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4A084 power?

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GeoB

Joined: 16 Jun 2009
Posts: 207
Location: Fresno, CA

Posted: Mon Jan 07, 2013 1:49 am Post subject: 4A084 power?

I am wondering if any of you know of anyone running a Teledyne/Continental 4A084 on a Kolb. I have a Firestar-I. Yes, I know they are heavy at ~127 lbs, they can be built to around 50 hp but prolly no more than that. Still... they are cheap and reliable and I wouldn't have to carry as much fuel. Parts are worlds cheaper than my Rotax DCDI 503. Just wondering...



GeoB

_________________
GeoB

"Members of Congress should be compelled to wear uniforms like NASCAR drivers, so we could identify their corporate sponsors"

HShack(at)aol.com
Guest

Posted: Mon Jan 07, 2013 9:12 pm Post subject: 4A084 power?

Too heavy for FS I.  Who said 50 hp?  Gov't rated at 10 hp,; it  may actually be 20 hp,  It is 48 c,i., doubt it can produce over 1 hp per  cube.

  

 I had one; fun to play with.  Don't waste your time .

  

 You already have the best engine for FS I.  Should be good for 500  hrs. before you need to spend any money.

  

 Shack

 SC

  

  In a message dated 1/7/2013 4:50:31 A.M. Eastern Standard Time,  gab16(at)sbcglobal.net writes:

  	  Quote: 	
		  -->    Kolb-List message posted by: "GeoB" <gab16(at)sbcglobal.net>



I am    wondering if any of you know of anyone running a Teledyne/Continental 4A084 on    a Kolb. I have a Firestar-I. Yes, I know they are heavy at ~127 lbs, they can    be built to around 50 hp but prolly no more than that. Still... they are cheap    and reliable and I wouldn't have to carry as much fuel. Parts are worlds    cheaper than my Rotax DCDI 503. Just    wondering...



GeoB



--------

GeoB



&quot;Members of    Congress should be compelled to wear uniforms like NASCAR drivers, so we could    identify their corporate sponsors&quot;





Read this topic    online    here:



http://forums.matronics.com/viewtopic.php?p=391746#391746

	


 [quote][b]

herbgh(at)nctc.com
Guest

Posted: Mon Jan 07, 2013 9:37 pm Post subject: 4A084 power?

There are three models  of these surplus engines...4a032. 4a042 and 4a084...the 084 is rated at 20 hp at 10,000 feet...It will fly a mini max with a redrive...doing so in  Wise Co.,Va.   will probably fly a  Firestar or Firefly... but a bit heavy..as is noted...  84 cubes...  Herb 



 

 At 11:12 PM 1/7/2013, you wrote:

 [quote]Too heavy for FS I.  Who said 50 hp?  Gov't rated at 10 hp,; it may actually be 20 hp,  It is 48 c,i., doubt it can produce over 1 hp per cube.

  

 I had one; fun to play with.  Don't waste your time .

  

 You already have the best engine for FS I.  Should be good for 500 hrs. before you need to spend any money.

  

 Shack

 SC

  

 In a message dated 1/7/2013 4:50:31 A.M. Eastern Standard Time, gab16(at)sbcglobal.net writes:

   --> Kolb-List message posted by: "GeoB" <gab16(at)sbcglobal.net>



  I am wondering if any of you know of anyone running a Teledyne/Continental 4A084 on a Kolb. I have a Firestar-I. Yes, I know they are heavy at ~127 lbs, they can be built to around 50 hp but prolly no more than that. Still... they are cheap and reliable and I wouldn't have to carry as much fuel. Parts are worlds cheaper than my Rotax DCDI 503. Just wondering...



  GeoB



  --------

  GeoB



  &quot;Members of Congress should be compelled to wear uniforms like NASCAR drivers, so we could identify their corporate sponsors&quot;



 



 

  Read this topic online here:



    http://forums.matronics.com/viewtopic.php?p=391746#391746



 

  

 [b]

GeoB

Joined: 16 Jun 2009
Posts: 207
Location: Fresno, CA

Posted: Tue Jan 08, 2013 1:11 am Post subject: Re: 4A084 power?

