I got my exhaust manifolds cleaned up and put on and I'm ready to put the crossover pipe back on. I was wondering if I needed to put the exhaust thermostat back on, so I began to look for a replacement.....well, It's not in my parts catalog and Dennis Carpenter has one for 1965.
What's up with that? The engine was rebuilt sometime around 1970. Was this added on at that time? Is it necessary? If I don't put it on, will it mess up the spacing?
Here is the one I have
By the way, I was able to get the exhaust studs at Orschlen's. I guess those studs are still used everywhere. (But they didn't have the nuts for the open end, they don't carry much fine thread stuff. Off to Ace Hardware tomorrow.)
If memory serves me right, they're called heat risers. Diverts exhaust through the intake manifold when engine is cold. If you leave it out, the crossover pipe will not fit exactly right. Yours appears to be in decent shape. Free it up and install it. Last time I saw a new one advertised, it was big $$$.
I think you're missing a pin that the spring hooks to. I bought a NOS one about a month ago on eBay for 25-30 Bucks. Mine was missing and I couldn't get the cross over pipe to seat without leaking without it. Here's a picture out of my 56 Manual.
OBTW with the butter fly closed the exhaust gases take the path of least resistance and back up through the intake manifold and into the other exhaust manifold bypassing the valve until it gets warm and opens up.
Do your intake, and yourself, a favor. Unless you live in cold country, tie it open. When these stick shut, the driver's side head cracks between 6&7. That's my story and I'm sticking to it. That's why Albatross now sports a 292 and a new exhaust.
Well, it's because a PO thought that they were fixing the broken spring and tied it shut by mistake. Sad, but true.
They are needed in the exhaust to get the spacing right. You could braze or weld it up open and never miss it if you don't live in cold weather land. Otherwise, buy a good used one. They're out there. I got manifolds, crossover, and a good valve for ~$70 shipped. The guy wrapped them all together with shrink wrap, boxed the mess with extra cardboard for packing, and they arrived in great shape.
Cut the butterfly out and weld up the holes and never look back.
That's my old school story that I am sticking to. It's way better than having it stick
shut and try and trouble shoot it. Ya will think all kinds of things are wrong except
that damn valve being stuck.
So it may be a bit cold blooded in the dead of winter. But ya most likely
will never miss it. But ya need it for the spacer to get the exhaust header
pipe to fit. Think about it, aftermarket headers don't come with that do they?