Intake manifold cracked
Melting Slicks
Joined: Nov 2016
Posts: 2,306
Likes: 1,582
From: East Metro (Twin Cities) Minnesota
St. Jude Donor '21
Lots of good ideas here - I was instantly thinking backfire as well - especially as you said 1 is blown out and 3 others appear to be bulging out - like they too experienced excess pressure.
\People boost these engines all the time to 13PSI ++ with no common issues that I am aware of but a backfire or multiple backfires could easily do this IMO. Have you had any odd drivability issues or anything happen in the past year so that would might indicate a backfiring occured?
You might want to toss on a cheap used LS1 manifold for a while to make sure it doesn't happen again before putting on that nice FAST manifold.
T4L
***EDIT - I see your other post now- looks like the FAST is on there. Listen carefully for any engine irregularities that might indicate you are getting a backfire - good luck!!
\People boost these engines all the time to 13PSI ++ with no common issues that I am aware of but a backfire or multiple backfires could easily do this IMO. Have you had any odd drivability issues or anything happen in the past year so that would might indicate a backfiring occured?
You might want to toss on a cheap used LS1 manifold for a while to make sure it doesn't happen again before putting on that nice FAST manifold.
T4L
***EDIT - I see your other post now- looks like the FAST is on there. Listen carefully for any engine irregularities that might indicate you are getting a backfire - good luck!!
Thread Starter
Intermediate
Joined: May 2021
Posts: 37
Likes: 4
From: North Carolina
Haha no nitrous or power adders at all. Just a stock engine. I've never experienced any symptoms while driving that would indicate that it ever back fired.
Thread Starter
Intermediate
Joined: May 2021
Posts: 37
Likes: 4
From: North Carolina
Lots of good ideas here - I was instantly thinking backfire as well - especially as you said 1 is blown out and 3 others appear to be bulging out - like they too experienced excess pressure.
\People boost these engines all the time to 13PSI ++ with no common issues that I am aware of but a backfire or multiple backfires could easily do this IMO. Have you had any odd drivability issues or anything happen in the past year so that would might indicate a backfiring occured?
You might want to toss on a cheap used LS1 manifold for a while to make sure it doesn't happen again before putting on that nice FAST manifold.
T4L
***EDIT - I see your other post now- looks like the FAST is on there. Listen carefully for any engine irregularities that might indicate you are getting a backfire - good luck!!
\People boost these engines all the time to 13PSI ++ with no common issues that I am aware of but a backfire or multiple backfires could easily do this IMO. Have you had any odd drivability issues or anything happen in the past year so that would might indicate a backfiring occured?
You might want to toss on a cheap used LS1 manifold for a while to make sure it doesn't happen again before putting on that nice FAST manifold.
T4L
***EDIT - I see your other post now- looks like the FAST is on there. Listen carefully for any engine irregularities that might indicate you are getting a backfire - good luck!!
Thread Starter
Intermediate
Joined: May 2021
Posts: 37
Likes: 4
From: North Carolina
There are plenty of threads on intake gaskets swelling. You're are obviously very bloated. Did you re-use the originals - if so, they could have been swollen and not seated properly. If you replaced them, what brand were they and have you been using any types of stop leak? A lot of oil gets into the LS1 manifold and the intake seals are exposed to it. These are just questions/observations. Nothing is mentioned if you actually had backfiring, or there are other modifications. I have seen out of position o-rings cause aluminum motorcycle cases to crack when the clamp load is applied. The engine would not have run like this for very long without codes and performance issues - much less the screaming of multiple massive intake leaks.
Race Director
Joined: Oct 2004
Posts: 12,864
Likes: 4,667
I'm not saying it did backfire, merely mentioned it as a possibility. Backfires aren't limited to manifesting on modified engines. Stock engines also backfire. Hell, even my lawnmower has! I'm inclined to believe what Ed R. suggested as the most likely scenario, with a misplaced O-ring the more likely culprit.
