Pulled My Headers...
03-18-2012, 10:06 PM
#1
Pulled My Headers... They needed to have the flanges faced (done) and im going to wrap them for ***** and giggles Hahaha but mostly for the containment of heat and to help protect my new wiring harness. Whilst inspecting my engine to make sure everything was ok I took pictures inside of the exhaust ports on my LT1.
Cyl 1.
Cyl 3.
Cyl 5.
Cyl 7.
Notice how the valves are whitish on cylinders 1 &3 but on cylinders 5&7 there darker. I know my bad tune and few exhaust leaks that i had on the header could cause something like this to happen. Along with perhaps the first 4 cylinders getting more air through the intake then the rear 4 due to design? What could cause that to happen?
Cyl 1.
Cyl 3.
Cyl 5.
Cyl 7.
Notice how the valves are whitish on cylinders 1 &3 but on cylinders 5&7 there darker. I know my bad tune and few exhaust leaks that i had on the header could cause something like this to happen. Along with perhaps the first 4 cylinders getting more air through the intake then the rear 4 due to design? What could cause that to happen?
03-18-2012, 10:14 PM
#2
The LT1 intake manifold is a great piece it will support cars into the 9s with work done on it. I bet some of your cylinders are burning lean. How many miles on the car? I just pulled my valves and replaced them at 105k.
What is your psi on the fuel rail? The front cylinders will have problems being starved of fuel because the fuel starts at the back of the rail then feeds forward.
What is your psi on the fuel rail? The front cylinders will have problems being starved of fuel because the fuel starts at the back of the rail then feeds forward.
03-18-2012, 10:27 PM
#3
i rebuilt the engine agood 15k miles ago. I feel the heads arent perfect. I forgot to mention i did a compression test. They were all around 190psi. I didnt do a leak down test but im confident the heads arent perfect. The machinist that rebuilt my engine and heads only hand lapped the valves.
03-19-2012, 12:43 PM
#4
TECH Fanatic
I've always heard that wrapping mild steel headers, assuming that's what you have, is a bad idea, at least from a longevity perspective.
03-19-2012, 01:18 PM
#5
03-19-2012, 05:22 PM
#6
Trending Topics
03-19-2012, 10:42 PM
#9
TECH Veteran
Moisture is not the culprit in wrapping headers. Obviously, there is going to be little moisture when the pipes are several hundred degrees. It is the trapping of the heat, causing premature metal degradation and fatigue. Less heat might be good for the surroundings, but bad for the headers.
03-19-2012, 11:12 PM
#10
Moisture is not the culprit in wrapping headers. Obviously, there is going to be little moisture when the pipes are several hundred degrees. It is the trapping of the heat, causing premature metal degradation and fatigue. Less heat might be good for the surroundings, but bad for the headers.
03-19-2012, 11:17 PM
#11
Moisture is not the culprit in wrapping headers. Obviously, there is going to be little moisture when the pipes are several hundred degrees. It is the trapping of the heat, causing premature metal degradation and fatigue. Less heat might be good for the surroundings, but bad for the headers.
Spraying them with silicone barriers will do nothing but prevent staining of their material as their water/chemical resistance is gone after a few good heat cycles.
The heat retention and fatigue of the headers on a street NA engine isn't as bad as a turbocharged or road raced engine where heat and cycles are more extreme. I've cracked open a turbo downpipe at a bend from heat on a wrapped 14gauge mild steel pipe. Could have been the thinning of material at the mandrel bend, could have been the wrap holding heat there. Not sure, but I stopped using it when I removed the wrap and found that even though it was aluminized, it was rusting severely compared to the unwrapped portions which looked brand new.
