Exhaust Manifold Leak
#1
Exhaust Manifold Leak
Having a problem with an exhaust manifold leak.
455 bored 60 over with ceramic coated W Z exhaust Manifolds.
Manifold has been re surfaced and am using fel pro Gaskets.
Keeps blowing out the gasket at # 8 port . This has happened at least four times in 3000 miles since I built the engine. Usually after a 3hr run at highway speeds.
Last time I tried a double gasket -- same problem.
Don't think it would make any difference but engine is in a 53 Olds.
Any body have any ideas.
Thanks Jim
455 bored 60 over with ceramic coated W Z exhaust Manifolds.
Manifold has been re surfaced and am using fel pro Gaskets.
Keeps blowing out the gasket at # 8 port . This has happened at least four times in 3000 miles since I built the engine. Usually after a 3hr run at highway speeds.
Last time I tried a double gasket -- same problem.
Don't think it would make any difference but engine is in a 53 Olds.
Any body have any ideas.
Thanks Jim
#2
Hello Jim
There was a recent thread discussing this and Joe said that these engines came from the factory with no gasket between the exhaust manifold and head. You can do a search and read through that thread. Since you've already surfaced the manifold I'd try it without gaskets.
John
There was a recent thread discussing this and Joe said that these engines came from the factory with no gasket between the exhaust manifold and head. You can do a search and read through that thread. Since you've already surfaced the manifold I'd try it without gaskets.
John
#4
Let me clarify. While it is true that Olds did not use exhaust gaskets with factory manifolds, the use of gaskets should not be the cause of a gasket blowing out. When you take the manifold off, check both the manifold and the head with a straightedge.
#5
Joe
Thanks for the reply.
I had the manifold surfaced and last time I blew a gasket i did check it with a straight edge, however, I did not check the head. I will do that this time.
I had another thought. I am using C heads that I had ported, could the porting if not done correctly have anything to do with it?
Jim
Thanks for the reply.
I had the manifold surfaced and last time I blew a gasket i did check it with a straight edge, however, I did not check the head. I will do that this time.
I had another thought. I am using C heads that I had ported, could the porting if not done correctly have anything to do with it?
Jim
#6
Joe
Thanks for the reply.
I had the manifold surfaced and last time I blew a gasket i did check it with a straight edge, however, I did not check the head. I will do that this time.
I had another thought. I am using C heads that I had ported, could the porting if not done correctly have anything to do with it?
Jim
Thanks for the reply.
I had the manifold surfaced and last time I blew a gasket i did check it with a straight edge, however, I did not check the head. I will do that this time.
I had another thought. I am using C heads that I had ported, could the porting if not done correctly have anything to do with it?
Jim
#7
I need to replace or upgrade my exhaust manifolds also. My old mechanic in NY would not do them unless i had a set of good replacement manifolds he said that the metal tends to get brittle with age. Also what is the best way to take the bolts off when they have been on there forever.
#8
I need to replace or upgrade my exhaust manifolds also. My old mechanic in NY would not do them unless i had a set of good replacement manifolds he said that the metal tends to get brittle with age. Also what is the best way to take the bolts off when they have been on there forever.
If you have a set of replacements it might be best to just let a shop tackle the job. It isn't the easiest thing to deal with under the shade tree or in a driveway.
Last edited by Texascarnut; May 24th, 2009 at 02:59 PM.
#9
Also--Try tightening everything but the center bolt first....once tight go back and snug up the top center bolt. Don't crank the heck out of the top center bolt just get it nice and snug.
If you have access to a superflat surface...I mean very flat....you can put down some sticky backed sandpaper and slide the machined surface of the exhaust manifold around on that a little to double check the surfacing job.
Once you slightly sand it a little you will be able to see a pattern from the sandpaper and if it's not cutting uniformly that may show you where exactly the manifold is not mating up.
Also...once you initially remove the manifold and gasket check the side of the manifold and gasket that faces the exhaust ports in the head...look for "overhang" or areas where the manifold and/or gasket is hanging down into the exhaust stream. This area would be dark or "burned" where the exhaust stream is hitting it.
If you have access to a superflat surface...I mean very flat....you can put down some sticky backed sandpaper and slide the machined surface of the exhaust manifold around on that a little to double check the surfacing job.
Once you slightly sand it a little you will be able to see a pattern from the sandpaper and if it's not cutting uniformly that may show you where exactly the manifold is not mating up.
Also...once you initially remove the manifold and gasket check the side of the manifold and gasket that faces the exhaust ports in the head...look for "overhang" or areas where the manifold and/or gasket is hanging down into the exhaust stream. This area would be dark or "burned" where the exhaust stream is hitting it.
Thread
Thread Starter
Forum
Replies
Last Post
2blu442
Parts For Sale
2
March 7th, 2014 06:09 PM
atkinsom
General Discussion
7
May 29th, 2013 06:39 PM