I know the cylinders are ridiculously expensive. There are a lot of light twins sitting around rotting away. I would think a lot of those have the bigger case that you might be able to rebuild with normal angle valve cylinders for at least 300 hp. The difference in price might be pretty dramatic for the extra 15 hp.
There are also a lot of big Continentals out there. I have seen quite a few good deals on 520-550s. I think the Lyc 580 has a lot of competition out there.
I will pay up for lighter. I will also pay up for more power. But I do associate a dollar figure with both.
I believe the cost of a new IO580 will be less than half of the number you mention if purchased through Bearhawk for your Model 5 QB kit. I think the IO540 angle valve will be the most popular option but that is just a guess. When you order a kit I am happy to get firm pricing for you and help you buy. Mark
Does the IO580 gain the extra displacement by longer stroke or larger bore diameter? It's not hard to boost a parallel valve 540 to 300 HP, so I bet an angle valve 540 could be safely modified past 315HP. Lycon's CNC intake port work gains 5hp/cylinder verified by dyno.
I ran both 540 300 hp and Continental 520 and 550 Later Found aircraft put the ridiculously expensive IO 580 Boutique engine in the Expedition.
Even the 300 hp 540 is more expensive in any way than a 520 or 550 Continental, they use more fuel and the cylinder wear much worse than the smaller
260 hp 540s they are not even close to the same engine in operating cost and longevity ( Just a heads up). The Continental 300 HP engines are way lighter and cheaper.
Parts are super easy to get for them, they have a competitive after market for accessories and parts -- no so at all for the 580.
A ported 520 is a potent engine , not enough the 550 will do anything you ever need.
Ask any of the commercial Cherokee 6 operators the 540s wear the cylinders so bad that by 800- 900 hours they burn a quart of oil every 2 hours.
If I was to rate any of the big 6 cylinder engines the Lycoming 0-540 series is by far the best engine out there up to the fuel injected 260 HP next is the continental IO 520 and after that the
IO 550 after that the super heavyweight 300 hp Lycoming IO 540 and boutique engine IO580 in very last place.
I ran both 540 300 hp and Continental 520 and 550 Later Found aircraft put the ridiculously expensive IO 580 Boutique engine in the Expedition.
Even the 300 hp 540 is more expensive in any way than a 520 or 550 Continental, they use more fuel and the cylinder wear much worse than the smaller
260 hp 540s they are not even close to the same engine in operating cost and longevity ( Just a heads up). The Continental 300 HP engines are way lighter and cheaper.
Parts are super easy to get for them, they have a competitive after market for accessories and parts -- no so at all for the 580.
A ported 520 is a potent engine , not enough the 550 will do anything you ever need.
Ask any of the commercial Cherokee 6 operators the 540s wear the cylinders so bad that by 800- 900 hours they burn a quart of oil every 2 hours.
If I was to rate any of the big 6 cylinder engines the Lycoming 0-540 series is by far the best engine out there up to the fuel injected 260 HP next is the continental IO 520 and after that the
IO 550 after that the super heavyweight 300 hp Lycoming IO 540 and boutique engine IO580 in very last place.
Interesting experience. My Continental vs Lycoming experience is a bit different The 540 I have the most time behind by far is the TIO-540-J2BD which is 350HP and usually found on a pa31. It's the piston engine I have the most time behind by far. In a few thousand hours I never had a problem.
The other issue with continental is there is wildly less experimental aftermarket for them. Almost non existent.
The angle valve 360 is 5lbs per cylinder heavier than the parallel. I don't know why a NA 540 would all that much more than that. They do cost a lot more.
With the tdi what PSRU would you use? The “raptor-aircraft†guy made his own Cog style one. but he’s been having some issues with it. What about engine management systems? I to think a tdi Bearhawk would be great.
My 1st choice is a GMC crate engine LSA with a firewall forward PSRU swing a 4 blade MT. This combo will make 430hp with 550fbs of torque @ 3800 rpm
The TDI is not on the list due to weight. That is a heavy little engine. M-14-PF is also a heavy engine.
Last edited by Sir Newton; 04-29-2021, 10:45 AM.
Reason: spelling
I am also looking at the ls3. Doesn’t seem like very many down sides to an ls3 auto conversion the largest I can think of is resale value. But then again I wouldn’t be selling my Bearhawk.
I have ordered the LS3 crate engine. Firewall Forword Psru is matched to the LS3 engine. I am deciding whether to use the GMC ESM or go with an aftermarket product. GMC offers great support and all the tooling needed to support their engine.
Is there a reliable PSRU available? I spoke to the Robinson V8 conversion guy in Ontario that sells the LS3 - LS9 Seabee kits, but they haven't sent me any info yet and seem to be concentrating on other projects.
Is there a reliable PSRU available? I spoke to the Robinson V8 conversion guy in Ontario that sells the LS3 - LS9 Seabee kits, but they haven't sent me any info yet and seem to be concentrating on other projects.
This is the major issue. A properly engineered psru doesn’t exist and the ones that do are expensive. My Conti cost less to buy and field overhaul than the current LS psru offering cost.
I’d be happy to put an LS engine on an airplane. They are reliable and easy to maintain. I know jet boat guys with thousands of hours on their LS engines. One commercial outfit runs their LS engines to 5000hrs routinely but they replace them at that point. We just need a good psru.
Scratch Built 4-place Bearhawk. Continental IO-360, 88" C203 McCauley prop.
Seems like I've read about them in a few places recently. I think there is at most 2 aircraft flying, and "looking for investors" leads me to believe the answer to my question is doubtful.
I see corsair plans to have a 182 conversion in late 2022, they may have a viable product but it will be few years before it's proven, if it makes it to market.
I spoke to Ray @ MooseMods, he has quite a few hrs on his Moose demo on wheels with 525 hp, and has a couple 525 hp amphib/straight floats Moose conversions and a 430 hp 182 conversion and that will be flying soon. I think the Moose may have had his fuselage upgrades to 4000 lb gross, which would be a good test for the PSRU. They are getting a lot higher cruise speeds than an 0540 Moose, due to the more streamlined cowl, and the extra power.
Ray said they would de-rate the LS3 to 480 or 430 hp for take off only for the Bearhawk. In another year they should have a better idea on reliability with those 525 hp moose on floats. Will wait and see...
I see corsair plans to have a 182 conversion in late 2022, they may have a viable product but it will be few years before it's proven, if it makes it to market.
I spoke to Ray @ MooseMods, he has quite a few hrs on his Moose demo on wheels with 525 hp, and has a couple 525 hp amphib/straight floats Moose conversions and a 430 hp 182 conversion and that will be flying soon. I think the Moose may have had his fuselage upgrades to 4000 lb gross, which would be a good test for the PSRU. They are getting a lot higher cruise speeds than an 0540 Moose, due to the more streamlined cowl, and the extra power.
Ray said they would de-rate the LS3 to 480 or 430 hp for take off only for the Bearhawk. In another year they should have a better idea on reliability with those 525 hp moose on floats. Will wait and see...
How’s he getting 525 out of an LS3? I personally would be unwilling to run the rpms up high enough to achieve those numbers. A stock LS3 tops out in HP (400) at about 4500 rpm though gobs of power are available with engine mods. That’s plenty for a BH and 4500rpm for takeoff and climb is not big deal. Then you could pull it back to 3-3.5k and cruise all day long while making more power than a 540 running flat out.
Scratch Built 4-place Bearhawk. Continental IO-360, 88" C203 McCauley prop.
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