closetguy

My Feedback: (13)

is there anyone that has tried saito's pump & large bore carb for the 220.if so is there any performance gain with it?mine goes lean in the mid range,if i richen the low end to help the mid range then it is rich on low end.this is after adjusting the high end for peak whitch is 8000 with a 20-6 biela prop,then dropping to 7700 to fly. i thought that the larger carb would help?
Thanks

Hobbsy

My Feedback: (102)

CG, I ditched the backplate pump and run the big carb with an IronBay regulator, you should see about 200 rpm over the stock carb. The big carb is not the problem regulating the pressure from that stupid backplate pump arrangement is the problem. I use a 20x6 Just Engines Jen-C prop (Biela) same as yours.

closetguy

My Feedback: (13)

Hobbsy,thanks for the info, i got a cline regulator i will try that.
Thanks

Hobbsy

My Feedback: (102)

Here's my setup on the 2.20.

closetguy

My Feedback: (13)

Good idea with the fuel tank stopper.now that we now how low it will go what is top end readings?
ENJOY!

Sport_Pilot

Is this the same system that is used on the Saito 300 twin? It is essentially a needle used to control crankcase pressure into the tank, but is not a pressure regulator? Needles the pressure and allows the oil to pass through? Also where did you get that little wheel you used to neatly turn the corner on the fuel tubing?

Don M.

My Feedback: (5)

Hobbsy how much fuel does one of these things burn in an aerobatic plane in say 10 mins ? I waited for the OS200 but I'm a bit disappointed in what I'm seeing so I may go with the 220. I'm also waiting for the 220 gasser but I don't think it will ever come.

krayzc-RCU

My Feedback: (31)

wow

Hobbsy

My Feedback: (102)

Don, I called a friend of mine who has (3) 1.80s and a 2.20, he says the 2.20 with a 20x6 APC actually burns less fuel than his 1.80s do on a 16x8.

Ken6PPC

That seems impossible. I have always thought that more energy input is required to get more energy output. He isn't splitting atoms inside that 2.20 is he?

Hobbsy

My Feedback: (102)

Lower rpm.

seanychen

My Feedback: (4)

Also an over-bored engine tends to consume more fuel than the long stroke engine of same displacement. A prime example is Saito 82 v.s. Saito 91. Saito 91 puts out more thrust than the 82 at lower fuel consumption.

closetguy

My Feedback: (13)

Guy's mine burns 2ozs. a minute with a 20-6 biela prop at 8000 rpm's.it also a over rated as fare as power,maybe when i get a working regulator or pump it will improve but for right now it can't pull a 12-3/4 lb. Chip Hyde Tunnel Vision out of a hover with any authority. i should have bought a gasser.
ENJOY!

onewasp

You've got something WAY wrong!
A Saito 180 will yank a 12.75# plane out of hover.

A 220 is quite a bit more powerful than the 180 though I have not flown one.

onewasp

I've been 'around' engines (stroked; bored;bored and stroked -- you name it) for a long time.

I would love to know where you got that information and the reasoning behind it as I never experienced anything of the sort.
Assuming the same base engine, the bored only will tend to rev more quickly, while the stroker will have a higher torque rating and rev more slowly ( the piston speed also goes up)----all other factors being constant.

Fill me in please.
I simply do not see (nor have I experienced) the fuel consumption characteristic you cite.

Flyer95

My Feedback: (1)

Low pitch large diameter is not always the best combination for hovering and static thrust.
Saito recommends a 18x8 or 19x8 for the regular unpumped Saito220 and I would also use more pitch than 6.
My Saito 180 turns a MenzS 18x6 @8700rpm on only 10% nitro and pulls 18LBS static, measured with a fishing scale and that should be enough to pull a 13LBS out of a hover.

closetguy

My Feedback: (13)

Flyer95, i thought of that to i tried a PT Models 19-8 and got 7700 and a Mejzlik 18-8 at close to 9000 if i remember right? from what i have seen in numbers that i am in the ball park.the 20-6 prop was better than the smaller ones.the engine might be going lean in mid range,but today i was playing around with the needles and never ounce seen any bubbles in fuel line, so who nose.
ENJOY!

