JettPilot

My Feedback: (6)

Does anyone have experience with running both OS and Saito 4 stroke engines ? A couple things seem to be a given here, Saitos are lighter and have more power, take longer to break in, and are a bit harder to set up. These things are not really important to my application.

What I am looking for here is which one is the most reliable. I want to set up the engine, flip the prop and forget about it, I dont want to be messing with needle valves every weekend. Being able to run the engine at all powre levels and have it idle very well without quitting are also of great importance to me. And I want a minimum of maintenance. Which of the 2 engines does these things the best ?

Also I am looking for an engine that runs very smooth, is there any significant difference of the level of vibration between OS and Saito 4 stroke engines ? Also, how do the fuel usage of the same sized Saito and OS compare ?

I am going to buy either a Saito 56 or the OS 52 based on these factors. If any of your experiences posted here would be greatly appreciated.

Thnaks,

JettPilot

Harry Lagman

These are not necessarily givens. It depends on the actual model. Indeed, in the case of the Saito .56 versus the OS .52, the OS is very slightly lighter (according to the manufacturers' claims). In many cases in the other capacity breaks, Saito is considerably lighter per cubic inch, though.

I haven't found Saitos to be any more difficult to break in or set up than OS four-strokes , FWIW. Both the Saito and OS four-strokes in my experience are pretty much set and forget engines once they are dialed in properly.

Someone who has run these two engines back to back may chime in with more a qualified comparison.

William Robison

My Feedback: (3)

Jett:

I've run both brands, several different sizes in each.

Originally I preferred the OS four strokes, back in the dark ages they were a lot cheaper than the Saitos. As OS continued rising their prices I decided if I were going to pay the price I might as well have the more efficient engine. More efficient in power to weight, and power per cubic inch.

There are some few OS engines hat are more powerful than their equivalent size in Saito, but these engines tend also to burn a lot more fuel than their Saito equivalents.

The Saito engineering has just made a more efficient engine overall. I no longer have any OS four stroke engines.

Bill.

Hobbsy

My Feedback: (102)

Jett, I have a brand new OS .52, just barely broken in and an 11 year old Saito .56, I could run a couple of different props and fuel on Monday if you would like. I could give you their real life weight also.

Jack Hyde

My Feedback: (1)

I have both an OS91 4stroke and a Saito 91 4 stroke. I have flown a UCanDo 46 with each and my overall impression is I couldn't tell which was in the plane if I hadn't looked before I flew. Both start immediately and run fine when they are set right. Neither requires a lot of fiddling day to day. They both pull vertical about the same. The difference in weight is not enough to notice, a few ounces on a 100 ounce plane. If I had to replace one right now I would not have a good reason to pick one over the other. I will say the vast majority of 3d fliers seem to pick Saito for reasons I don't know.
I was just running my Saito at home and the best I can do with it is a little less RPM on a 14x6 than my OS. The Saito is still under 2 gal run time. I have the impression they are very close in power when run in and tuned right.

TimC

Did you change your mind Jett, or are you just trying to stir things up?

Flyboy Dave

My Feedback: (21)

Buy the Magnum .52, and keep the other hundred bucks in your wallet.

FBD.

saitofreak

Asked myself the same question Jett, and ended up buying both. Not particularly a fan of OS, but have always wanted the 52. These are well established engines with proven track records, and are enjoyed by many modellers all over.
Take your pick.

car147

I run both, and would say it's personal choice... both are great engines.

Hobbsy

My Feedback: (102)

I just ran and weighed the Saito .56, OS .52 and Enya .53TN
Prop Bolly 12.5x6
Fuel==PowerMaster 15% with 18% syn/castor blend
Saito with Fox Miracle plug, top rpm==9.791==idle 2,101
OS with OS-f plug=============9,240 first run, 2nd run after 24oz more fuel==9,570==idle 2,069
Enya with Stock Enya plug========9,640==idle 2,070
I dedicated another 16oz tank plus half tank from first run to the OS realizing something was wrong. I estimate another 45 minutes will bring the OS up with the rest.

Weights
Saito .56==15.9oz
OS .52===15.4oz
Enya .53==15.7oz
YS .53===1lb=2oz, just because it was laying there.

Harry Lagman

Thanks for the test results TW - great post.

Hobbsy

My Feedback: (102)

Thanks Harry, I neglected to mention, all the weights are with the mufflers on and the washer and both prop nuts. The Saito is equipped with the new straight pipe and cast muffler. I am a new user of both the PowerMaster fuel and the Bolly props, I think I'm going to like both.

