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-   -   Saito Rusted Guts = Lost RPMs? (http://www.rcuniverse.com/forum/glow-engines-114/11300277-saito-rusted-guts-%3D-lost-rpms.html)

apwachholz 11-17-2012 06:47 AM

Saito Rusted Guts = Lost RPMs?
 
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<span style="font-size: large;">Oh Great Saito Guru's</span><span style="font-size: large;">
</span>
I've beenthoroughlyreading the Club Saito threads and have taken note of a few things I belive will help with my engine issues. I wanted to get a few confirmations or rejections, however, to ensure that I'm going in the proper direction regarding my Saito FA-62A AAC. I've had it for 5+ years and did a complete tear down and inspection two years ago and all was looking great - Until recently when I couldn't get my engine to run, even at factory default settings. Ugh.... So, questions:

1. Is the best practice to simply replace rusty bearings?
2. Is it best to use After Run Oil even if the fuel states you don't need it (kinda like insurance, use it/have it 'cause it can't hurt)?
3. How does one get corrosion this fast (possible theory's) in a single year (didn't run it for 8 months)? I use Morgan CoolPower 15%nitro (4-stroke blend)
4. As a 4-stroke noob, any helpful links on RE-assembly of a Saito would be helpful.(*see side note) My engine has run fine since the tear down, albeit, a little hot and less RPMs - so I'm willing to admit I might have screwed up but can you even run an incorrectly timed Saito??


(*Side Note: I did a tear down and rebuild of my O.S. .91 two years ago and had issues because I re-assembled and didn't have the timing correct. Thankfully a fellow RC'r who's a gear head helped me break it down at the field and we got it up and running in 30 mins. But, that was an O.S. and I had a mentor....)

Thanks Everyone.

-andrew

<div><span style="color: rgb(255, 0, 0);">Update:</span></div><div>Per TimBle (http://www.rcuniverse.com/forum/m_11..._2/key_/tm.htm) he's got some good insights. He should know, as he helped me write a castor/synthetic comparison article. How's it going TimBle!? :)</div><div></div><div>"I suspect that there are other reasons for the corrosion many see in their engines.</div><div></div><div>1) rust is already present in the metal used for the steel components of the engine. Poorly processed steels and veryhigh carbon steels are prone to surface corrosion no matter what we do to them. Lets face it, hobby engines are low volume so the steel used is going to in proportion to the final cost of the engine...</div><div></div><div>2) Poor quality methanol is being used</div><div></div><div>3) dirt /contaminant ingestion via the engines carb would be trapped in the crankcase and if there are salts i.e. flying in an area close to the ocean or salt pan or salt lake,</div><div></div><div>4) Copper ions from poor quality brass fuel tubing, brass clunks etc. I tend to use aluminium and steel components in my fuel systems."</div>

TFF 11-17-2012 07:20 AM

RE: Saito Rusted Guts = Lost RPMs?
 
New bearings and a clean job. With the rough stuff in there, the bearing is like a gravel road. It will erode other things too.

earlwb 11-17-2012 07:59 AM

RE: Saito Rusted Guts = Lost RPMs?
 
Yes replace the bearings. ARO may or may not work well as it needs to get into the cambox area too. Just squirting some in the intake on a four stroke engine doesn't lube the bottom end. Some folks squirt in a good amount of ARO into the engine via the crankcase vent.  After emptying the fuel tank or pull the fuel line off the engine, hook up the glow ignitor,  start the engine and let it run out any residual fuel left inside. Give it a few extra cranks too. Then use the ARO on it. 

High nitro content glow fuel and all synthetic oil tends to setup the engine for more corrosion. Living in a salt air environment or high humidty locale can also lead to corrosion.

I have had good success merely using no nitro or up to 5% nitro glow fuel in my engines. I also use a fuel with a blend of synthetic and castor oil so I get the best of both worlds, so to speak. Anyway, I do not bother with ARO and I can go years without having to replace bearings.

But there seems to be some incredibly unlucky fellows that just have no end of problems with the engines. You your engine experiences may vary.


mike early 11-17-2012 08:01 AM

RE: Saito Rusted Guts = Lost RPMs?
 
I just put a crankshaft that looked like that in antifreeze in a crockpot overnight. All the little bumps were gone. It's still a little rust-colored but I suspect some of the mess was castor deposits or something. There's no visible pitting. The engine had been sitting for many years. One of the rings had corroded tight into the groove. The engine probably would have run, but I am sure it would have been down on power.

What did your ring look like?

Campgems 11-17-2012 05:30 PM

RE: Saito Rusted Guts = Lost RPMs?
 
