---------------------------------------------------------- Pietenpol-List Digest Archive --- Total Messages Posted Sat 09/08/07: 12 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 04:57 AM - Re: Engines (Bill Weir) 2. 09:27 AM - Re: Big Bore&Short Stroke Versus Small Bore&Long Stroke (MICHAEL SILVIUS) 3. 09:29 AM - Aileron Gap - GN- 1 Grega plans (Wayne Poole) 4. 09:49 AM - aluminum struts (Brian Kraut) 5. 10:48 AM - Re: aluminum struts (Ed G.) 6. 11:50 AM - Re: Re: Engines (MICHAEL SILVIUS) 7. 01:00 PM - Re: Big Bore&Short Stroke Versus Small Bore&Long Stroke (AzevedoFlyer@aol.com) 8. 01:47 PM - New Realtime Spell Checker Added To Matronics Forums! (Matt Dralle) 9. 05:37 PM - Re: Aileron Gap - GN- 1 Grega plans (Gene & Tammy) 10. 07:48 PM - Re: Aileron Gap - GN- 1 Grega plans (Brian Kraut) 11. 07:48 PM - Re: aluminum struts (Brian Kraut) 12. 08:59 PM - Re: Aileron Gap - GN- 1 Grega plans (Max Hegler) ________________________________ Message 1 _____________________________________ Time: 04:57:32 AM PST US From: "Bill Weir" Subject: Pietenpol-List: Re: Engines Let me add a couple points re automobile engines for Piets. My son and I laid out the table to start a Piet and hen he got into the two jobs stage of life and I've become too old but here are a couple thoughts we had. Ed Lubits took his Piet to Oshkosh in the early 80s with a Ford 1600cc Fiesta engine with his own design timing belt reduction. Worked well. We did not weigh a VW Rabbit turbo diesel but that is certainly one to which we gave thought. Does anyone have the weight of one with a reduction drive? One can buy a gear reduction drive for about $1800 out of Montreal set up for either Subaru EA81 [1800cc] or a Suzuki 1000 or 1300. Suzuki built a very pretty 1300cc twin cam and with the afore mentioned reduction that was the way we intended to go. Although the Subaru idea never left us mostly because of the amount of research on that engine. I think one could obtain acceptable results with the 2.2 or 2.5 Subaru running direct drive but because of the size of prop one needs for a Piet the rpm would be limited and the hp accordingly. And, of course now that there seems to be good success putting one on a Zenith there is work being done on at least one locally. Bill Weir ----- Original Message ----- From: "Pietenpol-List Digest Server" Sent: Saturday, September 08, 2007 2:56 AM Subject: Pietenpol-List Digest: 10 Msgs - 09/07/07 > * > > ================================================= > Online Versions of Today's List Digest Archive > ================================================= > > Today's complete Pietenpol-List Digest can also be found in either of the > two Web Links listed below. The .html file includes the Digest formatted > in HTML for viewing with a web browser and features Hyperlinked Indexes > and Message Navigation. The .txt file includes the plain ASCII version > of the Pietenpol-List Digest and can be viewed with a generic text editor > such as Notepad or with a web browser. > > HTML Version: > > > http://www.matronics.com/digest/digestview.php?Style=82701&View=html&Chapter 07-09-07&Archive=Pietenpol > > Text Version: > > > http://www.matronics.com/digest/digestview.php?Style=82701&View=txt&Chapter 07-09-07&Archive=Pietenpol > > > =============================================== > EMail Version of Today's List Digest Archive > =============================================== > > > ---------------------------------------------------------- > Pietenpol-List Digest Archive > --- > Total Messages Posted Fri 09/07/07: 10 > ---------------------------------------------------------- > > > Today's Message Index: > ---------------------- > > 1. 03:38 AM - Re: ELT info (Gene & Tammy) > 2. 04:08 AM - Re: voltage regulator () > 3. 08:23 AM - Re: Engine question (LWATCDR) > 4. 11:02 AM - Re: Engine question (AMsafetyC@aol.com) > 5. 12:58 PM - battery life (skellytownflyer) > 6. 04:43 PM - Re: Engine question (Gordon Bowen) > 7. 05:45 PM - Re: Big Bore&Short Stroke Versus Small Bore&Long Stroke > (AzevedoFlyer@aol.com) > 8. 07:55 PM - Potential Auto engine for Pietes (Gordon Bowen) > 9. 07:59 PM - Re: Pietenpol kids (Rick Holland) > 10. 10:45 PM - Re: Engine question (Scott Schreiber) > > > ________________________________ Message 1 > _____________________________________ > > > Time: 03:38:04 AM PST US > From: "Gene & Tammy" > Subject: Re: Pietenpol-List: ELT info > > Rob, did the NTSB ever come up with a cause for the crash that killed > Mike and his student? > Gene > > > ------------------------------------------------------------------------- > ----- > > > 9/6/2007 8:36 AM > > ________________________________ Message 2 > _____________________________________ > > > Time: 04:08:49 AM PST US > Subject: RE: Pietenpol-List: voltage regulator > From: > > Thankyou very much for that info. > > > ________________________________ > > From: owner-pietenpol-list-server@matronics.com > [mailto:owner-pietenpol-list-server@matronics.com] On Behalf Of > AzevedoFlyer@aol.com > Sent: September 6, 2007 5:00 PM > Subject: Re: Pietenpol-List: voltage regulator > > > Harvey, > > My admittedly modest contribution, after suffering with related > problems. > > Besides voltage and current (Amps), you have to know if your generator > is type "A" or "B" circuit. > > All Delco Remy generators are type "A." For better explanation, go to > www.aerotechlou.com, "Troubleshooting alternator and generator issues". > > As an example: my Pacer has a Delco Remy generator (hence type "A") 12V > and 35 Amps. The VR recommended is Electrodelta VR300, which will cost > you app. $150.00. > > The automotive version -- performancewise the same as the aircraft grade > - is a VR22, generally found or ordered from NAPA / Car Quest and the > like. It was used in GM Corvair cars and is still used by many a farm > tractor. It should cost you around $35.00. One last word: buy American. > The current Chinese crop is worse than the toys they make, in the words > of people in the known (Ecorse Electric/MI). > > Best of luck, > > Miguel > > N8714D > > PA22/20-150 > > > ________________________________ > > > > .. > > > ________________________________ Message 3 > _____________________________________ > > > Time: 08:23:44 AM PST US > From: LWATCDR > Subject: Re: Pietenpol-List: Engine question > > > Not exactly correct. In fact way off. > For an aircraft engine you do want HP you want all the HP you can get > but you want it at the right RPM. The correct RPM will be based on > the size of the prop and you maximum airspeed. > So if you are not going to use a reduction system you will probably > want a pretty long stroke. But even then it isn't that simple. The > bore can also make a difference because the size of the valves will > effect the amount of power you get out of the engine. Some people > tried to make what where called bicycle pump engines way back when. > They had a very long stroke and a small bore. They ended up making > very little power because they couldn't breath well. An example on the > other end of the scale is a modern high power hemi engine like they > use in top fuel racing. They make a huge amount of toque but the peak > is very high in the RPM band. > Oh and yes it gets even more complex. You have things like induction > and exhaust system to take in account as well. I will not even start > on flame travel and forced induction. > > So the ideal engine would have a just the right stroke to bore ratio > for turning the prop that you want to turn. > The biggest bore and shortest stroke would honestly be the worst > possible engine for a plane like an Aircamper it would have very > little torque. > > I too have been thinking about the VW TDI. I did the math and it seems > a little on the heavy side compared to the Model A but would make a > lot more power. VW makes a nice 3 cylinder TDI in the EU which could > be a great fit for an Aircamper but info on it is hard to find. Both > Honda and Nissan are going to be bringing TDIs to the US soon so they > could also be very interesting. > The big problem I see with all the TDIs will be the crank. All modern > motors are very optimized for what they do. I just don't know if the > thrust bearings will handle the load a > > On 9/5/07, Gordon Bowen wrote: >> >> >> Find an engine with the shortest stroke and largest diameter pistons. >> Torque turns the prop, not max. hp. Low rpm torque comes from short >> stroke >> and large diameter piston engines, ie. diesel engines and storebought >> aircraft engines. You can look until the next ice age, but you ain't >> gonna >> find too many cheap engines made for cars that meet the above torque >> requirements at low rpm. OR Option 1--- bite the bullet and buy engine >> designed for the job, like a Lycosaurus. Option 2--bite the bullet again >> and get a firewall forward system like the Subaru's modified, somewhat >> proven and for aircraft. Subarus still need a PRU, do to rpm needed to >> get >> torque. Benefit of Subarus is the fact the pistons are oppossed like VW >> or >> Corvair, thus they don't vibrate themselves to death at high rpms. >> Biggest >> problem with looking a alternate sources of power is waste of your time >> and >> money. I know it's called experimental, but the engine alternative >> experiment has been beaten to death by every type and sort of homebuilder >> and some spam cans with ie. 4.3L Chevy engines, or alumimum block ole >> Buick >> V-8's. There's tonnes of research and experiment documentation out there >> in >> internet-land for your consideration. The power systems that have >> worked >> and are working are well documented. >> Gordon >> >> ----- Original Message ----- >> From: AMsafetyC@aol.com >> To: pietenpol-list@matronics.com >> Sent: Wednesday, September 05, 2007 5:44 AM >> Subject: Re: Pietenpol-List: Engine question >> >> >> What changes would one have to make to an engine to get the majority of >> hp >> out at a lower rpm, rather than making it a 6500 rpm screamer? I would >> much >> rather improve the low rpm output if possible than go full rpm and >> redrive. >> >> Any suggestions on building a low rpm high output engine suggesting a max >> rpm in the 2500 to 3500 range? >> >> I would really like to use the ford 2.0 L OHC metric engine (Pinto) I >> already have in stock if at all possible! Any info on building that is >> greatly appreciated! >> >> John >> >> >> ________________________________ >> title=http://discover.aol.com/memed/aolcom30tour/?ncid=AOLAOF00020000000982 >> href="http://discover.aol.com/memed/aolcom30tour/?ncid=AOLAOF00020000000982" >> target=_blank>AOL.com. >> >> href="http://www.matronics.com/Navigator?Pietenpol-List">http://www.matronics.com/Navigator?Pietenpol-List >> href="http://forums.matronics.com">http://forums.matronics.com >> >> > > > ________________________________ Message 4 > _____________________________________ > > > Time: 11:02:07 AM PST US > From: AMsafetyC@aol.com > Subject: Re: Pietenpol-List: Engine question > > As this all sounds like a balancing act but then engine torque/rpm issues > can be mitigated in some degree by matching up a propeller to that engine > to > determine the best combination to avoid exceeding the 92% of Mach speed > at the > > propeller tip at a maximum allowable Rpm. which at any luck will be at > the > max torque. > > I located this calculator to help make those calculations and plugging in > a > number of variables. > > _http://www.pponk.com/HTML%20PAGES/propcalc.html_ > (http://www.pponk.com/HTML%20PAGES/propcalc.html) > > Like most things in this life, its not the end all but it certainly helps > take much of the guess work out of the balancing act. > > John > > BTW does anyone have a resource for torque curve charts I want to check my > engine options to see what they actually look like on the torque charts > > > http://discover.aol.com/memed/aolcom30tour > > ________________________________ Message 5 > _____________________________________ > > > Time: 12:58:19 PM PST US > Subject: Pietenpol-List: battery life > From: "skellytownflyer" > > > Well I bought new Gell cell battery last summer when I got my Tri-pacer > annualed.Yea > I know it's not a *iet-but is aircraft.I didn't fly much and it was dead > by mid-winter.messed around and charged it back up and flew once or twice > but > still had to jump it.but didn't take it back in time to get it > replaced.now > I'm wondering if there are any tricks to getting a gel cell to accept a > charge? > I put a solar panel on the roof of the hangar in winter and kept it hooked > up > but it won't maintain a charge.wondering if hitting it with a heavy > charger > might wake it up-have tried slow charge and it seems to indicate enough > voltage > to cut back pretty quick but just won't hold.might crank it that day but a > few > days later-go back and it's dead.Gill put out some bad batteries I > know.but > I'm a tightwad and would'nt mind trying to get a little use out of > it.still planning > on starting cover on my GN-1 wings in about 6 weeks.Raymond > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=133284#133284 > > > ________________________________ Message 6 > _____________________________________ > > > Time: 04:43:01 PM PST US > From: "Gordon Bowen" > Subject: Re: Pietenpol-List: Engine question > > > I think the original thread on this discussion came regarding how to get > by > without the PRU using a car engine. Guess if one was building an engine > for > a tractor pull then having the long stroke for leverage on the crank good > idea, or if building a NASCAR engine for routine 9000rpm (short stroke) > would be great but we're talking aircraft. Engines like Lyco have very > large > bore and short stroke. Designed to run hours at a time for decades at 2500 > rpm and at peak torque. Think the reason for big bore aircraft engines is > first for durability and then improved breathing and lower frictional > losses. Without PRU cannot run any car engine at RPM's needed to get to > peak of torque curve, so what can you do to move the torque curve peak > back > to say 2700 rpm. Very few options. Don't think any car engine is designed > for long durations of 4000 rpms even if you use a PRU. Could make cam > changes to open small valves on small cylinders but in a big bore engines > you already have larger and unshrouded valves away from the cylinder > walls, > no need to experiment with the cam. To adjust for poorer fuel/air burn in > bigger bore you'd need two plugs per cylinder. The shorter stroke would > mean less losses due to friction and less vibration. Subaru's seem to > work > for aircraft because they are 3.46" bore and 2.591" stroke, but still > need > two plugs and PRU to get the advertised 125hp. To get a car engine to > work > so it could run like a aircraft engine you have to consider: vibration > (less > with short stroke), and fuel/air vacuum pumping by the intake stroke of > the > cylinder (bigger valves on big bore engines). Someplace there's a website > for a guy that builds VW engines for racing, he had made many changes in > the cams and still came to the conclusion it all came down to bigger bore > engines means better breathing and less frictional losses. I have a V-6 > 3.8L Ford engine with supercharger down at the hanger in FL, including > motor > mount, 225hp at 5200 rpm according to Ford. I'll donate it to anyone who > wants to put it on their C-172 and do the flight testing with or without a > PRU. Big fan of idea auto engines for aircraft, but haven't seen anything > I'm willing to fly, yet. > Gordon > > > ----- Original Message ----- > From: "LWATCDR" > Sent: Friday, September 07, 2007 7:23 AM > Subject: Re: Pietenpol-List: Engine question > > >> >> Not exactly correct. In fact way off. >> For an aircraft engine you do want HP you want all the HP you can get >> but you want it at the right RPM. The correct RPM will be based on >> the size of the prop and you maximum airspeed. >> So if you are not going to use a reduction system you will probably >> want a pretty long stroke. But even then it isn't that simple. The >> bore can also make a difference because the size of the valves will >> effect the amount of power you get out of the engine. Some people >> tried to make what where called bicycle pump engines way back when. >> They had a very long stroke and a small bore. They ended up making >> very little power because they couldn't breath well. An example on the >> other end of the scale is a modern high power hemi engine like they >> use in top fuel racing. They make a huge amount of toque but the peak >> is very high in the RPM band. >> Oh and yes it gets even more complex. You have things like induction >> and exhaust system to take in account as well. I will not even start >> on flame travel and forced induction. >> >> So the ideal engine would have a just the right stroke to bore ratio >> for turning the prop that you want to turn. >> The biggest bore and shortest stroke would honestly be the worst >> possible engine for a plane like an Aircamper it would have very >> little torque. >> >> I too have been thinking about the VW TDI. I did the math and it seems >> a little on the heavy side compared to the Model A but would make a >> lot more power. VW makes a nice 3 cylinder TDI in the EU which could >> be a great fit for an Aircamper but info on it is hard to find. Both >> Honda and Nissan are going to be bringing TDIs to the US soon so they >> could also be very interesting. >> The big problem I see with all the TDIs will be the crank. All modern >> motors are very optimized for what they do. I just don't know if the >> thrust bearings will handle the load a >> >> On 9/5/07, Gordon Bowen wrote: >>> >>> >>> Find an engine with the shortest stroke and largest diameter pistons. >>> Torque turns the prop, not max. hp. Low rpm torque comes from short >>> stroke >>> and large diameter piston engines, ie. diesel engines and storebought >>> aircraft engines. You can look until the next ice age, but you ain't >>> gonna >>> find too many cheap engines made for cars that meet the above torque >>> requirements at low rpm. OR Option 1--- bite the bullet and buy engine >>> designed for the job, like a