montana 500 newsletter - antique auto...

Montana 500 NewsletterNov-Dec 2005 Volume 5 No. 6

Montana Cross Country T Assn.1004 Sioux Road

Helena, MT 59602

www.montana500.org

2005 Officers and Directors:

President: Rick CarnegieVice President: Mark HutchinsonSec.-Treasurer: Janet CerovskiDirectors:Rick Carnegie 2007Tom Carnegie 2008Janet Cerovski 2007Tony Cerovski 2008Gary Ebbert 2006Mark Hutchinson 2007Doug Langel 2006Mike Robison 2006Nan Robison 2008

Meeting Secretary: Jillian CaplesCorrespondence and newsletter: Tom Carnegie

Membership dues $10.00Touring class: $25.00Endurance runner: $35.00

Cover photo: H.H. “Hal” Wilson ofColorado. Hal recently passedaway. Please see article later in thisnewsletter. Photo from Model T Times.

Editor’s Message

Rick has picked the Comfort Inn as the base hotel this year. Below isinformation I have copied the from the company’s website. It is myunderstanding that they have RV parking.

Comfort Inn (MT418)450 N. Interchange , Dillon, MT, US, 59725Phone: (406) 683-6831 Fax: (406) 683-2021The Comfort Inn® hotel is conveniently located off Interstate 15, just one mile from theBeaverhead County Museum. This Dillon hotel is minutes from the University ofMontana-Western.Guests of this Dillon hotel will enjoy amenities like the free expanded continentalbreakfast, free local calls and free coffee. After a long day on the road, be sure to takeadvantage of the indoor heated pool with adjoining sundeck. This is a pet-friendlyhotel; a nightly fee applies.Business travelers will appreciate the meeting room that accommodates up to 20 peo-ple for most events and business functions. Access to copy and fax service is alsoavailable.Kick back and enjoy a movie on HBO, located in all guest rooms. Pizza, popcorn and afew cold deli items are available in the hotel's mini-kitchen. In addition to standardamenities, some rooms include refrigerators and microwaves.Staying a while? The hotel offers laundry facilities for guest convenience. The hotel'sinformation kiosk lets guests know what's available in the area. Truck parking is lo-cated on the property.The hotel also offers a 100% Satisfaction Guarantee. What are you waiting for?Come stay at the Comfort Inn hotel and experience an inn-credible time in Dillon.

Tom Carnegie - newsletter editor

President’s Message

(this space reserved for president’s message)

A Poor Man’s OscilloscopeBy Tom Carnegie

In order to better understand the function of a model T timerit is useful to look at its operation with an oscilloscope. Agood deal of money can be spent on an oscilloscope, butthere are reasonable alternatives. With a bit of pokingaround, one can find circuits and software to convert yourexisting PC into a decent oscilloscope. I chose instead tobuy a commercial unit that plugs into the parallel port of thecomputer. The unit I got was manufactured by Pico and wasless than $100.00 including the software at the time of thiswriting. The model number was ADC-10. It has some limi-tations as an oscilloscope, but is quite ideal to test theswitching properties of a timer.

Job Description

The job of the model T timer is to ground the coil for eachcylinder at such a time as to allow the plug to fire and ignitethe fuel in the combustion chamber. The model T timer isessentially a single-pole four-throw switch. In a perfectworld a switch would either be on, or off. In the real worldit never happens quite this way.

The perfect model T timer would not only turn perfectly on,then off, it would do it at exactly 90-degree intervals overthe range of rpm’s that the engine operated. The previouspicture shows a nearly ideal waveform for a Model T timer.It is from a Duntley timer, turning at 1000 rpms. To clarify,in this article in regard to degrees or speed, unless otherwisestated, I will refer to timer rotation as opposed to crankshaftrotation. The timer rotates at ½ crankshaft speed, thereforeall speeds and degree figures for the crankshaft are twicethat of the timer. The timer also needs to dwell in the “on”position for a certain amount of time. This dwell period isnot too critical as long as it is adequate. I will explain betterlater on.

Solid Ground

There are basically two ways in which mechanical (non-electronic) timers function. Most timers are what I call the“wiper” kind. The way they operate is to have a wiping con-tact that is connected to the camshaft. This wiper then con-tacts a commutator that is wired to the coil box. In the sec-ond kind, the commutator is self-grounding and the cam isused as a triggering device. Triggered timers have some ad-vantages over wiper timers, but aren’t allowed on the Mon-tana 500. Wiper timers have at least two disadvantages. Oneis that the wiper is scooting across the commutator contact.It never really makes a solid connection, but rather arcs andsparks its way across the contact surface. Two is that thewiper must get its ground through the camshaft, which istheoretically rotating on a film of oil. Some folks have saidthat there may be an advantage to using metal timing gearsbecause the cam can then ground through the gears to thecrank. That may be true, but the gear teeth should have anoil film on them and the crankshaft should also be riding onoil! Some other folks say that the timer brush (wiper) getsits ground through the tin shield that is used to hold the feltin place. Even so, it is still a wiping situation between thebrush and the shield.

