It's on the drivers side of a 1987 F-250 5.8L 4brl . It hasn't been hooked up since we've had it. Anyone know what it is and what position it should be in ?
Thanks,
Marty

 

pictures are worth more then a thousand words my friend

 

Pic tomorrow. Thanks.
Marty

 

I suspect it is a heat riser from the old school method of building heat in the engine faster. The flapper closes to build up back pressure in the exhaust. It was and still is an awful design IMHO.

 

"It was and still is an awful design IMHO. " Needed a good laugh this morning!

 

+100. The flapper should be permanently set in the open position or removed completely.

 

I'm not sure what other heat risers are like, but the one on my truck (before I took it off) just pulled air from around the exhaust manifold up into the air intake when cold. There wasn't anything in the actual exhaust stream in the setup used on my '87.

 

That thing just catches heat off of the manifold and sends it to the breather.. A heat riser closes off (for the most part) the manifold and forces the exhaust through a passage in the intake manifold to the other exhaust manifold to heat the intake up quicker..

Darn things never did work worth a crap!!!!!

 

Hmm, I guess I just haven't worked on anything old enough to have one of those. Where does the exhaust go after going through the intake manifold?

 

To the manifold on the other side of the engine.. both heads have a passage matching the intake to allow this..