Lycosaurus. Option 2--bite the bullet >>> again >>> and get a firewall forward system like the Subaru's modified, somewhat >>> proven and for aircraft. Subarus still need a PRU, do to rpm needed to >>> get >>> torque. Benefit of Subarus is the fact the pistons are oppossed like VW >>> or >>> Corvair, thus they don't vibrate themselves to death at high rpms. >>> Biggest >>> problem with looking a alternate sources of power is waste of your time >>> and >>> money. I know it's called experimental, but the engine alternative >>> experiment has been beaten to death by every type and sort of >>> homebuilder >>> and some spam cans with ie. 4.3L Chevy engines, or alumimum block ole >>> Buick >>> V-8's. There's tonnes of research and experiment documentation out >>> there >>> in >>> internet-land for your consideration. The power systems that have >>> worked >>> and are working are well documented. >>> Gordon >>> >>> ----- Original Message ----- >>> From: AMsafetyC@aol.com >>> To: pietenpol-list@matronics.com >>> Sent: Wednesday, September 05, 2007 5:44 AM >>> Subject: Re: Pietenpol-List: Engine question >>> >>> >>> What changes would one have to make to an engine to get the majority of >>> hp >>> out at a lower rpm, rather than making it a 6500 rpm screamer? I would >>> much >>> rather improve the low rpm output if possible than go full rpm and >>> redrive. >>> >>> Any suggestions on building a low rpm high output engine suggesting a >>> max >>> rpm in the 2500 to 3500 range? >>> >>> I would really like to use the ford 2.0 L OHC metric engine (Pinto) I >>> already have in stock if at all possible! Any info on building that is >>> greatly appreciated! >>> >>> John >>> >>> >>> >>> ________________________________ >>> title=http://discover.aol.com/memed/aolcom30tour/?ncid=AOLAOF00020000000982 >>> href="http://discover.aol.com/memed/aolcom30tour/?ncid=AOLAOF00020000000982" >>> target=_blank>AOL.com. >>> >>> href="http://www.matronics.com/Navigator?Pietenpol-List">http://www.matronics.com/Navigator?Pietenpol-List >>> href="http://forums.matronics.com">http://forums.matronics.com >>> >>> >>> >>> >>> >>> >>> >> >> >> > > > ________________________________ Message 7 > _____________________________________ > > > Time: 05:45:36 PM PST US > From: AzevedoFlyer@aol.com > Subject: Re: Pietenpol-List: Big Bore&Short Stroke Versus Small Bore&Long > Stroke > > Piet Friends, > I have to pitch into this subject. > 1 - There is no relationship between PCU (Power Cylinder Unit: piston, > rings > and cylinder) wear and bore X stroke combinations. A large range can be > made > to achieve expected life limits. > 2 - For aircraft engines, the overriding design objective is lightness and > lower BSFC (Brake Specific Fuel Consumption). Minimizing thermal losses > (hence > > lower BSFC) favors big bores and few cylinders. Given more displacement > per > cylinder, less of the same are necessary to generate the power needed, > hence > less weight. Example: 4 cyl. Lyc.O-360 versus 6 cyl. Cont. O-360: both are > real 200HP engines. The Lycosaurus has lower BSFC (more mpg) and vibrates > more. > > The Contisaurus has higher BSFC (less mpg) and is smooth as silk. > Smoothness > > comes from lower thrust loads (the force pistons exert on cylinder walls) > and > better balancing of primary/secondary forces and internal binaries, a > natural with 6 cyl. configuration. So, a large displacement per cylinder > rotating > > at lower speed is capable of generating the same power as a lower > displacement > > rotating at higher speed. Short strokes, as said before, implies high > conrod > angularity and higher thrust load. Higher thrust load generates friction > losses and greater wear, if same materials are used. > 3 - Given the above, large bores predominate. Thus large valves can be > used, > resulting in filling efficiencies (so called volumetric efficiency) far in > excess of those achieved by the run-of-the-mill automotive engine. > However, > large valves do not induce the high turbulence levels needed for fast > combustion. Thus the extreme sensitivity of our slow revving, big bore > aircraft > > engines to fuel Octane rating. Higher Octane fuels are needed to preclude > detonation but this slows combustion even more! Therefore, twin spark > plugs are > needed > to expedite things. In effect twin spark plugs slice the combustion > chamber > in 2 and ensure freedom of detonation under high loads. Incidentally, > this is > > the root explanation for speed loss when checking magnetos. Normal > combustion is, paradoxically, very slow (20 to 100 m/s). Very high revving > engines > > (Ferrari V12 comes to mind) have tiny pistons/combustion chambers and get > away > > with a single spark plug. > 4 - Our Lycosaurus and Contisaurus are not perfect (...and in some aspects > irritably so, example in point carbs and mechanical fuel injection, not to > mention single timing magnetos...) but are unbeatable in their primary > function: > > reliability/safety. > 5 - Can one turn an automotive engine into a good aircraft engine? The > answer is an unequivocal YES. > 6 - Done properly, almost any automotive engine should have at least 1000h > TBO. > Sorry for the lengthy mail. Intention was to contribute +. > Cheers, > Miguel Azevedo > PA22/20-150 > > > ________________________________ Message 8 > _____________________________________ > > > Time: 07:55:58 PM PST US > From: "Gordon Bowen" > Subject: Pietenpol-List: Potential Auto engine for Pietes > > For those of you bent on trying an auto conversion for your Piete > project, especially considering the prior thread re H.P and torque, > etc. > You may want to look into the engine and chain-driven gears for the > Toyota Prius, engine no. 1NZ-FXE. Only 1.5L but very light all aluminum > engine, twin overhead cam, good torque at 4200 rpms. Probably be hard > to find a wreck but with more cars on the road each year, they'll > eventually be plentiful. Google it, you'll find lots of data on engine > and drive train (no clutch or torque converter). Maybe not enough to > swing a big prop or