

Mark, do you know if the Avipro mount will fit the IO470? It looks the the 520D induction is the same/very similar as the IO470F induction.

Did you reshape the firewall to fit the Acclaim cowl? It think it will look great. I've been thinking about using a SR20 cowl with the IO360.

[mswain]

Pics of the 520. Will be adding upper engine mounts. Cowl is Mooney Acclaim

Mark, would you be interested in starting a thread on your Acclaim cowl? I really want to do the round inlets like you've got on the Acclaim cowl. I never really thought about starting with the cowl off another plane.

I'd be interested in learning what it takes to make it work? Looks great!

Mike

[Glenn Patterson]

This is to share information and not push one engine over another but to share information. We were offered the opportunity of picking up a Continental IO-360 from a local air service that flies about 20 Cessna 337's for fire spotting across northern Ontario. The mechanics had removed a pair off a 337 where the owner wanted to install a pair of Corvette 350 based engines. The front engine was a low time engine and fortunately they had sold the props as they may not have been a good choice for a Bearhawk on floats. How you set up your engine depends on its primary use.

We have installed a IO360 Model G Continental 210hp engine in our 4 place Bearhawk with a MacCauley 203 CS prop. I modelled it after the IO360 Continental upgrade STC's used for Cessna 170 & 172's. The engine for our build is a front engine from a Cessna 337. The engine mount is a Cessna 337 rear engine mount modified to mount to the Bearhawk fuselage with engineering assistance from Bob Barrows. We borrowed a bare block as a tool to align and set up the engine mount. We hope to have our project running and flying by summer. The stock exhaust interfered with the rear engine mount as the front mount is completely different so it was opted to use Experimental Aircraft Exhaust in North Dakota to fabricate the exhaust. It is a dual header 3 into 1 with dual mufflers & 2 heat cuffs constructed in all 321SS. The exhaust is expected to bump up the hp slightly.

Continental IO engines have a fuel return line so it requires adding a return fitting at the top of the 2 fuel tanks. There is also the option of using a return tank which is common in Cessnas & Maules with Continental IO engines. The fuel injection is mechanical & pressure regulated as the engine delivers and returns about 50% over what the engine requires. Maule put out a bulletin to increase the return & vent lines to 3/8" so we used the same. The mechanics tell us that the mechanical fuel injection is simple and reliable. The fuel consumption is about 8 - 9 gph at cruise
The Continental IO360 is used to power Cessna 172's on floats, for engine upgrades on 170,172's and some Maules. Dave Miller has a well documented site on his Stinson rebuild using the engine and it is well appears to be a good performer with floats. Stinsons and Cessna 172's are roughly the same size as a Bearhawk.

http://members.shaw.ca/flightlines/stinson_rebuild.htm

https://www.youtube.com/watch?v=-m_QWCcMYzI

IMG-20131112-00003.jpg IMG-20131009-00102.jpg IMG-20140501-00059.jpg

The International Cessna 170 Association has good information & support on installing a Continental IO-360. One veteran AME who has done these conversions was adamant that we install the fuel return tank. He knew of aircraft that did not use them & had serious problems. Could probably debate this one to death but Cessna's & Maules with Continental IO engines have header tanks. The one advantage of the tank is that 50% of the fuel is constantly returned so the return tank keeps the fuel recirculating to the engine & the main tanks make up the difference. The return tank vents to the main tanks. Would recommend that you research this to death and arrive at your own comfort level. Cessna 337's return to the tank but if the pilot is pulling from an aux tank and the fuel always returns to a main tank then he can run the engine out of fuel. The return tank has no fuel returning to the mains so a pilot has the option of running on one tank or both without any concern where the return fuel is accumulating so it is simple fuel valving & fuel management.
The MacCauley 203 prop is common with Cessna 180's and used on many variants of the Continental engines. The best IO-360 engine if you can find one is the Model K as it has a slightly heavier crankshaft and a 2000 hr TBO. Most Continental IO360's have a 1600 TBO.

The dream one day is to install a dual electronic ignition and with the exhaust gain more horsepower along with a cooler running engine.

