Originally Posted by Daleo56
We took the Thunderbird out for a shakedown cruise this weekend. Prior to changing the ignition system I wanted to get an idea of performance and mileage. We have a standard route but the wife and I take. It is 40 miles of freeway 20 miles of sidestreets and another 40 freeway coming home. We also stopped for a quick breakfast during the route to give those car time to cool down.
It is hard to tell with the stock temperature gauge but I believe I ran around 200° the first half of the trip. After a quick stop for food we started again and I seemed to run slightly hotter. By the time we got home the engine was running even warmer at around 210 degrees. The weather outside was 80+ degrees with 75% humidity. After we got back to the shop and parked at about a quart came out of the overflow hose. The temperature laser at that point read 220 at the thermostat housing since I had access to the reader at the shop.
We had never gone more than a few miles around town prior to this so I have no comparison for temperatures or performance.
After letting it sit for a couple of hours I remove the 14 pound cap and started the engine to watch water flow. The thermostat open at 180, which was a new thermostat I had put in a couple of months ago , and the flow seemed OK. It never got above 185 or so idling at the shop.
There was a prior long thread by a member name rock-and-roll where Dave mentioned all the things to check and they seem to be OK. I have no frame of reference for degrees or heat for this type of engine but that seems a little warm.
Anyway I am going to install a Milodon 16406 thermostat and add a transmission cooler to see if that helps. The fan and radiator are stock and clean. The water pump does not leak. The compression is the same on all cylinders and there are no bubbles or smells in the water. Yes, I am running 100% water since we changed the intake gaskets. I have been waiting for a test run before I add coolant.
The mild overheating may be caused by corrosion of the water flow block-off built in to the head gaskets. I'll see if Yellow Rose would be willing to post an emailed photo.
Here are the 2 pix that Woobie sent me to post.