heavy plane, but a good potential. > Gordon > > ________________________________ Message 9 > _____________________________________ > > > Time: 07:59:15 PM PST US > From: "Rick Holland" > Subject: Re: Pietenpol-List: Pietenpol kids > > I received one a couple days ago also. Very thoughtful of them. I took > wood > shop in high school and enjoyed it but I can't imagine how exciting it > would > have been to have worked on a project like a Pietenpol. Especially getting > to take a ride in it knowing that I had built a part of it. > > Rick > > On 9/4/07, Oscar Zuniga wrote: >> >> taildrags@hotmail.com> >> >> I received a nice laminated photo of the "Piet kids" in the mail last >> week. >> I think they sent out photos to everyone who contributed to their >> restoration project and trip to Oshkosh. Very encouraging to see young >> people carring the 75 year old design into the 21st century and beyond! >> >> Who knows; there might be a daydreaming young student doodling in class >> right now, working on a biodiesel Piet or a hydrogen Piet or something >> else >> like that, even as we speak... >> >> >> Oscar Zuniga >> San Antonio, TX >> mailto: taildrags@hotmail.com >> website at http://www.flysquirrel.net >> >> _________________________________________________________________ >> Test your celebrity IQ. Play Red Carpet Reveal and earn great prizes! >> >> http://club.live.com/red_carpet_reveal.aspx?icid=redcarpet_hotmailtextlink2 >> >> > > > -- > Rick Holland > ObjectAge Ltd. > Castle Rock, Colorado > > ________________________________ Message 10 > ____________________________________ > > > Time: 10:45:55 PM PST US > From: "Scott Schreiber" > Subject: Re: Pietenpol-List: Engine question > > > This is all very odd to me. We have a Lotus that runs a Toyota 2ZZ based > engine built by Yamaha and it turns almost 9k stock, and is turning 12k > after the build. It is like driving a sportbike with a steering wheel. My > other daily driver is a Subaru 04 STi that put down 300 stock and is now > at > just over 500 after a larger turbo, IC, injectors, pump etc. and ECU > reflash. That is where my auto mindset comes from. When I first started > building I looke at auto and aero engines as the same. HP + HP etc. After > allot of looking at the real world I came to see that they are very > different an that people like Gordon have a real point. Granted the model > A > engine was not that different from an aero engine in many respects. The > more > I get used to it, and as I start down the road of building my second > plane, > an Acro Sport II, I see that a 360ci 4Cyl which would be terrible in the > auto world makes sense in the aero world. That said, the PSRU is a valid > idea and Subaru engines are ideal if any are for conversion. I really > wanted > to run an EA81 in my Peit and I do think it could have worked but the A65 > won out for various reasons, chiefly insurance. > > -Scott > > > ----- Original Message ----- > From: "Gordon Bowen" > Sent: Friday, September 07, 2007 7:42 PM > Subject: Re: Pietenpol-List: Engine question > > >> >> >> I think the original thread on this discussion came regarding how to get >> by without the PRU using a car engine. Guess if one was building an >> engine for a tractor pull then having the long stroke for leverage on the >> crank good idea, or if building a NASCAR engine for routine 9000rpm >> (short >> stroke) would be great but we're talking aircraft. Engines like Lyco have >> very large bore and short stroke. Designed to run hours at a time for >> decades at 2500 rpm and at peak torque. Think the reason for big bore >> aircraft engines is first for durability and then improved breathing and >> lower frictional losses. Without PRU cannot run any car engine at RPM's >> needed to get to peak of torque curve, so what can you do to move the >> torque curve peak back to say 2700 rpm. Very few options. Don't think >> any >> car engine is designed for long durations of 4000 rpms even if you use a >> PRU. Could make cam changes to open small valves on small cylinders but >> in a big bore engines you already have larger and unshrouded valves away >> from the cylinder walls, no need to experiment with the cam. To adjust >> for poorer fuel/air burn in bigger bore you'd need two plugs per >> cylinder. >> The shorter stroke would mean less losses due to friction and less >> vibration. Subaru's seem to work for aircraft because they are 3.46" >> bore and 2.591" stroke, but still need two plugs and PRU to get the >> advertised 125hp. To get a car engine to work so it could run like a >> aircraft engine you have to consider: vibration (less with short stroke), >> and fuel/air vacuum pumping by the intake stroke of the cylinder (bigger >> valves on big bore engines). Someplace there's a website for a guy that >> builds VW engines for racing, he had made many changes in the cams and >> still came to the conclusion it all came down to bigger bore engines >> means >> better breathing and less frictional losses. I have a V-6 3.8L Ford >> engine with supercharger down at the hanger in FL, including motor mount, >> 225hp at 5200 rpm according to Ford. I'll donate it to anyone who wants >> to put it on their C-172 and do the flight testing with or without a PRU. >> Big fan of idea auto engines for aircraft, but haven't seen anything I'm >> willing to fly, yet. >> Gordon >> >> >> ----- Original Message ----- >> From: "LWATCDR" >> To: >> Sent: Friday, September 07, 2007 7:23 AM >> Subject: Re: Pietenpol-List: Engine question >> >> >>> >>> Not exactly correct. In fact way off. >>> For an aircraft engine you do want HP you want all the HP you can get >>> but you want it at the right RPM. The correct RPM will be based on >>> the size of the prop and you maximum airspeed. >>> So if you are not going to use a reduction system you will probably >>> want a pretty long stroke. But even then it isn't that simple. The >>> bore can also make a difference because the size of the valves will >>> effect the amount of power you get out of the engine. Some people >>> tried to make what