The Ford Barn - View Single Post - 21 stud deck height, gasket thickness, etc. questions.

Bored&Stroked · 11-02-2021, 07:26 AM

I went back an reviewed both the 59AB and 8BA prints - they both show 10.445 - 10.450. So maybe it is different (not by much), though that earlier print doesn't show a manufacturing tolerance . . . so we don't know the low and high end of the range. It would not surprise me if all blocks were supposed to be the same . . . within a range of tolerances.

On the crank, as Frank mentioned the first slinger is the rear thrust surface and I guess also a slinger and the second one is the actual oil slinger that rides inside the pot-metal rear main seal-plate pieces. Some folks will remove the second slinger (on the crank grinder) and put in a later type rope seal. (And use the later pot-metal seal plate - or whatever you call it).

Also on the later crank, obviously the mains are different sizes from your 36 or so crank. I have no idea as to if there are any counterweight or other "fitment" issues if one was going to rework the mains and run the later crank.

I've not built early 21 stud engines, so I can't recommend exactly what the process is - though I've seen some custom seal plates/work done on the rear main caps to handle it.

11-02-2021, 07:26 AM	#25
Bored&Stroked Senior Member Join Date: Jan 2011 Location: Central Ohio Posts: 5,071	Re: 21 stud deck height, gasket thickness, etc. questions. I went back an reviewed both the 59AB and 8BA prints - they both show 10.445 - 10.450. So maybe it is different (not by much), though that earlier print doesn't show a manufacturing tolerance . . . so we don't know the low and high end of the range. It would not surprise me if all blocks were supposed to be the same . . . within a range of tolerances. On the crank, as Frank mentioned the first slinger is the rear thrust surface and I guess also a slinger and the second one is the actual oil slinger that rides inside the pot-metal rear main seal-plate pieces. Some folks will remove the second slinger (on the crank grinder) and put in a later type rope seal. (And use the later pot-metal seal plate - or whatever you call it). Also on the later crank, obviously the mains are different sizes from your 36 or so crank. I have no idea as to if there are any counterweight or other "fitment" issues if one was going to rework the mains and run the later crank. I've not built early 21 stud engines, so I can't recommend exactly what the process is - though I've seen some custom seal plates/work done on the rear main caps to handle it.