The engine pros is that the engine was bench tested at 210hp in its life so these engines can make their rated hp. Dual electronic ignitions can give a 6% hp improvement, improve fuel economy and make for a cooler running engine. The engine with electronic ignition & exhaust could make another 15+ hp which is makes total hp close to some 470's and 540's on mogas but 90 lb.s lighter. The air intake & fuel injection is on the topside of the engine which eliminates the air inlets on the belly of the cowl. The engine clears the cowl by 1/2" but part of that was given by slicing and raising top of nosebowl slightly. Prop flanges of Continentals are common between IO360's & 470's. 6 cylinders start quicker and run smoother than a 4 cylinder. No carb ice with IO.
The bed mount at the front was not friendly to the typical Bearhawk nosebowl so we had to modify it. There may be better nose bowl choices. The upside was we tried to emulate the Mountain Goat STOL cowl underside that looks like it is STOL friendly.
Not many options for a propeller for the Cont IO-360 but there are lots of MacCauley 203 CS props available and they have a wide range of blade lengths. It is one standard blade and they cut it to the required length. The prop purchase was a first run prop that we had overhauled so the overall prop cost was $6200. The cost for the CS prop was fairly reasonable.
One caution on using the Cirrus SR20 nose bowl is the prop that you actually use. The Cessna 337 prop had an extension built into it to push the prop out to give more room for a creative cowl. I suspect that may be the case for the SR20. The Cirrus is a 3 blade prop and one would have to know if it was suitable for a BH. If the Bearhawk is to be on floats then you may be using a MacCauley 2 blade C203 series and the blades mount closer to the engine flange which reduces the space between the prop & engine that was there for the 337. The fuel pump and governor are tight behind our nose bowl. There probably was about a 4" more room with the 337 and it may be similar with a Cirrus.
If you have an opportunity to look at a Cirrus then examine the engine mount as it may hug the engine tighter or be a total different arrangement. There is zero similarity between a Cessna 337 front and rear engine mount. Cirrus may have developed a more compact arrangement.

The one trial & error that I believe we may have is the prop length. We have an 82" prop and the STC for the Cessna's & Stinsons is 80". My partner wanted to go longer but every inch out on the ends eats a lot of horsepower. It is $250 to trim it.
The one mod since is these photos are glassed in ducted inlets up to the engine to clean up air going into the cowl. I must say that I really like Marks cowl from the instant he first showed it to the group. It is a great cowl like the James Engineering & the LoPresti speed cowls that really clean up the front and combined with a pressure cowl gives speed improvements.
Time will tell if this engine was a good choice. Hope this may be of some assistance.
Glenn
BH727

[whee]

Great info Glenn! As I've said the TCM IO360 is my engine of choice but I wanted to explore other options. I was thinking that using a Maule engine mount would be one of the easiest ways to go but I don't really know that for sure. Lycon said they can build me a 235hp IO360 using the stock compression ratio so it would still be mogas compatible. I have a while before I'll be shopping for an engine so it is great to find someone that is going down this road before me.

[Glenn Patterson]

The pictures turned out larger than anticipated. That is one advantage of electronic ignitions is that they are mogas friendly as the timing adjusts to rpm which eliminates the pre-ignition which is the primary purpose of 100LL avgas. I read an article by the EAA examinining alternatives to 100LL and the easy fix was electronic ignitions with 92 octane mogas. The 92 octane is a common refinery product that would lower aviation fuel costs and the refiners adjust or eliminate the additives for aviation use only. The headache is converting aircraft to electronic ignitions with STC's and the availability of proven ignition systems. E-Mag are working on a 6 cylinder P-Mag which we have our name penciled in for one when they begin production. They simply replace the mags and generate their own power for spark the same as a mag. E-mag had some initial teething problems but have a good 4 cylinder product that they are working on getting STC's. We will install one for starters and after there is some time on the first one then pick up the second one to get the full benefit of the ignition. LightSpeed claim that electronic ignitions will give a 4% hp increase with one ignition, 6% increase with dual and a 10% fuel savings. Miller claims 8gph with his Stinson and a local pilot with a Bushmaster told us that he averages 8.5gph.

The fuselage was built to take any engine up to the Lycoming 540 which is easy when constructing and leaves the door open for options. It is easy to modify a mount to fit a BH. We borrowed a cracked bare block from an aircraft engine rebuilder. I cut two discs with the router that fit tight in both ends of the block. The bare block was set up on a wood stand & a string line from the tailpost ran through the block and set it up so that the string did not touch the small disc center holes. Measured off all the fuselage ref points to make sure the string line accurately represented the thrust line and center of the engine. If you search "Router Methods" in this forum you can see how I used the router. Bob Barrows kindly gave us the sizing for the tubes to attach bed mount. We used on old style of Cessna 337 bed mount that we got for $100 locally. Cleaned off all the attachments for the 337 which was put on the bare block before we set it up. Eric Newton has an excellent write up in his 4 place manuals. If you can build a fuselage then the mount is more of the same.


Since you have not chosen a power plant then you have a clean sheet to work with and can evaluate all the options. Make up a spread sheet based on what you intend to use the airplane for. If you are just wheels then a 360 - 390 engine is more than adequate unless you need to go to the upper limits for speed. Planes do not go fast with floats w/o emptying their tanks quickly.

