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badbob

Joined: 07 Jan 2007
Posts: 8
Location: Willamina, Oregon

Posted: Sun Feb 25, 2007 10:26 am Post subject: Engines

I show 3200rpm if my math is correct. Thats still Mach 1.146.....thats

        amazing! I have never had to figure Mach at temps that cold!!

        BBRRRRRRRR!!! LOL

        Bob in Oregon

_________________
Bob Johnson
601XL scratch built.
badbob0007(at)earthlink.net

ashontz

Joined: 27 Dec 2006
Posts: 723

Posted: Mon Feb 26, 2007 12:15 pm Post subject: Re: Engines

 	  billmileski wrote: 	
		  Fuel type:  The 912S requires premium auto fuel.  The HKS has a similar compression ratio (11.3:1) and will be no different.  The Jabiru requires 100LL, and if you want to run 100LL this is a good choice -- the Rotax suffers reduced gearbox life if always using 100LL.  There may be an issue with 10% ethanol in auto fuel and the Rotax, but I am expecting them to say it's okay.



Bill Mileski

Ledyard, CT 	




I'm sure it does. You'd never hear dieseling at those RPMs. My 140hp outboard engine apparently used to require premium. I didn't know this and put 87 in it. I never ran the thing about about 3500 anyway (about 22 mph with my old wellcraft v-20 steplift fishing scowl). The last time I ran it open a piece of the piston cracked off and hit the spark plug and put the gap out of commission. Oddly enough, even with a bit of scoring from the chunk floating around in there the cylinder still had compression. When I torn it apart and replaced the piston and rebored/honed the cylinder I also installed a recommended head shim that effectively lowers the compression and allows it to run on 87 octane. Runs sweet now, like a new engine, but nipped about 2 mph off the top end. Probably more like a 125hp now. Apparently it was pre-igniting whenever I ran the puppy wide open. You'd never hear it though. Not good for the cylinders. At least I could just anchor up. Actually, now that I think about it, t still ran on three cylinders. Those engines are amazing. I had a 1977 140 Johnson about 10 years ago that some wahoo at the marina talked me into buying a 14" prop instead of a 13.5". Not only was it slower getting out of the hole, but after a few years it actually broke the crankshaft. Believe it or not it was a hairline crack in the crank balance weight and the only indication was a very slight amount of play in the flywheel, maybe two degrees more back and forth than you'd normally get. Ran for 2 years like that at 2/3 speed top throttle as I usually do, til I opened it up one day for a ride after a fishing trip and that hairline crack really broke up, and yet it still putted into the ramp, but the bearing races in the case were all scored so there was hardly any case side compression (2-cycle) for the and the adjacent cylinder.

amyvega2005(at)earthlink.
Guest

Posted: Wed Feb 28, 2007 6:30 am Post subject: Engines

you can have 2 engines out on teh field and you still need to have ADs.   Reason there are so many ADs is becuase the manufacturer has identified a potential situation that requires preventative maintenance.  EX; there is an AD on rotax on the Magnetic metal collector, and details how to remove the peice and replace.  If there were one engine out in the field, you would need an AD.  Rotax is a great engine, if you like water cooled engines.  I prefer a auto fuel running air cooled engine.  Jabirus have only 20 amp alt out put, you can ad an Alt.  Corviar is a good engine, if you want to build an engine.  Lycomings and Contis are tryed and true as well. but 60 year technology.   Rotec, nice.   Franklin is a GREAT engine, smoot as butter when running, just tough to find parts due to selling of company.   Look at what you want to burn, look at what you want to spend, look at what you want to maintain.  and read the ADs.  tells how many potential problems there are.



JUan



--

ashontz

Joined: 27 Dec 2006
Posts: 723

Posted: Wed Feb 28, 2007 8:02 am Post subject: Re: Engines

 	  p.mulwitz(at)worldnet.att wrote: 	
		  Hi Brandon,

No, I don't have a specific reference on the supersonic prop tips.  I 

wonder if your Texan tips are actually going supersonic or if they 

are just transonic.  Do you get a sonic boom?

There is a nice prop tip speed calculator on the Culver prop web 

site.  You can plug in the RPM and prop diameter to get an estimate 

of the mach number for the tips.  Of course, mach number varies a 

great deal with air conditions, but it still might be interesting to see.

I am amused by the responses I am getting to a post I didn't think 

would be at all controversial.  I was merely trying to help Robert 

understand the answer to his question of why some engines run at such 

high RPM.  Your question about tips going over mach 1 was also 

mentioned by Roy while he strongly defended the ancestry of the Rotax 

engine design.  I guess I am just an irritating guy . . .

