exhaust flapper thing (for warmup)

[vortec]

mine doesn't seem to be operating properly. bad diaphragm, probably. i'll proabably just hold it open with some wire, for a while. i just want to make sure which lever position indicates that it's open. i tried tying it in each position, but the exhaust sound and pressure didn't seem to change as much as i expected, so it was hard to tell. i know removing the y-pipe is the best way to tell, but the y-pipe was a pita to bolt back on after i swapped my engine, so i'd like to leave it on. probably got bent a little, offroad.

thanks.

 

[JIM88K5]

The spring inside holds the valve closed, vacuum opens the valve....

 

[Clod_King]

My old truck had one that constantly mucked up on me. leaking, usually. My old boss told me to remove the thing.

But my engine blew up before I had the money/time to do it.

 

[Cornfield creations]

They make a heat riser blank. If you wanted to remove it and utilize your y-pipe without mods. Most exhaust shops should carry it I imagine. I know we keep one in stock. Just the block minus the butterfly.

 

[lochenjons]

What year? I know my truck (77 k5) is different from my friends 78, his has a cable or something go from his to somewhere, havent really looked at it though. What makes you think it isnt working?

 

[Jason4x4]

just be careful, I put an engine in a chevy one time, cause it had a rod knock. Turns out someone welded the valve, and it was closed, seems the engine didn't like it too much.

 

[lochenjons]

just be careful, I put an engine in a chevy one time, cause it had a rod knock. Turns out someone welded the valve, and it was closed, seems the engine didn't like it too much.

Haha why???

 

[vortec]

it's an 82 with a remanned year-appropriate 350 and stock manifolds for now.

ah, spring holds it closed. ok, cool. that's what i needed to know. wasn't sure if it was closed by vacuum or opened by it.

What makes you think it isnt working?

the lever position doesn't appear to change when with engine temp (yes, the vac tube is good). and, i've got an exhaust leak i can't track down. the extra pressure of a closed butterly valve in there could be making it worse. if i relieve it, the leak itself would still exist, but not be so pronounced.

They make a heat riser blank.

that could be a good way to go.


muchas gracias, mi amigos. (oops, shifted into spanish. blame my coworker from honduras)

 

[roadnotca]

If you do brave taking the Y off again, you can just cut the tin off the shaft. Mine, the tin blew off, so I wondered "what the $%^&?"
I had to cut the exhaust to remove trans & T-case; there were the pieces in the mouth of the CAT.

 

[vortec]

might be the way to go. it would be worth the hassle of removing the pipe to just go ahead and dig the problem out. i had to use a small crowbar to wedge it into place last time. 2 joints within a few inches of each other and pipe slightly out of alignment makes a perfect recipe for an exhaust leak. SOMEBODY probably bonked the exhaust on a rock or something. i wonder who (and how many times).

 

[vortec]

ok, i took the &%$ exhaust apart, yesterday and the spring holds mine OPEN, not closed. that's good. but i was a little surprised to see that. and getting that y-pipe back on was even more of a pita, this time. of course, last time, it wasn't 33 degrees outside according to my thermometer. that's unpleasantly cold for us texas guys.