Author Topic: Squint Scale Curtiss Model K Aero I4  (Read 23336 times)

Offline Dave Otto

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Re: Squint Scale Curtiss Model K Aero I4
« Reply #300 on: June 14, 2024, 10:41:17 PM »
Nice work on the plugs Ron!

Dave

Offline RReid

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Re: Squint Scale Curtiss Model K Aero I4
« Reply #301 on: June 15, 2024, 12:46:55 AM »
Quote
I pressure test my plugs with the shop air compressor, about 8bar. I found I had cracked the Corian on a couple of swaged plugs.
That comment definitely upped my incentive to do the test. The first plug (the one in the previous pictures) passed with flying colors. The second one finished does make a few bubbles. I think I made the fit of that insulator to the body just a little to sloppy. Learning curve.

Quote
I assume the swaging helps grip the electrode to keep it from being pushed out from combustion chamber pressure too. 
I hoped it might, but doesn't seem to. The wire electrode (0.032” music wire) didn't fit the second plug as nicely as it had in the first one. The swaging didn't change that at all. I have plenty of  that wire, and am hopeful to find a bit that gives a snug fit. Otherwise the JB Weld may have to come into play after all.

I did break-off one of the teensy #67 drill bits inside an in-process insulator. The flutes quickly fill up with Corian swarf, which proved annoying to clear, having to pick it off with the tip of an X-acto knife. I started putting a bit of soap on the drill, which helped a lot, keeping the swarf from “sticking”. Learning curve.

Dwulfe, Kim and Dave – Thank you guys!
Regards,
Ron

Offline stevehuckss396

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Re: Squint Scale Curtiss Model K Aero I4
« Reply #302 on: June 15, 2024, 01:45:09 AM »
Those are nice looking spark plug parts there, Ron!

Too bad about Steve Huck's spark plugs.  Did he stop making spark plugs completely?  Or did he just stop making the 10-40 ones?  Hope he's doing OK.  Haven't heard from him here in a long time.

Kim

I'm good! Just stopped making plugs. Tax laws changed and made it impossible to do.

I'm still tinkering with small engines, acting as president of the Metro Detroit Metalworking Club,  and working on and building anything that the granddaughters thinks is fun.

If anybody needs to make plugs I can provide drawings for many sizes and electrode configurations
Do not be like the cat who wanted a fish but was afraid to get his paws wet.

Offline RReid

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Re: Squint Scale Curtiss Model K Aero I4
« Reply #303 on: June 15, 2024, 02:06:43 AM »
Thanks for checking in Steve! :cheers:
Would you be willing to post your drawings in the plans section here? If so, that would be a great resource!
Regards,
Ron

Offline stevehuckss396

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Re: Squint Scale Curtiss Model K Aero I4
« Reply #304 on: June 15, 2024, 10:54:42 AM »
I would have to sit down and put together a multi page PDF file. I have . . .
#6-56 conventional and surface discharge
#8-40 conventional and surface discharge
#10-40 conventional and surface discharge
1/4-32 conventional, surface discharge, and side fire.
Then I have different insulators for the 1/4 inch plugs. Tapered with the standard cap. Also have a straight insulator with smaller brass cap so a boot can be used.
4 boot sizes.
I can also detail the tools I use. Might take a few weeks!

I am going to the show in Indiana and will bring some with me. I can probably part with a few and also answer any questions about making them.
Do not be like the cat who wanted a fish but was afraid to get his paws wet.

Offline RReid

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Re: Squint Scale Curtiss Model K Aero I4
« Reply #305 on: June 15, 2024, 05:03:40 PM »
That's a substantial body of work and intellectual property. Whether, when, and how much you decide to post is of course entirely up to you, but any that you do choose to contribute will be very much appreciated! Even the simple drawings you had posted on your website are of value (I have those, but others may not).

Sounds like you have no shortage of things to keep you busy! :ThumbsUp: :cheers:
Regards,
Ron

Offline RReid

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Re: Squint Scale Curtiss Model K Aero I4
« Reply #306 on: June 16, 2024, 06:13:07 PM »
For scale. The NGK is out of our '67 VW. The RMRs have all passed both the pressure test and the spark test. :pinkelephant:
Happy Father's Day to all those who are Fathers! :cheers:


Regards,
Ron

Offline cnr6400

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Re: Squint Scale Curtiss Model K Aero I4
« Reply #307 on: June 17, 2024, 02:28:02 AM »
 :ThumbsUp: :ThumbsUp: :ThumbsUp: Great looking family of spark plugs! Were they having a picnic for Father's Day in your picture, sitting on a plaid blanket?  :Lol:

Glad to hear the little ones passed the testing.  :cheers:
"I've cut that stock three times, and it's still too short!"