Paul

At 09:00 AM 2/24/2007, you wrote:

 	  Quote: 	

 >> As RPM increases, the speed of the propeller tip

also increases >>according to simple geometry.

True.

 >>  As the propeller tip approaches the speed of sound

 >>it becomes inefficient,

True.

 >>and if allowed to hit the speed of sound it can be

destroyed.

I would love to see your reference on this one.  The

Texan I fly on weekends has the tips go supersonic

just about every flight.  I haven't done the math, and

don't care to, but you can hear the difference when it

takes off.  When I take off, I pull back the prop as

soon as I get the gear up, and it purrs by.  Most of

our pilots leave the prop up until at altitude.  The

sound is a high pitched whine.  The difference in RPM

is only 100 - 200.  You can often hear the same thing

on Bonanzas and others if the prop is left up.

R/

Brandon

601 HDS / TD / Corvair

70 hours

Never miss an email again!

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---------------------------------------------

Paul Mulwitz

32013 NE Dial Road

Camas, WA 98607

--------------------------------------------- 	

Just working the numbers, a 72" prop spinning 2750 rpm will give a tip speed of 590mph. about 160mph short of the speed of sound. Quick thinking may lead someone to think that if the plane is moving at 160mph that the tip speed will reach supersonic. I'm not sure this is the case though. Consider the prop has about a 15 degree pitch on it at the tip which would result in a relative pitch when moving through the air at design speed of say 2 degrees (and if constructed correctly that 2 degree relative pitch should be constant through to the hub). That being the case the prop tip would see only a quarter (sin 15 degrees = .258) of the 160 mph forward component, or about 41 mph. To get the full 160mph component the plane would need to be moving about 621mph. I don't think the relative prop tip speed on a Bananza or T-6 Texan ever breaks the sound barrier, and may not even be hitting transonic. That 621 mph figure would explain why 1940s propeller fighter design and prop efficiency topped out at about 495mph (about 130mph short of supersonic tip speed). Hold that 130 mph difference for the bizarre transonic region where things start to become hairy, including whatevers happening at the prop tip. Apparently 90% of the work is done by the outside 10% of the prop. That being the case, as soon as it starts to go transonic you're going to see a major loss of efficiency.

I'd also venture to guess something pretty catastrophic would occur if you got a p-51 up to top speed, left the throttle wide open and then started to feather the prop to 45 degrees (if it's possible).

Last edited by ashontz on Wed Feb 28, 2007 8:18 am; edited 1 time in total

ronlee

Joined: 25 Dec 2006
Posts: 141

Posted: Wed Feb 28, 2007 8:11 am Post subject: Re: Engines

There is one thing no one has addressd yet is the surface speeds of large and small displacement engines. Small engines have shorter strokes and smaller crankshaft journals. An engine with a two inch stroke will have to turn twice as fast to get the same piston surface speed as a large engine with a four inch stroke. The same holds for crankshaft journals etc. Also the centrifugal force increases as rotating parts increase in size as they swing a larger arc. In essence, smaller engines do not encounter that much if any  increase in stress over large engines. A high RPM engine with a reduction for final output RPM such as a propeller can have a much smaller crankshaft, as much less torque is being transfered to the business end of the crankshaft. The end torque is increased through the gearbox. With a direct drive engine all the final torque must be carried by the crank, so it must be much heavier.

Ron L.

_________________
Ron Lee
Tucson, Arizona

ashontz

Joined: 27 Dec 2006
Posts: 723

Posted: Wed Feb 28, 2007 8:25 am Post subject: Re: Engines

 	  ronlee wrote: 	
		  There is one thing no one has addressd yet is the surface speeds of large and small displacement engines. Small engines have shorter strokes and smaller crankshaft journals. An engine with a two inch stroke will have to turn twice as fast to get the same piston surface speed as a large engine with a four inch stroke. The same holds for crankshaft journals etc. Also the centrifugal force increases as rotating parts increase in size as they swing a larger arc. In essence, smaller engines do not encounter that much if any  increase in stress over large engines. A high RPM engine with a reduction for final output RPM such as a propeller can have a much smaller crankshaft, as much less torque is being transfered to the business end of the crankshaft. The end torque is increased through the gearbox. With a direct drive engine all the final torque must be carried by the crank, so it must be much heavier.

Ron L. 	




It's not the surface speed as much as the stress from reversal of strokes. Higher revving engines will generally have a shorter stroke and a larger bore to displace the same amount of expanding gas. There's still plenty of stress in the reversal of strokes, but probably not as much as a long stroke. The smaller cranks and bearings is probably more due to the fact that the higher revving engine is creating more HP per pound, but not as much torque, therefore no need for a heavy crank. The torque gets developed in the PSRU.



If the higher revving engine had a longer stroke, it would need that larger crank just for handling the reversal of strokes as well as handling the reduced torque and you'd be back to square one with the large crank. With shorter strokes less crank and connecting metal is needed to handle the stress and therefore a smaller crank is needed an is also sufficient to hanlded the lower torque which gets converted later by the PSRU.

planecrazydld(at)yahoo.co
Guest

Posted: Wed Feb 28, 2007 9:27 am Post subject: Engines

do not archive

   

  I've always heard that the limiting factor are the piston reversal loads at the top of the exhaust stroke.



ashontz <ashontz(at)nbme.org> wrote:

  [quote]--> Zenith-List message posted by: "ashontz" 

ronlee wrote:

 	  Quote: 	
		   There is one thing no one has addressd yet is the surface speeds of large and small displacement engines. Small engines have shorter strokes and smaller crankshaft journals. An engine with a two inch stroke will have to turn twice as fast to get the same piston surface speed as a large engine with a four inch stroke. The same holds for crankshaft journals etc. Also the centrifugal force increases as rotating parts increase in size as they swing a larger arc. In essence, smaller engines do not encounter that much if any increase in stress over large  engines. A high RPM engine with a reduction for final output RPM such as a propeller can have a much smaller crankshaft, as much less torque is being transfered to the business end of the crankshaft. The end torque is increased through the gearbox. With a direct drive engine all the final torque must be carried by the crank, so it must be much heavier.

 Ron L.


	




It's not the surface speed as much as the stress from reversal of strokes. Higher revving engines will generally have a shorter stroke and a larger bore to displace the same amount of expanding gas. There's still plenty of stress in the reversal of strokes and would probably be equal. The smaller cranks and bearings is probably more due to the fact that the higher revving engine is creating more HP per pound, but not as much torque, therefore no need for a heavy crank. The torque gets developed in the PSRU.



--------

CH601XL - Corvair

www.mykitlog.com/ashontz





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ashontz

Joined: 27 Dec 2006
Posts: 723

Posted: Wed Feb 28, 2007 9:49 am Post subject: Re: Engines

[quote="planecrazydld(at)yahoo.co"]do not archive

   

  I've always heard that the limiting factor are the piston reversal loads at the top of the exhaust stroke.



ashontz <ashontz> wrote:

  [quote]--> Zenith-List message posted by: "ashontz" 

ronlee wrote:

 	  Quote: 	
		   There is one thing no one has addressd yet is the surface speeds of large and small displacement engines. Small engines have shorter strokes and smaller crankshaft journals. An engine with a two inch stroke will have to turn twice as fast to get the same piston surface speed as a large engine with a four inch stroke. The same holds for crankshaft journals etc. Also the centrifugal force increases as rotating parts increase in size as they swing a larger arc. In essence, smaller engines do not encounter that much if any increase in stress over large  engines. A high RPM engine with a reduction for final output RPM such as a propeller can have a much smaller crankshaft, as much less torque is being transfered to the business end of the crankshaft. The end torque is increased through the gearbox. With a direct drive engine all the final torque must be carried by the crank, so it must be much heavier.

 Ron L.



	




It's not the surface speed as much as the stress from reversal of strokes. Higher revving engines will generally have a shorter stroke and a larger bore to displace the same amount of expanding gas. There's still plenty of stress in the reversal of strokes and would probably be equal. The smaller cranks and bearings is probably more due to the fact that the higher revving engine is creating more HP per pound, but not as much torque, therefore no need for a heavy crank. The torque gets developed in the PSRU.