The above photograph shows a Duntley timer. The contactsground through the case rather than through the camshaft.

Pictured above is a waveform from a Model T magneto. Thehighpoints of the waveform occur every 22.5 degrees ofcrankshaft rotation. Whether the highpoint points up ordown from the center (zero line) is not important, either

pulse will energize the coil. The flywheel is indexed to thecrankshaft in such a fashion as to cause the high point to oc-cur at certain exact times. The useful times these pulses oc-cur listed from retarded to advanced are: 4 degrees afterTDC, 18.5 degrees BTDC and 41 degrees BTDC. Ron Pat-terson and Steve Coniff have written an article that goes intomore detail on this subject. It can be found on the Internet athttp://www.mtfca.com/encyclo/Ignition.pdf. It should benoted that these timing figures apply only to when the car isrunning on “mag”. When running on battery, the timing iscontinuously variable throughout the aforementioned range.Chiefly because six volts is not enough to properly energizea Model T coil, model T’s don’t run well on battery. Assuch this article will be confined to issues dealing with mag-neto operation. For every revolution of the timer there arethirty-two pulses from the magneto. Of the thirty-twopulses, twelve are useful, three for each cylinder. An ideallyfunctioning timer would operate as a selector for these usefulpulses. Even a less than ideally operating timer could be

fairly adequate.Above is the waveform of a well functioning Newday timer.The dotted line shows the maximum that is possible for thetimer to let through. Although the waveform is slightlyragged and doesn’t come up to the maximum line, it is likelyfunctionally equivalent to the Duntley timer shown earlier.As mentioned earlier, a timer must turn on then stay on

(dwell) for a certain amountof time. How long it dwellsis not critical as long as atleast one pulse of the mag-neto fires the coil. During adwell phase, the coil couldfire several times. The onlyimportant one is the first one.All subsequent firings duringthis particular dwell phase areredundant. So what is thesignificance of all this? Thetimer needs to turn on cleanlyat the central timing point,(see side bar), which corre-sponds to the zero point ofAC voltage generated by themagneto. If the timer doesn’tturn on cleanly, the timingwill be affected.

The graph below shows theresults of a flapper timer witha weak spring. Dependingon where your spark lever isset, this could have a minor,or significant impact on thespark function.

The timing is fairly stable at theuseful points mentioned in thetext. What exactly happens tothe timing as the spark lever isadvanced?

Starting at a certain point, whichI will call the central point, asyou begin to advance the sparklever, the timing immediatelybegins to retard. This retardationis logarithmic, so it is nearly im-perceptible at first. As you con-tinue to advance the lever, theretarding will accelerate in rela-tion to the advancing of thelever. At a point in time as youcontinue to advance the lever,the spark will become unstable,then jump ahead in timing. Asyou continue to advance thelever the spark will now advancein a logarithmic fashion, fast atfirst, then slower and slower un-til it reaches the new centralpoint, which is 22.5 degrees ad-vanced from the old centralpoint. As you continue to ad-vance the lever, the timing willbegin to retard and the cyclestarts over again.

Hal WilsonTom Carnegie

Hal Wilson passed away recently. I knew himfrom when I ran in the Montana 500 the seventies.I will describe my first impression of him. I don’trecall what year it was, but on this particular runhis car was disqualified in the pre-race inspectionbecause he had relocated his fuel tank underneaththe dash instead of underneath the seat. At thattime it was common to switch body parts aroundfrom year to year. His car had very early flat stylefenders and a 1925 or so body. His thought wasthat since 1926-7 cars had their tank in the cowl,why not an earlier car? At some point in the pre-race meeting the drivers voted to overturn the in-spectors’ and directors’ decision and allow Hal torun his car that year. I understand that Hal was afull-bird Colonel in the air-force and generally hadthe stoic demeaner fitting to the rank, but I couldtell that he was affected by the show of supportfrom the drivers. The next year another car wasdisqualified at the start and Hal stood up at the pre-race drivers’ meeting and made a motion to allowthis fellow to run. The motion passed. Hal andseveral other fellows from Colorado were quite in-volved in T road racing and formed their own racecalled the Colorado 500 that ran for several yearsin Colorado. Hal was known to drive his model T(usually a brass roadster) great distances. He likedto drive from Colorado all the way into Canadaand into the Arctic circle, often on primitive roads.He had articles published in both the Vintage Fordand the Model T Times.