TimC

Great test TW. I think all the YS fans would love it if you spun up the .53 with the same fuel/prop.

Hobbsy

My Feedback: (102)

I'll do it, it will have to wait until Monday though. Even on 15% nitro I'm sure it will kick their fannies.

Harry Lagman

OK - here's my entry for the YS .53 sweepstake: 11,200 rpm

CRAZYRYAN

My Feedback: (1)

i wouldnt care much of the two id just pick one but they are bit pricy like previous someone said buy a magnum that what i did and i have very good luck with it its a .91 in my sukhoi not a problem with it and then i bought an old super cub from a friend of mine with a os gemini 1.60 flat twin its 13 years old man!! running as strong as ever!!!!!! just go either way dont get too picky

TimC

No way Harry. Not an "r" past 10,500.

JettPilot

My Feedback: (6)

Thanks for the posting of the RPM's etc. etc Torque Wrench , thats really great information. I am not at all interested in a Magnum, I wont risk the trouble to save 100 bucks. I was the highest quality engine that will last the longest, I have never been happy when I have bought cheap anything. Performance seems pretty close, not enough to really make one stand out over the other. For me its still a Saito 56 or an OS 52.... Given the close performance, Idle, etc. etc. I will definately get the Saito if the vibration levels and reliablity (no deadsticks) are close This engine is for a plane with a video camera on it, so vibration levels are important.

How do the two engines compare in Vibration when you run OS and the Saito, any huge difference Torque Wrench ?

JettPilot

loughbd

The major difference between Saito and OS is the spelling.

Hobbsy

My Feedback: (102)

Jett, that would a very close call, but if I had to give one the edge it would go to the OS. The OS does not have the authoritative sound that the Saito has but that may be just the muffler styles. The Saito spent most of its life turning a 12x6 three blade at about 9,000 rpm on a H9 Cherokee 40, no deadsticks. One thing I'm not used to is the very broad needle the OS has, peak and very rich are about 1/2 turn apart, whereas on the Saito its about 4 clicks. I'm with you on the M and TT engines, they never get considered.

stelios

My Feedback: (4)

OS run smoother compared to Saitos.

Stelios

XJet

I think that's solely because the OS is a heavier motor so there's less vibration. My Saitos run like a Swiss watch at idle and are very strong when WFO.

JettPilot

My Feedback: (6)

I think the broad needle is a good thing, it allows you to set it more precisely and probably is not as prone to losing its setting. Having a big change for every click makes the Saito needle to sensitive, but I can live with it []

When comparing the Saito .56 to the OS .52 the weight is within an ounce of each other, the Saito being the heavier one. But with a weight difference less than an ounce, its not enough to ever make a difference in vibration or anything else... Maybe the OS is just a little smoother than the Saito, but from what you all say the difference in vibration levels is very slight... I am leaning towards the Saito for the little extra power and higher quality. Only if there were a big difference in vibration would it become a deciding factor.

I sure appreciate everyones input here, lots of really good information

JettPilot

Hobbsy

My Feedback: (102)

Jett et al, I ran a test of the OS .52, Saito .56 and RCV .58, I used an 8oz Sullivan Flex Tank and PowerMaster 15% Fuel as before. I let each engine warm up for 60 seconds. Then went to full throttle, peaked rpm and reduced 200 rpm for 5 minutes. I then reduced the throttle to 7,700 rpm for 7 minutes, then reduced it to 7,000 for 3 minutes, back to full until the engine began to pull bubbles. Reduced the throttle to 5,500 until it quit.
Prop==Bolly 12.5x6

OS .52
Full throttle 5 minutes====9,500 rpm
Reduced to 7,700 for 7 minutes
Reduced to 7,000 for 3 minutes
Back to full until bubbles appeared in the fuel line 2 minutes
Reduced to 5,500 until quit 1 minute



Saito .56
Full throttle 5 minutes 9,750
7,700==7 min.
7,000==3 min.
Full throttle until bubbles appear==4.5 minutes and 9,750
Reduced to 5,500 until quit==1 minute

RCV .58
Full throttle 5 minutes==8,950 rpm
Time at 7,700 and 7,000 same as the others.
Full throttle until bubbles appear 5 minutes, 8,950.
Reduced to 5,500 to quit 1.5 minutes.

YS .53==10,330 rpm.

Harry Lagman

Once again, TW, thanks for that excellent test information.

Ouch - my guess wasn't even close.

TimC, I respectfully bow before you! [sm=thumbup.gif]