Intake manifold crack
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Joined: Mar 2005
Posts: 52
Likes: 3
From: Ontario
Intake manifold crack
I have found a crack in my intake manifold.It is at the carb base and runs between the two large ports at the back.I have recieved two answers locally.
1. It is fine,they all do that ,run it.
2. It is very common because of excess heat from the crossover port with the potential for sucking hot exhaust gases into the air fuel mixture and acting as a vacuum leak(impossible to tune).The remedy for race engines is to block the crossover entirely to remove the excess heat as it is only required for cold weather running.
My question is.As my car is only going to see fair weather is blocking this crossover all together the correct fix?
It appears that this was a design issue with these engines that is easily remedied by restricting the crossover with a gasket (to late for me)and I am not sure that any replacement I may find will not have the same issue.Anyone else been down this road?
1. It is fine,they all do that ,run it.
2. It is very common because of excess heat from the crossover port with the potential for sucking hot exhaust gases into the air fuel mixture and acting as a vacuum leak(impossible to tune).The remedy for race engines is to block the crossover entirely to remove the excess heat as it is only required for cold weather running.
My question is.As my car is only going to see fair weather is blocking this crossover all together the correct fix?
It appears that this was a design issue with these engines that is easily remedied by restricting the crossover with a gasket (to late for me)and I am not sure that any replacement I may find will not have the same issue.Anyone else been down this road?
Le Mans Master
Joined: Feb 1999
Posts: 6,807
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From: Hoosier
Cruise-In III Veteran
Blocking the crossover is no big deal. If the crack does effect a vacuum leak then weld it. Is it aluminum or cast iron? Since you would have to take it off anyway, just replace it with an Edelbrock Performer manifold. I'd guess the costs of welding or replacing will be about the same.
Thread Starter
Advanced
Joined: Mar 2005
Posts: 52
Likes: 3
From: Ontario
It is cast and is already off of the car.I was hoping to retain it as it is original to the car.If blocking the crossover is no big deal then that is route I'll take.
Thanks for the reply
Thanks for the reply
Le Mans Master
Joined: Oct 2002
Posts: 5,714
Likes: 6
From: Silver City NM
St. Jude Donor '05-'07
Easier and less expensive than having it welded is to buy some JB Weld (epoxy) and patch up the crack. You can get that stuff ay any hardware store.
Should work just fine.
Dep
Should work just fine.
Dep
