fastest four stroke
 

I know its not extreme speed but some in might know. I would like to know plane and engine combo. I would think 150 would be an easy number to look at.

RE: fastest four stroke
 

My Corvette is good for just under 200mph....

RE: fastest four stroke
 

OS 120 1-2 hybrid with pump in a Hangar 9 Mustang (60 size) 15X7 3 blade. Over 100mph. Timed it comes out to about 120 130mph.

RE: fastest four stroke
 

i've seen a hugely oversized ys 4 stroke in a dago flat out zooming around our field. i don't know how fast but it was silly fast.

RE: fastest four stroke
 

How but the guy with the Phoenix models Strega and the YS 110 in it?

RE: fastest four stroke
 

Mine has been clocked on radar at 130mph on 20% nitro. You can get alot more power out of the motor if you up the nitro %.

RE: fastest four stroke
 

I havent done it yet but i was thinking of putting a ys 170 in a H-9 miss america, but still dont think it will get over 130. maybe going smaller like the ys 63 in a 25 size plane like a modded LR-1

RE: fastest four stroke
 

little tony or minnow w/ a ys 140 sd50 w/ a jett90lx

RE: fastest four stroke
 

How about 245 kmh?

http://www.exclusiv-aircraft.de/videos/geebee245.html

RE: fastest four stroke
 

What is the limiting factor with the model 4 stroke design? We take 10,000 rpm for granted, but it really is asking a lot of those tiny valve springs. Is the rest of a typical model valve train strong enough to allow better springs? The manufacturers already have done all the testing to get a balance between longevity and power, but I wonder if anyone has said "heck" to longevity and done a build up that made a significant improvement?

RE: fastest four stroke
 

actually, yes they have, if one wanders through the tower web site, os sells a a car version, of the 26 surpass , its rated up to 22k, it has tuliped intake valves etc, a very short intake tract and a very large carb, one the biggest issues with current four stroke is their poor intake and exhaust port design, the bottem ends are usually fine, also they could put much larger intake valves in the head, rpm isnt such a big issue for valve trains, one has only to look at modern sport bikes, with redlines in excess of 14-5k

RE: fastest four stroke
 

Cp and finney I have a O.S 30 that i have messed with. used some of the car parts and it turns a APC8x7 at about 16,500 -17,000 if i remember. This is on 10% too. It doesnt like much more than that in nitro. I could lower the compression some to help. I cant get the car cam anymore unless I buy a used complete engine just for the cam. it flew a GP 25 spitfire at around 95. the sound is really cool too really revs fast. I had higher rpm on the stock springs than the car ones but I am not reving to 26,000 either.

RE: fastest four stroke
 

Seems like you run into a barrier with the .90-1.40 engines when it comes to swinging a 14"-15" prop fast enough for decent pitch speed even with a square prop like a 14x14. I mean just to get a 140mph pitch speed you need to turn a 14x14 at 11,000rpm which is no easy task. The bigger engines don't rev that high and even a good 1.20 two stroke on a pipe running 40% fuel will have a hard time to get to this rpm Seems to be the reason why so many people are just going down to 40 size birds where a 12" or 13" prop will suffice.

RE: fastest four stroke
 

GTO FTW!

http://i165.photobucket.com/albums/u...S/DSC_0003.jpg

RE: fastest four stroke
 

Where's the engine?
That looks like the backside of my washing machine :D

RE: fastest four stroke
 

ls motor a bowtie worth having[8D]

RE: fastest four stroke
 

Oh ya, I'm just being a smart-azz....but you gotta admit that it looks like a plumber's nightmare.
This is what a hotrod engine should look like:

RE: fastest four stroke
 

oh yeah hemi elephant motors[>:]

RE: fastest four stroke
 

I doplered my YS 1.10 powered PM Strega at 134 on 30% heli. I've had guys blow by me running 60% on a cleaner airframe. A few guys are running an APC 13.5x13N or 13x13N around 11,000 on the ground. Pretty impressive once they unload in the air. I think 150 is likely. I believe Richard Verano turns a 14x14 at about 10,500 on his YS 120 on 60% and his plane is very fast.

RE: fastest four stroke
 

i agree, with four strokes adding more pitch is much more effective when you up the nitro! better to load up the engine than try to spin it higher, and throw another shim or gasket in it.

RE: fastest four stroke
 

Whats under the hood?

RE: fastest four stroke
 

Who sells 60% anyway? I can only imagine how much a gallon of that costs. Also what's a YS120 burning at that level like 2oz per minute?

RE: fastest four stroke
 

all the major fuel makes have it for the boat guys, and yes the fuel flow is very high:D one of the things not many think of is also the oil flow is much higher also, per minute, which is a good thing....

RE: fastest four stroke
 

Most of the guys I know blend their own 60%. The boat fuel has too low oil content. Once you add more oil, you no longer have 60%. They are not sport flying when they're run the high nitro. They are racing and a couple extra bucks per tank full is the least of their worries.

RE: fastest four stroke
 

Bet your hotrod doesn't get 34mpg and thrown down a solid 600+ to the wheels, is able to drive coast to coast with AC on and still use pump fuel. All without overheating, throwing blower belts, or squirting oil out the timing cover/rear main seal. Never mind that I sit in the car and tune with a laptop instead of a box of jets and a timing light. I like my car.

I worked in autoracing for 10 years as a cylinder head machinist for a Comp Eliminator engine builder so I've lived that pain. (69 442 with an Enderle injected 427 dry sumped olds motor was my first car at 19 years old)

NO THANK YOU.:D:D