--------

CH601XL - Corvair

www.mykitlog.com/ashontz





Read this  8:00? 8:25? 8:40? [url= http://tools.search.yahoo.com/shortcuts/?fr=oni_on_mail&#news] Find a flick[/url] in no time

 with the[url= http://tools.search.yahoo.com/shortcuts/?fr=oni_on_mail&#news]Yahoo! Search movie showtime shortcut.[/url]  	  Quote: 	
		  [b] 	




I don't know. Seems like they're all pretty drastic really. You figure an engine turning 6000 rpms with a stroke of 2 inches will accellerate the piston from zero to X (halfway between top and bottom of the stroke it will experience it's maximum velocity) in .0025 seconds, and then back to zero again in the same timeframe. With a two inch stroke the moment arm would be 1 inch which would translate to 52.35 feet per second or about 35 miles mph. from zero to 35mph in .0025 seconds is, hhmmm, a lot of Gs. acceleraton=velocity change/elapsed time = 52.35ft per second/.0025 sec = 20,800 ft per second per second! Is that possible. Is my math right? Divided by 32ft per second per second (1G)= 650Gs. Is that possible? Is my math right. So a two pound piston would feel like a 1300 lbd weight at that speed as far as the crank is concerned.

bryanmmartin

Joined: 10 Jan 2006
Posts: 1018

Posted: Wed Feb 28, 2007 12:24 pm Post subject: Engines

The pitch angle of the blades is irrelevant. The tip speed of the

propeller is just the vector sum of the rotational velocity and the

forward velocity. The speed of sound at standard sea level conditions is

 770 mph. This speed would be the hypotenuse of the right triangle

formed by the two velocity vectors so: sqrt(770^2 - 590^2)=495 mph. So

for this example, a forward speed of 495 mph would result in the tips

just reaching Mach 1. A 160 mph forward speed would give a tip speed of

611 mph, sqrt(590^2 + 160^2)=611.



 -------------- Original message ----------------------

From: "ashontz" <ashontz(at)nbme.org>

 	  Quote: 	
		   

 

 

 Just working the numbers, a 72" prop spinning 2750 rpm will give a tip speed of 

 590mph. about 160mph short of the speed of sound. Quick thinking may lead 

 someone to think that if the plane is moving at 160mph that the tip speed will 

 reach supersonic. I'm not sure this is the case though. Consider the prop has 

 about a 15 degree pitch on it at the tip which would result in a relative pitch 

 when moving through the air at design speed of say 2 degrees (and if constructed 

 correctly that 2 degree relative pitch should be constant through to the hub). 

 That being the case the prop tip would see only a quarter (sin 15 degrees = 

 .258) of the 160 mph forward component, or about 41 mph. To get the full 160mph 

 component the plane would need to be moving about 621mph. I don't think the 

 relative prop tip speed on a Bananza or T-6 Texan ever breaks the sound barrier, 

 and may not even be hitting transonic. That 621 mph figure would explain why 

 1940s propeller fighter design and prop efficien!

  cy topped out at about 495mph (about 130mph short of supersonic tip speed). 

 Hold that 130 mph difference for the bizarre transonic region where things start 

 to become hairy, including whatevers happening at the prop tip. Apparently 90% 

 of the work is done by the outside 10% of the prop. That being the case, as soon 

 as it starts to go transonic you're going to see a major loss of efficiency.

 

--
	


Bryan Martin

N61BM, CH 601 XL, 

RAM Subaru, Stratus redrive

do not archive

_________________
--
Bryan Martin
N61BM, CH 601 XL, Stratus Subaru.
do not archive.

ashontz

Joined: 27 Dec 2006
Posts: 723

Posted: Wed Feb 28, 2007 12:29 pm Post subject: Re: Engines

 	  bryanmmartin wrote: 	
		  The pitch angle of the blades is irrelevant. The tip speed of the

propeller is just the vector sum of the rotational velocity and the

forward velocity. The speed of sound at standard sea level conditions is

 770 mph. This speed would be the hypotenuse of the right triangle

formed by the two velocity vectors so: sqrt(770^2 - 590^2)=495 mph. So

for this example, a forward speed of 495 mph would result in the tips

just reaching Mach 1. A 160 mph forward speed would give a tip speed of

611 mph, sqrt(590^2 + 160^2)=611.



 -------------- Original message ----------------------

From: "ashontz" <ashontz>

 	  Quote: 	
		   

 

 

 Just working the numbers, a 72" prop spinning 2750 rpm will give a tip speed of 

 590mph. about 160mph short of the speed of sound. Quick thinking may lead 

 someone to think that if the plane is moving at 160mph that the tip speed will 

 reach supersonic. I'm not sure this is the case though. Consider the prop has 

 about a 15 degree pitch on it at the tip which would result in a relative pitch 

 when moving through the air at design speed of say 2 degrees (and if constructed 

 correctly that 2 degree relative pitch should be constant through to the hub). 

