Are 4-strokes better in the cold than 2-strokes?
 

Im in Ontario and its winter here. I have a GMS 47 and i wanted to fly durring winter
It started but died when i open to half throtle, I think its a lil too cold. Im looking at an OS 52 surpass...for the next plane. So are 4-strokes better in the cold than 2-strokes? and what is the operating temperature range for 2 and 4 strokes. ohh wait one more...which is better, OS 52 surpass or Magnum XL52 [&:]. Thanks guys

RE: Are 4-strokes better in the cold than 2-strokes?
 

I think that they are about the same in the cold. 2s versus 4s Best to start them up inside if that's possible. We used to do that with our .049's when we were kids. Flew U/C and the school yard was next to a friends house.
The OS and Magnum engines are a lot alike. Choose by what you prefer and can afford. [&:]

RE: Are 4-strokes better in the cold than 2-strokes?
 

Also try a higher nitro fuel.....every bit helps!

Jerry

RE: Are 4-strokes better in the cold than 2-strokes?
 

It sounds like you didn't adjust the carb for the colder air and it's too lean. Colder air is denser and needs a richer neeldle setting. Otherwise I've had good results with both 2's and 4's.
Personally, I suspect the O.S. might be a bit better quality but as to whether it's a better value, I doubt it. We don't seem to have metallurgists to test them for us and give a definitive answer, just plenty of uninformed opinions like mine.

RE: Are 4-strokes better in the cold than 2-strokes?
 

I've been using 10% nitro...so should i move up to 15%?. :( Lately its been freezing here in Ont...-15*C to -20 [:@] and it wont get better anytime soon, is that way too cold?
Ive read the reviews and stuff for the two engines and Im going with the Magnum...its $40 cheaper than OS at tower

RE: Are 4-strokes better in the cold than 2-strokes?
 

I don't think the nitro is a real issue. I've flown models in -20 F temps, using a couple of drops of lighter fluid to start the engine. We used an exhaust hose from a car to warm the engines first, and 4 cycles seem to run as well as 2 strokes. One thing we learned quick is to have No grease or oil anywhere in the servo geartrain or bearings. At those temps, it'll turn into a solid mass. Also, use a bigger flight battery pack, as the cold derates batteries a lot. I've never seen any detrimental effects to the engine from cold temp flying. Your fingers are another matter though, ha.

RE: Are 4-strokes better in the cold than 2-strokes?
 

4 strokes are not as good because they do not have sufficient oil in the top end on cold start ups (in our canadian winter) and exess wear can occur if not properly warmed up. 2 strokes are the best desighn as long as they are warmed up because the oil mixed (or injected) in the gas is always lubracating the piston ring etc, as soon as it is fired up. Also 2 strokes can handle higher RPM then 4 strokes because of there design, 4 strokes have valves, which is the main reason for the low reving capabilities. 4 strokes are a more "bottom end power" designed for high stress situations (trucks,cars etc) 2 strokes are snappier, and rev up alot higher, and in my opinion, seem alot more reliable as long as the gas/oil ratio is properly mixed and the engine is taken care of.

Hope this helps.

RE: Are 4-strokes better in the cold than 2-strokes?
 

Try to say this to pattern flyers or warbird guys who are using 4-strokes in their planes. It seemed like you need to do some searches and some readings in the Glow Engines forum.

For starter, read these threads:

* [link]http://www.rcuniverse.com/forum/m_1170834/mpage_1/key_4%252Dstroke/anchor/tm.htm#1170834[/link]

* [link]http://www.rcuniverse.com/forum/m_1217154/mpage_1/key_2%252Dcycle%252C4%252Dcycle/anchor/tm.htm#1217154[/link]

* [link]http://www.rcuniverse.com/forum/m_1325882/mpage_1/key_4%252Dstroke%252C2%252Dstroke/anchor/tm.htm#1325882[/link]

RE: Are 4-strokes better in the cold than 2-strokes?
 

Hey Trung,

TIP - the longer you wait before starting (in the cold) the more difficult it will be to start the thing! I once started a Webra .60 at home - placed the idling airplane in the back of my car and drove to the flying site. I wouldn't advise doing this unless you have a BIG van with LOTS of circulation of fresh air!

I'm in Ottawa and I had trouble starting an OS .65 LA (at -27 Celcius) last week. So, I used an old trick we used to do when I lived in northern Quebec (Sept Iles) in the 60's - place the engine head directly in front of your vehicles (running engine) exhaust pipe outlet - if it doesn't start then it's not because of the cold. It doesn't take much heat to loosen the oil in the cylinder head to get it to fire - in fact I was thinking that those small butane torches available at hardware stores would be good - just be careful not to burn the fuel line!

If you have a cowl (like I have on my Sterling PT-17) run a piece of vacuum cleaner hose (or something) from exhaust to engine head under cowl. I have started engines at -52 degrees in northern Quebec like this without fail.

I just moved (two years ago) from Florida (JAX) and never did get to fly my airplanes - what do I do when I get back to Canada - I get real busy with flying again! And boy it is cool out there this morning - -27 with a HIGH of -20 this afternoon (think I'll place my own head near trhe exhaust!)

Ron

RE: Are 4-strokes better in the cold than 2-strokes?
 

Here is another uninformed opinion. My TT46pro runs poorly at 15-30F. When I wrap a little foil around the cylinder to keep more heat in, it runs great. I would like to try a 4 stroke in the same conditions. I think it would do better due to the much higher exhaust temps of the 4 stroke. I'm thinking the combustion chamber would stay hotter. On the two stroke, the fuel is absorbing heat from the bottom end and not vaporizing. The 4stroke fuel is only cooling the top end. The high for today is to be 6F, but I won't be out in it. Just another uninformed opinion, Mike

RE: Are 4-strokes better in the cold than 2-strokes?
 

Ahhh, cmon, Mike! It isn't that bad out! I'll be flying this afternoon if the wind dies down. My LT-40 on floats is just begging to go drift jumping today. It's -7 right now in Conrad.

RE: Are 4-strokes better in the cold than 2-strokes?
 

Thanks for the advice guys but heres another question
Well I said above that Im going for the MAgnum instead of OS
but I changed my mind now what about OS 52 surpass, YS 63, Saito 56
The YS one obviously costs the most but is it worth it or one of the other two is better for their costs?

RE: Are 4-strokes better in the cold than 2-strokes?
 

In theory, 2-strokes should do better in the cold because their glow plugs ignite on every stroke, not on every other stroke. However, 4-stroke glow plugs are hotter, thus retain heat better. So, both 2-strokes and 4-strokes should do equally well in the cold.

As for your engine choices, it depends on the type of flying that you do. All three mentioned engines are great. If you like to fly slow and scale, then go with the Saito 56. If you want to burn a hole in the sky, then get the YS 63, which is quite heavier than the Saito 56 but puts out as much power as other .91 4-strokes. The OS 52 doesn't have the power output as the other two.

RE: Are 4-strokes better in the cold than 2-strokes?
 

Im thinking bout the pheonix model Giles or Sukhoi or maybe a 40 sized scale plane
so I think Ill get the saito 56. Isnt the Saito non-ringed? I think i saw that somewhere on RCU, I might be wrong. Would that make saito engien harder to start? Hey do you guys know if they sell Saito engines in vietnam? cuz I saw on the OS site and they have a dealer there and I have relatives there that can get it for me for a cheaper price.

RE: Are 4-strokes better in the cold than 2-strokes?
 

All single-cylinder Saito engines are ringed. On the majority of 4-strokes, oil from blow-by gets to the bearings through the ring gap.