Rudolph Hart

Hello fred dave and popey are right,they don't wear unless you do something really silly.Hard chrome barrel and valve seats so don't be tempted to "grind" those either,they'll outlast you.Same as a nikasil coated two stroke barrel if you like.

SrTelemaster150

One can use a very mild abrasive like toothpaste to help clen up the valve faces W/the seats. The toothpaste will clean the surfaces & perhaps dress up the softer valve surfaces, but it will ot affect the hard chromw valve seats.

The toothpaste cleans up completely W/water.

blw

My Feedback: (3)

You *can* do those things, but it sure is better to not do them unless you have the excessive damage/wear and no money. Just an opinion but I'm with Dave and OF on this.

SrTelemaster150

Toothpaste will not harm the seats. It will merely clean them & burnish the valves..

Fred L

My Feedback: (2)

i don't have any loss of compression, i just wanted to do something with the piston ring that comes in the rebuild kit. i guess it's kinda like those ABC cylinders ( aluminium, brass, chrome), i think the OS 46 fx was like that. best in that case to just leave well enough alone. i have honed some gas airplane engines with brake hones, worked pretty good. i know that just replacing the ring and not the cylinder would probly be a worse condition. i have polished cd's with toothpaste....very cool trick, and it probly could be used as a lapping compound. Hmmm....wonder if i could use the ring in my nose?

Cougar429

My Feedback: (3)

Unless there is unusual wear in the bore I would simply install the new ring and do a standard break in procedure. If there are signs of excessive bore wear then a new cylinder is in order in any event.

Depending on the gen of the motor I would also avoid touching the valve seats. The earlier Saitos used plating on the alloy head material and they were never to be touched up. If you tried the plating would come off and you would then be running the valve directly on the alloy. This would likely be a recipe for short life expectancy. I believe one of the easiest ways to determine if it is the earlier generation is those had metal throttle arms. This may not always be the case as the newer plastic throttles were a direct swap.

The newer gen Saitos have brass insert valve seats and I believe those can be polished.

p.s. With the hardened liners in some of our Fox engines you could expect to install several rings before the liner would have to be replaced. Each new ring required a break in as with new, but took a while.

Ernie Misner

Didn't Bill Robison once say he would spin a round pencil eraser in the valve seats with his fingers just to clean them up?

If I run out of toothpaste can I brush my teeth with valve grinding compound?

Thanks,

Ernie

Rudolph Hart

You can certainly try that one ernie,please let everyone know how it went..or you could be lazy by walking into the bathroom without bothering to turn the light on first.That's when you get to spray shaving cream under your armpits.

Hobbsy

My Feedback: (102)

Ernie, that's exactly what WR said.

lopflyers

My Feedback: (12)

[quote]ORIGINAL: Fred L

i have recievers in about half, it's a mixture of 2.4 and fm. i bought two storage sheds 24' x 12' that i keep em all in. Just bought a rebuild kit for my Saito 91 , paid $31 on ebay. it says it has both bearings, all gaskets, carb rebuild, piston ring, and the rubbers at the top of the pushrod tubes. The front bearing was leakin some oil so i figured why not, i'll have to take most of it apart to get to the front bearing anyhow. My question is what is the best way to hone the inside of the bore, do i just wrap some sand paper around my pinky? i would think i need to hone it if i'm installing a new piston ring. last month i refreshed some of the batteries in a few planes, bought 12 -2200mah nimh 5 cell batteries.... they said free shipping on orders over $50!
[/quot

wow, i have a friend in one of the clubs that o fly from that have 110 planes. He even have a webpage.
I have 7 And my wife complains

SrTelemaster150

The idea that the mild abrasives in toothpaste could damge a hard chrome valve seat seems a bit absurd.

lopflyers

My Feedback: (12)

My wife thinks I'm addicted and she's tried to get me to see a shrink. I made an appointment but, she canceled it when she found out he was into RC planes too.


RJ

[/quote]


So true, there is a shrink that flies with us. He evens gives advise to people over the phone in front of us.

captinjohn

Ernie....it looks like you posting just to have something to do. Go flying or work on your airplane equipment.............

rich6170

Saito's?
Hmm I currently have 54 airplanes..... saito 300 twin for my Giant F4u Corsair.. 150 on my GiantBigStick ... 180 on the 1/4 Sopwith Pup.....170 Triple radial on my 1/4 Fokker DR1.....120 on my VenusII.....and I am working on a 14ft wingspan B24 Liberator that I have 4 91's for....Oh and I have a 72 on a Great planes .60 Cub.... Do I qualify for the club?? Come to think of it all my 4 stroke engines are Saito's...in fact they are all Golden Knights except the 120 in the venus. As my GF says.. they are petty!!!!!
Rich

rowdyjoe

My Feedback: (9)

What ever you do, turn the light on. I made that mistake once and got my viagra confused with my rogain. Ihad plenty of hair but, it was so stiff I couldn't comb it.

RJ

Rudolph Hart

Now that's how i'd describe a brainwaveif you ever buy shaving cream in it's tube form you can end up brushing your teeth with it by mistake,you're in the dark of course until the mistake becomes painfully obvious,over to you ernie

SR you did say abrasive in your post,can't go that well on chrome can it? or is the hardness level much different than your average old bumper bar on a car.

Fred L

My Feedback: (2)

It was my gf that suggested i get the Sukhoi, she must have thought i was in the dumps. Next time you want a plane do like me......pout~!

SrTelemaster150

Isn't that how the female gender usually operates?

Rudolph Hart

Don't be silly,we are capable of doing anything it takes to get the aeroplane you need for the sweetest sounding saito you ever heard,now that's livin

SrTelemaster150

If it won't harm the soft plastic of a CD I don't see how it could harm a hard chrome valve seat.

captinjohn

If toothpaste would damage a crome surface....I sure would like to see that....how about a photo ....from the guy that stated that!!!!!!

PacificNWSkyPilot

My Feedback: (19)

Maybe toothpaste delivered by way of some sort of a power tool. Otherwise, it would take you most of the day and WHOLE LOT of toothpaste. I think the rag or whatever you're applying it with would have just as much in the way of abrasive qualities, if not more.

There's a kind of toothpaste, used by Dental hygienists, called prophy paste. That actually has pumice in it. You could lap a valve with the heavier version of that stuff. That's why you have to rinse out your mouth (or why they rinse it out for you, depends on the dentist), and why you feel little bits of grit afterwards.

But regular toothpaste has not had pumice in it for decades now. Bicarb of soda, stuff like that. Nothing truly abrasive.

And yes, I am an expert witness when it comes to this.

~ Jim ~

blw

My Feedback: (3)

The point is that nobody ever said that. Go figure.

PacificNWSkyPilot

My Feedback: (19)

Hmmm.

lol

Never mind. . .

~ Jim ~

SrTelemaster150

You apply the toothpaste to the valve face, insert the valve into the guide & use your fingers to rotate the valve from the outside in a pulling, spinning motion. I does not "grind" or "lap" the valves as much as it cleans/polishes the surfaces thouroughly removing stubborn varnish.

Water cleans up all traces of the toothpaste.

We used to use toothpaste to burnish brass gear cogs in slot cars way back when. You could get the gears meshing so smoothly that they were nearly silent. The noise from the raw gear teeth was energy lost. The quieter gears allowed more power to go to the wheels.

There are still mild abrasives in tooth paste. The harsh abrasives were removed way back in the '60s.