Rescuing the Build from Hell - bore crack?
Racer
Joined: Mar 2008
Posts: 428
Likes: 0
I had something similar on a 350 motor from a junkyard, it also sat in my garage for a year before being torn down. Whatever fluid that was in the cylinder when to the low side. It did clean up with a .030 bore. It was basically around the same spot, which was where the top of the piston was at rest.
Le Mans Master
Joined: Jan 2006
Posts: 6,497
Likes: 136
From: Butler Pa
The ONLY way is with a sleeve.
Racer
Joined: Mar 2008
Posts: 428
Likes: 0
The post was just to inform billa that I had something similar that went perpendicular to the bore and provide an explanation for how it got there on my block.
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
The point was very simple, the engine had been sitting around and its history was unknown. The engine came from a private junkyard; the hood was on it as well as the air cleaner. Being a freebee, the price was right for a seasoned 71 350. Besides, engines don't really scare me.
The post was just to inform billa that I had something similar that went perpendicular to the bore and provide an explanation for how it got there on my block.
The post was just to inform billa that I had something similar that went perpendicular to the bore and provide an explanation for how it got there on my block.
Race Director
Joined: Mar 2006
Posts: 14,112
Likes: 27
From: Florida
I would find out from the Ronald House, who the builder, machine shop, shadetree was that put the engine together like this was, so that I was sure never to let them touch anything.
It should have been bored etc.
How much does the winning bidder have in this. Ronald house already got their money, right?
Besides overheating, were there any other problems such as burning
oil etc?
I would be tempted to just use it as is, otherwise your looking at least boring this one jug etc.
BTW, we do a lot with our local Ronald house too. Wife has the plaques of recognition hanging on a wall. It's a pretty good cause.
Thread Starter
Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
It's a great cause, if kinda tough sometimes. Brave kids, brave parents. My wife does the dinner supervision there every Sunday, when organizations come in to make a hot meal. I do that with her sometimes, and we're always there for Thanksgiving and Christmas when it's impossible to get volunteers. And I end up being the "go to" guy every once and a while when something off-the-wall comes up
Thread Starter
Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
I won't buy GEN I pre-86 cores any more as they're junk 4 out of 5 times. Even the ones that look wet can be junk from many overhauls, etc. I'll take 'em if they come to me - but my days of paying even $50 is over. Pretty much just 86-up roller-cam blocks any more. They're generally first-run, the bores are usually just about perfect and of course you get an easy roller-cam installation - usually even the lifters are OK if the engine is tight and wet.
My shop is pretty cool - flat $75 for the hot tank, 'flux, pressure check and general inspection
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Racer
Joined: Mar 2008
Posts: 428
Likes: 0
I won't buy GEN I pre-86 cores any more as they're junk 4 out of 5 times. Even the ones that look wet can be junk from many overhauls, etc. I'll take 'em if they come to me - but my days of paying even $50 is over. Pretty much just 86-up roller-cam blocks any more. They're generally first-run, the bores are usually just about perfect and of course you get an easy roller-cam installation - usually even the lifters are OK if the engine is tight and wet.
My shop is pretty cool - flat $75 for the hot tank, 'flux, pressure check and general inspection
Melting Slicks
Joined: Jun 2009
Posts: 2,709
Likes: 3
From: Savannah GA
My take on those pics is leftover ridge from the previous bore. Unfortunately not all shops think like mechanics... this is an example of "good enough for who it's for" work. I suspect if you were to mike all these bores you would also find taper and ovality not removed as well, and they are all likely at the ragged outside edge of spec.
Thread Starter
Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
Le Mans Master
Joined: Nov 2008
Posts: 5,691
Likes: 12
From: columbus oh
My take on those pics is leftover ridge from the previous bore. Unfortunately not all shops think like mechanics... this is an example of "good enough for who it's for" work. I suspect if you were to mike all these bores you would also find taper and ovality not removed as well, and they are all likely at the ragged outside edge of spec.
Thread Starter
Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
I'm aware of where the ridge is - my point was that this mark could not be a ridge.
Melting Slicks
Joined: Jun 2009
Posts: 2,709
Likes: 3
From: Savannah GA
Two more possibilities... a "bruise" from a seperated valve head contacting the wall, not overbored but honed at last assembly? Or possibly a casting flaw not revealed until wiped clean by the running in? I do see some vertical scoring associated with the suspect area; carbon particles trapped in the mold? Do you know if the .040 is a fresh rebore or simply "freshened"?
Pro
Joined: Jun 2009
Posts: 613
Likes: 3
From: Fleetwood PA
I agree it looks like a valve dropped at some point, or a ring gave up. I would be very surprised if it was a crack. If it doesn't test out as a crack,and you have honing hatch marks all the way through the blemish I wouldn't worry too much about it.
