Milwaukee Midget

[roygoodwin]

Just a thought, but if the pin bores changed, might the pistons not be quite as round as they once were ?  I'd think it'd be worth checking, dunno what could be done, but seems like you'd want to know "inquiring minds want to know" and all that.

Roy

[Milwaukee Midget]

Just a thought, but if the pin bores changed, might the pistons not be quite as round as they once were ?  I'd think it'd be worth checking, dunno what could be done, but seems like you'd want to know "inquiring minds want to know" and all that.

Roy

Yeah, that's a potential headache, too.

I dropped them off already for the honing - I'll have them back on Wednesday.  The pin issue was something that Baurle, the company who did the work, says sometimes rears its ugly head, but he made no mention of any circumferencial distortion.

Nevertheless, I do own a 2-3 micrometer, and I'll be checking them for roundness before I install them.

Hoping this doesn't turnout to be a ship-sinker.

[Speed Limit 1000]

Modern pistons may not be round. Ask the manufacture for drawings. You can't check them if you don't know what the numbers should be. Did you try to install the pins "wet"?

[Milwaukee Midget]

Modern pistons may not be round. Ask the manufacture for drawings. You can't check them if you don't know what the numbers should be. Did you try to install the pins "wet"?

?

and then

?

I'm aware that Honda had experimented with oval pistons - I think for Formula 1 - but you'll need to educate me on why an egged piston would provide an advantage that a manufacturer would work toward.  You've got me digging for the spec sheet.

By wet, I assume you mean with alcohol.  Yes, still tighter than before the coating.  There appears to be no coating overspray in the pin bore.

[Jack Gifford]

For at least 70 years now, piston shapes have almost universally been non-cylindrical. If you have success obtaining a blueprint of your pistons, it will be obvious.

[Speed Limit 1000]

Modern pistons may not be round. Ask the manufacture for drawings. You can't check them if you don't know what the numbers should be. Did you try to install the pins "wet"?

?

and then

?

I'm aware that Honda had experimented with oval pistons - I think for Formula 1 - but you'll need to educate me on why an egged piston would provide an advantage that a manufacturer would work toward.  You've got me digging for the spec sheet.

By wet, I assume you mean with alcohol.  Yes, still tighter than before the coating.  There appears to be no coating overspray in the pin bore.

If they go in wet you will be able to see small burnished spots that could be the problem

[fordboy628]

Just a thought, but if the pin bores changed, might the pistons not be quite as round as they once were ?  I'd think it'd be worth checking, dunno what could be done, but seems like you'd want to know "inquiring minds want to know" and all that.

Roy

Midget, et all,

Modern pistons are NOT round.    There is SIGNIFICANT cam, barrel & taper built into the piston dimensionally at room temperature.    This is to allow for, and compensate for, the thermal differences between measurement at room temp and operation at running temp.    The idea is for the piston to "conform" better to the "presumably round" bore at operating temps.   Whether or not the piston actually becomes "round" or not, doesn't really matter.    All it needs to do is keep the ring seal intact and the rings functioning, AND, not scuff or distort the bore, or, compromise the ring seal in any other way, or bind the wrist pin, etc.

I'm not worried about this "distortion" of the piston from the autoclave, UNLESS, the rings bind in the grooves.    The piston is an alloy slug, subjected to cannonball type acceleration loads, with reversals of direction cannonballs never see.     (Although, I would argue that cannonballs can see VIOLENT decelerations . . . . .  )    Pistons distort under loads and thermal inputs, it is simplistic to think otherwise.

If you want to borrow my dial bore gauge to double check the clearances, let me know.    As long as the pistons "fit" the bores within tolerance, things will be fine.   Checking & double checking is just part of being an "Engine builder" Vs. an "Engine assembler".     You pick which one you want to be.     Oh, and I just had someone tell me about how much time he felt guys "waste" checking dimensions when assembling engines.          His engine seized on the first drag strip pass this past weekend . . . . . . .    I wonder what he knows that I don't.   
 
Fordboy

[Milwaukee Midget]

Oh, and I just had someone tell me about how much time he felt guys "waste" checking dimensions when assembling engines.         His engine seized on the first drag strip pass this past weekend . . . . . . .    I wonder what he knows that I don't.  
 
Fordboy

Today, probably the cost of a new set of bearings and other sundry items.

Thanks, all. Again, I'm still a student on this stuff.

It's what I don't even think about thinking about that bites me in the bullocks.

After seizing up the valve in the head two years ago in a guide that was set up by a pretty well respected shop dealing with these engines, I don't want to be assuming anything anymore.

