cracked manifold

[hcox10]

hi
how much boost will i loose with a hairline crack.
is there any thing i can use to seal the crack without
taking it off and weld it.
thanks harold

 

[fbodlovr]

I cant imagine you losing much, if anything at all honestly. As long as it really is JUST a hairline. If you dont want to take it off, put some JB weld on it. That should seal it up, and last quite a while. Wont look that great though.

 

[Jerryl]

hi
how much boost will i loose with a hairline crack.
is there any thing i can use to seal the crack without
taking it off and weld it.
thanks harold

Not to be a "stick in the mud", but ....... Unfortunately, you need to take the header off if you want to fix it right.
Get it welded.

I cant imagine you losing much, if anything at all honestly. As long as it really is JUST a hairline. If you dont want to take it off, put some JB weld on it. That should seal it up, and last quite a while. Wont look that great though.

Depending on its size, the hairline "may" not have a lot of effect on boost AT medium levels, but will effect your BLM's.

The "average" exhaust temps range from 1000 -1700F
Std JB weld is rated to 500F and will not hold.
"JB Kwik" is rated to 300F

 

[fbodlovr]

oh jeez!!! I look stupid as hell! I thought you were saying you had a hairline crack in your intake manifold for some reason. Yeah, I know. JB weld wont work on an exhaust header. WELD IT UP!! lol

 

[Jerryl]

oh jeez!!! I look stupid as hell! I thought you were saying you had a hairline crack in your intake manifold for some reason. Yeah, I know. JB weld wont work on an exhaust header. WELD IT UP!! lol

Don't worry man.
Actually, he did not specify which manifold and I "ass-umed" he implied "exhaust", since I have never heard of a cracked intake.
In case it is in the intke ........ JB will work up to 27 PSi for sure

 

[hcox10]

cracked manifild

hi
i am sorry i should have told you nice people
it is exhaust manifold on passengers side.
without getting it welded how much boost will i lose.
thanks harold

 

[Jerryl]

hi
i am sorry i should have told you nice people
it is exhaust manifold on passengers side.
without getting it welded how much boost will i lose.
thanks harold

Here is what I would do, depending on your goal.
As much I hate to promote but have to (since they are the only ones that have an aftermarket piece right now) get the Poston's PS exhaust.

Or wait till X-mas and get whatever G-Body Parts comes out with.

Edit:
I would worry more about the tune than just a boost number.
You can always make up for a loss in boost by "cranking it up"
But a bad tune can take out a motor.

 

[Turbo Riviera]

Don't worry man.
Actually, he did not specify which manifold and I "ass-umed" he implied "exhaust", since I have never heard of a cracked intake.
In case it is in the intke ........ JB will work up to 27 PSi for sure

I have a cracked H/A intake manifold... I used Fel Pro 1200's but put 'em on funky the first time. Torqued the manifold down and cracked the pass, front ear by the coolant passage. Over time it gets a crusty green powder on it.

 

[Dwayne]

............if you can hear the leak at idle, then you will be compromised as to how much boost you can make at wot.......another thing to keep in mind is that the hairline crack probably opens up some when hot and under a load......your best bet would be to bite the bullet and pull it off and fix it right once and for all..........good luck

 

[84GNGary]

hi
i am sorry i should have told you nice people
it is exhaust manifold on passengers side.
without getting it welded how much boost will i lose.
thanks harold

Never mind the boost how about your BLM's.
A cracked header will suck in air and cause high BLM's. The leak is seen by the O2 sensor and thinks the engine is lean and then adds fuel when you really don't need it. This can wash down the oil in your cylinders. Also you will never be able to tune the car with abnormal BLM's so how much HP will you loose, a lot with an untuned car thats running rich. Pull the header and have it welded. The stockers were 409 stainless so you can let a welder know just in case.