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castings #'s


daveid
02-22-2005, 11:53 PM
if i were to give you guys my casting #'s off my 400 block could someone here tell me what year it was built. I dont want to spend 20 bux on a book that for now id only use once.
Also, not trying to sound dumb but before i buy and parts for an engine rebuild too, i should take the block in right and have them check to see if its ever been bored out?

thanx
david

MrPbody
02-23-2005, 12:41 PM
The casting date on a small block Chevy is located on the right side (passsenger's) at the rear, on the top of the bellhousing "flange". It is a 4 digit "alphanumeric" code. The first digit is a letter. That letter corresponds to the month (A = Jan, B = Feb etc.). The letter "I" was not used. The second and third digits are the day of the month. The last digit is the last number of the year. Example: B124 Feb 12, 1974 We know this, as there were no 400s made in '64 OR '84, so logical deduction gets us to '74. While locations on blocks and heads differ from one family to another, this is the dating convention used by GM, across all lines, at least from '55 through '96. Probably more.

Yes, take the engine out and tear it down, keeping pistons in order. If you intend to reuse the cam and lifters (not recommended unless relatively new or "special"), keep the lifters in order, too. They MUST go back in on the same lobe they came off.
Take it all down to your machinist and have him determine what you need, and maybe, what you might WANT. Understanding the "need" is something not to negotiate, but "WANT" is entirely a negotiation.
It is marginal, at best, to bore a 400 smnall block past .040". I know, I've seen them at .060 and live, too. BUT... I've seen them die a horrible death from overheating, too, when at .060", and all tune points correct, and cooling system working well.

daveid
02-23-2005, 02:18 PM
thanx for the help again. i think if i was to bore it id do .30 over if i even bored it. im just looking for around 400 hp. i was thinking about just replacing the rings on the engine and then just using it again like that but id rather take it all apart and learn it all. That has alawys been a dream of mine, to be able to build engines.

thanx again for the help
david

MrPbody
02-24-2005, 08:33 AM
David,
It's a common misconception, that boring adds power. It can, IF the over-bore is a lot. A .030" over bore is merely to "clean up" the bore, and provide a new finish for good quality parts. Most replacement pistons are "compensated" to maintain the current compression ratio (the pin is about .020" higher in the piston over stock).
I would recommend, if the 400 is standard bore now, to bore it no more than .020" the first time, if that will rid you of the cylinder taper and "bad" spots. Insist on using a deck plate when honing to size. 400s are notorious for out-of-round and taper. The plate simulates the head being bolted on, distorting the tops of the bores in a similar manner. Thus, when finished and the head bolted back on, the cylinder comes back "round". This is good for both power and longevity. The few extra bucks are worth it.
As for ringing it, measure the bores first. If any are more than .005" tapered or .003" out-of-round, bore it. Chances of a set of rings seating in a worn out bore are pretty bad.
Have fun! Get a book!

Jim

daveid
02-24-2005, 02:32 PM
thanx, i just ordered a book and also the boxwrench 8 point engine building video. Thanx again fo the help.
david

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