The Stovebolt Site Forums The Shop Area Engine Shop Rebuilding Chevy V8, Questions.......

I finally pulled the motor out of my 79 today, and I have a few questions. First of all, the 3 center crank bearing caps have 4 bolts each, but the front and rear crank bearing caps have only 2 each, is this a 4 bolt main?

Next, I found that who ever owned the rig before blew the motor up, the #2 piston has a broken connecting rod and has dented the crank bearing journal, will the machine shop be able to fix this?

And lastly, I pulled these numbers off the rear of the block, where can I find out how to decode them (GM 14810207 I think), and on one side of the block it shows the number 207, what does this mean? I want to know what size motor this is, i think its a 350, but not sure.

Thanks for your guy's help in advance!

- Shane
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Yes, it's normal for the 4-bolt engines to have only the three center bearing caps with four bolts. If the bore size is 4", or close to it, you've got a 350 cubic inch engine. If the bore is 4 1/8", it's a 400 CI engine. There is a stamped number just ahead of the passenger's side cylinder head. The 2 or 3-letter code at the end of the number sequence can be converted into cubic inch displacement, carburetion, horsepower, and year of manufacture by just about any salvage yard, using the Hollander parts interchange manual.

If the crankshaft has more than minor scoring, it will need to be replaced. Try Ebay Motors for listings of new, not reground crankshafts. A new, standard diameter Eagle brand crank can be had for just over $200.00, plus shipping. A reground crank without a serviceable exchange shaft will cost you almost that much at most rebuilding shops. Id guesstimate a parts cost of around $600.00 to rebuild your engine, if you shop carefully. That would include a new or reground crankshaft, pistons, bearings, cam and lifters, and gaskets. Add $250.00 or so for machine work such as a good cleanup, reconditioning cylinder heads, boring the block, reconditioning connecting rods, etc. You can cut corners on a rebuild, but it will rise up and bite you in the butt in the long run!
Jerry

Try here to decode your serial #

http://www.nastyz28.com/sbchevy/sblock.html

You may want to start here http://www.chevyasylum.com/tech/decode.html if you want to figure out which number is whch.

There are probably other places but these'll probably work for you and at least get you started.

If it was a '79 and a 4-bolt main, and the original engine, it can't be a 400. The 4-bolt 400s were only used in the very early '70s.

Actually, the crank CAN be reused. But it has to be welded and turned. And then I would suggest having it nitrided again to harden the surface that has just been reworked. But it really depends on the depth of the scoring.

If it is 0.030" or less in depth, the machinist can turn the crank down to that level, and then thicker bearings are used.

My suggestion is to take the crank to a good machinist and see what he thinks. If it can't be saved, then yes, you can find a new crank for a few hundred bucks.

Expect to have the new rotating assembly rebalanced. Especially if you're replacing the connecting rods because one broke.

Another note on the bore...the 327 also used a 4" bore, but unless the engine was changed to a 327, they were not installing 327's anymore in 1979, so you probably do have a 350.
And if you rebuild the 350 0.030" overbored, you will have a 355.

Thanks for your guy's help so far. Well, so far I have found that this motor is probably a 350. Also, I will be takeing the block to a community college where I can have it hot tanked, bored, whatever for free.

I also plan on getting 2 new connecting rods, turning the crank no more than .020", estimated at $80 for all bearing journals (if it can be saved), .030" over is just cutting it too close, and told to get another crank at that point. Also getting a master rebuild kit, approx. $250.

Other than that so far, I have another list of other parts I need to get as well, timing cover, oil pan, valve covers, Air cleaner Assembly, push rods (if its not in the kit), clutch kit, have my flywheel turned/ground (estimated $8), and thats all I can come up with for the moment, LOL.

Yup, I have quiet an expensive project on my hands, but I pray that I will have it done by summer time!

- Shane
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Actually, that's really cheap as far as engine rebuilds go. I've got 10 grand into a 427 Chevy big block so far.

Compared to a 502 crate motor, is it worth it? Probably not. But then again, SCCA will let me race a 427 but not a 502.

Make sure you tell the instructor to have the students bore the block with the correct plates bolted up where the heads go (the name for that escapes me at the moment..."hone plate"?). But anyway, if it's overbored without that plate bolted down, it will result in an out of round condition when your heads get bolted down.

They're called "torque plates", and they're only necessary during the final cylinder honing, not the rebore job. Be sure the bolts holding the plates down engage the same number of threads in the block as the head bolts, or the whole operation is worthless. It does make a difference in the piston clearance when it's done correctly.
Jerry

Thanks for the replies. A quick update: I found out that my crank is worthless. But luckily one of the instructors will be able to get me another crank for free. He will also turn my flywheel for me, since the cost at the machine shop was actually $35, not $8.

My block is also in the hot tank as of right now, as well as the flywheel, being degreased. I also have another buddy who will see how much he can get me a master rebuild kit from one of his friends, and see if he can beat the $255 price.

Other than that things are going great so far, and Im glad I know the people I know, otherwise I would not be as far as I am. i learned a lot of tricks on removing freeze plugs, oil galley plugs, etc, from the instructor.

Has anyone here heard of PAW (Performance Automotive Warehouse)? They seem to have great prices, you can order their catalog online, costs $10 I think. Heres a link to thier site: Performance Automotive Warehouse

- Shane
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Oh yeah, I've ordered from them before. They're pretty good. I think they get the deals because of high volume...kind of like a Walmart for auto parts. I like their catalogue. Very detailed. If you can't find it in their catalogue, it probably isn't made.

Question - If I get the block bored .030" over, will it still be ok to run a stock cam? I really dont know what cams to look for for more performance so I was going to stick with stock.

Another update, the block is at the machine shop, and I wont get it back in 1-2 months because they are very busy. My mechanics teacher also didnt have a crank, but I took the one that was suppossed to be bad, and had the machine shop send it in to be welded and then returned. I am also having the cylinders bored out .030' over because the rust in each cylinder was a little too much. I've also painted the heads, and cleaned "All" of the bolts so far, and finished putting the front end back on the truck (grille, headlight bezels, triming) after cleaning the paint off them. Tomorow I might work on the front bumper, think I will paint it flat black, not sure yet.

Since im waiting for the block and crank to be done, I figured I would start on the dirty work cleaning parts, and saving up money. I only have about $350 dollars right now, but I need more!!

- Shane
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