Milwaukee Midget

[jacksoni]

IO -

I've been humbled - but I have been made smarter for it.

http://www.epi-eng.com/piston_engine_technology/piston_motion_basics.htm

And I owe you another beer. 

What bugs me is that I took painstaking efforts to accurately measure this.  I realized I had a rare opportunity to check the actual relationship of two different rod lengths side by side on a common axis to their relative piston travel.

And I see where one would think I inverted the numbers, and that the results would indicate that's what happened.  But man, I double checked them - I made a point to accurately assign the correct number with the correct cylinder.  So to that end, I don't know where the mistake is, and I'm having a difficult time accepting that there is one.

Maybe I should just go back to something simple.

Anybody want to give me a hand with my cold fusion project?

MM- I have not tried to do the math but your quoted site (epi-eng.com) may provide the answer to your "error". The site points out that more than half the piston motion occurs before 90* and less than half after 90* of crank rotation. Would not the effect of rod length on piston position be also along those lines so that the position of the piston above 90* be greater for one rod and perhaps less with the other below? You get what I am saying? Is just a thought and may be an explanation for your measurements which were taken at less than 90*, that is coming from BDC if I read your post correctly. I may be way off base here but am just wondering.

[fordboy628]

     My office was in EGV for a few years, then in Lincolnwood, and I lived in Roselle '75 - '85. My garage in Roselle was where I first started doing customer work on race cars as I terminated my job with Honeywell. In the first part of the eighties I rented some dyno time from ProMotor as I did some intake and exhaust development on a Porsche 924 race engine.

     Yes, Slim, the Don Nichols led Shadow CanAm operation ran out of what became the ProMotor shop.

     Mark, did you ever work with Bill Truesdale at Apex?

     vic

Vic,

When the Apex Humbuggery and Racing Shop opened it's doors circa '72/'73 (?? failing memory . . . .)   Bill Truesdale and I were partners.     Did a lot of machine work and chassis work on a bunch of SCCA sports cars.    Somewhere I used to have a bunch of photos of me tig welding the roll cage for Andy Boone's trick B-Production Corvette and Clark Lance's C-Production Lotus Elan.    I did all the welding on the frame/roll cage for Bill's D-Production Europa, including all the custom machined pieces.    I stayed there for several years until I went to work for John Hadjuk's exotic car (read Ferrari/Maserati/Jaguar/etc/etc) and race car shop.

Small world.    And yes, I've been around the block a time or two . . . . . .
 
Fordboy

[fordboy628]

Anybody want to give me a hand with my cold fusion project?

midget,

I thought that was what I was doing . . . . . . . . . .
 

Happy Easter!! to all, and to all a good night!!    (Wait, uhhmm, maybe that's not quite right . . . . . . .    Oh well!!)
Slightlyconfusedboy

[Milwaukee Midget]

Anybody want to give me a hand with my cold fusion project?

midget,

I thought that was what I was doing . . . . . . . . . .
 

Happy Easter!! to all, and to all a good night!!    (Wait, uhhmm, maybe that's not quite right . . . . . . .    Oh well!!)
Slightlyconfusedboy

No - this one is the hot fusion aversion project.

[Elmo Rodge]

Europa like a Lotus 47?  Wayno

[4-barrel Mike]

"Apex Automotive was opened by Bill Truesdale in 1973 for one reason...he couldn't find anyone to do the kind of work he needed done on his race car. A 1967 Lotus Series II Europa."

http://www.apexae.com/about/index.html

Mike

[fordboy628]

Europa like a Lotus 47?  Wayno

Sort of.    Bill's car was a Renault powered Lotus Type 46.    Renault engine, gearbox, non adjustable suspension.    The 46 was the "road" version.

 
Fordboy

[fordboy628]

"Apex Automotive was opened by Bill Truesdale in 1973 for one reason...he couldn't find anyone to do the kind of work he needed done on his race car. A 1967 Lotus Series II Europa."

http://www.apexae.com/about/index.html

Mike

Absolutely true.    Bill got tired of being f'ed around by the likes of the "Wizard Works" and "Speed Performance".

 
Fordboy

[krusty]

     HA! I knew I'd met you back in the dark ages. Apex did both block and head work on the engines for my F/P Volvo P1800 and my 1275 Spridget in the Sseventies. I remember Andy Boones car and the Europa. The Chicagoland area had plenty of sports car enthusiasts, and CenDiv and MWCSCC had plenty of racing. Small world indeed. This has opened a part of my memory I didn't know I hadn't killed off....

     vic

[Milwaukee Midget]

HELP!

