Ray Dzi

Guy's, check your heat riser. Mine was stuck shut or partially closed. Took a few days of spraying Kroil and tapping and prying.
Went for a drive and top end is so much better. Like new found horse power.

Oldsguy

Good point. That thing will rust shut if not used often.

JohnnyBs68S

I remember dad spraying that thing down w/ WD40 nearly every spring to keep it working properly. When I put on dual exhaust back in the '80s, I just disconnected the spring so that it would stay open. I'm sure mine is rusted pretty solid by now, but at least its in the open position.

oldcutlass

If it stuck once it will stick again. Most of us gut the valve and braze over the holes.

Oldsguy

Most of us gut the valve and braze over the holes.

https://classicoldsmobile.com/forums...le-one-166026/

I did that, look at the last post in the thread.

Ray Dzi

your link takes me to your air cleaner housing repair. Is that what you wanted me to view?

Oldsguy

yeah, I took out the guts of the flapper style heat valve and everything associated with it. The only difference is that I tried to weld instead of brazing. I burned some mighty holes that day.