Read my local newspaper today and in "Car Talk" the brothers talk about how running with your cats removed will eventually destroy your valves due to heat. I have never heard of this before. What is the scoop?
Removing cats destroys valves
- Thread starter Juice
- Start date
Juice said:
I normally find the "Car Talk" guys entertaining, informative and knowledgeable. I will have to see this cat's removed causing valves to burn column. May have to send off an email to them.
Post the article, please. If they are making such a claim, I want to see the evidence. :tongue: Due to "heat"? What, less of it?
I don't know about that, but on the Car Talk website, you can vote for the ugliest car:
Car 1: Hummer H2
"The automotive equivalent of Aunt Bertha."
Car 2: Scion xB
"Takes the cube to new levels of ugliness."
Car 3: Pontiac Aztek
"That didn't just get hit with an ugly stick; it came charging out of the ugly forest!"
Car 4: Honda Element
"A rollover would improve its looks!"
Car 5: Chrysler PT Cruiser
"So ugly, I get mad just looking at it."
Car 6: BMW 5 Series
"With the granny glasses headlights and awkward body creases, it looks like a Pontiac on acid."
Car 7: Chrysler 300
"Did Chrysler have the had the head of a cow in mind when designing this car?"
Car 8: Chevrolet Avalanche
"Adorned with more plastic than Anna Nicole Smith."
Car 9: Subaru TriBeCa
"Looks more at home in Prague."
Car 10: Dodge Magnum
"The Welsh Corgi of the car world — wishes to be a big dog, but too short to the ground."
Car 1: Hummer H2
"The automotive equivalent of Aunt Bertha."
Car 2: Scion xB
"Takes the cube to new levels of ugliness."
Car 3: Pontiac Aztek
"That didn't just get hit with an ugly stick; it came charging out of the ugly forest!"
Car 4: Honda Element
"A rollover would improve its looks!"
Car 5: Chrysler PT Cruiser
"So ugly, I get mad just looking at it."
Car 6: BMW 5 Series
"With the granny glasses headlights and awkward body creases, it looks like a Pontiac on acid."
Car 7: Chrysler 300
"Did Chrysler have the had the head of a cow in mind when designing this car?"
Car 8: Chevrolet Avalanche
"Adorned with more plastic than Anna Nicole Smith."
Car 9: Subaru TriBeCa
"Looks more at home in Prague."
Car 10: Dodge Magnum
"The Welsh Corgi of the car world — wishes to be a big dog, but too short to the ground."
Juice said:
Engines require a certain amount of back pressure to keep the new charge of air and fuel from flowing out of the exhaust valve as both valves are open during the last portion of there exhuast stroke. If too much unburn mixture flows past the exhaust valve the mixture will burn in the exhaust port and header, causing burning and overheating of the valves. This is more of an issue with drag cars where the run no exhaust pipes and shorty open headers. With the NSX, the run of the headers, and exhaust is long enough to create adequate back pressure to avoid the burned valve issue with or with out cats. The only time to keep an eye on this would be if your headers dump directly into an open pipe in a race car. This situation would warrant an EGT probe to monitor temps. These temps can always be controlled with cam timing and A/F adjustment, of course this is much beyond the stock ECU capability.
I had over 42,000 miles on my last motor, 25,000 with out cats. When I tore down the motor, the valves were in such good shape I didn't even grind them when I put it back together.
from all other reading. Removing Cat will make a better flowing exhaust track hence retaining lower heated gas in the exhaust. better flow also better high end hp.
Lower heat in the exhaust and header will give better longevity to a motor. However there is the legal and enviroment issue regarding cat removal.
Personally I hate the exhaust stains and smell when cat is not installed. with minimal gain for street use from a No cat system and all the legal issues it isnt really worth it for a street driven car.
Lower heat in the exhaust and header will give better longevity to a motor. However there is the legal and enviroment issue regarding cat removal.
Personally I hate the exhaust stains and smell when cat is not installed. with minimal gain for street use from a No cat system and all the legal issues it isnt really worth it for a street driven car.
titaniumdave said:
I currently am running Taitec headers, test pipes, and center exit exhaust. The bypass pipes have a bung weld for a thermal temp sensor. Currently, I am installing HKS sensors into the bungs to be decoded by my CAMP system. With that being said, I am not tapping into the header off of the #1 cylinder to get "true" exhaust temp readings as recomended by HKS. Any idea what temps I might be looking for once I am up and running?
Similar threads