 That being the case the prop tip would see only a quarter (sin 15 degrees = 

 .258) of the 160 mph forward component, or about 41 mph. To get the full 160mph 

 component the plane would need to be moving about 621mph. I don't think the 

 relative prop tip speed on a Bananza or T-6 Texan ever breaks the sound barrier, 

 and may not even be hitting transonic. That 621 mph figure would explain why 

 1940s propeller fighter design and prop efficien!

  cy topped out at about 495mph (about 130mph short of supersonic tip speed). 

 Hold that 130 mph difference for the bizarre transonic region where things start 

 to become hairy, including whatevers happening at the prop tip. Apparently 90% 

 of the work is done by the outside 10% of the prop. That being the case, as soon 

 as it starts to go transonic you're going to see a major loss of efficiency.

 

--

	


Bryan Martin

N61BM, CH 601 XL, 

RAM Subaru, Stratus redrive

do not archive 	




Actually, that sounds right. The math still explains why the 500mph marks was about it for propellers.

n801bh(at)netzero.com
Guest

Posted: Wed Feb 28, 2007 4:36 pm Post subject: Engines

That is accurate. Would you like the short or long answer on why this is? 

do not archive

Ben Haas

N801BH

www.haaspowerair.com



-- David Downey <planecrazydld(at)yahoo.com> wrote:

 do not archive

  

 I've always heard that the limiting factor are the piston reversal loads at the top of the exhaust stroke.



ashontz <ashontz(at)nbme.org> wrote:

 [quote]--> Zenith-List message posted by: "ashontz" 

ronlee wrote:

 	  Quote: 	
		   There is one thing no one has addressd yet is the surface speeds of large and small displacement engines. Small engines have shorter strokes and smaller crankshaft journals. An engine with a two inch stroke will have to turn twice as fast to get the same piston surface speed as a large engine with a four inch stroke. The same holds for crankshaft journals etc. Also the centrifugal force increases as rotating parts increase in size as they swing a larger arc. In essence, smaller engines do not encounter that much if any increase in stress over large engines. A high RPM engine with a reduction for final output RPM such as a propeller can have a much smaller crankshaft, as much less torque is being transfered to the business end of the crankshaft. The end torque is increased through the gearbox. With a direct drive engine all the final torque must be carried by the crank, so it must be much heavier.

 Ron L.


	




It's not the surface speed as much as the stress from reversal of strokes. Higher revving engines will generally have a shorter stroke and a larger bore to displace the same amount of expanding gas. There's still plenty of stress in the reversal of strokes and would probably be equal. The smaller cranks and bearings is probably more due to the fact that the higher revving engine is creating more HP per pound, but not as much torque, therefore no need for a heavy crank. The torque gets developed in the PSRU.



--------

CH601XL - Corvair

www.mykitlog.com/ashontz





Read this   8:00? 8:25? 8:40? Find a flick in no time

with theYahoo! Search movie showtime shortcut.  	  Quote: 	
		  



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planecrazydld(at)yahoo.co
Guest

Posted: Wed Feb 28, 2007 5:14 pm Post subject: Engines

do not archive

   

  I always want teh long answer - as long as it is defensible!



"n801bh(at)netzero.com" <n801bh(at)netzero.com> wrote:

  [quote]  That is accurate. Would you like the short or long answer on why this is?

  do not archive

Ben Haas

N801BH

www.haaspowerair.com



-- David Downey <planecrazydld(at)yahoo.com> wrote:



  do not archive

   

  I've always heard that the limiting factor are the piston reversal loads at the top of the exhaust stroke.



ashontz <ashontz(at)nbme.org> wrote:

   	  Quote: 	
		  --> Zenith-List message posted by: "ashontz" 

ronlee wrote:

 	  Quote: 	
		   There  is one thing no one has addressd yet is the surface speeds of large and small displacement engines. Small engines have shorter strokes and smaller crankshaft journals. An engine with a two inch stroke will have to turn twice as fast to get the same piston surface speed as a large engine with a four inch stroke. The same holds for crankshaft journals etc. Also the centrifugal force increases as rotating parts increase in size as they swing a larger arc. In essence, smaller engines do not encounter that much if any increase in stress over large engines. A high RPM engine with a reduction for final output RPM such as a propeller can have a much smaller crankshaft, as much less torque is being transfered to the business end of the crankshaft. The end torque is increased through the gearbox. With a direct drive engine all the final torque must be carried by the crank, so it must be much heavier.

 Ron L.