Thanks for your reply Shack!



I hate it when someone asks a question then argues with someone who answers him! This isn't my intent here. Since this is a public forum and we have a public conversation here I am citing some information that I have collected from good sources, simply to keep the lurkers from making wrong decisions.



> Too heavy for FS I.



I have been wondering about this. Reason I was considering it is that the FS has a reasonably good gross weight (which I forget), and with not all that many structural changes it became a 2-place. The wings are not as strong as the 2-place but they are about the same sq footage. That being said, I have no clue if it is *really* too heavy.



My 503 weighs about 98 lbs. The 084 weighs 127 lbs complete with prop in  a typical setup.



The 084 would be operated direct-drive. At the slow speeds of the FS-I, I think the advantage goes to the 503 with the gear reduction unit.



>  Who said 50 hp?  Gov't rated at 10 hp,; it  may actually be 20 hp



From a military manual:



Bore: 3"

Stroke: 3"

Displacement: 84.8 cu in

Rated continuous net hp: 20 (at) 3600 rpm

Max hp 33.3 (at) 3600 rpm

Max torque (at) 2000 rpm; 60.3



This is to 5000 ft.



Note that we free up some serious hp when we remove the huge cooling fan.



Also, remember I said that the 084 cab 'built' to about 50 hp. This is without raising the low compression ratio. 084 experts (true experts) suggest that one NOT raise the CR because it would lead to over-heating. One expert markets an EFI setup for this engine. Over-all he seems to be a conservative can-do person, very believable. His engine is close to 50 hp based on the size/pitch of prop he spins with it. Most of us interested in the 084 accept that it produces 42-44 hp stock, w/o the fan. About 1/2 hp/cu inch.



> It is 48 c,i., doubt it can produce over 1 hp per  cube.



we are looking at the 084, 84 cu inches. I think you are remembering the smaller 2-cylinder, the 2A042 (42 cu inches)

  

> I had one; fun to play with.  Don't waste your time .



Now I am not sure if you had the 042 or the 084. There is a video on Youtube with a fella flying around just fine with the 042 on a Minimax. I have seen videos of several planes flying with the 084 but none of them were Firestar-I's. IIRC I have an old pic of a Kolb with an 084 but I can't seem to dig up more info on it. I already have three 084's. Haven't had a chance to crank them up yet. I am planning to build a big workshop but it will be months before that happens.

  

> You already have the best engine for FS I.



That is gratifying to hear. I like thinking about these swaps but will probably just learn to like a ring-ding.



> Should be good for 500 hrs.



Mine hasn't been run for 5-7 years. I expect I will have to tear it down and replace seals, from what I have heard. TT = 38 hours.



Have you seen the 4A032? Cute lil 4-banger! About 70 lbs. I doubt it would ever be of use for flight but maybe on a Kart! I see that a class of karting using the Honda 390 or clone is getting popular. At 13 hp it really scoots. How much nicer to have a 4-banger with cute lil zoomies sticking up! I am guessing that it will put out ~14 hp.



GeoB

_________________
GeoB

"Members of Congress should be compelled to wear uniforms like NASCAR drivers, so we could identify their corporate sponsors"

neilsenrm(at)gmail.com
Guest

Posted: Tue Jan 08, 2013 7:56 am Post subject: 4A084 power?

Just a few more thoughts.

The RPMs listed are real close to my direct drive VW. Thrust is what makes a airplane fly, that and MONEY. The horse power needs to be converted to thrust and at a 3600 working RPM you are restricted to a small prop somewhere around 58" or less. The general rule is the bigger the prop the more HP is turned into thrust until the prop tips go supersonic.. My direct drive VW used to turn a good portion of its power into noise instead of thrust. Also the rated max torque is at 2000 RPM. I configured my latest VW to have maximum torque in the cruise to takeoff RPM range. Unlike a car a aircraft engine doesn't need very much torque at low RPMs but does require the most torque at cruise and takeoff RPMs. 