<div style="margin: 0in 0in 0pt">New bearings is a must. +1

On an engine with that rust, I would first clean things with Dawn Power Dissolver. That makes sure the red is really rust, not baked on oil. It also gets all the baked on oil off. It is not an over night treatment. It will eventually start to discolor the aluminum. For the rust cleanup, I like CLR. If the part is left in it to long, it takes a black oxide finish. Most of that can be cleaned off with s scotch bright pad.

The only issue with assembling a Saito is the cam timing is easy to get wrong as it is somewhat difficult to hold the timing while you are putting the cam housing back on the engine. I use a this piece of flat shipping container clear plastic. Even the stuff the use to hold the collars nice in new shirts. Take you digital calipers (every one has a set or two don't they?) and close them on the cam gear teeth. You want them to engage the gear at the bottom surface of the cam housing. Lock the calipers there. Then lay them on the piece of flat plastic and scribe two lined to the inside of the caliper. Use and Xacto knife and cut a segment out of the plastic along these lines. This is your timing tool. It works for all Saito cams. You set the dot to the bottom, and slip the U shape you just cut onto the cam. Make sure the gasket is between the U and the timing tool. Set the engine at TDC and drop the cam housing in place. Slip the U timing tool out from under the housing and your timing is set. Some of the Saito allow you to lift the cam follower out the top. In that case, you can simply use the push rod as a timing tool Remove the intake lifter. and drop the push rod in the hole. There is an oil hole on the cam and when the push rod engages the hole, it is in time for TDC. You can't get it off a tooth even though it is a loose lock. Either of these methods will work whith the engines that you can remover the lifters out the top.

A bit of white lithium grease on the cam and lifters, as well as the rocker pivots and push rod ends is a good idea. There isn't much oil that migrates up through the cam to the top end, so the cam, lifters and rockers are somewhat oil deprived.

Last, I've never been a fan of Cool Power. Ido like the Morgan Omega though.
Don</div>

apwachholz 11-17-2012 06:35 PM

RE: Saito Rusted Guts = Lost RPMs?
 
<div><span style="font-size: medium;">@Campgems</span></div><div>"There isn't much oil that migrates up through the cam to the top end, so the cam, lifters and rockers are somewhat oil deprived." - Camgems</div><div></div><div>This is what concerned me most. Not that there wasn't oil in the rockers but, that there was a lot of it when I removed the rocker covers. My intentions are to check all the gaskets (have replacements) and double check the crank case to ensure nothings messed up. Granted, I'd rather have oil in there then not but, the amount of oil seemed excessive. The investigation continues&hellip; :)</div><div></div><div><span style="font-size: medium;">@mike early</span></div><div>I'll have to inspect the ring this evening when I do a little disassembly. I picked up a rear bearing today (no front bearings in stock) so hopefully I'll be able to tear down and build up again tonight. When I've torn down other 4 strokes and typically the front bearing was found in pretty good shape so, here's hoping. Deets to come.</div>

mike early 11-17-2012 09:36 PM

RE: Saito Rusted Guts = Lost RPMs?
 
Best way I've found to confirm cam timing is correct is to temporarily install cylinder and pushrods without the piston or valve covers. turn the crank until both valves are open the exact same amount. the valve springs will hold it that position. turn the engine around and look at the crank. if it's at TDC, it's good to go. if it's closer to 11 or 1 o'clock, it's off a tooth or two...

ckreef 11-17-2012 09:48 PM

RE: Saito Rusted Guts = Lost RPMs?
 
Not sure about a FA .61 but I just rebuilt my FA .91. I made a cam timing tool and it keep the cam gear in the correct position for installation. Got the timing right 1st time I tried. Anywho you can check this out in the following thread and the Power Point presentation within that thread.

www.rcuniverse.com/forum/m_11279139/tm.htm



apwachholz 11-17-2012 09:51 PM

RE: Saito Rusted Guts = Lost RPMs?
 
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<div><span style="font-size: medium;">@mike early</span></div><div>I popped open the engine and after some mild finger scrubbing with water and Bar Keepers Friend, I removed a light residue from normal engine wear and tear. Once I washed the parts thoroughly and gave them a hefty after run oil rub-down, the piston and ring looked really good. Excellent! However, as I'm peering into the exhaust shaft, the valve is pretty coated in gunk. Looks like I'll be doing some cleaning...</div><div></div>

Sport_Pilot 11-18-2012 07:12 AM

RE: Saito Rusted Guts = Lost RPMs?
 


