Cleaning / Overhauling the block
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Joined: Oct 2014
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Cleaning / Overhauling the block
So, Im about to put on some new cylinder heads and camshaft on my 68' 327 engine.
I took of the old heads yesterday and there is quite some bit of carbon built up in the cylinders and on the top of the pistons. To the point where the pistons are all black, and so are the cylinder walls.
I therefor decided to take the engine out of the vehicle and give it a proper overhaulin.
This is something that I havent done before, so I am looking for some good tips and pointer on what and how to do it.
How would you recommend cleaning the pistons and cylinder walls, and what else should I do to the block as long as it is out of the engine bay anyway?
Anyone got a link to a good guide on this or got some tips for me?
I took of the old heads yesterday and there is quite some bit of carbon built up in the cylinders and on the top of the pistons. To the point where the pistons are all black, and so are the cylinder walls.
I therefor decided to take the engine out of the vehicle and give it a proper overhaulin.
This is something that I havent done before, so I am looking for some good tips and pointer on what and how to do it.
How would you recommend cleaning the pistons and cylinder walls, and what else should I do to the block as long as it is out of the engine bay anyway?
Anyone got a link to a good guide on this or got some tips for me?
Race Director
Joined: May 2005
Posts: 10,674
Likes: 122
From: Millington Illinois
St. Jude Donor '08-'09
If you do this you will have to bore and torque plate hone engine. You can not reinstall the rings, install new rings ect. If you do that you need new pistons, rebalance, recondition crank and rods, and it goes on and on. If you had good compression and oil pressure leave it alone. If not a complete, 100% rebuild. No other options. Short block rebuild will cost you about $2000 minimum plus cam, heads gaskets, valvetrain parts ect. Rebuilding it as a 327 is really counter productive. No replacement for displacement.
Last edited by 63mako; Dec 21, 2014 at 05:01 PM.
Le Mans Master
Joined: Oct 2010
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From: melbourne florida
2023 C3 of the Year Finalist - Modified
very few cases can you run a ball hone through it and throw a set of rings on it and have it live. better off going through it. cleaning old pistons are a waste of time, unless you like clean garbage.
Melting Slicks
Joined: Jul 2005
Posts: 3,389
Likes: 83
From: Norfolk Virginia
I would recommend that you go to a local automotive machine shop in your area and have long talk with them BEFORE you do anything. If you have never been through an engine rebuild you have much to learn, and much to spend also. I'm not trying to be a smart a--, just trying to be honest. Good luck and keep us informed of you progress.
Le Mans Master
Joined: Oct 2007
Posts: 7,455
Likes: 977
From: RI, Now Franklin/Nashville TN
I just did this exercise after thinking that I would just update the L-82 with heads and cam…wrong. Ended up pulling the engine for a .030 bore, new pistons, rings, bearings, reconditioned the L-82 forged crank, reconditioned L-82 forged rods, new oil pump, new harmonic balancer, engine balance, new Clutch kit and reassembly of the short block by my builder-$3,500. I did everything else including roller cam, AFR 180 aluminum heads, misc parts/bolts etc. All in $6,000 for everything-my labor free-sort of. Reused: HEi distributor, L-82 aluminum intake, Holley 4175 650 CFM Qjet carb, Stewart Stage 2 water pump, shorty headers…..BUT the engine is a player now….Well worth the time, effort, and money I spent on the original L-82…much prefer over a crate engine.
Last edited by jb78L-82; Dec 21, 2014 at 06:36 PM.
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Joined: Oct 2014
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I just did this exercise after thinking that I would just update the L-82 with heads and cam…wrong. Ended up pulling the engine for a .030 bore, new pistons, rings, bearings, reconditioned the L-82 forged crank, reconditioned L-82 forged rods, new oil pump, new harmonic balancer, engine balance, new Clutch kit and reassembly of the short block by my builder-$3,500. I did everything else including roller cam, AFR 180 aluminum heads, misc parts/bolts etc. All in $6,000 for everything-my labor free-sort of. Reused: HEi distributor, L-82 aluminum intake, Holley 4175 650 CFM Qjet carb, Stewart Stage 2 water pump, shorty headers…..BUT the engine is a player now….Well worth the time, effort, and money I spent on the original L-82…much prefer over a crate engine.
Then another 1000$ for new pistons and so on mounted.
