Author Topic: Milwaukee Midget  (Read 3255740 times)

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Offline Jack Gifford

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Re: Milwaukee Midget
« Reply #5670 on: March 08, 2016, 01:32:19 AM »
Nice work Chris.
Was the dial bore guage maintained at a controlled fixed temperature? :evil:
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Offline fordboy628

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Re: Milwaukee Midget
« Reply #5671 on: March 08, 2016, 05:54:50 AM »
Rover Wellington* – a favorite of the Midlands working class - typically served braised in a glycol/petroleum gravy or prepared in - or AS - a pressure cooker.

Bake in a preheated 225 degree oven on middle rack for 70 minutes until internal temperature reaches 180 F.

Serve with Old Speckled Hen.

 

Actually, I’m just checking for what kind of bore growth we’re seeing in the casting.  This is to determine the proper OD for the sleeves we’re looking to have made.  We’re done with the factory “slip-fit” arrangement.

Room temp 70 F   
   
                Longitude      Width
1            3.314         3.313
2            3.314         3.315
3            3.315         3.315
4            3.314         3.314

Heated to 180 F       Checked with a TruTemp #3519 instant read thermometer . . .

             Longitude      Width
1            3.322         3.320
2            3.320         3.321
3            3.320         3.321
4            3.321         3.320

Checked mid bore, but top-to-bottom never wavered more than .001

*not recommended for those with a low iron condition.





WOW!!

That is ~ .006" growth on the Ø  !!!    Waaay more than I expected.     I think it is unlikely that the barrel expands that much.    I'll bet the barrel is trying to do the "Hula" at 8500 rpm.

Combined with the 1.5mm wide barrel seating area, it's no wonder the seal is marginal at 180 degrees F.

I'm thinking that some discussion with Darton is required about this.

BTW, nice work.

AND, although Old Speckled Hen is always a good selection, since the main course is so light, doesn't that require something lighter?   Say a lager, a pilsner or even a weiss?    Mebbe Alagash White or St. Bernardus Wit.      You know, sorta like white wine with fish . . . . .

Saaayy, what's the perfect brew to drink with brine shrimp as the main course?     A shrimp and suds pairing will be a necessary menu item for the next trip to the salt.   

Heeey Gogs, do you have a portable barbie?

 :cheers: :cheers: :cheers:
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Offline Milwaukee Midget

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Re: Milwaukee Midget
« Reply #5672 on: March 08, 2016, 07:58:21 AM »
Nice work Chris.
Was the dial bore guage maintained at a controlled fixed temperature? :evil:

Yes, by using it to stir my Gin and Tonic on the rocks.   :wink:
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Well, I guess we're making a LOT of progress . . .  :roll:

Offline Milwaukee Midget

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Re: Milwaukee Midget
« Reply #5673 on: March 08, 2016, 10:26:56 AM »
. . . AND, although Old Speckled Hen is always a good selection, since the main course is so light, doesn't that require something lighter?   

This block is starting to remind me of a Coors Light can.
"Problems are almost always a sign of progress."  Harold Bettes
Well, I guess we're making a LOT of progress . . .  :roll:

Offline Milwaukee Midget

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Re: Milwaukee Midget
« Reply #5674 on: March 08, 2016, 12:39:06 PM »

Combined with the 1.5mm wide barrel seating area, it's no wonder the seal is marginal at 180 degrees F.

I'm thinking that some discussion with Darton is required about this.


Well, yes.  The engine's design premise - slip fit liners and full height compression of the girdle, block and head with long fasteners - combined with modern, minimalistic casting techniques - it's a thinker.

Just thinking out loud - they've come a long way since the Vega - perhaps Hypereutectic Aluminum liners?
"Problems are almost always a sign of progress."  Harold Bettes
Well, I guess we're making a LOT of progress . . .  :roll:

Offline Milwaukee Midget

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Re: Milwaukee Midget
« Reply #5675 on: March 08, 2016, 12:49:20 PM »

That is ~ .006" growth on the Ø  !!!    Waaay more than I expected.     I think it is unlikely that the barrel expands that much.   


I think I have a new experiment to conduct this evening!  :cheers:
"Problems are almost always a sign of progress."  Harold Bettes
Well, I guess we're making a LOT of progress . . .  :roll:

Offline Peter Jack

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Re: Milwaukee Midget
« Reply #5676 on: March 08, 2016, 01:12:32 PM »
This chart may prove handy and save you a few burned fingers. You'll notice the coefficient of expansion of aluminum is almost twice that of steel.

http://www.engineeringtoolbox.com/linear-expansion-coefficients-d_95.html

Pete

Offline Rex Schimmer

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Re: Milwaukee Midget
« Reply #5677 on: March 08, 2016, 02:47:13 PM »
Doing a little "pie are square, three bags full" I can come up with a diametrical increase of .0045 inches but you are seeing .008 inches which must mean that the deck and block expansion is also affecting the bore expansion. Looking at a cast iron sleeve, which would not be affected by the block expansion, I get a OD increase of approx .0024 inches so you have  a .005-.006 clearance. You may be right in thinking about an aluminum sleeve with a hard surface coating on the bore. Do they make such a thing?
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Offline Interested Observer

