Glowgeek

Extensive main gear mount rebuild on 50cc Yak fuse. A bit of a challenge on a foam belly fuse. Saito 45 and Crunchies 50 out of the cleaning tub, waiting on parts.

Hobbsy

My Feedback: (102)

They don't have everything so I pick and chose between them and Horizon. They are pretty quick though.

https://www.hobbyplastic.co.uk/index...parts&x=13&y=7 Read carefully, there are a lot of non 50 parts mixed in.

Shipping===£6.20

Glowgeek

Tried out my new Harbor Freight Ultrasonic cleaner and LA's Totally awesome cleaner for the FA50. It worked for a couple of minutes and stopped vibrating. Exchanged it at HF for a new one and the heater wouldn't turn on. Got a refund. Ended up cooking the FA50 at 150°f in the crock pot with green antifreeze, that always works if you have time to wait. Parts come out of the crock, get rinsed with hot water and then brushed down and with DNA while still warm. One more rinse with hot water, blow dry and sprayed with corrosionX. LA's cleaner works very well, even without an US cleaner, but not for hard baked on castor (very dark brown or black).

Has anyone here tried a weak solution of muriatic acid to brighten up these old engines? My 45 is pretty dark from oxidation and also has white powdery corrosion in several places.

erieqc

Glowgeek

I wouldn't use it on polished aluminum either, muriatic acid etches aluminum and leaves a more of a matte finish. I've used a paste to clean the oxidation off my aluminum canoe, i think it has some sort of acid in it to work like it does. Thing is, if you don't spray it off with water soon enough it will re-oxidize in a minute or two and give that milky looking finish you were talking about.

I have tried muriatic on a K&B cast muffler but I think the solution was too strong. The part actually started fizzing like an alka seltzer! Lol. It looked bright and uniform in color while it was submerged but once removed it oxidized to dark grey within two seconds. Anyway, I'll do some experimenting with the same busted muffler to see if I can dial in a solution that will remove the oxidation layer more slowly. That should give me time to get the part into a buffer solution before re-oxidation occurs.

I like bright Saitos.

FlyerInOKC

My Feedback: (6)

It would be easier to paint it pink!

Rudolph Hart

No updates on the pink panther yet mike?

Glowgeek you could try a weak solution of vinegar (put the rest on your hot chips) and water or maybe lemon juice. Muriatic, or in it's slightly purer form hydrochloric acid, is used to etch aluminium before painting, it's to harsh for saito's and should never be used.

Gary when the students all protest on their own time and not take a day off school i MAY start to think about fitting something electric to the duke after they throw away their mobile phones and give up airconditioning etc so i think i'm safe. I like all the pics you see of gas or diesel powered gen sets charging batteries for clean electric powered vehicles. Came home from the three day classic bike racing stinking to high heaven of methanol and castrolR hyuk hyuk, i ain't gonna shower for a week

Hobbsy

My Feedback: (102)

Lonnie, to what extent are you rebuilding the 45 and 50, thanks, the last one I got from Crunch is pretty strong. I debated about getting the longer crank but settled on the short one, It is long enough for most props.

Hobbsy

My Feedback: (102)

Pete, while you were off sniffing castor clouds, I ran the 50 Cap sent to me with great results turning one of your home grown Bolly Clubman 11.5 x 6. Thrust equals 5.80 pounds.

Glowgeek

Tear down and clean up, bearings, tappets, carb kit, gasket set and pushrod cover seals. The piston ring appears ok on both engines, no glazing on the edge surface. Everything else looks good.

Pete, thanks for the tips.

Hobbsy

My Feedback: (102)

Thanks, I reused both the ring and piston in the 50 I fixed up, I placed the ring gap over the rear of the wrist pin, I always do. The compression was a little soft at first but after the 40 minute run it is solid. I had a slightly better looking cam, so it's in there with new lifters.

Incidently, I calculated the thrust for the Bolly 11.5 x 6 at 10,570 rpm, I think 5.8 pounds is pretty good. I used an APC wide for the style since the Bolly blades are wider than the APC blades. The Xoar 12 x 6 at 9,320 makes 5.06, 9,320 is probably not the best rpm for the 50. The 56 turns the Xoar 12 x 6 at 9,860.

Check this calculator out if you don't mind. It's the one Quicky advocates. http://www.godolloairport.hu/calc/strc_eng/index.htm

Glowgeek

That's the same calculator I use. Very handy for matching engines to planes and selecting initial prop sizes to try for flight.

Crunchies FA50 had badly flat spotted tappet edges from being run while gummed up (tappets not spinning in bores) but oddly had no dents on the cam lobes. First time I've seen that.

Hobbsy

My Feedback: (102)

I am convinced that the dents occur during over revving, I prop for mid 9's and have never had a cam get dented. I do prop the little 30 and FA 40-a in the 10's though.