It's hard to tell from a photo, but that does not look like rust. I don't know how accurate the photo color is, but the color is too brown and not red enough to be rust. Also the surface is too slick. I think you are looking at castor varnish. However it could be covering up rust. I would soak it in some antifreeze overnight to see what it uncovers.</p>

apwachholz 11-18-2012 07:51 AM

RE: Saito Rusted Guts = Lost RPMs?
 
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<div>Its starting to come back to me how much fun this is. The crankshaft is concerning me because I'm having a hard time getting it out. Pulled out the butane torch, heated up the crankcase, attempted and got no movement. I'm worried it'll end up like my O.S. .91 where I couldn't get the bearing out at all and ended up purchasing a new crankcase. Kinda' frustrating...</div><div></div><div><span style="font-size: medium;">@Sport-Pilot</span></div><div>The 'damage' appears to be more varnish related like you said. But the crankshaft is pretty corroded (for my taste). I've got a Dremel and some soft tips so I'm going to polish off the parts with Bar Keepers Friend.Its been working fantastic thus far for removing all gunk.</div>

apwachholz 11-18-2012 10:29 AM

RE: Saito Rusted Guts = Lost RPMs?
 
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Before and after image of the crankshaft with steel brush and polish (Dremel tools). Got the thing out after hammering it on the concrete. That thing was IN there. Only bummer part is that my bearings are not nudging one bit....Arrrg.....http://www.rcuniverse.com/forum/js/f...msn/pirate.gif

mike early 11-18-2012 01:56 PM

RE: Saito Rusted Guts = Lost RPMs?
 
Worst case on the bearings is push/slam the front one out with a screw driver/rod with some propane heat.
Then the same technique in the other direction on the rear bearing. A perfectly sized socket and an extension is a good choice for the rear and the extension alone on the front... If the rear bearing opening is too small for an extension to pass through for the front bearing, I use a 1/4" sized extension and small socket.

How did you remove the thrust washer? I use a cheap tool I bought at Harbor Freight. If you don't remove the thrust washer, getting the crank out is a lot harder....

apwachholz 11-18-2012 08:21 PM

RE: Saito Rusted Guts = Lost RPMs?
 
<span style="font-size: medium;">@mike early
</span><span style="color: rgb(255, 0, 0);">[*embarrassed look on face*] </span>Well, I kind of didn't remove the the thrust washer (I'm assuming its the washer that the prop bumps up against?). I just got frustrated and gave the crankshaft a good whackhttp://www.rcuniverse.com/forum/js/f...sn/biggrin.gifI did have a small stack of post-it notes in between to avoid direct hammer cotact with the shaft. What tool do you use from Harbor Freight?I was able to get the front bearing out with a well sized wooden dowl, propane heat, and a few good hammer hits to the dowl. I think I'll look a the socket and extension for the inside bearing. Good call on that....
<br type="_moz" />

Old Fart 11-19-2012 04:47 AM

RE: Saito Rusted Guts = Lost RPMs?
 
I think sooner or later someone here is going to say hey toughen up princess,bolt that thing to an engine test bed with the needles right open and flick the prop some..:)

mike early 11-19-2012 05:12 AM

RE: Saito Rusted Guts = Lost RPMs?
 
It looks like this. But If mine came with 2 sizes, I've lost one. I don't remember it costing this much, but it's worth it, man. I have 7 saitos....

http://www.harborfreight.com/bearing...set-93980.html

MetallicaJunkie 11-19-2012 05:37 AM

RE: Saito Rusted Guts = Lost RPMs?
 

Quote:

ORIGINAL: apwachholz

<span style=''font-size: medium;''>@mike early
</span><span style=''color: rgb(255, 0, 0);''>[*embarrassed look on face*] </span>Well, I kind of didn't remove the the thrust washer (I'm assuming its the washer that the prop bumps up against?). I just got frustrated and gave the crankshaft a good whack [img][/img] I did have a small stack of post-it notes in between to avoid direct hammer cotact with the shaft. What tool do you use from Harbor Freight? I was able to get the front bearing out with a well sized wooden dowl, propane heat, and a few good hammer hits to the dowl. I think I'll look a the socket and extension for the inside bearing. Good call on that....
<br type=''_moz'' />
i've been scared myself a few times removing the crankcase bearings.....my last one i had to heat up the case with a torn till it was practically smoking, i then put on a welders glove and slammed the sizzling hot crankcase on a wooden bard and it came right out....

Sport_Pilot 11-19-2012 07:06 AM

RE: Saito Rusted Guts = Lost RPMs?
 
Yes the castor varnish tends to stick too and build up on a spot of rust. But that's a good thing as it helps prevent the rust from spreading. It does make it look worse than it actually is, however.

apwachholz 11-19-2012 08:26 AM

RE: Saito Rusted Guts = Lost RPMs?
 
