Pistons, Rings and Bearings removed!

badvs3vil

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Hi again everyone. I am continuing tearing down my 400BB engine. I just pulled my first piston. I removed the top ring and popped back in the hole to measure the gap. Its around .042in. Not sure if that is ok or not. I also can see brass in the bearings, so those need to be replaced correct?

Also in the last pic, what are those numbers?

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GOLDMYN

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I believe those markings told the assemblers @ the factory, what weight pistons go in which cylinder, I've seen that many times.
 

Davea Lux

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Ring gap should be measured about 2" from the bottom of the bore, this is where the wear to the bore is usually the greatest. Be sure the ring is square in the bore before measuring. Factory spec was from .013-.052 for compression rings and .015-.062 for oil rings. If your measurements are accurate, you rings are still within specs but since you have the engine apart, do the ring job now. You also need to measure taper and out of round for the block to be sure the bores are still within specs. On a seasoned block it is usually better to use the cast type rings. Be sure to remove the ridge at the top of each cylinder with ridge removal tool and be sure to clean each of the rings grooves completely, carbon build up can cause you new rings to fit too tight in the bore resulting in breakage.

Your bearings are wear metal tracked, that is a small chunk of wear metal, usually from the cam lobes has gotten past the oil filter and been drug across the bearing surface creating a groove in the soft bearing material. These bearings need to be replaced. You should mic the crank shaft and and check it for pitting before proceeding to order bearings. You would also want to check the oil pump gears for impacted wear metal and pitting.

Dave
 

thethee

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Having never taken an engine that far apart these threads are very interesting, subscribed.
 

badvs3vil

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Well I got the crank out as well. Im actually going to take the block into the machine shop and have them check it for me and also hot tank it. Here is what the main bearings looked like.


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1970FuryConv

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I'd check the crankshaft bearing surfaces for burrs or ridges. They can be polished off with a long thin piece of fine grit sandpaper, generally 400 grit, and fast side to side motion (like shoe shine boys used to do when they buffed out your shoes)
 

Davea Lux

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If you have ridges that you feel moving a fingernail across them, the crank should be turned.

Dave
 

CBODY67

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The crank might "polish" rather than needing to be "turned", but if the existing journal size is out of the "standard" realm, it'll probably need to be cut .010" anyway.

After the bores were cut and honed, my late machine shop operative would use an Allen head socket to position the ring in the cyl bore (which at that time was the same top as at the bottom) and check the ring gap there. It was consistent after he got the ring "square" in the hole with the socket, that way. The "ring end gap" spec should be in the FSM or similar.

Most of the paint and such markings you reference are probably for use at the engine plant, which have very little to no equivalent in the outside world, I suspect, but mean something to the people in the plant.

Keep us posted on how things come out.

Take care,
CBODY67
 

mrfury68

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Utilizing the services of a machine shop is a smart move. You are this far along, and having completely disassembled the engine, it would be foolish not to have machine work done and everything gone over. Continued success on your project and keep us posted.
 

John Kirby

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If you do the machine shop work you will need to replace the pistons, rings and bearings. Might as well have the heads looked at too. Not sure of the year but if they were leaded gas versions the seats really need to be replaced with hardened versions. Did the engine backfire through the carb frequently? If so new valve guides are needed too. Unfortunately your wallet will take a beating.
 

badvs3vil

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If you do the machine shop work you will need to replace the pistons, rings and bearings. Might as well have the heads looked at too. Not sure of the year but if they were leaded gas versions the seats really need to be replaced with hardened versions. Did the engine backfire through the carb frequently? If so new valve guides are needed too. Unfortunately your wallet will take a beating.

Heads are already at the shop, they are 452's with hardened seats. It never back fired.
 

1970FuryConv

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Somehow, I thought this was an economy build. If so, crankshaft looks nice from what I can see of it. Polishing the crank journals and having oil passages cleaned out is much preferred in my opinion.

BTW: did you have to ridge ream the top of the cylinders to remove the pistons & rods? If not, given your ring gap measurement in spec, this could be a low wear engine. Maybe you can save $ and reuse the pistons.

If you are going to bore the cylinders and replace the pistons, I'm interested in what pistons you choose. Thanks for the pics!
 

badvs3vil

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Somehow, I thought this was an economy build. If so, crankshaft looks nice from what I can see of it. Polishing the crank journals and having oil passages cleaned out is much preferred in my opinion.

BTW: did you have to ridge ream the top of the cylinders to remove the pistons & rods? If not, given your ring gap measurement in spec, this could be a low wear engine. Maybe you can save $ and reuse the pistons.

If you are going to bore the cylinders and replace the pistons, I'm interested in what pistons you choose. Thanks for the pics!

Exactly my plans with the crank. As far as the engine goes, I couldn't feel a ridge with my finger nail. However, I am going to have the shop check it out and let me know how out of whack it is. If I do need to bore it, I will get new pistons and will make sure they are 0 deck. If its ok, I will just reuse what I got I guess.
 
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badvs3vil

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I get my cam and parts tomorrow. Already called the machine shop and let them know ill be dropping off the block and crank tomorrow.
 

twostick

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If you are going to zero deck the engine which could be a good idea, you need to revisit your cylinder head decision. This is going to raise your compression ratio by a good bit. Assuming a .030 over flat top piston .090 in the hole, it will go from about 7.5:1 to 8.9:1.

Iron open chamber heads will not play nice with premium pump gas there but an aluminum closed chamber head with .039 quench will likely be fine on 87 regular depending on your camshaft specs and certainly good with any premium fuel. Rebuilding those 452s puts a sizable dent in the cost of an aftermarket stock type replacement head.

And while I'm here spending your money, you are probably in for a custom piston to get that to zero deck. Most of those run floating pins so on top of the cost of resizing your rods and new bolts, add in bushing the small end. Resizing and new bolts isn't as cheap as it once was either and you will quickly find yourself in the same boat as the heads, not a big upcharge for new H beams that are MUCH lighter and stronger. Combined with your much lighter also new pistons makes for a really snappy throttle response.

And we haven't even addressed crank machining...

So to bring a point to my long winded response, you should add up ALL the costs to make all your current components as good or better than new and compare it to a 440Source 4.25" stroker kit. You may be amazed at how little more it would cost to add a 100 cubic inch kick in the pants to your ride and there is NO replacement for displacement.

Kevin
 
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