Ford 300 Inline Six

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mayhugh1

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Terry, what are the holes or divots in the ends of the HSS cutting tools in your ring cleaver.

Thanks.

Chuck
Chuck,
They are divots. The adjusting screws move the cutters forward, but since they're not spring loaded some method is needed to pull them back. The divots provide a place to grab them. The one in the top cutter really isn't needed, but the bottom one is used after cleaving (if that's even a word). - Terry
 
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Terry, have you tried the Chaddock method, in which the last operation on the rings is a shave off the OD to final size?

IMHO that would eliminate the preliminary heat treatment, blank roundness, light testing, and much of the high scrap rate.
 

mayhugh1

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Terry, have you tried the Chaddock method, in which the last operation on the rings is a shave off the OD to final size?

IMHO that would eliminate the preliminary heat treatment, blank roundness, light testing, and much of the high scrap rate.
Charles,
I tried that technique more than a dozen years ago on my very first engine - the Howell V-twin. I was just learning to machine at the time and don't recall the details right now, but I do remember struggling with its fixturing requirements. I shifted over to Trimble's method on my next engine. I probably need to take another look at it. Plenty has changed since those days. - Terry
 

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Here you are, straight out of the dictionary.
Cheers
Andrew
 

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mayhugh1

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Piston Rings Part 2.

The Trimble articles describe the construction of a special purpose fixture required to support the rings during their heat treatment. Equations were provided for the dimensions of a mandrel and spreader dowel which are its key components. This fixture isn't difficult to make, but its dimensions are specific to a particular ring diameter, and this one was my fourth.

In the past, I've enclosed the fixture'd assembly in an argon-filled stainless steel foil bag order to protect the rings from scale deposits during heat treatment. After a number of builds I realized that scale build-up really wasn't a problem in the controlled temperature environment of an oven, but mysterious deposits continued to show up on the rings even when they were bagged. Typically, minor burnishing with a white Scotch Brite pad was enough to remove them while still supported on the mandrel.

Initially I suspected the deposits were lead coming out of the 12L14 that I typically used to machine the mandrel, but switching to 1020 didn't eliminate them. I didn't bag the Ford rings, but I machined the fixture from 303 stainless and thoroughly cleaned it and the rings with acetone before heating.

The fixture'd rings were heat soaked at 975F for three hours and allowed to cool overnight. Those pesky black deposits showed up again but only on the rings themselves and the spreader dowel which was a length of drill rod. The stainless steel mandrel, bolt, and nuts remained clean and shiny. This makes me wonder if those deposits are actually carbon coming out of solution from the cast iron and, this time, also out of the high carbon alloy of the drill rod.

Although they were easily burnished from the ring surfaces while still on the mandrel, this time the rings were stuck fast together. This wasn't at all unusual, but in the past the rings were easily separated with a sharp Xacto knife (starting from the ring gap). I didn't account for the rings' smaller areas when I tightened the mandrel bolt to clamp everything together, and this time probably got it too tight. Eventually, I got them apart, but I had to reheat the stack (sans mandrel) to 400F to do it.

After separation, their faces were lapped one last time on a glass plate using 1000 grit grease. After a thorough cleaning in solvent, their outside surfaces were individually burnished with a Q-tip in a lame attempt to polish them free of any remaining deposits.

The final step was to sort the rings by light testing them. A simple fixture was turned from black Delrin to adapt a 200 lumen flashlight to the bottom end of the spare liner inside which each ring was checked. Admittedly, my grading/acceptance criteria is pretty subjective, but it's kept particularly poor rings out of my engines.

The tests were done in a totally dark room where, ideally, light should only be seen escaping through the ring gap. Such rings received an "A" grade and will become the top compression ring in each cylinder. With all the machining and measuring uncertainties that can creep into the numerous process steps while trying to work within tenths, A's can be tough to get. Out of 23 rings, I wound up with only 6.