Rick Neilsen

Redrive VW Powered MKIIIC

On Tue, Jan 8, 2013 at 4:11 AM, GeoB <gab16(at)sbcglobal.net (gab16(at)sbcglobal.net)> wrote:

 [quote]--> Kolb-List message posted by: "GeoB" <gab16(at)sbcglobal.net (gab16(at)sbcglobal.net)>

 Thanks for your reply Shack!

 I hate it when someone asks a question then argues with someone who answers him! This isn't my intent here. Since this is a public forum and we have a public conversation here I am citing some information that I have collected from good sources, simply to keep the lurkers from making wrong decisions.

 > Too heavy for FS I.

 I have been wondering about this. Reason I was considering it is that the FS has a reasonably good gross weight (which I forget), and with not all that many structural changes it became a 2-place. The wings are not as strong as the 2-place but they are about the same sq footage. That being said, I have no clue if it is *really* too heavy.

 My 503 weighs about 98 lbs. The 084 weighs 127 lbs complete with prop in  a typical setup.

 The 084 would be operated direct-drive. At the slow speeds of the FS-I, I think the advantage goes to the 503 with the gear reduction unit.

 >  Who said 50 hp?  Gov't rated at 10 hp,; it  may actually be 20 hp

 >From a military manual:

 Bore: 3"

 Stroke: 3"

 Displacement: 84.8 cu in

 Rated continuous net hp: 20 (at) 3600 rpm

 Max hp 33.3 (at) 3600 rpm

 Max torque (at) 2000 rpm; 60.3

 This is to 5000 ft.

 Note that we free up some serious hp when we remove the huge cooling fan.

 Also, remember I said that the 084 cab 'built' to about 50 hp. This is without raising the low compression ratio. 084 experts (true experts) suggest that one NOT raise the CR because it would lead to over-heating. One expert markets an EFI setup for this engine. Over-all he seems to be a conservative can-do person, very believable. His engine is close to 50 hp based on the size/pitch of prop he spins with it. Most of us interested in the 084 accept that it produces 42-44 hp stock, w/o the fan. About 1/2 hp/cu inch.

 > It is 48 c,i., doubt it can produce over 1 hp per  cube.

 we are looking at the 084, 84 cu inches. I think you are remembering the smaller 2-cylinder, the 2A042 (42 cu inches)

 > I had one; fun to play with.  Don't waste your time .

 Now I am not sure if you had the 042 or the 084. There is a video on Youtube with a fella flying around just fine with the 042 on a Minimax. I have seen videos of several planes flying with the 084 but none of them were Firestar-I's. IIRC I have an old pic of a Kolb with an 084 but I can't seem to dig up more info on it. I already have three 084's. Haven't had a chance to crank them up yet. I am planning to build a big workshop but it will be months before that happens.

 > You already have the best engine for FS I.

 That is gratifying to hear. I like thinking about these swaps but will probably just learn to like a ring-ding.

 > Should be good for 500 hrs.

 Mine hasn't been run for 5-7 years. I expect I will have to tear it down and replace seals, from what I have heard. TT = 38 hours.

 Have you seen the 4A032? Cute lil 4-banger! About 70 lbs. I doubt it would ever be of use for flight but maybe on a Kart! I see that a class of karting using the Honda 390 or clone is getting popular. At 13 hp it really scoots. How much nicer to have a 4-banger with cute lil zoomies sticking up! I am guessing that it will put out ~14 hp.

 GeoB

 --------

 GeoB

 &quot;Members of Congress should be compelled to wear uniforms like NASCAR drivers, so we could identify their corporate sponsors&quot;

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dan42101(at)yahoo.com
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Posted: Tue Jan 08, 2013 9:34 am Post subject: 4A084 power?

