engine experts step inside please
Drifting
Joined: Jun 2009
Posts: 1,277
Likes: 275
From: Leo IN
Wow! That's a bit of oil in those cylinders!
Looks like there is a significant either ridge or someone went to town with a ridge reamer and there is a significant bevel at the top of the cylinder bore. If either is the case, it's not right.
As well, are those nicks in the bores? It's hard to tell with the pics.
Anyhow, a bore should look like:
(for the whole article, see: http://www.popularhotrodding.com/eng...ing/index.html)
Most OEMs and ring manufacturers say the angle of the scratches in the crosshatch pattern should be about 45° to each other, or about 22° to 32° to the horizontal deck surface. The crosshatch angle should be the same throughout the length of the cylinder and not flatten out at either end.
Not trying to kick over a hornet's nest, but I'm curious if someone tweaked two cylinders (enough to deeply score the bore), that were bored out .060 and stuffed with re-builder quality pistons. Looking at the second pic, it looks like they did not get all of the nicks out of the bore.
Again, it's hard to tell from the pics, but if you only have 1000 miles on the engine, I'd be looking to get my money back from the business and going elsewhere that will do quality work.
Hope the business is a stand-up business....
-- Joe
Looks like there is a significant either ridge or someone went to town with a ridge reamer and there is a significant bevel at the top of the cylinder bore. If either is the case, it's not right.
As well, are those nicks in the bores? It's hard to tell with the pics.
Anyhow, a bore should look like:
(for the whole article, see: http://www.popularhotrodding.com/eng...ing/index.html)
Most OEMs and ring manufacturers say the angle of the scratches in the crosshatch pattern should be about 45° to each other, or about 22° to 32° to the horizontal deck surface. The crosshatch angle should be the same throughout the length of the cylinder and not flatten out at either end.
Not trying to kick over a hornet's nest, but I'm curious if someone tweaked two cylinders (enough to deeply score the bore), that were bored out .060 and stuffed with re-builder quality pistons. Looking at the second pic, it looks like they did not get all of the nicks out of the bore.
Again, it's hard to tell from the pics, but if you only have 1000 miles on the engine, I'd be looking to get my money back from the business and going elsewhere that will do quality work.
Hope the business is a stand-up business....
-- Joe
Race Director
Joined: Mar 2009
Posts: 19,777
Likes: 4,592
From: Canada's capital
2020 Corvette of the Year Finalist (appearance mods)
C1 of Year Finalist (appearance mods) 2019
If I was you, I'd be checking in to a new 502 crate motor because by the time you get finished with this one, you'll have a pile more dough in it and still a questionable overbored motor. Just sayin z'all. Oh......and Sue the bastard who put that together....!
Melting Slicks
Joined: Dec 2009
Posts: 2,099
Likes: 59
From: Grande Prairie
2024 C2 of the Year Finalist - Modified
2020 C2 of the Year Finalist - Modified
2019 C2 of Year Finalist (appearance mods)
Put me in the non-expert class, but that looks like a valve guide, or more probably, a valve seal issue to me. Maybe the inner spring or damper has a bit to small of an I.D. and is messing with the valve seal.
Also, and I know you know this, a .060" over is just fine and within factory limits for 396 4-bolt main blocks.
Also, and I know you know this, a .060" over is just fine and within factory limits for 396 4-bolt main blocks.
Last edited by Thorson; Dec 30, 2010 at 02:03 AM.
Race Director
Joined: Jan 2003
Posts: 17,655
Likes: 3,665
From: Central Arkansas
I'm not a big fan of litigation but I think I would seek out a well-respected builder or mechanic and have them inspect and document what you have - and be prepared to head to court if the shop doesn't take care of you. Hopefully they will, but anyone who would put that together in the first place and pass it off to you as good to go - is probably not going be very cooperative or trustworthy (or maybe just not competent). Something about doing the same thing over and over and expecting a different result.
Le Mans Master
Joined: Nov 2008
Posts: 5,691
Likes: 12
From: columbus oh
Put me in the non-expert class, but that looks like a valve guide, or more probably, a valve seal issue to me. Maybe the inner spring or damper has a bit to small of an I.D. and is messing with the valve seal.
Also, and I know you know this, a .060" over is just fine and within factory limits for 396 4-bolt main blocks.
Also, and I know you know this, a .060" over is just fine and within factory limits for 396 4-bolt main blocks.
as far as legal action??......fuggetaboutit!
Melting Slicks
Joined: Sep 2003
Posts: 2,669
Likes: 5
From: Florida Gulf Coast
St. Jude Donor '05-'06-'10-'11
That is a lot of oil. I would say a combination of what has already been mentioned. Bad valve guides / seals. Incorrect piston / ring sizing. The pictures of the cylinder walls look very questional to me. Bad bore job and honing as well?? I see no evidence of any fresh crosshatch. The shiny spots in the bore might be from the flash but I am betting the pistons have matching wear marks. Looks like a 5th grade shop class did their first rebuild. 
Lawyers don't come cheap. Spend your money with a first class engine builder instead.
Lawyers don't come cheap. Spend your money with a first class engine builder instead.