So back to where I am going. Examine all engine options including a Lycoming 540. Why? If you need hp then look at a Barrows or similar 540 with a prop. There are lots of available engines and props to come up with a good deal and if it is thousands below your dream engine then it will take a life time of flying to make up the cost difference with fuel savings. Barrows also published a great price a few years ago for new Superior or TCI engine that was a 360 that or a 390. some like the handling of the BH with the lighter engine. Factor in the prop & governor with your pricing. We used a MacCauley 203 as that was the prop recommended in the STC's that is common to Cessna 180's & 182's with lots available. We could have looked at props used on Maules for prop models but Maules are scarce here. The Lycomings have more prop options and companies supporting those engines. The Continental IO-360's commonly have a 1600TBO vs the Lycoming 2000TBO. We have a friend who is an AME flying a Cessna with 180 with well over 2000 hours flying on condition. It snaps to life, is in good shape and purrs so he is leaving it alone and flying it. He really babies his engine and gets on other pilots about how they use their engines. Making TBO is both good engine management and luck.

One reason we got excited about the possibilities with the Continental IO-360 besides getting at a good price. In my research for engines it was learned that Lycomings sometimes do not make their HP rating which is the reason that PowerFlow exhausts can get such a nice power improvement on a Lycoming by improving efficiencies through exhaust flow. The log & documentation for our engine had a bench test that verified that it made full 210hp. The mechanics and our pilot friends said that the Continental IO-360 burned less fuel and had lots of power. We thought if we used an electronic ignition, improved exhaust that the engine should put out between 225 - 230 hp. The exhaust may give 5hp with an electronic ignition then it could get about 12 more. This would give power similar to some 470's & 540's with an engine weighing 90lbs less. The fuel burn is reasonable so further weight savings could be with carrying less fuel as most of the flights are to local lakes so typically an 1.5 hours for a day trip. We are surrounded with lakes in every direction. Taking a page from what I am saying. Dual electronic ignitions cost over $3K and are easier to obtain for Lycomings.

If you have not started then please consider the kit. Ken Wardstrom told us to buy the wing kit at a minimum but we thought we could build the wings quick. We just past the 10 year mark and have kept at it fairly steady over the years. We expect to be complete by summer. A lot changes in a pearsons life in 5 years - 10 years. I think that all the costs factored in there is not much savings in scratch building the wings and they take a lot of labour. We would have been flying years ago if we used the kit. The reality is the plane is going to cost what it is going to cost with scratch or kit build. It is going to take money and thinking that scratch building is a less expensive route may be misty eyed thinking. Factor in all the tools, equipment, consumables, auxiliary materials, shop heat, electricity, shipping etc it is all costs off setting the savings of a scratch built. I think if the all the total costs of a scratch built is accurately compared to a kit build that the difference is not worth the extra years to get it done. The odds are much greater that the airplane will get finished with a kit. When we are done we can take pride in the quality of the craftsmanship but it comes with a cost. Eric Newton pounded out his scratch built BH 4 seater at an amazing speed but he must of spent every available minute of his life at that time to get it done. He built the kit Patrol in the same time span but at a more leisurely pace and has a great airplane. We did not log our hours but we passed the 2500 hour mark sometime ago. That was what Ken Wardstrom knew after he scratch built that he was trying to save us from. Something to investigate as well.

All the best.
Glenn
BH727

[whee]

Thanks again Glenn. Will be interesting to see what you think of the IO360 once you get to flying.

[Mark Moyle]

On the Acclaim cowl...it is wider than the beahawk....is the same width as the widest point on the second station at the instrument panel....To form the firewall I had to wrap the form with 1/4" by 1" flat bar.. Then flow form and flute to get the shape. Wasted two sheets of stainless before success. The bottom of the cowl is deeper than stock... But I wanted the extra room for the small header tanks under the floor...for the continental. The acclaim cowl is long enough on top...but needs work. Had to remove honey comb structure... Have to add layers of carbon fiber...which I haven't done. Bottom will also need a lot of work. Sticking to the standard cowl would be much much easier. That said I'm still moving forward. I haven't decided if I'll build a form to make a fiberglass cowl using the acclaim cowl as a pattern....thing is I've never worked with carbon fiber....fiber glass sure... One thing to think about....keep it stock...every modification requires time...lots of it.. I don't believe the Avipro mount will work on the IO470F....


