Block bore help
Thread Starter
Intermediate
Joined: Jan 2015
Posts: 45
Likes: 1
From: Killeen Texas
Block bore help
So I recently purchased my 77, and its ran alright most of the time. Carb was flooding and bought the rebuild kit. It came in today and going to rebuild it tomorrow. After I took the carb off, curiosity got the best of me and I wanted to see what kind of lifters it had. (Unfortunately, just hydr. tappet) Then I pulled the plugs, one of which had some serious deposits on them. Thinking it could probably use a head job since I have no idea how old the motor is I pulled off the heads so they could go to the machine shop. Well, half the cylinder with the questionable plug is rough and pitted about two inches down(picture attached). So, I know this means it needs bored. (BTW the pistons are .020 over, so this has been done before) Ive never done this so Im just looking for advice. I know Ill need new pistons/rings to fit the size of the new bore, and bearings. Can I reuse the connecting rods? Do I take it apart before I drop it off, or do they fix it and reassemble? I plan on stopping by and talking to the shop tomorrow, I just dont want to look stupid or get ripped off.
Last edited by 77vet; Jan 19, 2015 at 07:41 PM. Reason: image
Le Mans Master
Joined: Oct 2006
Posts: 7,123
Likes: 433
From: Gladstone MO
C3 of Year Finalist (appearance mods) 2019
Couple of options. You can tear it down yourself and take the machine shop the crank, rods, pistons and block. They can bore to whatever will clean it up and fit new pistons, or you can have them build the short block for you. Have them install ARP rod bolts and recondition the rods.
Or you can take them the pieces, have them measure the crank, bore and fit pistons and install them on the rods, and give you the new bearings and rings for you to assemble.
Another option is get yourself an aftermarket short block and use your heads. OR just get a complete engine.
Get a written estimate for the whole thing how ever you want to go and figure out how much you want to spend. Probably some other options too.
Or you can take them the pieces, have them measure the crank, bore and fit pistons and install them on the rods, and give you the new bearings and rings for you to assemble.
Another option is get yourself an aftermarket short block and use your heads. OR just get a complete engine.
Get a written estimate for the whole thing how ever you want to go and figure out how much you want to spend. Probably some other options too.
Thread Starter
Intermediate
Joined: Jan 2015
Posts: 45
Likes: 1
From: Killeen Texas
Thanks. I found a shop on eBay thats in Dallas (only a couple hours away). They have an assembled 350 for about $850. It's all stock stuff though, so its not like I could get any extra performance out of it. Seems like it'd be cheaper if I rebuilt mine.
Safety Car
Joined: Nov 2008
Posts: 3,716
Likes: 551
From: Seattle Washington
First of all I would figure out why that one Cylinder looks so bad. I would guess rust and that it sat for a long time with water in the bore. So where did the water come from. Cracked Head. Block Blown Gasket ? I'd be carful buying rebuilt Engines that are great price deals. You will never get more than You paid for.
Pro
Joined: Oct 2005
Posts: 505
Likes: 8
From: Houston Tx.
Do some research on shops. Find a Corvette club and see who everyone uses. I've seen hi-tech appearing shops do terrible work. The shop I use is small, dirty and at the back of a cheesy looking industrial park, but the guy is excellent and is old school when it comes to working on old engines.
Drifting
Joined: Jun 2010
Posts: 1,781
Likes: 15
From: Oxford Ohio
It's already .020 over bore, pitting like that probably won't clean up at .030, as you're only taking .005 per side. So at best .040 or .060. Just do a couple things. Remove your casting hole plugs, often called freeze out plugs and look at the cylinder wall through the holes. You're looking to see if there has been pitting from the inside. It should be dimpled or orange pealed looking. Sometime you can have issues from the inside that go undetected. Second have the cylinders sonic tested to see how much you have to work with. Most good shops will have a sonic tester.
You don't need as much wall thickness as you'll read online sometimes, but at .060 there is a chance you could be getting a bit thin. There are a lot of .060 engines running around out there.
Like was said recondition the rods. ARP bolts. The original rods are forged I beams so they'll handle enough power to make you happy.
It would be nice to have a forged crank, I', suspecting a 2442 crank in this one most likely, a cast crank. Still ok for the power you're after as it sounds to me. Like was said before, caution with inexpensive short or long blocks.
A must, torque plate hone and balanced short block
You don't need as much wall thickness as you'll read online sometimes, but at .060 there is a chance you could be getting a bit thin. There are a lot of .060 engines running around out there.
Like was said recondition the rods. ARP bolts. The original rods are forged I beams so they'll handle enough power to make you happy.
It would be nice to have a forged crank, I', suspecting a 2442 crank in this one most likely, a cast crank. Still ok for the power you're after as it sounds to me. Like was said before, caution with inexpensive short or long blocks.
A must, torque plate hone and balanced short block
Thread Starter
Intermediate
Joined: Jan 2015
Posts: 45
Likes: 1
From: Killeen Texas
Thank you for all the responses. While running around getting prices, I stumbled across some selling a complete stock 454 for $350. So instead of spending money on machining the 350, Im doing a 454 swap. They say it ran well when it was pulled, and Im pulling it apart tomorrow to see how good it looks. Hopefully this one doesnt need much work. Now Im off to buy headers, pulleys, and a cam.