Â Â Â ENGINE Q&AÂ - your engine questions investigated

Experimenter - November 95Â Q.Â Â Dear Engine Q&A - To answer the questions about engine horsepower ratingsÂ in the September EXPERIMENTER, I can suggest some rules of thumb that I have heard through the years. They seem to be good approximations.1) To get the effective prop swinging horsepower for small direct drive four-cycle engines, divide the cubic inches by two. That makes an O-200 Continental a 100 horse engine. The hopelessly weak Corvair rated at 150 hp in a car has 145 cubic inches like the 65 hp Lycoming, and thatâ€™s about all it can do. The 750 cubic Hisso engine is rated at 150 horses but has an effective propeller power of 375 hp. Thatâ€™s why it can turn an eight-foot propeller and fly a big airplane that a 150 hp Lycoming can barely taxi. The source of this rule was Hobart Sorrell (now deceased) of Tenino, Washington. His crafty wits produced the Guppy biplane that flew on a Cushman golf cart engine.2) Using the effective power described

 above, you can multiply times 4-1/4 to get the approximate thrust with typical propeller efficiency of 85%. Source of this rule was John Thorp (deceased) of the T-18. See "Cowling and Cooling of Engines" which appeared in SPORT AVIATION some years ago (Ed. Note: This series appeared in the November and December 1963 issues).Hopefully, these two have left a legacy that we can all use. When a reduction gear is applied to the engine, the effective power is multiplied by the gear ratio.I havenâ€™t tried to extrapolate the formula to two stroke engines because I have very little experience with them. I canâ€™t tell what the effective power is of the little 70 horse drone engine that one sees buzzing away on a Bensen Gyrocopter for instance.Yours truly - Bertran Copp, Monmouth, OregonQ.Â Â Dear Mary - In the September 1995 EXPERIMENTER, Jim Delaney of Coralville,Â Iowa asks whether a Continental A-65, a 65 hp Rotax and a 65 hp Volkswagen all produce the same

 thrust. Assuming the same airplane and properly matched propeller/engine/airplane combination for best cruise, the answer is yes, theoretically. Propeller efficiency differences will produce the only variation in performance. This usually amounts to only 2 or 3%. Thus, horsepower is a valid method of comparison for correctly matched propellers because thrust is directly related to horsepower.Often static thrust is erroneously thought to be an indicator of flight performance. A propeller designed for maximum static thrust will severely limit cruise speed. This type of design is only suitable for helicopter rotors. It is an over-simplification if applied to airplanes. Proper propeller design involves matching thrust to drag and finding the best cruise to climb tradeoff. Putting it all together involves difficult and tedious calculations. I am a consulting aeronautical engineer and author of a computer program called "prop optimizer" that matches propeller

 to engine and airplane automatically.Many design studies I have done indicate that there is an optimum propeller size and rpm for any engine/airplane combination. Airplanes, even of one design, can vary considerably in drag due to manufacturing differences. Therefore, if best performance is desired, the propeller should be individually matched for each airplane. Specific questions may be directed to me at 916/622-1886.Sincerely - Don Bates, Placerville, CaliforniaQ.Â Â Dear Engine Q&A - I would like to know if there is a four-stroke engine out there in theÂ 65 hp range that would work on my new S-12XL, other than the Rotax 912 - one that doesnâ€™t require a second mortgage to purchase.The RANS S-12XL is an excellent aircraft, I believe. The engine to use on it has stumped me. The only two engines that I know of that might work are the new Yamaha four-stroke engine, which is unavailable at this time, and the Moto Guzzi, which is unproven on a pusher

