Jon, try fitting that seal around the crankshaft flange without a speedy sleeve. I think you'll find that it has an end gap that way, also.
Jerry
I've done that, Jerry. I have 2 cranks...one a 1959 in the engine currently and a 1956 here also (not being used). The 1956 measures 3.874~3.875" and a brand new Fel-Pro seal (held together tightly) measures 3.870". Holding it on the end of the crank, it isn't loose, but by the same token it isn't tight. There's an end gap, but a pretty doggone small one. I know from the past it would not seal for very long in the 1956 block...maybe 6 months to a year. It never seemed to be quite tight enough against the crank when I used it.
As for the 1959 engine, the clearance between my main bearing and crank journal at the rear was .0015 when it went together 2.5 ~3 years ago. I haven't checked lately, but I'd imagine it might be .002" or so now. When I put the engine together, knowing the problems I had with the 1956 block, I put a piece of copy paper between the crank and the Viton gasket. I stopped adding self-adhesive aluminum tape shims to the Viton piece when I got what I considered decent resistance top/bottom doing that (pulling the 1/2" wide piece of copy paper out). As I recall, each layer of the aluminum tape was .002" thick and I had to add 4 layers to get the seal to fit tightly enough.
As for offsetting the seal in the grooves, back when Fel-Pro was still making this seal I spoke with a gent (who had been there when this seal had been created...was retiring as I recall the week we talked). In that conversation, he mentioned they had reverted to telling people not to offset the 2 pieces. I asked him why and he said there were two reasons...one, people would not follow instructions...they'd offset the pieces too much...an inch or more and according to him that pretty well guaranteed they wouldn't work correctly and two, research they'd done indicated the ends butted together evenly at the joint would provide more uniform pressure on both sides of the joint which was how the seal was designed in the first place. He said if you thought you had to offset them not to rotate them by more than 1/16" inch at the very most. He also said it was important to remember to use a non-hardening sealer on the pieces where they went into the grooves.
Somebody wondered if anyone had disassembled a block in which the Viton seal had been there since the engine was new. Yes...at least I believe so. I was told by the prior owner the 1959 block I have had never been disassembled. It was obvious the water pump had been replaced and it had a rebuilt starter and generator, but no evidence of overhaul work at all. I took a picture showing one of the Viton seals I removed compared with a brand new one...below. The original had worn by almost 1mm and it had obviously been leaking back there.
