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Discussion Topic:
Crankshaft Questions
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Crazy Horse |
08-11-2019 @ 4:40 PM
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Member
Posts: 3
Joined: Aug 2019
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I'm brand new here on the Early Ford website and I have a question. I've done a bit of research and I think that there were several differences between the last two versions of the Ford 239 V8's (such as cylinder head design, distributor location, etc). My question relates to the crankshafts found on Ford pickup trucks over this time span, specifically the crankshaft on a 1946 pickup vs the crankshaft on a 1949. If a person was to salvage a crankshaft from one of these versions, could it be used on the other? Hopefully I am asking this question in a way that it makes sense.
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carcrazy |
08-11-2019 @ 7:59 PM
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Senior
Posts: 1682
Joined: Oct 2009
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The crankshafts between 1946 and 1949 have some differences. The most notable one is that the 1946 uses full floating rod bearing inserts which rotate on the journals within the rods. The rod inserts in the 1949 engine are locked in place on the rods like most other engines. The oil distribution holes in the two crankshafts differ due to the difference in the types of rod bearing inserts employed. Crankshafts can be interchanged from one engine to the other once proper modifications have been made.
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Crazy Horse |
08-12-2019 @ 5:01 AM
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Member
Posts: 3
Joined: Aug 2019
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Thanks for the reply and information, very helpful for sure. My friend has been in touch with someone who has a used crank for sale but it is not very close to home and a first step would be to find out if it is interchangeable to begin with.
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42merc |
08-12-2019 @ 7:23 AM
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New Member
Posts: 126
Joined: Dec 2010
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The '49 FORD crank can be used in the '46 without modifications. The'46 crank will fit the '49, but will not oil the rods correctly due the single oil hole designed for full floating bearings.
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TomO |
08-12-2019 @ 8:37 AM
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Senior
Posts: 7264
Joined: Oct 2009
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I have a 29A crankshaft for sale. This was used from 1942-1948 and cannot be used with 8BA rods. Send me a PM if you are interested.
Tom
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37RAGTOPMAN |
08-14-2019 @ 10:38 AM
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Senior
Posts: 1969
Joined: Oct 2009
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hi before you buy any crankshaft make sure you have a shop that can grind it for you, not to easy to find today, and you can get 8 new rods for that specific crank. plus the bearing, do not resize the old ones, if possible, is you engine knocking now, why the need to change it,? you can also use a 4 inch MERCURY crank, 255 cubic inches, a book on flathead engines would be handy , hope this helps., 37RAGTOPMAN
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Crazy Horse |
08-15-2019 @ 5:36 AM
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Member
Posts: 3
Joined: Aug 2019
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Thanks for the reply. Actually, I am posting the question for my friend who is rebuilding the engine for one of his customers. The previous crank was at its limit for regrinding I believe. He has found a crank complete with the original set of Ford rods. It will be up to his customer to decide how much money he wants to put into this project, but there is a local shop who can do all of that stuff you mention. Those engines certainly have a LOT of history when you start looking into what happened through the years. I suspect that is the same for most engines that had such long runs of production.
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supereal |
08-19-2019 @ 8:05 AM
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Senior
Posts: 6819
Joined: Oct 2009
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We grind many crankshafts at our shop, and carefully check for problems before we commence. We address the need for bearing size, and rebalance the crank as necessary. A good many cranks are not suitable for grinding and polishing due to excess wear or damage.
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