View Full Version : Main Caps Not Numbered

11-24-2006, 08:25 PM
Working on a early engine block. Was told it's a 55 but ????. Block casting is # 535601 and stamp number is P I445I. What is it? The main caps have no numbers on them. Number 2, 3, 4 caps are not numbered. Does this mean the machining is so good they are exchangeable to each other? First block I have broken down that had no numbering on the caps. Thanks.

Start and Stage Your Studebakers

11-24-2006, 08:30 PM
It's a 1955 259cu.in. President engine. Goofy durned 1955 classifications anyway!
That's a first - no numbers on the caps. Hope you marked them as you took them off! [:I]

Miscreant adrift in
the BerStuda Triangle!!

1957 Transtar 1/2ton
1960 Larkvertible V8
1958 Provincial wagon
1953 Commander coupe

John Kirchhoff
11-24-2006, 10:09 PM
Those main bearing caps not being numbered, I wonder if they could be replacements and not the orginals?

11-24-2006, 10:50 PM
On my 289, only caps #2 and #3 are marked with a cast, raised numeral. Everything appears to be machined flush. Since the front and rear caps are readily indentifyable, there is no guess work. I would say that if you have the 3 nearly-identical center caps mixed up, that it still wouldn't be hard to figure which goes where, just by trial fitting them with the cap screws and see how they line up with the block mating surfaces. Maybe put a dial bore gage or snap gage in there to check them out after they are torqued. Don't do it with the crank and bearings in just yet, because getting them in the wrong spot may lock up your crank.

Neal in NM
11-25-2006, 10:38 AM
Had two customers in one month come in my shop with the same problem. They both complained that the plastic gage wasn't showing the right size and wanted me to measure the crank to make sure it was ground properly. On one engine both the rods and mains were mixed and unmarked. With CLOSE visual inspection I was able to arrange the caps in their proper order. Remove the bearing shells and look at the cross-hatch in each cap. You should be able to line up the cross-hatch marks between the caps and block. Once you think you have it right, torque the cap down without the bearing and measure the hole to make sure it is round and compare its size to a torqued cap that is known to be right. Neal

11-25-2006, 05:35 PM
Got here dead on. Crank turns fine. Thanks everyone.

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