Hey Gang: Jim Leis (RIP) at one time did a CAD drawing of the original Ford blueprint for a flathead cross-section. It showed dimensions for all the major areas of the block, crankshaft, cam, valves, angles, etc. I have a copy of the drawing, but only in image format (which you really can't zoom into). I want to make a parametric CAD model in SolidWorks to validate the dimensions - as I don't believe they are accurate as far as offsets and centerlines. If Jim was still with us, I'd just go to him . . . but sadly he has passed. I'd like to be sure of the dimensions I'm seeing on my poor copy. If you have them, please eMail to: [email protected] PS: I'll share the newly created one - along with the findings back to the HAMB! Thanks!
You really need to check out this thread on the Ford Barn: http://fordbarn.com/forum/showthread.php?t=156253&showall=1
I've seen the pre-war example -- which was based on a drawing out of England. The only part that is funny is that the dimensions are not actually possible (I built a parametric design with all the centerlines and dimensions plugged in). This means that I really don't know the crank/cam centerlines (in reference to the center of the block) - but I have measured the valve angles in my 42 Merc block and they do match the drawing. About the only way that those valve angles are possible, is with the camshaft offset (at least that is the way I see it). I wish I had a BIG CMM machine that I could use to figure out all the locations - maybe on a mill with electronic read outs! Dale
"Drawing out of England"...I think he started with the Ford USA or Canada service bulletin drawings that are on the back of the dyno sheets for various years. I hooked him up with the Ford England engineering text that explains the function of offset in engines, but the drawings there are not based on flathead V8, they are just drawings done to illustrate the geometry of the movements with offsets. If you look closely you can tell there is a bit of flavor from the Ford England 4 bangers, but they are essentially generic text drawings.
Hey Bruce - thanks for the clarification. The drawing he based his work upon I've seen a few times - I only wish I could find one that is correct and original from Ford . . .
Hey Gang Update: for those of you who are looking for dimensional details . . . I've just been going through the original Ford drawings for the 59AB and the 8BA engines (from the Ford archives) - Flat32 sent them to me. I've redrawn the critical dimensions in a parametric CAD program - such that I can validate them as accurate. What I mean by this is that when I draw the key centerlines/offsets/etc. and program in all the dimensions - the 'driving dimensions' will force the 'driven dimensions' to recalculate. This means that you can't really have a wrong dimension if all the lengths, angles, etc are correct. What I've learned is as follows: 1) The drawings are correct - the geometry, angles and dimensions do work out (this is very good news). Interesting facts (some are obvious): a) The crank centerline does drive the deck height - even though the bore centerlines are offset from the crank. This is obviously true or you couldn't have the same length pistons/rods on both sides of the engine. b) The bore angles are 45 degrees from vertical, but they are offset to the driver's side by .2651 inches. This results in the crank center-line versus bore center-lines to be offset by .1875" (in the bore center-lines) c) The cam center-line is also offset to the driver's side - by .0242 inches. d) The valve angles are the SAME between 59AB and 8BA (though different from earlier 32-41 engines. The passenger's side valve angle is 48.641 degrees and the driver's side is 51.385 degrees. e) The overall length from the center of the cam to the top of the valve seat is the same side to side (about 7.0675), but the valve angle causes the driver's side valve to be higher (at the top side) by about .044. This was validated today when I was at my machine shop, the valve guy measured the height differences (side to side) at about .040. Those of us who've worked on these engines for years can attest to the tops of the valves being up higher on the driver's side. As a side note, it is rumored that some head manufacturer's (heard Edelbrock at one time) actually made different heads side-to-side for the 24 stud center water-neck designs (to account for valve angle, valve heights and chamber volumes). Here is a PDF of the CAD design - hard to see here, but you get the point:
Now...did you ever get hold of Jim's drawings?? I think I have some clean small ones, 81/2X11, that I can locate. There are bigger ones, but I doubt I can find them until I accidentally trip over the things...my life has been pretty chaotic. And, do you have a copy of the Ford book with the Desaxe discussion and computations?
Hey Bruce, I do NOT have any of Jim's drawings in a very readable state. I'd love to have some bigger copies - hopefully in a CAD/Vector format. The drawings that I have for 8BA are pretty good, the 59X drawings that I have are really difficult/poor to read and I don't have anything that is pre-59x. I'd love to create another CAD drawing that has all the dimensions for 32 - 41 (though I'm sure there are differences there as well). If you have anything, would love to have it. Ultimately I plan to create a 3D CAD model of the 8BA - but I'm a bit busy at the moment, so it will take awhile. Thanks for all your input on this subject! Dale
Will try to locate what I have...one prewar, one postwar. PM me a mail address and I'll try to dig up a book.
The Jalopy Journal
