Exhaust Manifold Valve Service

Hello All,

I'm working on a 51 Buick with stock straight 8 and Dynaflow. Inspecting my exhaust man valve and although moves freely i'm missing the spring. Is there a problem with wiring this open other than cold starts? If going this route which way is open? lower arm pointing towards facing block or away? Attached a photo of my valve arm for reference.

Thanks

Thuff,

I included a picture of the service manual diagram showing the 3 positions of the valve. Based on this I'm going to say that arm in your picture should be pulled AWAY from the engine to put it into the "OPEN Heat OFF" position which is where you want it. I've gotta' say though, you are pretty lucky that your valve is not stuck tight! I've been into these straight eights for over two years now and you're the first I've met that didn't have a frozen valve. Most just bend the valve into that position (like me). Make sure you lube that shaft every oil change by squirting some graphite lube in there and working it back and forth.

Also wanted to add that you could put the spring back on there if you want. You can buy them here:http://bobsautomobilia.com/shop/manifold-parts/manifold-damper-spring-.-ms-333.html. If your thermostatic spring is still on the other side of the valve body and you put that damper spring back on there, your valve should operate as originally intended if lubed. You can't buy the little bracket that they attach to but you can do like I did and make one out of an old L-bracket. My valve doesn't work but I wanted it to look original so I put those things on there. Mine were missing too. Good luck and hope this helps!

Thuff51:

When the engine is hot and the thermostatic coil spring on the other side of the valve is in place and correctly installed, the square weight shown in your photo should be down, nearly horizontal and near the block. As the valve heats up the coil spring relaxes and the square weight drops down by gravity and opens the valve inside. The red spring is called the anti-rattle spring.

Joe, BCA 33493