2006 RULESNote: All cars that tour along must meet the rules flaggedwith a *.Note: Newly adopted or changed rules in italics.1 * Directors are responsible for interpretation of all

the rules pertaining to the Association. Decision ofthe Directors is final.

2 * All cars must comply with Montana license andinsurance requirements.

3 * No alcoholic beverages will be allowed in com-peting cars. Substantiated violation is cause for dis-qualification.

4 * Drivers performing in an unsafe or unsportsman-like manner will receive 1 warning. Second infrac-tion may result in disqualification upon review andaffirmative vote of 2/3 of the remaining drivers.

5 Not more than two people are allowed per en-durance car while under time.

6 * All drivers and relief drivers must be a paid-upmember of the MCCTA.

7 * No tailgating of support or tour vehicles or anynon-participating vehicles..

8 *All participating cars must have attached or placeddirectly on both sides a sign with name of sponsoror owner and hometown. Use three (3) inch letterspreferred.

9 * All "T"s will be available for subsequent inspec-tions at any time.

10 * All drivers and relief drivers must sign an En-durance Run waiver and Inspection Form

11 All T's must be assembled from stock parts and/orreproduction parts equal to stock specifications.Cars must have four fenders, splash aprons, run-ningboards, front splash apron, dash, and radiatorshell and all replacement body parts must be madeof metal, with the following exceptions:

12 * All competing cars must be equipped with twoheadlights and one rear stop/tail light in workingorder.

13 * Horn of any type in working order required.14 * Rear view mirror of any type required.15 * Emergency brakes must be in good working or-

der.16 Windshields must be stock for year of car. No al-

tering. Must have safety sheet of safety plate glasstop and bottom. Windshields to be completelyclosed and sealed.

17 * All transmission bands must be in good workingorder.

18 * Complete set of floorboards required.19 Body parts must be stock for year of car.20 * Padded seat and back rest of any type required.21 Original turtle deck may be replaced by some type

of substantially built box or turtle deck. Minimallength and width equal to size for stock turtle deckon that year of car, with floor, sideboards and end-gate. Sides and end no less than six (6) inches highfrom the floor and made of no smaller than 3/4 inchwood.

22 Rebuilt radiators allowed. Must be built to stockdimensions including tanks and side brackets.

23 Gas tank must be stock for that year of car andmounted in stock position. Gas strainers allowed.Fuel line not to exceed 3/8" I.D.

24 * At least 36 inches of 1 1/2 inch exhaust pipe re-quired, properly attached to and extending from theexhaust manifold.

25 Only stock cast iron or aluminum intake manifoldswith ports not to exceed 1 1/8" diameter are al-lowed. New manufactured manifolds with ports notto exceed 1 1/8" are allowed. No grinding or per-formance enhancing alterations of the intake or ex-haust ports allowed.

26 Oiling system options: One outside oil line al-lowed. No modifications of the inside oiling systemallowed. Transmission oil screen allowed.

27 Only stock Ford roller type, New Day, Andersonflapper type timers or Crystal timers allowed. Ball

or needle bearing rollers optional. Quick couplersNOT ALLOWED in timer wires. Internal timermaterial optional.

28 Rear ends must have 11 tooth pinion and 40 toothring gear. Ruckstell locked in high.

29 * Body must be painted, color optional.30 Hoods are not required. Tops of open cars, use of

muffler, and fans are optional.31 Holes must be drilled through the heads of the fol-

lowing bolts for braided seal wire: Left hand fronthead bolt, Right hand middle head bolt, Middle twosmall pan bolts, and a hole must be drilled throughthe threaded end of both bolts that fastens the car-buretor to the intake manifold.

32 Only NH swayback and/or Ford "F"swayback car-buretors allowed. Must be complete includingchoke butterfly. The Association's 0.710 inchgauge MUST NOT go through the carburetor.

33 Modifications of venturi and throat of carburetorsallowed as long as the Association's .710 gaugedoes not pass. Carburetor must be complete includ-ing all butterflies, adjusting needle, and stock sprayneedle. Butterflies must be original size.

34 No performance enhancing fuel additives are al-lowed. Cars must use straight automotive pump gasas fuel during the race time, starting with inspec-tion and continuing until the end of the race.

35 The top 3 cars will be torn down immediately fol-lowing the last flag. Additional teardowns will beput to a vote of the Endurance drivers. Endurancedrivers will vote to accept or reject items of ques-tion.