<div><span style="font-size: medium;">@mike early</span></div><div>I like the tool set for the bearings and I think that's going to be the route I'll take. While it is somewhat expensive, it's a lot cheaper then damaging the engine trying to remove them without the proper tools. :)</div><div></div><div><span style="font-size: medium;">@MetallicaJunkie</span></div><div>LOL! http://www.rcuniverse.com/forum/js/f...sn/biggrin.gifYes, that is exactly what I did with one of my engines. Had to use welding gloves to hang on to the crankcase. After talking to a friend who's an engineer for Delta, he said they would throw items into an oven to heat it up, then dump liquid nitrogen on the bearing and hammer it out.</div><div></div>My version of that is putting it in the freezer (in a plastic bag next to the frozen peas) then pulling it out, heating the crankcase quickly (but not so much as to fracture it), and then pound out the bearing. it seems to work better then doing it at room temp.

mike early 11-19-2012 10:56 AM

RE: Saito Rusted Guts = Lost RPMs?
 
I use a propane torch and a glove and a block of wood. Rarely, do I need to resort to the socket-extension method, but then too, I heat the case and use a glove.

Upon re-assembly with new bearings, I sometimes put the new bearings in the freezer if they are not going in without more force than I like.

Once I used too much heat on a crankcase and it would not hold the bearings tight enough afterwards. I permantly fatigued the aluminum, or something

Edwin 11-19-2012 12:35 PM

RE: Saito Rusted Guts = Lost RPMs?
 
I use a battery cable puller to remove the prop hub. You can get them from Harbor Freight too. Looks like this but doesnt cost this much. I paid about $15 I think.
http://www.drillspot.com/products/67...read_And_Reach
Edwin

apwachholz 11-20-2012 09:00 AM

RE: Saito Rusted Guts = Lost RPMs?
 
<div><span style="font-size: large;">Question 4 All:</span></div><div>What are the tools of the trade for dismantling an rc airplane engine? For those who enjoy it or are just starting to get into it - a list of tools that others have used that work (and are reasonably affordable) would be a great resource. I'm talking from a wood block (size and thickness?) to more sophisticated items like a bearing removal kit would be really nice to have on hand.</div><div></div><div>I have:</div><div></div><div style="margin-left: 40px;">Wood Dowels</div><div style="margin-left: 40px;">Diameter's "to fit" for hammering out bearings. Wood for the fact that they won't damage your parts (e.g., crankcase)</div><div style="margin-left: 40px;"></div><div style="margin-left: 40px;">Butane Torch</div><div style="margin-left: 40px;">For heating up engine casings to expand them for easier bearing removal.</div><div style="margin-left: 40px;"></div><div style="margin-left: 40px;">Fire Extinguisher</div><div style="margin-left: 40px;">For obvious reasons. If you're gonna torch something, you'd better have a way to put it out if it gets out of hand!</div><div style="margin-left: 40px;"></div><div style="margin-left: 40px;">Welding Gloves</div><div style="margin-left: 40px;">For handling super hot items (e.g., bearings and casings)</div><div style="margin-left: 40px;"></div><div style="margin-left: 40px;">Wood Block or Thick Workshop Table</div><div style="margin-left: 40px;">I don't ever use a hard surface to pound on my engines. And when I do (e.g., concrete floor) I pad it with a towel or thick newspaper to avoid direct contact.</div>

mike early 11-20-2012 10:10 AM

RE: Saito Rusted Guts = Lost RPMs?
 
I use a 2x4 about a foot long on my work table for crankcase-slamming. I use just work gloves to hold the engine after heating it with a propane torch. I rarely need anything besides that. When I do, I use a socket extension or a nut-driver of the proper size...a wood dowel of the proper size would be great.

For Installing Bearings, I pad my bench vise with rags and find the perfectly-sized socket to press the rear bearing in, so it goes straight. I once installed a rear bearing a little crooked and that will be the last time I slip on that banana peel. The front bearing I also use the bench vise padded with rags to press it in flush with the front of the case.

apwachholz 11-20-2012 11:19 AM

RE: Saito Rusted Guts = Lost RPMs?
 
<span style="font-size: medium;">@mike early</span>
Ah...! A vice.... brilliant... I need to get me one of those...http://www.rcuniverse.com/forum/js/f...sn/biggrin.gif

mike early 11-20-2012 11:29 AM

RE: Saito Rusted Guts = Lost RPMs?
 
I sometimes heat the case a bit and/or freeze the bearings before installation, they sometimes merely drop into the correct position...


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