I dont really feel that the block itself is worth that kind of money. I think im about 5000$ into my build already with cylinder heads, holley carburetor, new intake, camshaft, roller rockers, holley fuel regulators, NOS kit, oil cooler and so on.
The car is already fitted with custom built headers and a MSD ignition system and a racing clutch setup.
Think I'll be ending up with making sure the top of the block is flat and even, then mount the camshaft and cylinder heads on it as it is. If or even yet, When the block / pistons give in, Ill swap it for a 350 block instead and put some money into a better build with custom crankshaft and pistons on that one.
Last edited by vimzzz; Dec 22, 2014 at 10:57 AM.
Race Director
Joined: May 2005
Posts: 10,674
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From: Millington Illinois
St. Jude Donor '08-'09
I contacted the two companies in my town who mostly does work on V8 blocks, and they wanted about 2.500$ for a overhaulin of the block and cylinder honing.
Then another 1000$ for new pistons and so on mounted.
I dont really feel that the block itself is worth that kind of money. I think im about 5000$ into my build already with cylinder heads, holley carburetor, new intake, camshaft, roller rockers, holley fuel regulators, NOS kit, oil cooler and so on.
The car is already fitted with custom built headers and a MSD ignition system and a racing clutch setup.
Think I'll be ending up with making sure the top of the block is flat and even, then mount the camshaft and cylinder heads on it as it is. If or even yet, When the block / pistons give in, Ill swap it for a 350 block instead and put some money into a better build with custom crankshaft and pistons on that one.
Then another 1000$ for new pistons and so on mounted.
I dont really feel that the block itself is worth that kind of money. I think im about 5000$ into my build already with cylinder heads, holley carburetor, new intake, camshaft, roller rockers, holley fuel regulators, NOS kit, oil cooler and so on.
The car is already fitted with custom built headers and a MSD ignition system and a racing clutch setup.
Think I'll be ending up with making sure the top of the block is flat and even, then mount the camshaft and cylinder heads on it as it is. If or even yet, When the block / pistons give in, Ill swap it for a 350 block instead and put some money into a better build with custom crankshaft and pistons on that one.
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Joined: Oct 2014
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I am expecting the engine to give out at some point, specially with the new parts and NOS-kit adding extra pressure on the pistons. But with the prices for getting this block back to new and with new parts, Id rather run this block to the ground, and use next winter to build a new engine from a 350 block.
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Melting Slicks
Joined: Oct 2011
Posts: 2,748
Likes: 90
From: Sacramento California
C2 of Year Finalist (performance mods) 2019
2018 C2 of Year Finalist
Hope those pistons are forged if you are going to juice it.... Or youll be tearing it down much sooner with melted pistons...
Safety Car
Joined: Dec 2012
Posts: 3,820
Likes: 1,728
From: Summerville SC
I would suggest you look for a short block assembly. That would be the block, pistons etc. Everything but the top end,, which I guess you already have. If you had done the compression test first, it wouldn't be such a crap shoot. A lot of the big name vendors have these things, usually with a guarantee and there are options to get near th HP you think you might want. Just remember, the rest of the drivetrain has to hold up or you'll be chasing your tail. And yes, keep us updated with what you choose.
Thread Starter
Advanced
Joined: Oct 2014
Posts: 73
Likes: 1
I would suggest you look for a short block assembly. That would be the block, pistons etc. Everything but the top end,, which I guess you already have. If you had done the compression test first, it wouldn't be such a crap shoot. A lot of the big name vendors have these things, usually with a guarantee and there are options to get near th HP you think you might want. Just remember, the rest of the drivetrain has to hold up or you'll be chasing your tail. And yes, keep us updated with what you choose.
The block I have is a 1968 327 L79.
I know that my current parts and setup actaully will kill the engine at some point. If it will be on the first run, or somewhere along the way, I dont know.
I just know that what Im aiming for is a lot more than the block and pistons can handle.
But then again. I have a 327 block. I dont feel like wasting 3-4K on rebuilding that block. So I figure Ill just add my mods to it. Run it until it gives out, and then find myself a redone 350 block as a starter project. Ill transfer my cams, tops, carburetor and such to that one when the time comes.
Should I be ever so lucky to have it survive the season, Ill still get a new block next winter just for the sake of it.
But with so many people advicing me not to rebuild the 327, I wont. We'll just see what gives in first, the pistons or the rods.