 aircraft. What is your opinion? Who answers these questions? What about a Subaru?Sincerely - Don Herwander, Everett, WashingtonA.Â Â Dear Don - Weâ€™ll toss your questions out for our readers and see if, per chance,Â another S-12 owner is powering his aircraft with an alternate engine.Thanks for writing! - MaryQ.Â Â Dear Don - May I congratulate you on your column in the EXPERIMENTER as I feelÂ it is a very important part of that magazine providing the type of information that we all want regarding the Subaru engine.In the May edition, regarding the tip speed of propellers, was the decimal point in the wrong place? Should it have been .00436 and not .000436?I am building a Pober Pixie lookalike under our 95/10 category and will be powering it with a Subaru EA 81 imported from Japan with approximately 34,000 miles on it. (It appears to be in very good condition.)I will be using one of the carburetors that you recommend, but is there any reason we canâ€™t

 use the one that is on it - a Hitachi DCM 306-1 downdraft.With respect to the engine, I will be leaving it exactly as is with direct drive and a 52 x 26 propeller. However, I will need a thrust bearing and propeller extension. Could you please advise me where I can obtain these.I also believe with this combination I should get in the vicinity of 70 hp. Is this correct?Thanking you once again for all your help in the past and looking forward to meeting you maybe one day at Oshkosh if we can make it again. (We were over there in 1982 - a wonderful show.)Kindest regards - Joe Anderson, Queensland, AustraliaA.Â Â Dear Joe - Itâ€™s nice to receive a letter all the way from Australia. Your Pober PixieÂ lookalike is going to be a good looking aircraft. Thereâ€™s so many different aircraft to choose from, itâ€™s hard to select one you would really like.Regarding the Hitachi carburetor, it will work fine. The venturis are small and functional, but at this

 application, youâ€™ll want to use a larger venturi-type carburetor to give you more power, like the Ford Pinto carburetor Iâ€™ve mentioned before. If you look at them both together, youâ€™ll use the difference. Youâ€™ll need more air to give more perforrmance because youâ€™re running the engine at a higher rpm. The engine has to breathe.Regarding the thrust bearing, I donâ€™t think youâ€™ll need one. On the 52 x 26 you should get about 3600 rpm at about 60 or more hp because the engine doesnâ€™t get into the power curve, but you should get 325 - 330 lbs. of thrust.What kind of prop adapter are you using. If you donâ€™t have one, you need to get one that you can drill a hole in the center and tap the crank shaft to make a good secure connection.The comment on tip speed on prop was made by Ed Sterba and I canâ€™t answer that (Ed. Note: Yes, youâ€™re right, the figure should have been .00436 - we apologize for this error and any confusion this has caused

 our readers. The correct formula, then, is: Tip Speed = .00436 x diameter x rpm (with the tip speed in ft./sec. and the diameter in inches.)I hope Iâ€™ve helped in some way. Feel free to write any time.Yours truly - DonQ.Â Â Greetings, Don - Iâ€™ve found your work very informative and wonder if I could avail myselfÂ of some of your information services, while keeping same as short as possible.Iâ€™ve always been impressed with the formula for torque, rather than horsepower. In endeavoring to keep a Subaru conversion as simple as possible the thought occurred to me to try drive direct and with half rpms. Iâ€™ve often thought about a blower but with enough input, like a unit from an emission system, to keep a plenum full of intake air. Possibly a special cam shape may help in improving induction while exhausting more fully.I realize this sounds extreme, but it appears the engine has enough flywheel weight to ensure smooth running at low rpms. And, with the

 extant oil pump, has any thought been given to oil cooling? I would imagine any number of highly developed oil coolers might be available cheaply off of unused large airplane engines.Any thought or information in this very conceptual stage will be greatly appreciated. By the same token, if you have any special interests, Iâ€™d appreciate knowing them.All the best - Norman Benedict, Santa Maria, CaliforniaA.Â Â Dear Norman - Nice receiving your letter and the interest in Subaru powerplant conversions. If you use the EA-81 for small aircraft, straight drive, a 54 x 26 prop would give you 325 lbs. of thrust in the pusher type. You didnâ€™t mention the aircraft you wanted to use. I have no idea what horsepower you want, so weâ€™ll cover all the bases.EA-81 - 72 hp (ideal for small aircraft). With drive would give around 450-475 lbs. of thrust with a 2.2:1 ratio. Weight with redrive 180 lbs.Legacy - 130 hp, straight drive would give you 450-475 lbs. of