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[Glenn Patterson]

Mark makes a great point on keeping it stock & saving time. Our nose bowl was modified every way to Sunday. The top was cut to make a 5/8" lift so the cowl cleared the throttle body and sectioned to make it symmetrical. The white parts at the end of the day are the only original areas. The bottom is a complete fabrication where I mocked it up, made a mold off it then formed the new piece. I think it would have been faster to have made my own from scratch. At the end of the day when it is painted it will look like every other nose bowl except for the ducted air inlets. Mark's engine and cowl will look amazing when its done but he will have done a lot of work. His cowl has the advantage of being extremely efficient and will be an amazing looking Bearhawk. Mark and our project have this in common that we both have to modify cowls, make an engine mount & weld up a header tank or two. All of this takes a lot of time.

The Continental 470 have been used by many so it is likely is less work and you may get lots of guidance from others. The Lycomings on the other hand are plug and play with lots of options with mounts, nosebowls, props and accessories that could save months of work. For example RV's use Lycoming 360's and 540's. James Aircraft make RV cowls similar to Mark Moyles ovation cowl. May be possible to get the front section of a James nosebowl, a prop extension the same as RV' use and build your own streamline cowl without too much twisting and turning. http://www.jamesaircraft.com/

We had a gas welding set given to us & had the good luck to get a Smith AWS welding torch that our company no longer used for silver soldering. My partner is a professional welder and was doing beautiful work with the gas torch but said it would be better with TIG with less heat distortion and better for welding aluminum. The fuselage welded up nicely and is dead straight with zero twist. The Lincoln 225 precison wave welder was a $2100 touch and allowed us to build great parts and a very straight fuselage. We relieved the welds as they were being completed with the torch to reduce to avoid heat affected zones. Welder partner paid 2/3rds & gets to keep the welder but the project paid for a 3rd.

These are the kinds of costs that I was alluding to that creep in and eventually one is close or past cost of the kit. Some speak of buying lathes & metal brakes that are expensive ways to enable one to do work. It is great if one has a long term purpose for them or intend to build more or can clear them out for what was paid for them may justify the spending. We bought hydraulic cylinder tube for the struts and had a machinist friend do the rest for us for a minor cost and a local shop allows us to use their shear & brake. One thing that you need to factor in is at least 10% for consumables that is a project std which is all the misc such as tape, paper towels, sand paper, tape, degreasers, paint, wood, jig materials, weld rod, gases, safety gear, drill bits etc.. "Consumables" is a project term that I taught my partners that they now hate. Then have a tool budget as well. We used cordless drills that we had & a cordless Dremel with a drill head attachment for all the wing construction.

I have a lifetime of managing projects and did my best to stretch the dollars. I bundled the material orders into thousands at a time to be able to negotiate discount on volume & then negotiated a savings by paying cash. For example I went out for quotes on the steel and got a discount for volume as I made it clear that I was shopping for competitive quotes. Then I called the manager of the lowest quote and asked if I sent them a bank money order could I please have the percentage that is allowed by the vendor for a credit card card discounted from the order. About 4-5% is tacked on to vendor pricing in all businesses to compensate for the cost of them doing business with the credit card. The more perks that you get with your credit card affects the percentage charged by the credit card companies to the vendor. Vendors do not mind discounting the credit card transaction for cash as it is not money they see if you use your card. The second advantage is the vendor gets the money right away. The steel vendor offered a good price with a 10% discount for volume and then generously gave me 10% for cash. We saved roughly $750 on the steel. We combined the aluminum with another builder to get better pricing plus 10% & 10% for a shared savings of about $1400. Did the same for a $3000 hardware order. I secure the order with my MasterCard and then mail them a bank money order to release the order. The other advantage is that the order is large enough that the companies look for the best shipping rates from their shippers. That is roughly a $3000 savings for 3 orders which sounds good but then a chunk is clawed back by shipping costs. Ordering large volumes cuts down on being nickel & dimed for shipping multiple orders to get what you are going to need. Most vendors are willing to work with a person on large orders. There is not much mark up on the electronics such as Dynon's and radios so best watch for sales and see if can get 5% for cash. At the end of the day you are going to need all the materials and doing it by pay as you play is an expensive build. We estimated & bought all the aluminum in one order and after 10 years we will have to buy a piece to be able to do the wing and tail feather to fuselage flashing. The other thing to pay attention to is right sizing the orders to have just a little more than enough but not a lot of surplus materials as it is a loss. Shipping is an expense that has to be accounted for as well as it can roll up into a good expense. I have great empathy for the Alaska builders.

Thats a lot to chew on but it may help with decisions

Take care,
Glenn

[Battson]

Dual electronic ignitions can give a 6% hp improvement, improve fuel economy and make for a cooler running engine. The engine with electronic ignition & exhaust could make another 15+ hp which is makes total hp close to some 470's and 540's on mogas but 90 lb.s lighter.

