STATUS OF ENGINEERING
This engineering study is complete. It proves that an engine can be built to modern standards by changing a minimum number of parts. Preliminary calculations indicate that that the stresses at 150 HP and 5000 RPM are within the allowable limits (fatigue endurance limit) for commonly used automotive materials (Ductile iron connecting rod and crankshaft, gray iron cylinder block). Stronger materials (added cost) would easily allow higher HP and RPM without any redesign.
Additional processing (added cost) by rolling the fillets and nitriding would make the ductile iron crankshaft stronger (however this added strength would be lost if the crankshaft were ever reground in a later rebuild). Ductile iron connecting rods could be made stronger by shot peening.
The creative engineering for this study is complete, but the detail engineering is not complete.
The detail engineering tasks that still need to be completed include additional FEA analyses, small design changes as a result of the FEA, creation of drawings with notes and dimensional tolerances, selection of materials, specification of processes, and surface finishes. Engineering effort is also required for meetings with foundries and machine shops, and to write a Quality Assurance (QA) plan to assure that any hardware delivered meets all solid model, drawing, material, and processing requirements.
The cylinder block casting cores are all designed and documented with solid models. What remains is a small amount of engineering at the foundry to add draft and shrinkage allowance, make core boxes, and design the gating system. Engineering is also required at the machine shop to transform the "machined casting solid model" mentioned above into a program for CNC machines.
Several small cylinder block external discrepancies between the original Ford drawing dated 28 March 1929 and several original cylinder blocks produced were noted (mostly differences in fillet radius and centering of oil pan attachment bolt holes in their bosses). Engineers in the Model A era were mainly concerned with machined interfaces and what happened between these interfaces was often left to the discretion of pattern makers. The solid models created in this study are from the original drawing, but modified in an attempt to reflect actual hardware produced, but they are not 100% correct. With today’s technology, the external surfaces of an original cylinder block can be laser scanned to exactly create a solid model that is 100% identical to an original cylinder block. Cylinder block *A4619726* is an extremely good example because all of its’ oil pan attachment bolt holes are centered in their respective bosses. So, for this new cylinder block to match an excellent original example, the exterior of cylinder block #*A4619726* should be laser scanned and this laser scan will become the solid model of the exterior of the new cylinder block.
The redesign presented and described in this article is not optimal. If time and cost were no object, the design / FEA cycle could go through many iterations to finally optimize the design. Intake and exhaust port design could be improved upon with flow bench testing. Additional optimization could easily be achieved even with today’s materials. Exotic processing methods and coatings could be used to enhance performance. Metal Matrix Composites (MMC’s) and ceramics could also be utilized.