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Old Jan 06, 2013, 11:47 AM
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Yes, chromed cranks where available from I think it was Glenn Lee down in texas. I don't know if KK ever used them.

However, if you chrome the crank, the case has to be lapped to fit the slightly over sized crankshaft. So where does that leave us with this crankcase discussion???

I still use my lapped case, it is now about 38 years old. It also has milled mounting lugs to help with the "punched screew holes" (see the Eagle One article for that...)

George
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Old Jan 07, 2013, 10:31 AM
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Originally Posted by GeorgeG97322 View Post
...Have you lapped the backplate opening on the case yet. Often leaks ocure between the case and backplate. I also lap both ends of the plastic venturi body too.
George, I usually lay the back of the case on some 1000 grit on a piece of glass and give it a couple of twists, but never lapped the BP to the case. It had the radial mount type backplate on it on the plane, and a standard TD back on it on the test bench.

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Originally Posted by old4570 View Post
...See all those tiny imperfections trap oil [ lubrication ] and also = less surface area ..

Lap a crank into a case = less imperfection for oil , more surface area ...
I hadn't thought of it that way. That's a good point. I'm always afraid of taking too much aluminum off, especially since I don't know the history of any of my TDs. Plus I tend to be a bit ham-handed at times. I never seem to learn from that lesson.

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Originally Posted by aspeed View Post
I use 60,000 grit sandpaper, and no I don't know where to get any more. Some KK cranks were chromed back in the day.
60,000, wow, I thought 1000 was fine.

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Originally Posted by GeorgeG97322 View Post
...if you chrome the crank, the case has to be lapped to fit the slightly over sized crankshaft. So where does that leave us with this crankcase discussion???...
In that case I understand the argument for lapping the case.
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Old Jan 08, 2013, 11:42 AM
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I have used white car paint polish as lapping on the crank in the case.
It's fine, water soluable and fairly benign as to damaging the casting surfaces Slow work though. Chucking it in an variable speed drill can work well.... when used with intelligence..
Effectively sealing the engine can be by using 'Threebond 1211' sealant.
Very thin , watery sillycone type goop. Peels off in one piece even when microns thick.. V nice stuff.
Universally used in Factory race motorcycle engines..
~$20 a tube tho and not universally available.
Don't be too perf greedy, as TD cranks shear at ~25k rpms... far earlier if the socket isn't perfect.
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Old Jan 08, 2013, 01:48 PM
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...Don't be too perf greedy, as TD cranks shear at ~25k rpms... far earlier if the socket isn't perfect.
That shouldn't be a problem for me, I have no need to make it spin up that kind of speed. My Norvels take over the job when the need for speed arises. I just put a Big Mig on my newest Baby Streak. It's lighter than my older one too, so it should really go.
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Old Jan 08, 2013, 09:22 PM
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Yup.. I'm loving my Norvelsas well.
These are proving to be really nice/easy to live with motors. Shoulda bought some of these in early 90's when my brother first told me they were well worth owning.
But then who ever listens to family?
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Old Jan 09, 2013, 11:14 AM
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Yup.. I'm loving my Norvelsas well.
These are proving to be really nice/easy to live with motors. Shoulda bought some of these in early 90's when my brother first told me they were well worth owning.
But then who ever listens to family?
Good thing you're not family; you were one of a few trying to talk me into trying Norvels a year or two ago. I finally bit, and now I have three of them.

I still love my Tee Dees though. With my first Baby Streak I can go half way through a wingover and stand it on the end of the lines straight overhead and do a couple of tiny little loops before I bring it on over to the other side. It just has to be a perfectly calm day. That's my $32 dollar eBay .051, it's a little badass.
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Old Jan 09, 2013, 03:24 PM
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I like my TD's too, but there is a muffler rule at our club, so I am using my Norvels finally. It seems about the same power as the TD pretty much. I think I have to make a real 1/2A stunter or combat soon. I have a bunch of reedies to use up too but can't get motivated on them at all. Black Widows, and a reddish one etc. I pick them up at swap meets whenever they seem too cheap because they look so pretty.
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Old Jan 09, 2013, 07:41 PM
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I like my TD's too, but there is a muffler rule at our club, so I am using my Norvels finally. It seems about the same power as the TD pretty much. I think I have to make a real 1/2A stunter or combat soon. I have a bunch of reedies to use up too but can't get motivated on them at all. Black Widows, and a reddish one etc. I pick them up at swap meets whenever they seem too cheap because they look so pretty.
I got tired of messing with tanked reedies. The reedies with Killer Bee or product backplates are not so finicky and will run really strong, probably faster than any tanked Bee. Some of the product BPs had fine thread NVs too and they run really well on pressure bladders.

