Yet another exhaust manifold.
#1
New Member
Thread Starter
Yet another exhaust manifold.
Hello
My Valiant has a crack in the exhaust manifold for the 3rd time in 6 years. I am going to replace it again soon. Im wondering which manifold I should choose as far as material. Ive seen a variety of metals available with an array of price ranges. Heck, I have even seen plastic. Anyway, what do yall think? Tired of replacing manifolds.
1970 Valiant, 3.7 Slant Six. Completely stock. 60k orig miles
My Valiant has a crack in the exhaust manifold for the 3rd time in 6 years. I am going to replace it again soon. Im wondering which manifold I should choose as far as material. Ive seen a variety of metals available with an array of price ranges. Heck, I have even seen plastic. Anyway, what do yall think? Tired of replacing manifolds.
1970 Valiant, 3.7 Slant Six. Completely stock. 60k orig miles
#3
New Member
Thread Starter
Hey Racerhog
It seems to crack in different places every time. I was told once that its due to the block and manifold being of different materials and thus expanding and contracting at different rates. Plus living in Phoenix in extreme heat then going to the mountains where its much colder helps with the cracking. At any rate, it needs replacing again as my car is getting louder and louder.
It seems to crack in different places every time. I was told once that its due to the block and manifold being of different materials and thus expanding and contracting at different rates. Plus living in Phoenix in extreme heat then going to the mountains where its much colder helps with the cracking. At any rate, it needs replacing again as my car is getting louder and louder.
#7
Super Moderator
This is a good one for the leaning tower of Bob /////////
#8
Mopar Lover
Thanks Tom...lol
LTOP:... I agree with you on the temp change... Phoenix and a place like Prescott (PressKit) are and can be challenging when dealing with temperatures....
Most of the Cast Iron stuff your dealing with is more than seasoned to be up for using without having an issue! At least thats what I think.
Here is where I think you might be able to do some improvements....
Use the 5 minutes rule when starting the car, Let it warm up for 5 Minute.
And for shutting off the car, Let it Cool at idle for 5 minutes.
This will help the temperatures on both side of the heat cycle, cool down and warm up.
Know, I'm going on this info guessing that the tune up is all in good working adjustments. Not lean... Not rich... Not heavy in timing one way or the other.
Just food for thought. and something to try....
Just my 2 cents....
Iowan... What do you think?????
LTOP:... I agree with you on the temp change... Phoenix and a place like Prescott (PressKit) are and can be challenging when dealing with temperatures....
Most of the Cast Iron stuff your dealing with is more than seasoned to be up for using without having an issue! At least thats what I think.
Here is where I think you might be able to do some improvements....
Use the 5 minutes rule when starting the car, Let it warm up for 5 Minute.
And for shutting off the car, Let it Cool at idle for 5 minutes.
This will help the temperatures on both side of the heat cycle, cool down and warm up.
Know, I'm going on this info guessing that the tune up is all in good working adjustments. Not lean... Not rich... Not heavy in timing one way or the other.
Just food for thought. and something to try....
Just my 2 cents....
Iowan... What do you think?????
The following users liked this post:
LeaningTowerOfPowr (12-01-2016)
#9
Super Moderator
Iowan... What do you think?????
DANGER DANGER
I think it's in the tune up!
DANGER DANGER
I think it's in the tune up!
#10
I've seen v8's with this problem.
Might be a good idea to put a straight edge along the head and then along the manifold before assembly next time. Both may need surface grinding to true them up.
Might be a good idea to put a straight edge along the head and then along the manifold before assembly next time. Both may need surface grinding to true them up.
The following users liked this post:
LeaningTowerOfPowr (12-01-2016)
#12
Super Moderator
I forget that not everyone would know to cut let alone check a used manifold prior to installation, it's automatic with me, but check a head that's good.
#13
Mopar Fanatic
Im curious.
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