Offline Art K

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Re: Squint Scale Curtiss Model K Aero I4
« Reply #308 on: June 17, 2024, 02:54:12 AM »
Ron,
Great work on the spark plugs! Steve the Indiana show is on the wrong weekend. We did an anniversary weekend once, and that was enough.
Art
"The beautiful thing about learning is that no one can take it away from you" B.B. King

Offline RReid

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Re: Squint Scale Curtiss Model K Aero I4
« Reply #309 on: June 17, 2024, 04:55:09 AM »
Quote
Were they having a picnic for Father's Day in your picture, sitting on a plaid blanket?  :Lol:
Thanks CNR. Yes, a picnic stop on the way to the annual family reunion in Sparks, Nevada.

Thanks Art!
Regards,
Ron

Offline stevehuckss396

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Re: Squint Scale Curtiss Model K Aero I4
« Reply #310 on: June 17, 2024, 03:04:14 PM »
Ron,
Great work on the spark plugs! Steve the Indiana show is on the wrong weekend. We did an anniversary weekend once, and that was enough.
Art

That's what you get for not having a June wedding!
Do not be like the cat who wanted a fish but was afraid to get his paws wet.

Offline Roger B

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Re: Squint Scale Curtiss Model K Aero I4
« Reply #311 on: June 23, 2024, 08:01:39 AM »
Nice work on your spark plugs  :praise2:  :praise2:

Did your spare not pass? It would be useful to have an extra one or two in case you have problems when running the engine. ( I suppose you could always borrow the one from the Upshur or test them in that engine).
Best regards

Roger

Offline RReid

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Re: Squint Scale Curtiss Model K Aero I4
« Reply #312 on: June 23, 2024, 03:34:13 PM »
Thank you, Roger.

I somehow managed to bore one plug just a hair off-center, so that the wall to be swaged over was almost foil thin on one side. So, as both a save and a test, I did the JB Weld treatment on that one. In the end it did pass both the pressure and the spark test, so is available as a spare, as well as the original Steve Huck plug from the Upshur.
Regards,
Ron

Offline RReid

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Re: Squint Scale Curtiss Model K Aero I4
« Reply #313 on: July 12, 2024, 02:59:30 AM »
In between lots of interruptions, engine starting trials have begun. In other words the problem solving/trouble-shooting has begun.

The first thing to show up was that the restricted valve opening (caused by poor engineering) may be a problem. I commented on this possible problem child back in post #171:
“The other piece of royal fubar here is that way back in the design process I completely overlooked accounting for the fact that the rocker arms are asymmetric, with the pushrod side being longer than the valve side relative to the fulcrum point. This means that the actual valve lift is less than the lift of the pushrod at the cam. Being a low speed, low power engine, I think (hope) I'll still be OK here. There isn't room to increase the cam lift anyway, so it will have to be what it is. “

I have cams designed for direct action but a mechanism that includes an unaccounted for “rocker ratio” that reduces the actual valve lift.  Higher lift cam lobes could address this, but would contact the edges of the crankcase. So I addressed the issue by first making two new L-shaped pushrod clevis's that attach to the rocker at a point in-line with the intake valve rather than out at the end of arm as on the prototype. I installed these on cylinders #1 and #4. The one on #4 can be seen below, with the original style still in place on #3 behind it. Other than the new hole for the pin the rocker itself is unchanged, so the whole thing is reversible (say for display purposes), but I now get the full, intended valve lift.


With this modification I'm now getting somewhat consistent “pops” on #1 at least, and maybe occasionally #4. Enough encouragement to add the same mod to #'s 2 &3.

The other potential pothole I see is the intake log. It's asymmetric design, with the carb near #1 and a long run down to #4 has always bothered me, though it mimics the prototype pics I have. I also worry that it's volume is too great for good intake draw. I think a lot of fuel just pools in there. But one thing at a time.

I did also take time to add a one-way bearing to my cordless drill starter dog. For $13 (plus shipping) why didn't I do that way back when I was trying to get the Halfa started? :headscratch:
Regards,
Ron

Offline Roger B

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Re: Squint Scale Curtiss Model K Aero I4
« Reply #314 on: July 12, 2024, 07:40:25 AM »
That's a neat fix to the valve problem  :ThumbsUp:  :ThumbsUp:  :wine1:

Good luck with the starting trials  :wine1:
Best regards

Roger

 

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