This statement caught my attention. Can you explain how the addition of EI can man the engine run cooler compared to running fixed timing with mags?
I am having trouble putting all the details together in my head. Do you mean at partial throttle settings the engine will run cooler? I think either way (fixed or EI) you get the same setting at WOT?

[Battson]

On the Acclaim cowl...it is wider than the beahawk....is the same width as the widest point on the second station at the instrument panel....To form the firewall I had to wrap the form with 1/4" by 1" flat bar.. Then flow form and flute to get the shape. Wasted two sheets of stainless before success. The bottom of the cowl is deeper than stock... But I wanted the extra room for the small header tanks under the floor...for the continental. The acclaim cowl is long enough on top...but needs work. Had to remove honey comb structure... Have to add layers of carbon fiber...which I haven't done. Bottom will also need a lot of work. Sticking to the standard cowl would be much much easier. That said I'm still moving forward. I haven't decided if I'll build a form to make a fiberglass cowl using the acclaim cowl as a pattern....thing is I've never worked with carbon fiber....fiber glass sure... One thing to think about....keep it stock...every modification requires time...lots of it.. I don't believe the Avipro mount will work on the IO470F....


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I love that you've had a go at using a custom cowling. Good for you, the extra work will pay off with a great looking aircraft.

I note that the Mooney is a faster aircraft, and thus the cowl is designed with a lower cooling air inlet area. How will you tackle that difference?

[Glenn Patterson]

Hi,

I hope this helps. When I first got started building I looked at many engine options as aircraft engines are extremely old technology. At the end of the day there was no automotive engine conversion that we were interested in. We have a friend who put an auto engine on his Rebel and he is on his 2 redrive and still battling cooling issues. The best option was to stay with the Lycomings & Continentals. The next solution was to look for improvements that would improve performance, reliability & fuel economy. The EI hits all of the talking points. The engine came with fuel injection which was good and helps improve fuel economy. One strong advantage of EI is that the engine snaps to life quicker than with mags. There is no worse feeling than cranking an engine that is slow to star while sitting on a frozen lake after a day of ice fishing & hoping it comes to life. It always starts but the fingers are crossed and great relief when it catches.

E-Mag makes a P-Mag that will replace a mag and generates its own power the same as a mag. A pair working together makes a true EI with all the advantages. The E-mag system is an easier install than Lightspeed but both have been around long enough.

EI adjusts the timing to maximize the engine operation at all RPM's and some fire several times to ensure a 100% burn. That is one reason that the EI increases fuel economy as it maximizes the power from the fuel. The spark is several times stronger & hotter than mags. The mags are set at one setting & one of the articles say that timing is for the worst operating condition.

I clipped this from the LightSpeed ignition Articles: They are an interesting read. The EAA & Kitplanes have articles on how to eliminate 100LL & the best solution is EI ignitions. They have been successful in cars for 40 years and cars run a variety of fuels

At low MP operation, when mixture is lean of peak and timing is advances, all engine temperatures drop because very little fuel is being burned and the entire piston stroke is used for gas expansion which has a cooling effect. EGT's drop since all fuel has been burned when the exhaust valve opens. This condition can be demonstrated on the ground when advancing the timing reduces the exhaust noise so much that a propeller turning at only 500 rpm makes more noise than the pressure pulses emerging from the open exhaust pipes. At altitude, when mixture is set on the lean side of peak and timing is advanced accordingly, cylinder head temperatures can reduce by 80 degrees F, oil temperature by 25 degrees F, and EGT by 70 degrees F.

It is also possible to tune for octane variations. Octane number has a significant effect on flame front propagation with lower octane gasoline burning faster. When the engine is operated near stoichiometric ratio and ignition timing is advanced significantly, turning the one remaining magneto on or off will not produce an rpm variation. This indicates that the mixture is already burning when the magneto fires some 15-20 degrees later than those plugs operated by the electronic ignition. Before take-off, when both systems operate at manufacturer designed timing, the mag drop is even.

Here is more sources for EI information:

http://www.lightspeedengineering.com...aviation90.htm
http://www.lightspeedengineering.com...viation95.html
http://www.lightspeedengineering.com...zalezAvGas.pdf

http://www.emagair.com/intro.htm

http://cafefoundation.org/v2/pdf_caf.../ignition1.pdf
http://cafefoundation.org/v2/pdf_caf.../ignition2.pdf
http://cafefoundation.org/v2/pdf_caf.../ignition3.pdf


take care,
Glenn