 thrust. With redrive, 550-570 lbs. of thrust with a 2.1:1 ratio. The weight of the Legacy with drive would range from 180-210 lbs.Oil coolers have been used on Subarus and are easy to hook up. There are discharge fittings on oil pumps that you can use.I hope Iâ€™ve helped you. - DonQ.Â Â Dear Don - I have read with great interest the various responses to letters in theÂ EXPERIMENTER concerning the use of Subaru engines in homebuilt aircraft, and you obviously have an extensive knowledge of these powerplants.In the November 1994 issue of EXPERIMENTER there was a table published which defined general engine specifications, which I must assume was from official Subaru sources.When I study the table, I find that the highest horsepower developed by an EA-81 OHC engines in naturally aspirated forms do not achieve close to the advertised 98/100 hp advertised by all the major Subaru engine convertors for the EA-81.Any ideas how this massive discrepancy occurs

 other than a communal dose of advertising licence?I have already ordered a converted EA-81 engine (SHO) version from what I judge as a professional engineer to be the premium quality source, but I will most certainly be very pleasantly surprised if the actual power output is in excess of 100 rather than the advertised 118 hp. Your article appeared two months after I had placed my order after much deliberation on the relative merits of the Subaru versus the Rotax 912 or 914.Incidentally, there would appear to be equal optimism regarding fuel consumption of Rotax engines. A study of the genuine Rotax fuel flow charts will quickly reveal that one would have to lean the mixture to unburnable ratios to achieve the popular quoted figures. It was quite refreshing to read a report in the latest issue of KITPLANES of a flight test of the 914 in the Pelican which quoted realistic fuel consumption figures which do match the fuel burn rates shown on the Rotax

 charts for this engine.Any comments would be most welcome.Yours sincerely - Fred H. Tayler, Hoffman Estates, ILA.Â Â Dear Fred - Was nice receiving your letter and very interesting. The EA-81 enginesÂ that they advertise with higher horsepower is accomplished by different cams, shaving heads and polishing intake and exhaust ports,and sometimes increasing the size of pistons. Thatâ€™s how they accomplish the claimed horsepower.The fuel consumption of the Rotax engine probably involves an in-cockpit adjustment for the carburetor to lean out for better fuel consumption. You can also do that with the Subaru.I feel that the EA-81 stock works very well without adding cams, etc. I feel if it works, donâ€™t mess with it.I hope Iâ€™ve answered your questions.

Yours truly - DonÂ Â 

__________Â engine q&aÂ __________

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--- On Tue, 1/8/13, GeoB <gab16(at)sbcglobal.net> wrote:



From: GeoB <gab16(at)sbcglobal.net>

Subject: Re: 4A084 power?

To: kolb-list(at)matronics.com

Date: Tuesday, January 8, 2013, 3:11 AM






Thanks for your reply Shack!



I hate it when someone asks a question then argues with someone who answers him! This isn't my intent here. Since this is a public forum and we have a public conversation here I am citing some information that I have collected from good sources, simply to keep the lurkers from making wrong decisions

HShack(at)aol.com
Guest

Posted: Tue Jan 08, 2013 11:27 am Post subject: 4A084 power?

I had a  4ao32 and a 4a084.  I put a belt drive on the 32 and ran it on a mobile  test cart [prop driven]

Anemic at best.  Would make a very good engine  for a very large RC plane.  

  

 Also put  the 84 on the cart, direct drive.  Better, but still weak.  I got  rid of all the cooling tin, the cooling fan, and the shielding on the spark plug  wires.  I think weight was less than 120 something.  We tried several  different carbs; none helped much.

