Hobbsy

My Feedback: (102)

That will never be an issue, Saito has done it for 20+ years, I just looked and the 56 Alpha has a bronze bushing on the lower rod end but not the top. I doubt that the valve seats are even plated. Probably not cost cutting, just eliminating unnecessary cost, it doesn't make sense to pay for a feel good. The worst thing that happens to the seats is getting jammed up from using castor. I don't use castor fuels anymore. I'll look at my 95V in a while. That's my take anyway.

controlliner

My concern is without bronze inserts, the valve seats could stretch or pound out, actually widen to the point of the valve sitting deeper in the head. I wonder how much tapping action the seats can endure from the valves closing on them.

Hobbsy

My Feedback: (102)

It just doesn't happen, the only thing I've seen happen is a dented cam from too much clearance or over revving. The only time the valves would slam would be when over revved.

Hobbsy

My Feedback: (102)

The OS .56 Alpha and the .95v each have a bronze lower rod bushing but no upper busing and as near as I can tell no bronze valve seat or guide. Saito did away with that long, long ago and I've never seen a mention of it in the big Saito thread.

the Wasp

My Feedback: (1)

about my 61FX,
I had to replace the bearings in my 61FX, the engine has somewhere around 7 gallons on it, yes-yes my bad for not using more after run oil than I have,, but when I took it apart the piston and liner was in vary-vary good shape,

but the thing is>>>>, I have rebuilt OS 50 Heli engines before, but this 61FX is a much better made engine, I have to say I was impressed when I took it apart,, when I pulled the liner out I thought the Pin that held the liner in position was damage, but it wasn't, I could see that the Liner had a "V" cut into it (not a square cut like my 50s have), and I could see that the Pin was also pressed into the shape of a "V", this allowed the Liner to be reassembled exactly the way it came from the factory,

but then again it came to me that my Heli engines were Ringed engines and my FX was not, but never the less, I could see that the FX is a better made engine,

heavy ? yes !, my god it's heavier than a Saito 100, yet still, a very well made engine

don't over Lean it guys !!

Jim

Hobbsy

My Feedback: (102)

I recently purchased this OS LA .10, it was a little skinned up but in good running order. I mounted a new back plate since I had one. painted the head black and touched up the muffler.

OS LA .10
Plug===OS a3
Prop MA==8x5, a little too large maybe
Fuel==Wildcat 2/4 10% with 18% full synthetic
After 20 minutes at various rpm, it was used so this was just to get set correctly, I tached it
Max rpm==11,500
Best idle===2,650
For a non metered, non air bleed carb it sure is linear and clean at all rpm.
I have a 7x5 mounted on it now, I will run it a little later.

Hobbsy

My Feedback: (102)

I just re-ran the test using a MA 8x4 and the max rpm is 12,150, I need to order a couple of 7 inch props.

Mr Cox

Yes, a 7x4 prop is a better match. The .10 FSR and FP will do around 15000-15500rpm on an APC 7x4 prop and the stock muffler. A 7x5 prop is about the maximum useful load for the engine.

Here is a .10 FSR;

Hobbsy

My Feedback: (102)

Thanks Mr. Cox, I have a 7x5 and 7x4, (Xoar) coming in a couple of days. I'll post the results. The LA .10 is a sweet little engine and surprisingly quiet. Since have more experience with these .10's, is the OS A3 a good choice for the plug. Thanks, Dave

Mr Cox

I prefer the OS#8, I have never really liked the A3 plug....
I theory the hotter A3 plug might deal better with a too rich idle setting but that hasn't been any issue anyway (on 10% nitro) and the OS#8 gives a better overall performance, to me.

1QwkSport2.5r

I have an LA .25 that I'm going to do some experiments on in the future, so I ran it on the bench in bone stock form to get a baseline idea of how it runs to get a better idea of what to do to it. the only non-stock part of the engine is I stripped all of the paint off of it.