Rings that showed faint wisps of light leakage between the ring and cylinder wall were graded "B". My guesstimate is that the imperfections in these rings were due to circularity errors on the order of a few tenths and might even be a result of remnant deposits. These rings will likely bed into their cylinders during the first few several seconds of running (or maybe even during starting). I wound up with 8 of these, and they're destined for the pistons' second groove.

The "C" rings were saved as spares. Relative to the B rings, their leakages were noticeably brighter and were perhaps due to circularity errors that slipped through my process. More likely, however, they're a result of mishandling after being sliced from the blank. I wound up with 9 of these.

I should add that none of these C rings showed enough leakage through the ring'd test cylinder to be seen in daylight only. Whether or not they would have been 'good enough" for use is anyone's guess, but their grade will keep them out of the engine unless there's an installation catastrophe with the A's and B's.

Since I had more than enough A and B rings to cover my needs (and since I really don't enjoy making rings), the number one blank wasn't processed any further. The finished rings will be installed when the head is finally assembled to the block.

I have to say that even though the quality of the starting blanks was on par with what I've come to expect during my other builds, the quality of the finished rings was disappointing. Out of 23 completed rings, I expected to have some 15 A's and maybe 1 or 2 C's. My relatively poor yield may have been related to the tiny dimensions of these rather fragile rings. Compared with the hundreds of 1"+ rings I've made, these smaller more flexible rings were difficult to work with and seemingly more susceptible to handling damage especially while removing those #@% deposits. - Terry

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minh-thanh

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Hi Mayhugh1 !
I think...maybe this affects your ring
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When I fix the rings on the fixture, I usually press lightly - Bolts just keep the rings in place. then, the surface of the rings is usually flat before and after firing - or at least nearly flat . And it seems to make the rings better
 
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dnalot

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When I built my Holt I made my rings as you did and I made an interesting observation. Before heat treating I wrapped the rings with thick paper and secured it with scotch tape. I then covered the fixture with the rings with very fine "olivine" sand to help reduce the oxygen around the rings. I figured the paper would use up whatever oxygen was near the rings. The area that was covered with paper and scotch tape had very little carbon build up and it was these rings that turned out best.

Mark T

ring fix.jpg
 

Rustkolector

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Brownells sells a water based anti scaling coating that I have used with success. Its hot working range is 1000 -2300 F which is probably close enough to your heat soak range. When used the rings come out a uniform gray color after washing in hot water.
Jeff
 

L98fiero

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Brownells sells a water based anti scaling coating that I have used with success. Its hot working range is 1000 -2300 F which is probably close enough to your heat soak range. When used the rings come out a uniform gray color after washing in hot water.
Jeff
Here is a formula I got off a blade forum, can't remember which or I'd give the poster credit.

5oz boric acid (roach powder)
3oz borax ( 20 mule team is fine)
8oz denatured alcohol ( the cheap paint store variety, not the drug store stuff)
2oz satanite ( our old refractory friend)
3-4oz ocher (any color ocher - finely sifted dried red clay would probably work)
3-4oz gum tragacanth ( bottle of leather edge dressing)
water

Mix,adding additional alcohol until it becomes a well mixed thick paste.Add water until it becomes a slurry ( I think it needs some water to allow proper hydration and solution of some ingredients). Try it on a piece of steel to check results, and adjust the ingredients as needed. Keep in a tightly capped container,away from heat. Shake well each use, and paint it on with a small brush, or dip the blade and let the excess run back into the container. A batch should last for a long time.

Do not use above 1600F as the borates will become corrosive.
 

mayhugh1

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The bell housing should be a fun part to machine and, never having done one before, I've been looking forward to it. My hope since the beginning of this build has been to replace the faux starter in the original design with an electric motor.

My quarter scale Knucklehead's cranking requirement of 320 oz-in (23 kg-cm) was handled by a geared motor running through a one-way clutch. That motor was large for the scale of the engine, but a significant portion of it and its running gear were hidden inside the crankcase. Assuming a similar requirement for the fifth scale Ford and a 4:1 gear reduction from its ring gear, the motor would need to supply some 80 oz-in or 6 kg-cm.

