Welcome to Club SAITO !
10-21-2019, 03:17 AM
Ok Dave, if true I'll edit my post. If no chrome on the seats then why all the cautions about lapping them? I've read in more than one thread that it's ok to lap bronze seats but not ok to lap the aluminum seats because they are chromed. Bad info?
Last edited by Glowgeek; 10-21-2019 at 03:24 AM.
10-21-2019, 03:40 AM
Bill Robinson says the AAC cylinders have a thin chrome plating over the aluminum seats. He had a pretty good idea of what Saitos are all about.
http://www.rcuniverse.com/forum/glow...l-robison.html
http://www.rcuniverse.com/forum/glow...l-robison.html
10-21-2019, 03:41 AM
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Lower left by Clarence Lee, I think.
Personally, I never lap lap any of them, I have yet to see one that needed it. I've seen plenty of high time engines. Note compression ratio, it's the one I have.
10-21-2019, 03:44 AM
Ok you calculating people out there I came across a whole bunch of fuel a while back. Most of the fuel is 22% oil. And 30 % nitro. I would like to cut the nitro in half by blending methanol with the fuel. How much oil do I need to add back in to bring the oil content back up to 16%?
10-21-2019, 03:55 AM
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Bill Robinson says the AAC cylinders have a thin chrome plating over the aluminum seats. He had a pretty good idea of what Saitos are all about.
http://www.rcuniverse.com/forum/glow...l-robison.html
http://www.rcuniverse.com/forum/glow...l-robison.html
Us friends of his lovingly called him Way Out Willy, he missed the boat on that one. I think I have a busted 150 cylinder to saw apart, Gary may have one sawed apart already.
10-21-2019, 03:55 AM
Dave, sure the seats are machined directly into the casting on later AAC cylinders as noted by Lee. The question is whether or not Saito machined the seats before or after chrome plating, surely before plating, and whether or not they masked off the seats/chamber before plating....I doubt they did. I think the general consensus is that the aluminum seats are plated along with the rest of the cylinder wall.
PS, I could be wrong on this subject along with most others out there with the same opinion and I would have no problem admitting it, as you all know. If there is no chrome on the aluminum valve seats because Saito has deemed it unnecessary I have an 82 that I would love to lap a little. The exhaust seat has never been right on that one.
PS, I could be wrong on this subject along with most others out there with the same opinion and I would have no problem admitting it, as you all know. If there is no chrome on the aluminum valve seats because Saito has deemed it unnecessary I have an 82 that I would love to lap a little. The exhaust seat has never been right on that one.
Last edited by Glowgeek; 10-21-2019 at 04:16 AM.
10-21-2019, 04:29 AM
Like this 125 I have it’s missing. Like prop nuts man they don’t get sent with the engine vary often. Tru Turn is going to love me before long.
10-21-2019, 05:24 AM
For many years I had assumed the AAC Saito seats were plated. (Based on Silly Willy) Had not even given it much thought. Had I thought about it, I would have had doubts. In fact they are not.
Yes, I have and still do resurface the seats. I use a Comet Cleanser paste for fast cutting and Simichrome metal polish for fine finishing. For general light clean up I have always used a rubber pencil eraser, often with a touch os Simichrome.
Yes, there are many cases where the lapping has saved an otherwise doomed cylinder. I prefer to use a dummy valve made from hardened drill rod for tougher jobs or perhaps a throw away valve. Too much lapping will cut a groove into the valve. Do the light finish work only with the valve that will be used in the running engine.
The valve action itself tends to hammer form the seat and work harden it at the same time.
Yes, I have and still do resurface the seats. I use a Comet Cleanser paste for fast cutting and Simichrome metal polish for fine finishing. For general light clean up I have always used a rubber pencil eraser, often with a touch os Simichrome.
Yes, there are many cases where the lapping has saved an otherwise doomed cylinder. I prefer to use a dummy valve made from hardened drill rod for tougher jobs or perhaps a throw away valve. Too much lapping will cut a groove into the valve. Do the light finish work only with the valve that will be used in the running engine.
The valve action itself tends to hammer form the seat and work harden it at the same time.
10-21-2019, 05:53 AM
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For many years I had assumed the AAC Saito seats were plated. (Based on Silly Willy) Had not even given it much thought. Had I thought about it, I would have had doubts. In fact they are not.
Yes, I have and still do resurface the seats. I use a Comet Cleanser paste for fast cutting and Simichrome metal polish for fine finishing. For general light clean up I have always used a rubber pencil eraser, often with a touch os Simichrome.
Yes, there are many cases where the lapping has saved an otherwise doomed cylinder. I prefer to use a dummy valve made from hardened drill rod for tougher jobs or perhaps a throw away valve. Too much lapping will cut a groove into the valve. Do the light finish work only with the valve that will be used in the running engine.
The valve action itself tends to hammer form the seat and work harden it at the same time.
Yes, I have and still do resurface the seats. I use a Comet Cleanser paste for fast cutting and Simichrome metal polish for fine finishing. For general light clean up I have always used a rubber pencil eraser, often with a touch os Simichrome.
Yes, there are many cases where the lapping has saved an otherwise doomed cylinder. I prefer to use a dummy valve made from hardened drill rod for tougher jobs or perhaps a throw away valve. Too much lapping will cut a groove into the valve. Do the light finish work only with the valve that will be used in the running engine.
The valve action itself tends to hammer form the seat and work harden it at the same time.
I dunno if this says anything, but the seat is not shiny like chrome would be.
10-21-2019, 06:59 AM
Don't be embarrassed! Like I said, I had said and treated them as plated for years. Actually defied common sense. The heat and impact would delaminate most any plating. I figured Saito must have had an advanced process of some kind. I should have known.
10-21-2019, 08:01 AM
Is there a source for Jam and prop nuts and thrush washers other than Horizon? I have tried doubling up nuts and using washers from Ace Hardware but success has been spotty at best.
10-21-2019, 08:31 AM
Google "Class 10 Metrix Nut" in whatever size you're interested in. I get them for 25-35 cents a piece. I don't have any of those special two piece prop locking nuts, none of the preowned engines I bought came with them.
10-21-2019, 10:26 AM
I know most feel little incentive to lay out a few dollars in cash or perhaps allot some space, but a lathe is a surprisingly useful resource. Often cost less than putting a medium trainer in the air, they run for a lifetime and open up a new world of opportunity to supply useful, unique parts and devices to enhance the hobby.
I cannot remember the last time I had to buy a prop nut. I get a perfect fit every time. Metric hex stock is cheap and a bar lasts for many parts. Jam nuts and flare nuts at a moments notice. No waiting for mail order, no trip to the hobby shop. And parts that you cannot buy anywhere else.
Bearing installation mandrel
Vent elbow
Various elbows
The quiet muffler
Brass prop nut
Lathe turned velocity stack and a screwdriver locater for the idle needle.
Custom muffler
And , yes, a custom spinner nut. One of dozens, including custom lock nuts.
Metric hex stock from Metrics Unlimited.