where called bicycle pump engines way back when. >>> They had a very long stroke and a small bore. They ended up making >>> very little power because they couldn't breath well. An example on the >>> other end of the scale is a modern high power hemi engine like they >>> use in top fuel racing. They make a huge amount of toque but the peak >>> is very high in the RPM band. >>> Oh and yes it gets even more complex. You have things like induction >>> and exhaust system to take in account as well. I will not even start >>> on flame travel and forced induction. >>> >>> So the ideal engine would have a just the right stroke to bore ratio >>> for turning the prop that you want to turn. >>> The biggest bore and shortest stroke would honestly be the worst >>> possible engine for a plane like an Aircamper it would have very >>> little torque. >>> >>> I too have been thinking about the VW TDI. I did the math and it seems >>> a little on the heavy side compared to the Model A but would make a >>> lot more power. VW makes a nice 3 cylinder TDI in the EU which could >>> be a great fit for an Aircamper but info on it is hard to find. Both >>> Honda and Nissan are going to be bringing TDIs to the US soon so they >>> could also be very interesting. >>> The big problem I see with all the TDIs will be the crank. All modern >>> motors are very optimized for what they do. I just don't know if the >>> thrust bearings will handle the load a >>> >>> On 9/5/07, Gordon Bowen wrote: >>>> >>>> >>>> Find an engine with the shortest stroke and largest diameter pistons. >>>> Torque turns the prop, not max. hp. Low rpm torque comes from short >>>> stroke >>>> and large diameter piston engines, ie. diesel engines and storebought >>>> aircraft engines. You can look until the next ice age, but you ain't >>>> gonna >>>> find too many cheap engines made for cars that meet the above torque >>>> requirements at low rpm. OR Option 1--- bite the bullet and buy >>>> engine >>>> designed for the job, like a Lycosaurus. Option 2--bite the bullet >>>> again >>>> and get a firewall forward system like the Subaru's modified, somewhat >>>> proven and for aircraft. Subarus still need a PRU, do to rpm needed to >>>> get >>>> torque. Benefit of Subarus is the fact the pistons are oppossed like >>>> VW >>>> or >>>> Corvair, thus they don't vibrate themselves to death at high rpms. >>>> Biggest >>>> problem with looking a alternate sources of power is waste of your time >>>> and >>>> money. I know it's called experimental, but the engine alternative >>>> experiment has been beaten to death by every type and sort of >>>> homebuilder >>>> and some spam cans with ie. 4.3L Chevy engines, or alumimum block ole >>>> Buick >>>> V-8's. There's tonnes of research and experiment documentation out >>>> there in >>>> internet-land for your consideration. The power systems that have >>>> worked >>>> and are working are well documented. >>>> Gordon >>>> >>>> ----- Original Message ----- >>>> From: AMsafetyC@aol.com >>>> To: pietenpol-list@matronics.com >>>> Sent: Wednesday, September 05, 2007 5:44 AM >>>> Subject: Re: Pietenpol-List: Engine question >>>> >>>> >>>> What changes would one have to make to an engine to get the majority of >>>> hp >>>> out at a lower rpm, rather than making it a 6500 rpm screamer? I would >>>> much >>>> rather improve the low rpm output if possible than go full rpm and >>>> redrive. >>>> >>>> Any suggestions on building a low rpm high output engine suggesting a >>>> max >>>> rpm in the 2500 to 3500 range? >>>> >>>> I would really like to use the ford 2.0 L OHC metric engine (Pinto) I >>>> already have in stock if at all possible! Any info on building that is >>>> greatly appreciated! >>>> >>>> John >>>> >>>> >>>> >>>> ________________________________ >>>> title=http://discover.aol.com/memed/aolcom30tour/?ncid=AOLAOF00020000000982 >>>> href="http://discover.aol.com/memed/aolcom30tour/?ncid=AOLAOF00020000000982" >>>> target=_blank>AOL.com. >>>> >>>> href="http://www.matronics.com/Navigator?Pietenpol-List">http://www.matronics.com/Navigator?Pietenpol-List >>>> href="http://forums.matronics.com">http://forums.matronics.com >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>> >>> >>> >>> >> >> >> > > > ________________________________ Message 2 _____________________________________ Time: 09:27:41 AM PST US From: "MICHAEL SILVIUS" Subject: Re: Pietenpol-List: Big Bore&Short Stroke Versus Small Bore&Long Stroke Miguel: All that said, the direct drive Corvair engine as per William Wynne's recipe is consistently proven and in quite a reasonable sample that it can be done safely, by the average pedestrian and a low a cost as you can get. As you mention dual plugs helps prevent detonation and this is one of the finicky points in the Corvair running on single plugs. But once you replace the cam to relocate peak torque, replace cast pistons for forged in order to withstand the occasional occurrence of detonation and sort out the fine tuning out to keep it from happening, 100 hp with no redrive can be accomplished on that engine at a reasonable cost. I personally have become quite partial to the Mazda 13B rotary. No valves, no pistons, few moving parts and no opposing powerstrokes to shake it all appart. http://www.rotaryaviation.com/ For this one you do need a redrive to achieve reasonable numbers. But once over the 3000$ expense for that fine piece of machinery most of the rest of it is quite within the "beer money" means of this working stiff. A complete rebuild kit for a used core can be had for 500$ and a savable core can be had for a couple hundred. A "short block" (sans accessories) rebuilt engine can be had for 2500$ from various road racing suppliers if you opt to not rebuild a used core yourself. And it has no valves to burn out. It will do 150 to 180 hp and that is really babying it, as the folks in the track racing world are making 3 and 4 times that running at 9 thou RPM. Yes a bit much for the Aircamper, but the point is that affordable and proven auto engine conversions are out there to be had. Saludos Michael in Maine. (previously of Caracas where I was also once known as Miguel) http://rides.webshots.com/album/147451245dhnmgI ----- Original Message ----- From: AzevedoFlyer@aol.com To: pietenpol-list@matronics.com Sent: Friday, September 07, 2007 7:44 PM Subject: Re: Pietenpol-List: Big Bore&Short Stroke Versus Small Bore&Long Stroke Piet Friends, I have to pitch into this subject. 