36 The first, second and third place cars will be torndown by a panel of five inspectors appointed by theBoard of Directors. None of the inspectors may bea driver of the car to be inspected. If a car is dis-qualified, the next place lower will be inspected,until three have been found qualified. An inspectorwho is the driver of the car coming up for inspec-tion due to disqualification of another car will be

replaced by the directors with another inspector.All inspectors must vote.

37 Chassis parts may be assembled from any year Tparts.

38 Zerk fittings in place of oil and grease cups are op-tional.

39 Only Model "T" wire, wooden spoke or diskwheels allowed. May use Model "A" 21 inch wirewheel or 30 by 3 1/2" wire wheels.

40 Only stock Model "T" or Ruckstell rear-ends andaxles with:

-standard eleven tooth pinion

-forty tooth ring gear

-stock roller bearingsOptions: Bronze or roller thrust washers. Neoprene seals.41 Bolts on wishbone at rear of pan must be safety

wired. Front wishbone accessory braces on pre-1920 cars allowed. Use standard wishbone sizes.

42 Shock absorbers are optional.43 Use stock configuration spring sets with a mini-

mum of seven leaves per spring set.44 Use a group 1 six volt wet cell battery for magneto

system back up, lighting lamps, running horn andstarter. Six 1.5-volt dry cell batteries may be usedin lieu of the above 6-volt battery.

45 Cylinder bore not to exceed 3.825" maximum or3.750" minimum

46 Cast iron or aluminum pistons of stock Model "T"type required. Cast iron pistons must have a full setof .250" width rings in place. Aluminum pistonsmust have two (2) .125" width compression ringsand one (1) 0.1875" width oil ring in place. Knurl-ing of piston optional. Refer to Illustration for Pis-ton Dimensions

47 There must be one stock piston, rod and cap assem-bly in the engine. Exceptions: Cap may be drilledfor dipper, and grooved for oil. Choice of rod boltsand nuts optional. The other three (3) assemblies

can be balanced to this one.48 Rods must be Model "T" Ford script. Maximum

center to center distance of 7.030" measured fromcenter of rod journal to center of wrist-pin.

49 Only Ford script high heads allowed with the fol-lowing exceptions: No limit to amount of milling ofmating surfaces; Removal of metal in combustionchamber may be done to allow clearance for shoul-der of piston and head of valves. Refer to Illustra-tion for Head

50 The crankshaft must be Model "T" Ford Script witha stock stroke of four (4) inches. Chroming, hard-ening or grinding of journals allowed, not to ex-ceed 1.250" maximum or 1.208" minimum diame-ter.

51 Counter-balanced crankshaft not allowed.52 Valves: Stainless steel and swirl polished valves

are optional. For all valves use a minimum stemdiameter of 5/16", a maximum head diameter of1.500" and seating face of 45 degrees. Use eitherpins or two piece keepers. Hardened valve seats areoptional. Radiused, 45 degree or three angle seatgrinds allowable.

53 Use of offset key between crankshaft timing key-way and the crankshaft timing gear keyway is op-tional. Camshaft timing gear material optional.Camshaft gear may be drilled to realign camshaftpins for valve-setting purposes only.

54 Any cam that doesn't require modification of theblock may be used. Bearing bores must be standardsize, no relieving of the bearing bores. Camshaftbearings and seal optional.

55 Type of fourth main is optional.56 Type of band material optional.57 Gauges are optional.58 Design and use of water pump optional.59 "V" type belt and pulleys optional.60 Adjustable flat tappet lifters (push rods) of stock

dimensions, stem oversize to 1/32" allowed.

61 Balancing of rotating parts is optional.62 * Each car will come to a complete stop before

starting at the timers direction.63 Timing will begin as designated for each car

whether or not the car is on the starting line. Start-ing times can be adjusted at the timer's discretion.If the timers recognize a beneficial savings in time,a lagging car may be sent out ahead of its desig-nated time. Usually this will be discussed with theDirectors ahead of time. Time will start for this carwhen it leaves the starting line.

64 Removal of head or pan while at stop (not undertime) or on tour day will impose a time penalty of 1hour. Report this infraction to the inspectors imme-diately. Removal of head or pan under time must bereported to the inspectors at the first opportunity forreplacement of seal.

65 Changing the carburetor imposes a time penalty of15 minutes. Report the infraction to an inspectorimmediately. Replacement carburetor must meetthe requirements stated in the Inspection Rules.

66 Disabled cars will receive slow time for each legnot completed, plus a daily penalty of one hour. Inaddition, cars trailered in on the last day are not eli-gible for prize money or trophies.

67 Replacement of complete engine is cause for dis-qualification.

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