suck thru the head?
#1
suck thru the head?
Can the wrap off my V&H quiet baffles get sucked back thru the head and into the cylinder? I heard that when the poppping sound on decel happens its air going back thru. If this is so could it take some insulation with it? I am thinking of using ceramic blanket (2300 degres) and that probably wouldnt help things if this were true. Any experts out there?
#2
RE: suck thru the head?
If it were true, you would be sucking rain, bugs, dust and all other sort of nasties back into the cylinder.
Urban myth....the exhaust is pushed out by the piston raising on the exhaust stoke while the exhaust valve is open, the intake stroke, the intake valve is open and the exhaust is closed.
The popping on decel is unburned fuel getting into the muflers and then igniting caused by air leaks in the exhaust system or to rich of a mixture when the throttle is closed.
Urban myth....the exhaust is pushed out by the piston raising on the exhaust stoke while the exhaust valve is open, the intake stroke, the intake valve is open and the exhaust is closed.
The popping on decel is unburned fuel getting into the muflers and then igniting caused by air leaks in the exhaust system or to rich of a mixture when the throttle is closed.
#3
#4
RE: suck thru the head?
Reversion most certinly will take what ever is in the path and suck it into the head if the pipes are that bad. WE all get reversion in a certin area of our power band...how else would you explain the carbon build up on the back side of the intake valve and into the intake trac.
I've seen that ceramic pipe coating get sucked into the cylinder doing extinsive damage to the cylinder...how ever exhaust fiber glass, I doubt it ever makes it up the pipe far enough for reversion to take it into the cylinder.
As far as the exhaust valve being closed during the intake event....only with a stock cam. Overlap in a hi-performance cam has both valves open at the same time at TDC, the more over lap the longer they are open together.
I've seen that ceramic pipe coating get sucked into the cylinder doing extinsive damage to the cylinder...how ever exhaust fiber glass, I doubt it ever makes it up the pipe far enough for reversion to take it into the cylinder.
As far as the exhaust valve being closed during the intake event....only with a stock cam. Overlap in a hi-performance cam has both valves open at the same time at TDC, the more over lap the longer they are open together.
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#8
Join Date: Jan 2007
Location: Minneapolis Area, MN
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RE: suck thru the head?
ORIGINAL: Doc 1
...I've seen that ceramic pipe coating get sucked into the cylinder doing extinsive damage to the cylinder...
...I've seen that ceramic pipe coating get sucked into the cylinder doing extinsive damage to the cylinder...
I just had this done and I hadn't heard anything bad about ceramic coating headers.
#9
RE: suck thru the head?
Years ago people used to paint the inside of their pipes thinking it would stop the bluing of the chrome( due to a wrong AFR ) After these people realized that the heat coming out of the head was around 1300 degrees and the paint was for 650 degrees this wasn't working.......So some one got the bright idea to coat the inside of the pipe with a ceramic product. Good idea for the temp in the pipe but most people installed this product over a carbon layer and/or anoil soakedpipe. First time down the road the reversion pulse wave took the pieces of ceramic that came off from a poor bond back in to the cylinder doing a lot of damage the the cylinder and exhaust valve seat.
Now this has nothing to do with coating the outside of the pipe so be at ease if this is what you did...lol.
Now this has nothing to do with coating the outside of the pipe so be at ease if this is what you did...lol.
#10
Join Date: Jan 2007
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RE: suck thru the head?
ORIGINAL: Doc 1
Now this has nothing to do with coating the outside of the pipe so be at ease if this is what you did...lol.
Now this has nothing to do with coating the outside of the pipe so be at ease if this is what you did...lol.
Maybe I verify with the shop what was actually done to my pipe.