Before my dad got kicked upstairs into purchasing, he spent a number of years in inspection for Collins/Rockwell.  Nothing went to assembly without him checking the measurements and specs.  Checking dimensions is a tedious job, but one that Collins took seriously enough to pay people a decent living wage to do.

In those terms, it's becoming clearer and clearer, every passing day, precisely why a really well built race engine is so damned costly.  

A - I see guys going through the Summit and Jegs catalogues, pricing parts and putting together shopping lists, but it's not the components.  

B - I've got stacks of receipts from C&S for block and parts prep, and while Mel won't be buying a new boat with what I've dropped, it's not the machine work.  

C - Most of the basic tricks of high performance engine building have fallen into public domain, so I'm beginning to think it's not even the engineering.  

No, I'm now convinced that a significant portion of the cost of a really well built racing engine is -

D - the amount of time "guys 'waste' checking dimensions when assembling engines."

I'm choosing "D".

Because if you don't invest in "D", you'll wind up doubling down on "A", "B"  and "C".

And in advance - Dad - Happy Father's Day!  

[manta22]

Hey, Chris-- I'm impressed by your Dad's working for Collins.

They made the best electronic gear ever! I have a collection of their old stuff but they all still work: 32S1 receiver, 75S1 transmitter, KWM-1 transceiver, and an R-390A military receiver. The quality and design engineering that Collins put into their products was legendary. Thanks to you Dad for being part of such a class outfit. 

Regards, Neil  Tucson, AZ

[Milwaukee Midget]

Hey, Chris-- I'm impressed by your Dad's working for Collins.

They made the best electronic gear ever! I have a collection of their old stuff but they all still work: 32S1 receiver, 75S1 transmitter, KWM-1 transceiver, and an R-390A military receiver. The quality and design engineering that Collins put into their products was legendary. Thanks to you Dad for being part of such a class outfit. 

Regards, Neil  Tucson, AZ

And Neil, I think you'll appreciate that they had a really impressive surplus store. 

[manta22]

Hey, Chris-- I'm impressed by your Dad's working for Collins.

They made the best electronic gear ever! I have a collection of their old stuff but they all still work: 32S1 receiver, 75S1 transmitter, KWM-1 transceiver, and an R-390A military receiver. The quality and design engineering that Collins put into their products was legendary. Thanks to you Dad for being part of such a class outfit. 

Regards, Neil  Tucson, AZ

And Neil, I think you'll appreciate that they had a really impressive surplus store. 

Am I ever sorry I missed it!

Regards, Neil  Tucson, AZ

[Seldom Seen Slim]

When I was a kid ham Collins stuff was for dreaming.  Heathkit was more my speed.  but, thanks to who knows what lucky stars, the Heathkit plant was less than 20 miles up US 12 from where we lived.  I got to go up there now and then and spend my teenage budget (in other words, not much $$) on factory assembled kits and discounted items.  Way cool!

[manta22]

Jon;

I built my share of Heathkits, too-- a DX100, an SB10, AM & FM tuners, and a color TV. Too bad kids today don't have Heathkits to learn some electronics and get some practical hands-on experience. Computers are no substitute for actually building something.

Regards, Neil  Tucson, AZ

[Milwaukee Midget]

Jon;

I built my share of Heathkits, too-- a DX100, an SB10, AM & FM tuners, and a color TV. Too bad kids today don't have Heathkits to learn some electronics and get some practical hands-on experience. Computers are no substitute for actually building something.

Regards, Neil  Tucson, AZ

While I understand the economics of the electronics industry, I do lament the trend toward board replacement as a substitute for service repairs.  While I've never been really good with a soldering iron, and schematics still require an inordinate amount of time for me to dissect, I really think it's cheating to simply replace a board and call it a repair.

If anybody is willing to "repair" anything.

Wholesale replacement seems to be the trend - an indication of just how inexpensively electronics can be built today.

I can change out caps on an amplifier, but for what I'd have to charge, it's cheaper to just replace the whole board.

[Seldom Seen Slim]

I think my biggest-ever Heathkit was a color TV that I built for a buddy of my dad.  He bought the kit and probably paid me some magnificent some, and I had a ball putting it together.  Let's see -- my first two meter rig, and a DX40, I think, and for sure the 40 watt 2M amplifier.  I think there was some hi-fi stuff in there, too.

For those of you that don't have any idea -- Heathkits were good for learning.  The instructions were well and clearly written and had boxes to check by each instruction line.  The parts were included and the assembler (me) was to lay out all of the parts to make sure they were all there and to know where they were.  How do you learn color codes for resistors?  Building Heathkits did it for me.  I remember that by the time I got into electronics class in my senior year that I was the only one that already knew color codes.  In fact - I had to learn the mnenomics about "raping our girls. . ." and Roy. G. Biv.

Back to your car's story, Chris.