michel88 Posted June 6, 2008 Share Posted June 6, 2008 I recently put a rebuilt 47 Roadmaster engine in my car. I was going to rebuilt the original engine but it had a crack in the block. The engine was rebuilt by a professional mechanic who is a member of my local Buick club (Buick Owners of Maryland). The engine runs very well and is smooth and powerful. The problem is if I drive on an interstate highway at 60 or 65 mph it starts to run very hot quickly and it will boil and start blowing out coolant. If I drive at slower speeds under 45 or 50 it runs right at 180 degrees. It has been cleaned out inside the water jackets, new waterpump, and the radiator was cleaned by a radiator shop. I checked the radiator and the part number on the upper tank is 3113847 which is the corect number. It is supposed to be a 3" thick core on the Roadmaster series. I measured the bottom tank and it is only 2 1/2" thick. My friend has a 41 Roadmaster radiator and it measures 3" thick. I am not sure what is going on here. I need help figuring this out. Link to comment Share on other sites More sharing options...
Mark Shaw Posted June 6, 2008 Share Posted June 6, 2008 First, make sure the timing is advancing at hiway speeds. The old "springs and weights" spark advance mechanisms can get stuck due to lack of lubrication and cause overheating by running with retarded spark. Second, check your thermostat to make sure it is opening all the way at the correct temperature.Third, check your bottom radiator hose to make sure it does not collapse when running the engine hard.Fourth, If nothing else works, just slow down and enjoy the ride at 50 mph. I don't drive any of my Buicks over 45... Link to comment Share on other sites More sharing options...
michel88 Posted June 7, 2008 Author Share Posted June 7, 2008 Thanks for your ideas Mark, I will check out your sugestions. The spark advance sounds promising. Right now I have the thermostat out which I don't like to do. It seemed to make it run a little cooler but I don't usually take them out because the cooling system should function fine with the thermostat in and the long warm up puts wear on the engine. My main question is: why does my radiator have only a 2 1/2' thick bottom tank and core? My friend has small series radiator that has a 2" thick core and a large series with a 3" core. Did the early 40 large series have only a 2 1/2" core? I was hoping to drive it to Flint in a caravan with my club so it needs to be able to run faster than 50 mph. Link to comment Share on other sites More sharing options...
Mark Shaw Posted June 7, 2008 Share Posted June 7, 2008 I don't have a 1940 Buick available for comparison, but I expect to see a 41 later this weekend. I will measure it and advise.Can anybody on the forum help with these measurements? Link to comment Share on other sites More sharing options...
BUKE Posted June 17, 2008 Share Posted June 17, 2008 Hi I just happen to have 1940 century tank in my hand.it is 3in wide and 17in long.Hay i just posted my 50 post maid my day. I injoy the forum great help thank' guy' and gal's buke (frank) have a great BUICK day Link to comment Share on other sites More sharing options...
michel88 Posted June 17, 2008 Author Share Posted June 17, 2008 Frank, thanks for letting me know. This is mystery how my radiator is only 2 1/2" thick instead of 3". My top tank has the right part number maybe somebody damaged the bottom tank and adapted a thinner bottom tank and core? Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now