1 - There is no relationship between PCU (Power Cylinder Unit: piston, rings and cylinder) wear and bore X stroke combinations. A large range can be made to achieve expected life limits. 2 - For aircraft engines, the overriding design objective is lightness and lower BSFC (Brake Specific Fuel Consumption). Minimizing thermal losses (hence lower BSFC) favors big bores and few cylinders. Given more displacement per cylinder, less of the same are necessary to generate the power needed, hence less weight. Example: 4 cyl. Lyc.O-360 versus 6 cyl. Cont. O-360: both are real 200HP engines. The Lycosaurus has lower BSFC (more mpg) and vibrates more. The Contisaurus has higher BSFC (less mpg) and is smooth as silk. Smoothness comes from lower thrust loads (the force pistons exert on cylinder walls) and better balancing of primary/secondary forces and internal binaries, a natural with 6 cyl. configuration. So, a large displacement per cylinder rotating at lower speed is capable of generating the same power as a lower displacement rotating at higher speed. Short strokes, as said before, implies high conrod angularity and higher thrust load. Higher thrust load generates friction losses and greater wear, if same materials are used. 3 - Given the above, large bores predominate. Thus large valves can be used, resulting in filling efficiencies (so called volumetric efficiency) far in excess of those achieved by the run-of-the-mill automotive engine. However, large valves do not induce the high turbulence levels needed for fast combustion. Thus the extreme sensitivity of our slow revving, big bore aircraft engines to fuel Octane rating. Higher Octane fuels are needed to preclude detonation but this slows combustion even more! Therefore, twin spark plugs are needed to expedite things. In effect twin spark plugs slice the combustion chamber in 2 and ensure freedom of detonation under high loads. Incidentally, this is the root explanation for speed loss when checking magnetos. Normal combustion is, paradoxically, very slow (20 to 100 m/s). Very high revving engines (Ferrari V12 comes to mind) have tiny pistons/combustion chambers and get away with a single spark plug. 4 - Our Lycosaurus and Contisaurus are not perfect (...and in some aspects irritably so, example in point carbs and mechanical fuel injection, not to mention single timing magnetos...) but are unbeatable in their primary function: reliability/safety. 5 - Can one turn an automotive engine into a good aircraft engine? The answer is an unequivocal YES. 6 - Done properly, almost any automotive engine should have at least 1000h TBO. Sorry for the lengthy mail. Intention was to contribute +. Cheers, Miguel Azevedo PA22/20-150 ---------------------------------------------------------------------------- -- See what'target="_blank">Make AOL Your Homepage. ________________________________ Message 3 _____________________________________ Time: 09:29:48 AM PST US From: "Wayne Poole" Subject: Pietenpol-List: Aileron Gap - GN- 1 Grega plans We do not care for the Grega method of sealing the aileron gap with fabric. Can anyone suggest other ways? We are thinking about putting a radius filler on the aileron and an angle on the wing with about a 1/4 inch of gap. ________________________________ Message 4 _____________________________________ Time: 09:49:45 AM PST US From: "Brian Kraut" Subject: Pietenpol-List: aluminum struts I hear rumor that there is a place somewhere in Ohio that sells aluminum streamline tubing for Piet struts. Can someone point me to the place. Brian Kraut Engineering Alternatives, Inc. www.engalt.com ________________________________ Message 5 _____________________________________ Time: 10:48:41 AM PST US From: "Ed G." Subject: Re: Pietenpol-List: aluminum struts Try....WWW.Sky-tek.com/struts ----- Original Message ----- From: Brian Kraut To: pietenpol-list@matronics.com Sent: Saturday, September 08, 2007 12:49 PM Subject: Pietenpol-List: aluminum struts I hear rumor that there is a place somewhere in Ohio that sells aluminum streamline tubing for Piet struts. Can someone point me to the place. Brian Kraut Engineering Alternatives, Inc. www.engalt.com http://www.matronics.com/Navigator?Pietenpol-List ________________________________ Message 6 _____________________________________ Time: 11:50:30 AM PST US From: "MICHAEL SILVIUS" Subject: Re: Pietenpol-List: Re: Engines a 3 cyl in line Geo Metro block that looks suitable for a Piet. Fuel injected too. Note the plate sandwiched bewent the block and oil pan to allow a flange for a bed mount. http://www.airtrikes.net/engines.shtml michael in maine ________________________________ Message 7 _____________________________________ Time: 01:00:48 PM PST US From: AzevedoFlyer@aol.com Subject: Re: Pietenpol-List: Big Bore&Short Stroke Versus Small Bore&Long Stroke Michel, Fully agree with your appreciation of Mazda rotaries! I think highly of these powerplants and have been told by people from Washington State that even TBO is quite meaningless in this case. Somebody from Puyallup area stated that only when you cannot start easily is when you are being told that a rebuild is in order. The guy had 2000+h in one engine... I do not understand - maybe I do - why home builders have not zoomed into Wankels a long time ago. Almost no vibration, light, insensitive to Octane rating (heck, our military uses Curtiss-Wright designed Wankels with JP4 as fuel, direct injected and twin spark ignited...!), very compact frontal area, exceedingly robust internals, garanteed long TBO and so forth... What else do you want? Problem areas are higher BSFC ( more than compensated by lower frontal area and weight) and safely