A standard 22 mm (dia.) dc motor would be a perfect fit on the Ford, and George's bell housing could be easily adapted to it. However, published data on these motors show their torque to be hopelessly low even at stall.

A 390 size motor which is a little large for the engine's scale is the biggest I'd want to mount on its bell housing. Unfortunately, data on these motors show their torque is too low as well. However, there are some intriguing Youtube videos showing the (now defunct) Conley quarter scale V-8's being started with what might be a 390 brushed motor. I haven't been able to get an accurate enough estimate of its diameter to be really sure though.

A 550 or 750 size motor could be made to work, but their huge diameters would look out of place on the engine. A motor this size would be best hidden under the engine's display stand while driving it through a chain and sprocket. I spent nearly two weeks trying to come up with a configuration I'd be willing to live with, but in the end decided I'd rather drill-start the engine than mount it on top of a box.

Robotic parts suppliers (as well as Jameco), provide speed-torque data for their motors to help customers make informed selections. There's also an industry that supplies motors to RC enthusiasts that have been performance tuned using the armature wire gage. These suppliers use the actual number of wire turns on the armature segments of their brushed motors in order to compare them. I haven't a clue as to how to convert Turns to oz-in.

I ordered a couple of these 'performance' 390 motors to just try them. I chose 24 and 32 Turn motors for a relative comparison. I figured the best motors would be those marked with warnings about not being toys and cautions about dangerous hot surfaces.

Orders for 'in stock' motors were placed a few months ago from two different domestic suppliers. These motors are all manufactured in China, and so the first thing I received was schooling about a new definition of what 'in stock' can mean nowadays. After a few weeks I inquired as to why the motors hadn't shown up and was told their 'in stock' motors were in stock 'in the supply chain.'

Eventually they arrived, but before starting on the bell housing I wanted to do some testing. I did machine the engine's flywheel, however, and to be safe included both a ring gear and a socket for a drill starter. For my ballpark testing, each motor under test was fitted with a pinion gear, and both it and the flywheel were mounted to a heavy plate.

in the first test, the 83 tooth flywheel was driven by the 32 turn motor fitted with a 20 tooth pinion gear. I powered the 7.5 volt motor with a 12 volt sealed lead acid battery, and the test was performed by using the motor to lift a dead weight attached to the flywheel. The measured stall torque referred to the motor's shaft turned out to be 96 oz-in. This was a healthy although unsustainable improvement over the 20 oz-in typically advertised for 390 motors but was an indication that a 390 motor was not going to work.
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Another seat-of-pants test was to slow down the free spinning flywheel with my hand and compare the load on my hand with the felt torque needed to spin the flywheels on both my Knucklehead and Howell V-8. The results were clearly definitive and very disappointing. And so before finally getting the bell housing, I have some thinking to do. - Terry
 

mayhugh1

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Terry:
Have you researched Brushless DC motors (called BLDC) and their torque?
Dave,
No, I didn't look at them for this build, but I did for the Merlin. I still have the motors and controllers I bought when I looked at them for that project. If I remember correctly, there wasn't much advantage over brushed motors for a starter application and the peripheral electronics added more stuff to hide. - Terry
 

petertha

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I wonder if a planetary gear drive might help. It adds more length but diameter stays within the motor can OD. Another site I was on had the rpm/torque curves, this one just has the nominal specs. Yes an RC (brushless) setup is more peripheral stuff; ESC, throttle control... & likely more expensive for what you require.
 

mayhugh1

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I wonder if a planetary gear drive might help. It adds more length but diameter stays within the motor can OD. Another site I was on had the rpm/torque curves, this one just has the nominal specs. Yes an RC (brushless) setup is more peripheral stuff; ESC, throttle control... & likely more expensive for what you require.
Peter,
It was one of those very geared motors I used on the Knucklehead. I thought long and hard about using one of the ones I still have on hand. But, they're not only 550 size motors but with the planetary drive they would stick out past the front of the Ford engine. - Terry
 
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I did some experiments with a small motor and several different ratios of Meccano gears to crank the Westbury Seagull. I found that for that engine and the chosen motor, the best ratio was 50:1. Partly written up at Seagull Engine Construction Diary - Starter but although the gearbox is almost complete and has been tested, I am afraid the 'diary' write-up has mostly caught up to 2017. The gearbox model I recently posted under another thread, but here it is again: https://www.homemodelenginemachinist.com/attachments/starter-gearbox-pdf.132891/
 
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Arild

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The bell housing should be a fun part to machine and, never having done one before, I've been looking forward to it. My hope since the beginning of this build has been to replace the faux starter in the original design with an electric motor.