The thing about Norvels is they can have whatever power you need to make. The Big Mig .061 will swing a 6" prop at 17-19k but never bog, powering through an aerobatic pull like it never noticed, but not be too fast for a 7oz. plane. Or with a 5-1/2" prop at 23k rpm it will move the same plane near 100 mph, or muscle a big plane with no problem. With a 5-1/4" or 5" prop at 26-29k you'll have your hands full. Very versatile engines.
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Old Jan 09, 2013, 08:40 PM
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Some of the product BPs had fine thread NVs too and they run really well on pressure bladders.
.
I had thought that as well, thinking these might be an available / inexpensive source for bladder NVs' for my Norvels..but discussions with Bernie suggested I was mistaken... as all the Cox NV had same threads. Dunno frankly..
but I assumed, He of all people, would know his stuff.
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Old Jan 09, 2013, 08:55 PM
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Bernie is wrong on that one. I have never checked to see what the thread is. It looks very close to the 128 per inch on the KK needles.
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Old Jan 09, 2013, 09:37 PM
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I'm with Jim on this one... the KK needles were 128 TPI and one should remember that Dale Kirn worked for LM Cox as well as owning Kirn Kraft which became Kustom Kraftsmanship. Both KK's sold NV setups which were virtually the same and I have intermixed needles without any problems. I think the Ace NV which has a plastic collar uses the same needles as the KK's.

George
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Old Jan 09, 2013, 10:39 PM
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I think the stock Cox .049 needles are #4-80.
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Old Jan 09, 2013, 10:51 PM
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The KK needles fit the red backplate from the Cox Black Stuka engine. The needles even look the same. I also have an unknown white Cox backplate with the same threads. I screwed one in a couple of days ago just to see. I was thinking about making a remote NV.

Hank Nystrom at Texastimers sells a 128tpi NV that supposedly presses into a Norvel. I've been meaning to compare the measurements but haven't gotten around to it. He's still closed until Jan 11 or so. I think it would be easiest to just chuck the venturi in the box and put the new NV right through the holes in the engine. Bore them to fit and JB Weld it in place. They are splined too, so it should fit nice and tight. It might go into the hole where the old NV is. That way you'd still have the screen. A screen is good for me.
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Old Jan 10, 2013, 04:18 AM
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hmmm

A lot of TD mods come from the days when used engines and parts were plentiful and cheap !

Folk would mod and tune and the engines would scream , and maybe last 5 to 10 runs before something wore out or broke ..

Then they simply built a new engine , it was not uncommon to see TD fans with tool boxes full of parts , maybe enough parts to build several [ dozen ] engines . I remember one boast , where a writer boasted enough parts to build 50 engines .

Yes , some folks were serious about there TD's

These days , Id say you would most likely like to see more than 5 to 10 runs from an engine ..

A lot of the old time [ 70's - 80's mods ] are really not that suited to today's cost VS availability ..

By all means chrome the case where the shaft runs .. Dont over polish the chrome as the chrome is really ?? porous - lumpy - what ever , but great for minimizing surface area , offering a harder surface and better lubrication retention [ unpolished ]

If you have a good chromer , then they should be able to control the amount of chrome you lay down , a tenth of a thou should be plenty ..
If you have a few cranks of varying dia , to use , this would be best .

Find one thats just about right after chroming , and run it in with some 30% oil fuel , maybe 10 minutes , then another 10 minutes on 25% and then 10 minutes on 20% Dont lean out the engine , you want the shaft swimming in fuel [ lube ]

After this the high spots on the chrome should be gone or minimized ..

Now , check shaft fits again , and build the engine as you would a new one ..

Again everyone has there own way of doing things , and there are many right ways of building engines , the wrong way is when it does not work

And the way to learn to do things the right way , is to eliminate all the wrong ways of doing it ...
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Old Jan 10, 2013, 10:40 AM
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I made some brass sleeve bushings for a few worn out Baby Bees that wouldn't run reliably any more. The cranks would rock up and down after a while, and we practised a lot with the mouse racing. Talk about wasting time with the bushings, you get the tolerances just right and lapped, press it in the crankcase with a .001 interferance fit, and the you have to lap it again. We had to run the B Bee though, them's the rules. We used to drill out the backplate hole to go faster, and then you would need an extra pitstop etc.
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