  

 Sure, the  84 is flying on some planes, but I doubt any are flying out of a short  field.  Climb rate will be poor compared to a 503.[Even if it were 50  hp.]

  

 If I were  to put one on a plane, it would probably be on a lightly built Minimax.   Beef up the nose a little.  Paint up the engine real nice.  Put on an  efficient wood prop.

  

 Tractor  config. is much better at cooling than pusher.[without adding any  cowling].

  

 I had a  nice FS II w/ 503, just recently sold it.  Getting older and dumber meant  it was time to get out.

  

 Have fun  with the 84, just don't expect too much.

  

 Shack

   s such  se,     -->               - MATRONICS WEB FORUMS -



 [quote][b]

HShack(at)aol.com
Guest

Posted: Tue Jan 08, 2013 11:36 am Post subject: 4A084 power?

Using this formula, the 4ao84  would issue about 178 lb. thrust.   My 503 gave 375 lb. thrust [static].

  

 Howard  Shackleford

FS II

SC   

  In a message dated 1/8/2013 12:35:07 P.M. Eastern Standard Time,  dan42101(at)yahoo.com writes:

  	  Quote: 	
		     

To get the effective prop swinging    horsepower for small direct drive four-cycle engines, divide the cubic inches by    two. That makes an O-200 Continental a 100 horse engine. The hopelessly    weak Corvair rated at 150 hp in a car has 145 cubic inches like the 65 hp    Lycoming, and thatâ€™s about all it can do. The 750 cubic Hisso engine is rated    at 150 horses but has an effective propeller power of 375 hp. Thatâ€™s why it    can turn an eight-foot propeller and fly a big airplane that a 150 hp Lycoming    can barely taxi. The source of this rule was Hobart Sorrell (now deceased) of    Tenino, Washington. His crafty wits produced the Guppy biplane that flew on a    Cushman golf cart engine.   

2) Using the effective power described    above, you can multiply times 4-1/4 to get the approximate thrust with typical    propeller efficiency of  85% 	




 [quote][b]

herbgh(at)nctc.com
Guest

Posted: Tue Jan 08, 2013 2:39 pm Post subject: 4A084 power?

The 084 that is flying on a Hi Max is swinging a 62x40 prop at about 4000 rpms...Using a home made 1  to 1.66 redrive ratio... My bud who responded is the one who built the belted redrive.  Not sure of the thrust?  Likely over 200 lbs static...



   A friend has a firestar with a 377 and it flies very well...Herb  



 

 At 01:35 PM 1/8/2013, you wrote:

 [quote]Using this formula, the 4ao84  would issue about 178 lb. thrust.  My 503 gave 375 lb. thrust [static].

  

 Howard Shackleford

 FS II

 SC 

  

 In a message dated 1/8/2013 12:35:07 P.M. Eastern Standard Time, dan42101(at)yahoo.com writes:

  

  To get the effective prop swinging horsepower for small direct drive four-cycle engines, divide the cubic inches by two. That makes an O-200 Continental a 100 horse engine. The hopelessly weak Corvair rated at 150 hp in a car has 145 cubic inches like the 65 hp Lycoming, and thatâ€™s about all it can do. The 750 cubic Hisso engine is rated at 150 horses but has an effective propeller power of 375 hp. Thatâ€™s why it can turn an eight-foot propeller and fly a big airplane that a 150 hp Lycoming can barely taxi. The source of this rule was Hobart Sorrell (now deceased) of Tenino, Washington. His crafty wits produced the Guppy biplane that flew on a Cushman golf cart engine.

 

  2) Using the effective power described above, you can multiply times 4-1/4 to get the approximate thrust with typical propeller efficiency of 85%

 

  

 [b]

GeoB

Joined: 16 Jun 2009
Posts: 207
Location: Fresno, CA

Posted: Tue Jan 08, 2013 3:26 pm Post subject: Re: 4A084 power?