My quarter scale Knucklehead's cranking requirement of 320 oz-in (23 kg-cm) was handled by a geared motor running through a one-way clutch. That motor was large for the scale of the engine, but a significant portion of it and its running gear were hidden inside the crankcase. Assuming a similar requirement for the fifth scale Ford and a 4:1 gear reduction from its ring gear, the motor would need to supply some 80 oz-in or 6 kg-cm.

A standard 22 mm (dia.) dc motor would be a perfect fit on the Ford, and George's bell housing could be easily adapted to it. However, published data on these motors show their torque to be hopelessly low even at stall.

A 390 size motor which is a little large for the engine's scale is the biggest I'd want to mount on its bell housing. Unfortunately, data on these motors show their torque is too low as well. However, there are some intriguing Youtube videos showing the (now defunct) Conley quarter scale V-8's being started with what might be a 390 brushed motor. I haven't been able to get an accurate enough estimate of its diameter to be really sure though.

A 550 or 750 size motor could be made to work, but their huge diameters would look out of place on the engine. A motor this size would be best hidden under the engine's display stand while driving it through a chain and sprocket. I spent nearly two weeks trying to come up with a configuration I'd be willing to live with, but in the end decided I'd rather drill-start the engine than mount it on top of a box.

Robotic parts suppliers (as well as Jameco), provide speed-torque data for their motors to help customers make informed selections. There's also an industry that supplies motors to RC enthusiasts that have been performance tuned using the armature wire gage. These suppliers use the actual number of wire turns on the armature segments of their brushed motors in order to compare them. I haven't a clue as to how to convert Turns to oz-in.

I ordered a couple of these 'performance' 390 motors to just try them. I chose 24 and 32 Turn motors for a relative comparison. I figured the best motors would be those marked with warnings about not being toys and cautions about dangerous hot surfaces.

Orders for 'in stock' motors were placed a few months ago from two different domestic suppliers. These motors are all manufactured in China, and so the first thing I received was schooling about a new definition of what 'in stock' can mean nowadays. After a few weeks I inquired as to why the motors hadn't shown up and was told their 'in stock' motors were in stock 'in the supply chain.'

Eventually they arrived, but before starting on the bell housing I wanted to do some testing. I did machine the engine's flywheel, however, and to be safe included both a ring gear and a socket for a drill starter. For my ballpark testing, each motor under test was fitted with a pinion gear, and both it and the flywheel were mounted to a heavy plate.

in the first test, the 83 tooth flywheel was driven by the 32 turn motor fitted with a 20 tooth pinion gear. I powered the 7.5 volt motor with a 12 volt sealed lead acid battery, and the test was performed by using the motor to lift a dead weight attached to the flywheel. The measured stall torque referred to the motor's shaft turned out to be 96 oz-in. This was a healthy although unsustainable improvement over the 20 oz-in typically advertised for 390 motors but was an indication that a 390 motor was not going to work.
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Another seat-of-pants test was to slow down the free spinning flywheel with my hand and compare the load on my hand with the felt torque needed to spin the flywheels on both my Knucklehead and Howell V-8. The results were clearly definitive and very disappointing. And so before finally getting the bell housing, I have some thinking to do. - Terry
Hi, what you also can do is to open up the brush-motor and re-wind with a much thicker copper wire. This will dramatically increase the torque! They can not run long time, because the motor brush will melt (normally held in place with plastic). But for a start motor it's ok.
 

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