Couple A Questions
Yes, it snowed here in Iowa also. I like winter. Time to build things. Anyways I got a couple of questions. I've tore many motors apart this year. Some were sitting for some time and and good blocks but the main oil gallery's are rusted badly from mice building nest and moister collecting in the valve chamber. Pretty cool mouse to live in a old flatty huh? So my question is has anybody tryed to replace this tube before? Tried to repair one? Any ideas? Also have a '37 motor in good running shape. Would this motor have the rods that I would need to build a 4-1/8' stroker? I believe there is 2 different rods that can be used for this application. One a little stronger than the other. What would this motor have? Also have noticed that some '46-'48 cams have groove on one side of rear cam journal and some have groove on both sides of rear cam journal. Anybody know what gives on this. Well thanks in advance for any info you can help with and I still say the worlds flat. hotrod

V8CHRIS (Dec 7 1999 11:28AM) RE: Couple A Questions
Hotrod, I am aware of two types of small big end rods that can be used for a stroker. The one that you see written up all the time in the mags is the 21A rod. This I believe was used in '42 engines and the aftermarket. These rods replaced the 91A rods that look similar but are not as well reinforced where the big end meets the beam. 91A rods are much more plentiful. I would be interested in comments by others. V8CHRIS

JWL (Dec 7 1999 1:15PM) RE: Couple A Questions
It is not likely your 37 engine has the correct rods for the stroker. The 21A rods for strokers were used from 39 to 42 in the 85 HP (3 1/16 bore) engines. The earlier rods were thin at the crank end for use with bearings which had lips on them.

Anonymous (Dec 7 1999 1:21PM) RE: Couple A Questions
My old green 'bible' says that a '37 should have rods numbered 48-6200, but as Chris said they could be 91A-6200, but the best ones are 21A-6200, they are the ones to use in a stroker, if possible. Info is sketchy on cams, 91A-6250B was used in 39-41 with attached coil distributor with caps on each side, it was replaced by 21A-6250 which was used '35-'48, but with the above distributor you need an 11A-6280 cam adapter, which makes the late cam work with early distributor. Nothing specified about oil grooves??

Rolf (Dec 7 1999 2:36PM) RE: Couple A Questions
Forgot to sign previous message, but it just occurred to me that that '37 engine, if it has insert mains is a 'goody' highly sought after by early V-8 guys who want an easy to rebuild 21 stud engine. Just a word to the wise-

Hotrod (Jan 1 2000 9:45AM) 21A and 19A rods?
I tore a '40 motor down and it has a mix of 21A and 19A rods. They are supposed to be different but if they are I can't tell. Whats the difference? Does anybody know? If I was to build a stroker motor would they work mixed like this? There was 4 of each in this motor. I couldn't tell the difference till I looked for the number on then. Thanks for you thoughts. hotrod

Lars Brandow (Jan 1 2000 11:26AM) RE: 21A and 19A rods?
I would at least check the weight of them.But i guess thats a part of balancing the engine.

rumble seat (Jan 1 2000 4:47PM) RE: 21A and 19A rods?
hotrod: As you know, the 19A rods were used in '41 Mercs and the 21A rods were used in '42 Fords. According to Tex Smiths's Flathead V8 book, the 21A is more desirable since it has a thicker beam and is stronger. Both rods are the usual 7 inches long. Both are for crank rod journals 1.999 inches in diameter. In '46 Ford went to the bigger crank rod journals of 2.139 inches. Since one has a larger beam, I would hesitate to mix since grinding all that excess material away during balancing may weaken the rod. I would use 8BA rods since they're bearings are a whole lot cheaper and are not that hard to find. Someone else also had some mixed rods in an engine he recently bought. Maybe between the two of you there is a set.... rumble seat

Rolf (Jan 1 2000 10:53PM) RE: 21A and 19A rods?
This is the kind of question the auxiliary website BillB is working on can really help, as a matter of fact this issue was included in his prototype, check it out, also, a stock '40 motor has the smaller crank journals, and the rods were originally 91A, and were replaced by 21A that are a bit stouter in construction.

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