	




It's not the surface speed as much as the stress from  reversal of strokes. Higher revving engines will generally have a shorter stroke and a larger bore to displace the same amount of expanding gas. There's still plenty of stress in the reversal of strokes and would probably be equal. The smaller cranks and bearings is probably more due to the fact that the higher revving engine is creating more HP per pound, but not as much torque, therefore no need for a heavy crank. The torque gets developed in the PSRU.



--------

CH601XL - Corvair

www.mykitlog.com/ashontz





Read this     8:00? 8:25? 8:40? Find a flick in no time

with theYahoo! Search movie showtime shortcut.  	  Quote: 	
		      ====================================  ">http://www.matronics.com/Navigator?Zenith-List 

 	
	


  Dave Downey

  Harleysville (SE) PA

  Zodiac 601XL/Corvair?

   The fish are biting.

 [url=http://us.rd.yahoo.com/evt=49679/*http://searchmarketing.yahoo.com/arp/sponsoredsearch_v2.php?o=US2140&cmp=Yahoo&ctv=Q107Tagline&s=Y&s2=EM&b=50] Get more visitors[/url] on your site using [url= http://us.rd.yahoo.com/evt=49679/*http://searchmarketing.yahoo.com/arp/sponsoredsearch_v2.php?o=US2140&cmp=Yahoo&ctv=Q107Tagline&s=Y&s2=EM&b=50]Yahoo! Search Marketing.[/url] [quote][b]

n801bh(at)netzero.com
Guest

Posted: Wed Feb 28, 2007 5:41 pm Post subject: Engines

Defensible huh.... My time it too valuable to waste typing the answer to an inquiry like that.. 

 Have a happy time building your plane... 

definately DO NOT ARCHIVE 

Ben Haas

N801BH

www.haaspowerair.com



-- David Downey <planecrazydld(at)yahoo.com> wrote:

 do not archive

  

 I always want teh long answer - as long as it is defensible!



"n801bh(at)netzero.com" <n801bh(at)netzero.com> wrote:

 [quote] That is accurate. Would you like the short or long answer on why this is?

 do not archive

Ben Haas

N801BH

www.haaspowerair.com



-- David Downey <planecrazydld(at)yahoo.com> wrote:



 do not archive

  

 I've always heard that the limiting factor are the piston reversal loads at the top of the exhaust stroke.



ashontz <ashontz(at)nbme.org> wrote:

  	  Quote: 	
		  --> Zenith-List message posted by: "ashontz" 

ronlee wrote:

 	  Quote: 	
		   There is one thing no one has addressd yet is the surface speeds of large and small displacement engines. Small engines have shorter strokes and smaller crankshaft journals. An engine with a two inch stroke will have to turn twice as fast to get the same piston surface speed as a large engine with a four inch stroke. The same holds for crankshaft journals etc. Also the centrifugal force increases as rotating parts increase in size as they swing a larger arc. In essence, smaller engines do not encounter that much if any increase in stress over large engines. A high RPM engine with a reduction for final output RPM such as a propeller can have a much smaller crankshaft, as much less torque is being transfered to the business end of the crankshaft. The end torque is increased through the gearbox. With a direct drive engine all the final torque must be carried by the crank, so it must be much heavier.

 Ron L.


	




It's not the surface speed as much as the stress from reversal of strokes. Higher revving engines will generally have a shorter stroke and a larger bore to displace the same amount of expanding gas. There's still plenty of stress in the reversal of strokes and would probably be equal. The smaller cranks and bearings is probably more due to the fact that the higher revving engine is creating more HP per pound, but not as much torque, therefore no need for a heavy crank. The torque gets developed in the PSRU.



--------

CH601XL - Corvair

www.mykitlog.com/ashontz





Read this   8:00? 8:25? 8:40? Find a flick in no time

with theYahoo! Search movie showtime shortcut.  	  Quote: 	
		      ====================================  ">http://www.matronics.com/Navigator?Zenith-List 

 	
	


  Dave Downey

 Harleysville (SE) PA

 Zodiac 601XL/Corvair?



 

  The fish are biting.

[url=http://us.rd.yahoo.com/evt=49679/*http://searchmarketing.yahoo.com/arp/sponsoredsearch_v2.php?o=US2140&cmp=Yahoo&ctv=Q107Tagline&s=Y&s2=EM&b=50]Get more visitors[/url] on your site using [url=http://us.rd.yahoo.com/evt=49679/*http://searchmarketing.yahoo.com/arp/sponsoredsearch_v2.php?o=US2140&cmp=Yahoo&ctv=Q107Tagline&s=Y&s2=EM&b=50]Yahoo! Search Marketing.[/url]  	  Quote: 	
		  



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