Flyer95

My Feedback: (1)

closetguy,
All I know is that low pitch and low rpm is not a good combination for any kind of performance in any airplane. Pitch 6 is usually good if the engine can turn 9000rpm or more, and I think the Biela kind of flat props. like the APC:Ws. Maybe a MenzS 18x8, 19x6, 19x8 would do better.

I know that the Saito 180 does not need any pump or regulator and I can run it or hover the plane for as long as I wish or manage without it going lean. The fuel tank should however be behind the firewall, mine is.
My Saito220 is the standard version without the pump and I purchased it just because I liked the reliability and the power of the 180 so much, 220 is still new in box so I can not tell much there.

seanychen

My Feedback: (4)

Hello,

There is not really a well defined correlation between bore and fuel consumption. But larger bore means the cylinder can combust more amount of air-fuel mixture per cycle. When the piston is at TDC, the compressed air volume is basically what remains above the piston. This is not quite so obvious in 2-strokes, but I see it quite often in especially Saito 4-strokes. Why else do you think a larger bore will also increase torque?

seanychen

My Feedback: (4)

I find the Biela 20x6 load to be on the high side for my Saito 220. It is much more comfortable with APC 19x8W than Biela 20x6. Maybe I should try a lesser load 20x6.

closetguy

My Feedback: (13)

seanychen,i think the 220 is loaded a bit to much with the biela 20-6.i heard guy's using mejzlik 20-6 with good results never heard any numbers yet just that they like it better than a apc 18-6w that most like for 3d.but what i am getting at is were talking about a 2.20 4 strk. that is more happy spinning a os 160 or a 180 prop.i am going to try some more props and see what happens. you would think it would spin a 20" inch prop though more like a moki.
ENJOY!

onewasp

Sorry, but that simply isn't true.
Equal displacements will not have unequal volumes and compression stays the same here as we have defined only changes in bore or stroke. Equal CID is equal CID (by definition).
This applies to two and/or four strokes----makes no difference as volume is volume.

BTW re-read my post---I said the STROKER would have more torque (it will). Piston speed also goes up. (and that isn't all good)

Hobbsy

My Feedback: (102)

The wheel I used is a Sullivan Gasoline Conversion tank plug. My 2.20 turns a JustEngines Carbon fiber Jen-C (Biela) 20x6 at 8,150. Long stroke engine tend to build torque more quickly and have max torque at a lower rpm that a same sized big bore engine. When you thionk about it logically the longer stroke version has more leverage but the larger bore shorter stroke has more piston area to push so the amount of torque is seldom much dofferent. It's just in a different place rpm wise on the torqu curve. Timing, compression ratio and port shapes have more effect on the amount of torque than the bore and stroke.

There are lots of examples of engines that get better economy than their same size counterparts, two excellent examples are the Webra 1.20 and the OS 1.60. Both turn larger props than their same size peers and get better fuel economy.
I got a shipment today with an APN 18x8W to try on the Saito 2.20. I won't get to that until late next week. I'm leaving for Utah tomorrow to visit my son, he has an old Yamaha 920 V Twin ready for me to go for a couple of scenic cruises. I told him that " I didn't want to ride no buzzin 4 cylinder wannabee" and the 920 is as close to a real motorcycle as he has. Oh well.

onewasp

The problem Hobbsy is that you expanded a two dimensional issue into a multi dimensional cause and effect discussion.

Compression and timing were specifically left out along with all other factors which were other than bore vs. stroke.
Same issue as we used to face in short tracks with Midgets and the Ford V8-60 based engines vs the small Offys. Differences----try a Norton 180 in the V8-60------:-)
But not an allowed part of the discussion.

Stroke does indeed give torque increases----think hand crank.

Obviously the other areas (more particularly the compression ratios and fuels allowed) give real seat of the pants differences----been there done that too.
We also are guilty of tipping the nitro can until the pistons began coming out the exhaust----until then it was one fine ride!

BTW I'm surprised you like the ring-a-dings. My favorite ride is the Sabre V-4-------exactly the opposite of the ring-a-dings-----super smooth and hard to even hear anything other than the wind! Smells good too!
As always, to each his own.

Hobbsy

My Feedback: (102)

Wasper, the 920 Yamaha is a fourstroke V twin but is lightyears from being a Harley which is what I meant by a "real motorcycle". Engine designs are comprised of so many comprimises that its difficult to discuss without boiling it down to one single issue at a time. Thanks