LA .25 with stock E-2030 muffler, fuel is 12% nitro 23% oil, glow plug is an OS #8
7x5 MAS Scimitar - 18,000rpm
8x6 APC - 14,130rpm
9x6 APC - 11,640rpm

LA .25 without the muffler, all other things unchanged.
7x5 MAS Scimitar - 18,570rpm
8x6 APC - 14,880rpm
9x6 APC - 12,300rpm

The OS .25 FSR runs 1,000-1,500rpm faster as a comparison.

aspeed

I think it will be happier with the 8-6" It is in the power band of that motor. Check the measurement of the carb bore on the FSR, FX, AX, and then on the LA and you will see why it runs slower. I know the .40 is way bigger bore on the B bearing motors. Qksport, you know that posting in this thread makes you a dreaded OS engine user, possibly even an abuser. A fate worse than death.

1QwkSport2.5r

Everyone knows I'm not a fan of OS engines.. If I was a total hater, I'd just run it on some RC car fuel dead lean and let her melt down. But I'm not doing that. I'm doing some experiments to not only see what gains can be had, but also to test durability in the most unconventional manner possible. My hypothesis is the liner will peel at some point, but we will put that to the test. My test fuel has no synthetic oil in it (it seems to be castor oil tends to prolong the inevitable) and the nitro content is comparable to what many folks use in these engines. So if it survives my modifications, then we will test some more exotic fuels and tuning aids.

The fanboys will have a field day, but it's all in good fun. I can use a good laugh once in awhile. Besides... How often do you see an LA engine on a tuned pipe? I'm gonna try it.

Hobbsy

My Feedback: (102)

The little OS .10 is now properly equipped, and ready to mount on the Hayes mount.. I may need an exhaust extension to move the muffler below the fuse.

aspeed

I never saw one with a blue muffler or black head. It will sound and go better with no muffler!?

Hobbsy

My Feedback: (102)

Tower used to sell the blue muffler, but I painted that one and the head myself. The paint is not a perfect match, but close enough. They would never let me fly it with no muffler. The muffler extension is no longer listed, I'll have to make one.

1QwkSport2.5r

That mini Telemaster looks a lot like the Norvel Neofun Classic trainer I have. My Neofun came with an AME .061 originally and was later changed to an AP .061 and now has an FP .10 in the nose. I've been looking for a couple years now to find a Davis head for the FP .10. A fellow even offered to make me one, but never followed through.

Hobbsy

My Feedback: (102)

I just ran the OS .95v using two different Xoar props

OS .95 V with about 90 minutes run time
Fuel====Wildcat 2/4 10% nitro methane 18% full synthetic
Plug====OS-f
Exhaust=Stock
Xoar===15x6 max rpm=8,550
Xoar===14x7 max rpm=9,350
Idle with both==2,050

As mentioned during the break in, it's a nice smooth friendly engine.

aspeed

I think you need to buy a little Taig or Harbor Freight lathe to make your heads and other goodies. Happy Birthday to yourself.

1QwkSport2.5r

LoL.

Hobbsy

My Feedback: (102)

Thanks for bd wish. I went to the discontinued OS parts list and got the part number for the extension, searched for it at Tower and it came up as in stock. It's coming tomorrow. I've been lusting after the Micro=Mark lathe at Micro-Mark for a long time.

Mr Cox

A man's best friend.

aspeed

I have a Hardinge chucker turret lathe that I use for most stuff, but got a Taig at a garage sale, and keep it downstairs in the model shop. I use it once in a while for piddly things, and when it is too cold to go in the garage. I would like to get my milling machine downstairs too. It is about a ton. I was going to sell the lathe and mill when I did a 300 km move but could not sell them in time, so I kept them. The plan was to get a combination lathe/mill like the Smithy Granite series. For the hobby stuff, it would be fine, and I grew out of the street rod phase. The Harbor freight lathe seems pretty nice for models. It goes by other names too, King, Grizzly? It has a rheostat for speed control. There is a following on some forums with mods and helpful hints etc. I think it is a 7" swing, and is under $1,000 and even less when on sale which is every other month.

1QwkSport2.5r

A buddy of mine has a Smithy. He was making transmission parts for the company he worked for which essentially paid for the machine, but he has made a two-cylinder model Diesel engine on it as well as head buttons and other stuff. We were going to make some head buttons to fit Nelson plugs for a few engines, it never got to it as he moved back to Texas. I do need to look into getting a lathe, most of the stuff I'd want to make if need a lathe for.

Hobbsy

My Feedback: (102)

My dream lathe, the MicroMark 7x16 lathe.