handling the extreme exhaust heat. A solution to the last is the modern, space age heat blankets from Federal Mogul Corp (USA). Like any 2 stroke engine, Wankels benefit greatly from tuned exhaust systems but mutting exhaust noise might prove difficult. However, almost everybody loves the famous P51/Spitfire/Hurricane exhaust noise. Well, Wankels are closer to that than anything else out there... Nice to have met you. I am a Brazilian by birth and living here in this God's country for the last 10 years. Becoming an American Citizen this year! Cheers, Miguel N8714D PA22/20-150 ________________________________ Message 8 _____________________________________ Time: 01:47:54 PM PST US From: Matt Dralle Subject: Pietenpol-List: New Realtime Spell Checker Added To Matronics Forums! Dear Listers, Today 9/8/2007 I have added a new real-time spell checker function to all of the BBS Forums at Matronics. When you reply or create a new message on the Forums, you will notice that misspelled words will be high-lighted in yellow. If you left-click on the word, you will be prompted with a drop-down list of suggested spellings. http://forums.matronics.com Enjoy! Matt Dralle Matornics Email List and Forum Administrator ________________________________ Message 9 _____________________________________ Time: 05:37:11 PM PST US From: "Gene & Tammy" Subject: Re: Pietenpol-List: Aileron Gap - GN- 1 Grega plans Wayne, The way I sealed the gaps was by going to a sign company and buying a sheet of vinyl (matching the color of my plane) that they make letters for signs out of. I then cut strips (can be any size you want) and take the paper side off of 1/2 of the width exposing the sticky surface. I then place the two sticky sides together forming a tape that has the color I want (one color side up and one color side down) and has two sticky sides (one up and one down). I then form an "S" thru the gap sticking the tape to the top of the wing and the underside of the aileron. I know I have made this as clear as mud. Gene ----- Original Message ----- From: Wayne Poole To: Pietenpol-List@matronics.com Sent: Saturday, September 08, 2007 11:30 AM Subject: Pietenpol-List: Aileron Gap - GN- 1 Grega plans We do not care for the Grega method of sealing the aileron gap with fabric. Can anyone suggest other ways? We are thinking about putting a radius filler on the aileron and an angle on the wing with about a 1/4 inch of gap. ------------------------------------------------------------------------- ----- 9/7/2007 4:40 PM ________________________________ Message 10 ____________________________________ Time: 07:48:22 PM PST US From: "Brian Kraut" Subject: RE: Pietenpol-List: Aileron Gap - GN- 1 Grega plans I am going to do the ailerons in my Sky scout just like a KR-2 with a full length aluminum piano hinge. Brian Kraut Engineering Alternatives, Inc. www.engalt.com -----Original Message----- From: owner-pietenpol-list-server@matronics.com [mailto:owner-pietenpol-list-server@matronics.com]On Behalf Of Wayne Poole Sent: Saturday, September 08, 2007 12:30 PM To: Pietenpol-List@matronics.com Subject: Pietenpol-List: Aileron Gap - GN- 1 Grega plans We do not care for the Grega method of sealing the aileron gap with fabric. Can anyone suggest other ways? We are thinking about putting a radius filler on the aileron and an angle on the wing with about a 1/4 inch of gap. ________________________________ Message 11 ____________________________________ Time: 07:48:22 PM PST US From: "Brian Kraut" Subject: RE: Pietenpol-List: aluminum struts That is them. Thanks. Brian Kraut Engineering Alternatives, Inc. www.engalt.com -----Original Message----- From: owner-pietenpol-list-server@matronics.com [mailto:owner-pietenpol-list-server@matronics.com]On Behalf Of Ed G. Sent: Saturday, September 08, 2007 1:48 PM To: pietenpol-list@matronics.com Subject: Re: Pietenpol-List: aluminum struts Try....WWW.Sky-tek.com/struts ----- Original Message ----- From: Brian Kraut To: pietenpol-list@matronics.com Sent: Saturday, September 08, 2007 12:49 PM Subject: Pietenpol-List: aluminum struts I hear rumor that there is a place somewhere in Ohio that sells aluminum streamline tubing for Piet struts. Can someone point me to the place. Brian Kraut Engineering Alternatives, Inc. www.engalt.com title=http://www.matronics.com/Navigator?Pietenpol-List href="http://www.matronics.com/Navigator?Pietenpol-List">http://www.matronic s.com/Navigator?Pietenpol-List href="http://forums.matronics.com">http://forums.matronics.com ________________________________ Message 12 ____________________________________ Time: 08:59:24 PM PST US From: "Max Hegler" Subject: Re: Pietenpol-List: Aileron Gap - GN- 1 Grega plans Mine has the piano hinge... Max ----- Original Message ----- From: Brian Kraut To: pietenpol-list@matronics.com Sent: Saturday, September 08, 2007 9:47 PM Subject: RE: Pietenpol-List: Aileron Gap - GN- 1 Grega plans I am going to do the ailerons in my Sky scout just like a KR-2 with a full length aluminum piano hinge. Brian Kraut Engineering Alternatives, Inc. www.engalt.com -----Original Message----- From: owner-pietenpol-list-server@matronics.com [mailto:owner-pietenpol-list-server@matronics.com]On Behalf Of Wayne Poole Sent: Saturday, September 08, 2007 12:30 PM To: Pietenpol-List@matronics.com Subject: Pietenpol-List: Aileron Gap - GN- 1 Grega plans We do not care for the Grega method of sealing the aileron gap with fabric. Can anyone suggest other ways? We are thinking about putting a radius filler on the aileron and an angle on the wing with about a 1/4 inch of gap. href="http://www.matronics.com/Navigator?Pietenpol-List">http://www.mat ronics.com/Navigator?Pietenpol-List href="http://forums.matronics.com">http://forums.matronics.com ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message pietenpol-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Pietenpol-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/pietenpol-list Browse Digests http://www.matronics.com/digest/pietenpol-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.