Race Director
Joined: May 2005
Posts: 10,674
Likes: 122
From: Millington Illinois
St. Jude Donor '08-'09
Thanks for your reply.
The block I have is a 1968 327 L79.
I know that my current parts and setup actaully will kill the engine at some point. If it will be on the first run, or somewhere along the way, I dont know.
I just know that what Im aiming for is a lot more than the block and pistons can handle.
But then again. I have a 327 block. I dont feel like wasting 3-4K on rebuilding that block. So I figure Ill just add my mods to it. Run it until it gives out, and then find myself a redone 350 block as a starter project. Ill transfer my cams, tops, carburetor and such to that one when the time comes.
Should I be ever so lucky to have it survive the season, Ill still get a new block next winter just for the sake of it.
But with so many people advicing me not to rebuild the 327, I wont. We'll just see what gives in first, the pistons or the rods.
The block I have is a 1968 327 L79.
I know that my current parts and setup actaully will kill the engine at some point. If it will be on the first run, or somewhere along the way, I dont know.
I just know that what Im aiming for is a lot more than the block and pistons can handle.
But then again. I have a 327 block. I dont feel like wasting 3-4K on rebuilding that block. So I figure Ill just add my mods to it. Run it until it gives out, and then find myself a redone 350 block as a starter project. Ill transfer my cams, tops, carburetor and such to that one when the time comes.
Should I be ever so lucky to have it survive the season, Ill still get a new block next winter just for the sake of it.
But with so many people advicing me not to rebuild the 327, I wont. We'll just see what gives in first, the pistons or the rods.
Safety Car
Joined: Nov 2008
Posts: 3,720
Likes: 557
From: Seattle Washington
Sounds like You are new to this game and willing to learn. Now that You have the short block out You can mount it on an Engine stand and roll it around upside down and clean the carbon off the pistons inspect some bearings replace gaskets paint all kinds of stuff with out hurting anything.
It kinda sounds like Your not to concerned about blowing the engine up, as You don't think its worth all that much which is probably true. That is unless you also own the matching numbers car that goe's along with it. In that case it might be worth a lot more than You think.
Since SBC's overall are getting worth less with the popularity of swapping in LS based engines You might consider starting out with a 350 383 or 400 engine all of which are more common performance starting points than the 327. Now the sky is the limit, from $200 craigs list rebuildables to full blown complete engines. Sounds like You already have a top end for your build. You may consider a new GM crate long block, for about the same money as you were given for the rebuild. I would stay away from the local auto parts stores re-man good deal engines.
It kinda sounds like Your not to concerned about blowing the engine up, as You don't think its worth all that much which is probably true. That is unless you also own the matching numbers car that goe's along with it. In that case it might be worth a lot more than You think.
Since SBC's overall are getting worth less with the popularity of swapping in LS based engines You might consider starting out with a 350 383 or 400 engine all of which are more common performance starting points than the 327. Now the sky is the limit, from $200 craigs list rebuildables to full blown complete engines. Sounds like You already have a top end for your build. You may consider a new GM crate long block, for about the same money as you were given for the rebuild. I would stay away from the local auto parts stores re-man good deal engines.
Melting Slicks
Joined: May 2012
Posts: 2,192
Likes: 343
From: Allenton Wisconsin
The first engine upgrade for the 6t8 327 I did consisted of new Dart heads, Lunati roller cam Elde RPM air gap. Took the pistons out cleaned. Ball hone very slightly, mearured block, had tapered wear towards bottom, used the same rings and pistons [cast TRW] new bearings and pump, hand polished crank journals to get some of the nicks out. Reassembled the engine. Ya gotta love them 327s, [bigger bore shorter stroke] buzzed that engine to 7k for two summers. Ya I was worried about burning it up and I did, but it sure was fun. My point is - yes you can reuse your short block, do your top side upgrade. But that only opens the next can of worms Stage 2 a built short block [350core]. Now can number 3 a V1 upgrade. By the way U CANNOT use cast pistons and juice the engine. T
Le Mans Master
Joined: Feb 1999
Posts: 8,351
Likes: 75
From: Tampa Bay FL
I just did this exercise after thinking that I would just update the L-82 with heads and cam…wrong. Ended up pulling the engine for a .030 bore, new pistons, rings, bearings, reconditioned the L-82 forged crank, reconditioned L-82 forged rods, new oil pump, new harmonic balancer, engine balance, new Clutch kit and reassembly of the short block by my builder-$3,500. I did everything else including roller cam, AFR 180 aluminum heads, misc parts/bolts etc. All in $6,000 for everything-my labor free-sort of. Reused: HEi distributor, L-82 aluminum intake, Holley 4175 650 CFM Qjet carb, Stewart Stage 2 water pump, shorty headers…..BUT the engine is a player now….Well worth the time, effort, and money I spent on the original L-82…much prefer over a crate engine.
Le Mans Master
Joined: Mar 2005
Posts: 6,776
Likes: 2
From: Troutman NC
I just did this exercise after thinking that I would just update the L-82 with heads and cam…wrong. Ended up pulling the engine for a .030 bore, new pistons, rings, bearings, reconditioned the L-82 forged crank, reconditioned L-82 forged rods, new oil pump, new harmonic balancer, engine balance, new Clutch kit and reassembly of the short block by my builder-$3,500. I did everything else including roller cam, AFR 180 aluminum heads, misc parts/bolts etc. All in $6,000 for everything-my labor free-sort of. Reused: HEi distributor, L-82 aluminum intake, Holley 4175 650 CFM Qjet carb, Stewart Stage 2 water pump, shorty headers…..BUT the engine is a player now….Well worth the time, effort, and money I spent on the original L-82…much prefer over a crate engine.
Pro
Joined: Dec 2014
Posts: 699
Likes: 46
From: Charlotte NC
First step is always analyze what you have. No need for guesswork & speculation. Mic the bore - if you don't have a dial bore gauge (only a $50 tool) take it to the machine shop & they'll mic it for you. Takes about 1 minute. It'll either clean up w/ light hone or need boring. You already know it's not cracked. I bet it'll clean up fine because it's prob already 30 over. Just rering it. That's the beauty of a known good running motor - you know the balance is good, etc. Worst case boring is $110, cam brgs $50, new pistons $150-$550. I can go thru the entire long block under $1200, with 1/3 of that on the heads. There isn't anything wrong with a 327.
BTW - carbon is a natural by product of combustion. Any motor will have "black" pistons after just a few miles. Most of us don't drive our cars long enough to burn it off (hour down the freeway). Should wash off with almost any solvent & a nylon brush. Don't clean pistons with a wire brush & only glass bead the tops (never ring lands or skirts).
BTW - carbon is a natural by product of combustion. Any motor will have "black" pistons after just a few miles. Most of us don't drive our cars long enough to burn it off (hour down the freeway). Should wash off with almost any solvent & a nylon brush. Don't clean pistons with a wire brush & only glass bead the tops (never ring lands or skirts).
Last edited by 68notray; Dec 26, 2014 at 08:53 AM. Reason: forgot to add comment
Le Mans Master
Joined: Mar 2005
Posts: 6,776
Likes: 2
From: Troutman NC
Thanks for your reply.
The block I have is a 1968 327 L79.
I know that my current parts and setup actaully will kill the engine at some point. If it will be on the first run, or somewhere along the way, I dont know.
I just know that what Im aiming for is a lot more than the block and pistons can handle.
But then again. I have a 327 block. I dont feel like wasting 3-4K on rebuilding that block. So I figure Ill just add my mods to it. Run it until it gives out, and then find myself a redone 350 block as a starter project. Ill transfer my cams, tops, carburetor and such to that one when the time comes.
Should I be ever so lucky to have it survive the season, Ill still get a new block next winter just for the sake of it.
But with so many people advicing me not to rebuild the 327, I wont. We'll just see what gives in first, the pistons or the rods.
The block I have is a 1968 327 L79.
I know that my current parts and setup actaully will kill the engine at some point. If it will be on the first run, or somewhere along the way, I dont know.
I just know that what Im aiming for is a lot more than the block and pistons can handle.
But then again. I have a 327 block. I dont feel like wasting 3-4K on rebuilding that block. So I figure Ill just add my mods to it. Run it until it gives out, and then find myself a redone 350 block as a starter project. Ill transfer my cams, tops, carburetor and such to that one when the time comes.
Should I be ever so lucky to have it survive the season, Ill still get a new block next winter just for the sake of it.
But with so many people advicing me not to rebuild the 327, I wont. We'll just see what gives in first, the pistons or the rods.