I'm looking for a piston coating service - hopefully in the Midwest, but if they have quick turn-around, I'll ship.

My pistons will be back in about a week, and I've got a dyno session looming on the near horizon.

I checked the rule book for a sponsor - didn't see one.  Hopefully I can keep this outsource "in the family".

Thanks!

Chris

[Tman]

Looking in the Twin Cities

http://www.precisioncoatings.com/thermal-spray-coating-services.html


This one looks good.
http://www.racecoatings.com/

[Milwaukee Midget]

Thanks, Trent.  I've got a quote request into Line2Line coating up in Michigan.  Wisdonm sent me the recommendation on that.

It's focus time in Beerhaven - I've got to get this lump in running order in the next three weeks, but I'm at a bit of a standstill on the engine until rod bolts arrive.  They're an ARP product, but it's a Saenz proprietary piece, so rather than ordering them directly, Mel needs to get them through Saenz.

I hadn't even given them a thought until Fordboy suggested I check them for stretch.  That was a bit of an eye-opener, and damned near scared the bejeezees out of me.

I've since picked up a more accurate torque wrench.

The pistons are at C&S having notches cut to clear the new exhaust valves.  What little compression I picked up with the deeper valve just runs this thing too close for comfort, and would have eliminated any possibility of testing the cam timing.  So I end up with a zero sum on the CR, but a better flowing exhaust valve, and the possibility of a more usable curve.

So that's the eye I elected to have poked out.

I'll be shipping them off for coating as soon as I get them back.

But hey, that's okay - it's not like I don't have stuff to do on the car itself.

Here's a question - has anybody ever done their car with a DIY wrap job?  I've seen a number of youtube videos on it, and I'm wondering about the success rate.

The downside would be getting a color - it's limited to what 3M makes.  I've been told all other wraps are headaches, but I can get enough wrap for this thing for less than $350.00.  Oddly enough, one of the only things Kate has a strong opinion on with regard to the Midget is the color choice.  It wouldn't put us in front of the magistrate, but I'd need a pretty compelling argument at this point to change up the color choice, and the Kaiser-Frazer green is only available in paint. 

[Rex Schimmer]

Chris,
Regarding rod bolt stretch, is Fordboy concerned about the possible stretch of your existing bolts or is he thinking about measuring the stretch of new bolts when you install them as a way of accurately measuring preload? If your present bolts have stretched then I would think that you may not have torqued them to the proper level of preload. When you use bolts like APR's that are made from typically double vacuum melted alloy, with rolled threads, accurate heat treatment and proper surface finish and extreme quality stretching should not be a big concern, but it is pretty cheap insurance to go with new bolts, especially if it keeps the rod(s) inside the case at 9000 rpm. I know that we have discussed proper torquing of fasteners before but quality bolts,washers and nuts require good assembly  lubrication, most important place is under the bolt head, and if you can measure the preload by measuring the bolt stretch you will be more accurate.

Rex

[WOODY@DDLLC]

Good info Rex! 

Bolts are only glorified springs - you know what happens when you open the screen door too far or too many times! 

For everyone's review this has been a primary fastener resource for me over the years: http://www.boltscience.com/pages/tighten.htm

I think a complete mechanical engineering course could be taught using only fasteners and crankshafts - statics and dynamics!

[Milwaukee Midget]

Hey, Rex -

The bolts are the L19s. 

When I buttoned up the bottom end, Saenz had a stretch reference of .15 - .17 mm, and a "do not exceed" limit of 30 ft/lbs.  As I don't own a stretch gauge, and have never used one, I moved forward on the ft/lbs limit.  This was with a torque wrench that later chewed up my threads in my flywheel, and clearly overtorqued my rod bolts.   

When I measured the bolts, I saw .005 difference in lengths, so lesson learned.  I cut the needle off of the old torque wrench, and it now serves as a 1/2" breaker bar.

Inexperience on my part - rod bolts being another tuition upcharge.

One other thing I wish I had known - these L19 bolts - you are not supposed to touch them with your bare hands.  Corrosion is the issue that ARP sites.  So when the new ones arrive, I'll dig out the surgical gloves - but I would have never had thought that a chrome alloy bolt of this nature would be susceptible to casual contact with something as chemically benign as a guitar playing audio technician living in the shadow of the Miller Brewery.