Just found epoxy on block. Should I worry?
#1
Pro
Thread Starter
Just found epoxy on block. Should I worry?
The PO said that the engine was pulled, and the stock block was bored with new pistons, rings, crankshaft, bearing, etc.
I have the receipts from Summit for the parts, but nothing about who did the labor.
Anyway, I am tearing down the motor to rebuild it to a high (600+) HP turbo vert, and I run across this:
What do you guys think? A hairline crack developed, did they drop it at some point, or ?
Should I replace it with a different short block for piece of mind, or will it hold up fine and I am worrying for nothing.
I have the receipts from Summit for the parts, but nothing about who did the labor.
Anyway, I am tearing down the motor to rebuild it to a high (600+) HP turbo vert, and I run across this:
What do you guys think? A hairline crack developed, did they drop it at some point, or ?
Should I replace it with a different short block for piece of mind, or will it hold up fine and I am worrying for nothing.
#2
Race Director
Member Since: Dec 2010
Location: Atlanta, GA
Posts: 10,426
Received 1,261 Likes
on
1,056 Posts
2020 Corvette of the Year Finalist (performance mods)
C5 of Year Winner (performance mods) 2019
are you sure there is a crack or were they just trying to stop a leak?
#3
Pro
Thread Starter
#4
Race Director
Member Since: Dec 2010
Location: Atlanta, GA
Posts: 10,426
Received 1,261 Likes
on
1,056 Posts
2020 Corvette of the Year Finalist (performance mods)
C5 of Year Winner (performance mods) 2019
is it just black silicone or a hard epoxy?... it looks like silicone in the pics but hard to tell... if it's just silicone I would clean it all up and see what you're working with... it could be nothing and they were just being lazy not wanting to tear it down to fix a leak and since you're rebuilding it anyway you can fix all that
The following 3 users liked this post by neutron82:
The following users liked this post:
C5 Kirkland (09-26-2018)
#6
Race Director
Member Since: Apr 2017
Location: Hickory NC
Posts: 10,211
Received 863 Likes
on
667 Posts
2022 C5 of the Year Finalist - Modified
2020 C5 of the Year Finalist - Modified
St. Jude Donor '17-‘18-'19-'20-'21-'22-'23-'24
Rebrote raises a good point about the staining, though. Possibly scraping the silicone/epoxy off will help answer that question, too.
Good luck with this!
The following 2 users liked this post by Route99:
C5 Kirkland (09-26-2018),
CorvetteBrent (09-29-2018)
#7
Burning Brakes
Looks like a coolant leak coming from above. Does that hex plug under the black crap lead to an oil passage? Maybe someone tightened it too much and cracked the block causing an oil leak? Scrape or wire brush it off, clean the area and see what they were trying to fix.
Steve
Steve
Last edited by killian96ss; 09-26-2018 at 08:00 PM. Reason: Added information
The following 2 users liked this post by killian96ss:
C5 Kirkland (09-26-2018),
CorvetteBrent (09-29-2018)
#8
Racer
Looks a lot more like black RTV than epoxy, and it looks like they maybe got lazy and put silicon thers instead of changing the gaskets, or maybe for extra piece of mind. The plug above should go into an oil passage. Either way, get that stuff off and check it out before you spend a bunch of money, especially if the engine is already out. Another option is to just use it as an excuse to go big cube and turbo.
The following users liked this post:
CorvetteBrent (09-29-2018)
#9
Pro
Thread Starter
Scraped off what I could tonight with a pick. It is rubber, not epoxy. The pink stain was just coolant. I would guess there was a leak coming from that main bearing side bolt, and someone decided just to fill that hole (and on the inside of the bolt as well) with as much rubber sealant as they could. As to why it was leaking, I don't know. Pics are after I removed the bolt.
Last edited by C5 Kirkland; 09-27-2018 at 08:19 PM.
The following users liked this post:
CorvetteBrent (09-29-2018)