> a 3600 working RPM you areï¿½restrictedï¿½to a small prop



Thanks Rick. This is maybe the biggest draw-back. And with this engine it is a really big deal to attempt to raise the rpm of torque peak, unless I use EFI.. which will help there given I replace the entire intake manifold. I like doing/planning engine mods, done that for like 45 years. I have a coupla Generac engines I plan to modi-fly, I'd rather express myself there.



I wonder about the over-heating issue I have been told about. Sure, more power generally means more heat. So, if I raise my CR  I add to the thermal loading of the engine, IN THEORY. But since higher CR adds power and efficiency (or just efficiency which effects power), why couldn't I just back off the throttle a tad and lower the thermal loading? Should give greater available power for a short time plus yield better mpg. I think. I am actively soliciting comments on this idea.



Sure, at full throttle the EFI will produce more heat also but I don't want a setup that requires full throttle all the time.



GeoB

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GeoB

"Members of Congress should be compelled to wear uniforms like NASCAR drivers, so we could identify their corporate sponsors"

GeoB

Joined: 16 Jun 2009
Posts: 207
Location: Fresno, CA

Posted: Mon Jan 14, 2013 11:36 pm Post subject: 4A084 power?

 	  Quote: 	
		  Using this formula, the 4ao84  would issue about 178 lb. thrust. 


	


Les Smoot (who has worked for the military I think) claims he has rebuilt

over a thousand 4A084s. He still builds and modifies them. He has put

together an EFI package for the 084, most of it off-the-shelf from a vendor,

that he feels produces around 50 hp. He claims that he gets 230-240 static

thrust from these direct drive engines. It wasn't 100% clear to me if he was

talking about the generic engine or his EFI models. Sounded like he was

talking abut the generic version.



I have a great video he made. He talks about his EFI setup. He demonstrates

his EFI engine running. Sounds SO GOOD! I would like to post it where folks

can get to it but it is 287 MB. any ideas?



GeoB

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GeoB

"Members of Congress should be compelled to wear uniforms like NASCAR drivers, so we could identify their corporate sponsors"

jackinkeywest

Joined: 20 Mar 2012
Posts: 36
Location: Key West, FL

Posted: Tue Jan 15, 2013 4:15 am Post subject: 4A084 power?

George,



As a suggestion, you can go to YouTube dot com and upload the video for FREE.  Then you can send us the YouTube link and we can easily view it.



V/R,



Jack L. Lockamy

Atlantic Targets & Marine Operations (ATMO)

Pier D-1, Bldg. B27CG

Trumbo Point Annex

NAS Key West, FL  33040

(305) 293-2078 office

(305) 293-4345 FAX

DSN 483-4343

(301) 997-6808 cell

jack.lockamy(at)navy.mil



--

smime.p7s

Description:

Download

Filename:

smime.p7s

Filesize:

5.44 KB

Downloaded:

621 Time(s)

GeoB

Joined: 16 Jun 2009
Posts: 207
Location: Fresno, CA

Posted: Tue Jan 15, 2013 1:33 pm Post subject: Re: 4A084 power?

[quote="GeoB"] 	  Quote: 	
		  Using this formula, the 4ao84  would issue about 178 lb. thrust. 	




There is a video on Youtube showing an 084 pulling 215 lbs. Dunno about anything else, mods, etc.

_________________
GeoB

"Members of Congress should be compelled to wear uniforms like NASCAR drivers, so we could identify their corporate sponsors"

GeoB

Joined: 16 Jun 2009
Posts: 207
Location: Fresno, CA

Posted: Tue Jan 15, 2013 1:34 pm Post subject: Re: 4A084 power?

 	  jackinkeywest wrote: 	
		  you can go to YouTube dot com and upload the video for FREE 	




Thanks, I'll do that

GeoB

_________________
GeoB

"Members of Congress should be compelled to wear uniforms like NASCAR drivers, so we could identify their corporate sponsors"

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