Many Model A owners will need their engine overhauled at some point. There are great many questions that come up when this occurs. We strongly encourage owners to do careful research, as there seems to be a lot of shops that claim they know engine building, but few that really do. Questions such as, babbitt or inserts, ring gaps, piston-to-cyl wall clearance, piston choices, camshaft choices, proper cleaning of the water jacket, valve clearances (lash), bearing clearances, and such need to be addressed. Word of mouth from the pros on this board will usually steer you right. Several of us have extensive engine building experience and would be happy to entertain questions and suggestions. It is important to note that in many respects, engine building is not something you want to skimp on. Clearly owners are looking for reliability and longevity. We can help you find that. But, of course, you get what you pay for.
We recently knew of a guy who bought a "freshly rebuilt motor" from a third party, "for a good price", and his complaint was, "I can't turn it over with the crank" RUN away, do not buy that motor. It has been built WRONG. Once he got it running, it quickly locked up, having spun the rear main bearing. I have seen line-boring done off-center. I have seen timing gears beat to hell because of improper assembly. I have seen piston-to-wall clearance done very wrong. The list is endless.
Be aware that any engine, and particularly the Model A engine, has peculiarities that MUST be taken into account for a proper build. For example, in most Model As, cylinders 3 and 4 run 10-20° hotter than 1 and 2. Your IR temp gun tells you so. As soon as the water returning from the radiator enters the block via the inlet on the driver's side of the block, between cyls 2 & 3, it is immediately sucked forward by the water pump. Little cooled water is left to circulate around the water jackets of 3 and 4. If this is not taken into account, you can have major problems. Those that are used to building a Chevy or Ford modern small block, for example, will be out in left field on an A motor.
Engine overheats can lead to shrunk (collapsed) pistons, a topic for another time, but we have seen it many times. In the meantime, make sure your newly rebuilt engine is timed properly, and had the water jacket properly cleaned during rebuilding, and get yourself a good radiator.
We recently knew of a guy who bought a "freshly rebuilt motor" from a third party, "for a good price", and his complaint was, "I can't turn it over with the crank" RUN away, do not buy that motor. It has been built WRONG. Once he got it running, it quickly locked up, having spun the rear main bearing. I have seen line-boring done off-center. I have seen timing gears beat to hell because of improper assembly. I have seen piston-to-wall clearance done very wrong. The list is endless.
Be aware that any engine, and particularly the Model A engine, has peculiarities that MUST be taken into account for a proper build. For example, in most Model As, cylinders 3 and 4 run 10-20° hotter than 1 and 2. Your IR temp gun tells you so. As soon as the water returning from the radiator enters the block via the inlet on the driver's side of the block, between cyls 2 & 3, it is immediately sucked forward by the water pump. Little cooled water is left to circulate around the water jackets of 3 and 4. If this is not taken into account, you can have major problems. Those that are used to building a Chevy or Ford modern small block, for example, will be out in left field on an A motor.
Engine overheats can lead to shrunk (collapsed) pistons, a topic for another time, but we have seen it many times. In the meantime, make sure your newly rebuilt engine is timed properly, and had the water jacket properly cleaned during rebuilding, and get yourself a good radiator.
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