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Re: Milwaukee Midget
« Reply #5678 on: March 08, 2016, 04:17:40 PM »
Chris,
I did some calcs similar to Rex’s using tabulated values for thermal expansion and got about the same results as he did.  Comparing your measurements, your effective coefficient of thermal expansion would be about 50% greater than anything I can find listed for aluminum/alloys.  Seems suspicious. 
If you re-run the experiment, you might try measuring across a longer baseline in addition to each bore--like from #1bore wall to #4.  Do you have a long vernier or maybe tie a dial gauge to a square?

Offline Milwaukee Midget

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Re: Milwaukee Midget
« Reply #5679 on: March 08, 2016, 05:27:16 PM »
Hi, IO -

Help me review what I did - as to the tools I have available, I've got an inside mic, a bore gauge, T bore gauges, 1,2,3 and 4" OD mics, two dial indicators and a pair of calipers, one a dial, the other, digital readout.

I tried to ball park numbers with the calipers to no avail due to clearances in the block.  The T-bore gauge I used to confirm the inside mic dimensions cold - checking the two tools against each other.  I did this because I haven't used in ID mic very regularly, and I wanted to feel comfortable with the results I was getting.  I used the first cylinder bore as a baseline reference, and set the dial bore indicator to zero.  From there, the additional numbers were generated by reading the dial bore and adding to the reference number.

When the block got hot, the dial indicator was used to determine the bore changes, the readings were added to the reference number, and that it was how those numbers were generated.

I've got extensions for my ID mic, and I think I COULD determine overall growth of the block both lengthwise and widthwise.

I'm hoping an interference fit with a heated block and cold liners is possible.

Let me see what I get with the liner tonight.  I'm thinking if we can get to a .005 interference fit cold, even hot, it should still be tight enough with clamping pressure, O-rings, and a more stable step cut.

Definitely more stable than the stock configuration.

My concern at that point is cracking the block . . .
 

"Problems are almost always a sign of progress."  Harold Bettes
Well, I guess we're making a LOT of progress . . .  :roll:

Offline salt27

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Re: Milwaukee Midget
« Reply #5680 on: March 08, 2016, 07:48:46 PM »
You may be right in thinking about an aluminum sleeve with a hard surface coating on the bore. Do they make such a thing?
Rex

Nikasil

Offline Interested Observer

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Re: Milwaukee Midget
« Reply #5681 on: March 08, 2016, 08:03:13 PM »
Chris,
Upon looking up what a TruTemp 3519 is, I think the root of the problem is that it gave you a lower reading than what the actual temperature was.  That kind of instrument, I believe, is intended to be rather immersed in the measured object, with considerable contact along the stem.  Given a hard-surfaced object like the K block, just touching it at one point is likely not enough to give a proper reading.

I think your oven’s temperature reading (225 F) was probably closer to the actual temp of the block after 70 minutes exposure.  If one does the expansion calculation using that number, a differential of 155 F, with a nominal thermal expansion coefficient, I got 0.0059”.  Very close to what you measured originally.

Offline Milwaukee Midget

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Re: Milwaukee Midget
« Reply #5682 on: March 08, 2016, 08:17:44 PM »
Indeed, it is a cooking thermometer.  I placed it in one of the bolt holes on the side of the block and left it in contact for about a minute until the thermometer stopped climbing.  It's accuracy is likely suspect.

I just conducted the experiment on two of the liners.  At 70 F, I saw 3.310 OD on each - after pulling them out of the oven at 180 for 45 minutes, and having no better method of checking the temp, the growth went to 3.312, which is in line with Rex's estimate.

Now that Kate is home, and when she finishes making dinner, I'll reheat the block to 180 according to the oven, and recheck the block.

Yes - methodology is key to accuracy . . . Back to the laboratory . . . Thanks for checking my work.  :cheers:
"Problems are almost always a sign of progress."  Harold Bettes
Well, I guess we're making a LOT of progress . . .  :roll:

Offline manta22

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Re: Milwaukee Midget
« Reply #5683 on: March 08, 2016, 08:19:07 PM »
Chris;

Any chance of borrowing a thermocouple for that measurement?

Regards, Neil  Tucson, AZ
Regards, Neil  Tucson, AZ

Offline Milwaukee Midget

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Re: Milwaukee Midget
« Reply #5684 on: March 08, 2016, 08:25:40 PM »
Chris;

Any chance of borrowing a thermocouple for that measurement?

Regards, Neil  Tucson, AZ

Not before bed time.  :wink:
"Problems are almost always a sign of progress."  Harold Bettes
Well, I guess we're making a LOT of progress . . .  :roll: