Valve Stem Adjustment With Non-Adjustable Original Tappets

[H. L. Chauvin]

1. I learned this vintage method of valve stem adjustment in conjunction with using original Model A tappets while re-seating/lapping many Model A valves over 56 years ago. Learned it from from my vintage Auto Manufacturer trained Uncle, a professional, full time mechanic who was born in 1905.

2. Because of working with removing only a few thousandths of an inch off of the bottoms of valve stems at a time, it was always determined best to use vintage hand crank emery wheel grinders for less vibrations and better accuracy.

3. If one does not have a hand crank grinder, they can be purchased on E-Bay and if need be, later fitted with about an 80 grit or finer "new" precise grinding wheel which may cost about $3.00. The grinding wheel can be trued side to side, (if needed), with round paper disc shims on one or both sides of the grinding wheel.

4. These are the types of hand crank grinders which can be very securely fastened to a work bench or a table with a bottom hand turned clamping screw.

5. One can make a wood, valve holding jig out of three (3) pieces of a 1x4, such as an approximately 12" long horizontal piece; and two (2) attached vertical pieces approximately 4" tall. Provide a vee cut in the tops of each of these two (2) vertical 1x4's, at the exact same heights, (approximately 3" high or the very close to the height of the grinding wheel's axle of the securely fastened hand crank grinder.

6. Secure these two (2) vertical wood vee pieces of 1x4, (spaced approximately 4" apart), screwed to the 1x4 horizontal plank, i.e., spaced to fit the cylindrical valve stem. With a round file, trim wood in the bottom of each vee to insure that the valve stem will be set parallel to the bottom plank, and so the valve will be level with the top of the work bench, and more importantly that the valve will be set 90 degrees horizontally to the vertical "side" of the grinding wheel.

7. After securely clamping the hand cranked grinder to the work bench/table, (wife's Dining Room Table works great), use a small carpenter's square to set the valve in the valve jig at 90 degrees to the side of the emery wheel, (i.e., valve stem set both vertically and horizontally at 90 degrees to the grinding wheel), and securely clamp the 1x4 wood jig to the work bench with a separate "C" clamp. Measure both 90 degrees horizontally and vertically to the grinding wheel very carefully as one is clamping the 1x4 valve holding jig.

8. By securely holding the valve in the vee, and letting it firmly touch the side of the grinder, turn the crank grinder to remove very little from the end of the valve stem, (if required), and after a few seconds, try same for vertical clearance between the end of valve stem and the original tappet.

9. If one removes slightly too much off of the end of the valve stem, one can re-lap the valve with valve grinding compound to make the valve sink slightly deeper in the block to get proper clearance between the end of the valve stem and the original tappets.

10. Provide .011" clearance on intake valves and .013" on exhaust valves for "A" & "B" engines for trouble free noiseless valves.

11. Try one valve first to witness how little metal has to be removed after lapping valves. It just requires a little common sense and a little patience. My last valve job done like this lasted over 36 years with no problems, until I dismantled my 1930 coupe.

[Russ/40]

Photo?

[H. L. Chauvin]

Hi Russ,

No photo, send your email and I'll try to send quick 2 minute freehand pencil sketch.

[katy]

https://www.google.ca/search?q=hand+...w=1024&bih=610

[H. L. Chauvin]

Hi Katy,

Thanks for multiple pics of different hand crank grinding wheels. I have three (3) hand crank grinders left by my Dad.

The "pink" stones are the real fine grit and really "best" for fine, and very accurate valve
stem work.

Everybody in our neighborhood used to bring scissors to my Dad, (born 1902) for him to sharpen their scissors on his delicate hand cranked "pink" stone.

When finished sharpening scissors, he could slightly open the scissors in any position and cut thick brown wrapping paper like when cutting paper while using sharp straight razor blade.

[George Miller]

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Very good explanation. I might add, it is best to return the valve to the same hole it came from. Because all the valves will not be the same in length after lapping.

I know that you know that and any one who has done it knows that. But some one who has not done it might not think about it.

[H. L. Chauvin]

Hi George,

1. Valve Tappet/Valve & Valve Guide Wood Stand Jig:

A. For temporary Model A valve storage while lapping valves and/or partially rebuilding/restoring a Model A engine, you mentioned an important point to add for those not familiar with precision Model A valve location details.

B. In order to make such a jig, we used to drill (16) "pencil marked and numbered" holes in (2) separate thin wood planks, and provide and secure one (8) hole plank on top of the other (8) hole plank secured below.

C. Next, we marked the top planks (1) through (4) for pairs of valves placed in matching valve stems; and the bottom plank was marked (1) through (8) for
corresponding "original" tappets.

D. These separate markings on separate stacked planks were provided to insure that
tappets and valves in matching valve stems went back together in their same original holes in the Model A engine block.

E. The Number one (1) two holes in the top plank was for the two valves located near the radiator; and an "I" was marked near #1 holes for the intake valve placed in the corresponding intake valve guides, & an "E" was marked for exhaust valves placed in corresponding exhaust valve guides; hence, when completed the (8) top holes were marked: (#1 - I) & (#1 - E) …….. (#2 - I) & (#2 - E) ………. etc.; and valve tappet holes on the plank below were marked #1 through #8.

2. Caution: We learned that many of the later replacement, "Non-Ford" Model A steel valves were not interchangeable because they were manufactured differently; e.g., if one mistakably provided an intake valve in an exhaust valve location, this milder steel intake valve would burn in the first 500 or so miles -- Ford always cautioned to use only Ford valves .............. but many of the "cheep, cheep. cheep" Model A owners always bought the cheaper replacement "Non-Ford" valves.