Glowgeek

I can see where valve float would cause cam dents as well, or a sticky valve even, but I have seen it happen with my own engines twice, before I became an advocate of aro and lower castor content fuel. My rebuilt 56 and 62 (including new tappets) but both suffered from tappet beveling and cam denting when run after prolonged storage over the winter months. The valves weren't sticky and those rebuilds never saw the sunny side of 11K in flight. I was using a much higher castor content fuel back then so gumming was an issue. The tappets were stiff in the bores when I tore them down, thereby my assumption.

Edit: Give some thought to how much heat would be generated at the tappet/cam interface on opposite sides of the tappets if they could not spin freely in their bores. Over reving or a sticky valve can cause cam denting, agreed, but the tappet would show a normal circlular wear pattern if allowed to freely spin in its bore imo. My 56, 62 and Crunchies 50 were flat spotted on opposite sides of each lifter.

FlyerInOKC

My Feedback: (6)

Since you asked, I picked up the Circus Pink Monokote late Friday. Not bad match too (see pic) However; this weekend was shot down building and leveling a base for the metal shed to store the new backup generator. I hope to get the shed completed this week. Its a Click-Well Shed made in Oz! I finally got the insurance claim approved on Friday for the storm damage and the contractor is coming by today with the paperwork so I can get that started. I am getting a new roof, gutters, roof turbines, garage doors, and Electric Heat Pump. 80+ mph winds really do a number on trees and the flying debris tears everything else up. I also have to do a bit of shopping to replace the damaged electronics.

acdii

Good match. Purple sunburst on the wing?


I have so many things that are water damaged in my house, but have a $2500 deductible too. The only real fix for the money pit is a gas leak.

Jesse Open

Jesse Open

FlyerInOKC

My Feedback: (6)

I was lucky, there was a contractor who had a relationship with AAA Insurance and he waived my $2000 deductible on the roof. I have cost of replacement so the electronics were settled at the cost of new equipment. With all the damage in the county the insurance premiums are going to jump again, they went up $400 this year, but you kind of expect that. I will get that little surprise next September when the insurance renews.

I'm going with white/red checkerboard on the vertical fin and rudder I have just enough to do it. I was thinking of adding some angled red strips on the top across the cord and maybe black or white on the bottom. I have a little of all three colors on hand. I haven't the cash right now for decals. The LHS I buy at these days after my regular shop retired is more of a R/C car place and he doesn't have much in stock. It took a little over two weeks for him to get the pink Monokote in stock. He blamed it on coming from the California warehouse, I think he didn't have enough to order and waited a week. He did charge me the same price as Tower and there was no freight so I can't complain about that.

Glowgeek

Yes, the cam damage (dents) have always been on the closing side of the lobes, and more so on the exhaust lobe than the intake in every case. I dont however think it's coincidence that every Saito engine I've torn down that exhibited cam dents also had the coinciding tappet flat spotted on both sides. In the case of my rebuilt 56 and 62 all can say is the tappets and cams went south in less than 10 hrs flying time after the rebuilds. They were never over revved, the valve lash never exceeded. 004" but the tappets were not free to spin in the bores when I tore them down.

During the cam and tappet replacement this last time the tappet bores were cleaned spotless.
It'll be interesting to see how things look after 100 hrs with lower castor % and religious use of aro.

Disclaimer: I am not and never claimed to be an engine failure analysis expert.

Jesse Open

Jesse Open

Hobbsy

My Feedback: (102)

Nor have I seen excess wear on cams of my own nor on the ones I got from w8ye, Gary or Captain Crunch. I have one cam with a huge dent, the others are smaller. I use the OS gauge at a slightly draggy slide. So far so good. For years I used the Saito gauge with excellent results also.

Glowgeek

I use a .0015" feeler gauge. The valve springs are so light on these model engines so I make sure the feeler has almost no drag. The end result is probably closer to .002"-.0025. I check the lash after the first 40 min run in period and again after each half gallon of fuel until things stabilize. Once a season after that. Never see more than .004" on my engines. On used engines I've bought and those rebuilt for others I've seen the lash as wide as .014". Those cams are always dented.

Rudolph Hart

I use a tallyho roll up cigarette paper, if you can gently pull it through the gap without tearing it your done. We used to use rolly papers to check clearance on heavy barreled varmint rifles after glass bedding the action and barrel to a new stock.

ps my re distilling of fine spirits friend popped into work today with a part for me to paint. I'd been mulling over cleaning methods for aluminium on our saito engines and since he knows a lot about chemicals, i asked him if he thought coca cola would be worth trying. He got this look on his face like a baby the first time it get's it's arse slapped, biggest insult to fine spirits he's ever heard of.