Hot running y-block

steve fritz

Well-known member
Just rebuilt a 256 Mercury y-block and installed in my 54 Mercury. Everything is stock and it runs way over to the right side of the dash temp gauge. Today was a rather hot/humid day and I took it out to a car show about 30 miles from home. Mostly highway speed, 55-65 mph and the needle ran right over to H and stayed there the whole trip, both ways. Car seemed to run well. no sign of boil over, etc.
The gauge has read 3/4 of the way to H ever since I put the engine together. It goes to the midlle reading within 3 minutes of cold start up???? I have about 500 miles on it now in the last couple weeks. The car seems to run best with intial timing about 12 degrees. Would this be contributing to the high temp?? Any other ideas about why the temp is so high? I have another y-block in a 57 Ford, and it never gets above mid point on the temp gauge. Can I expect higher temp readings from a fresh rebuild, untill I get more miles on it??
Any ideas or experience on this would be appreciated.
Steve
 
Well if it's not throwing water out then you should be ok .
I would take a stab at it and say the sending unit went up . They can go bad overnight for no reason . I would either get a new sending unit or get a new temp Gage and place under the dash . Also the timing will make an engine run hot also but I don't think that is your problem .
If you have done all that driving with the engine still running fine and you are not loosing anything from the radiator then you are fine . Still get a Gage or sending unit before taking a trip .

Jim
 
Buy a meat thermometer at the grocery store or a radiator thermometer at a parts store.

Run the car until the temp gauge does to its normal position (in your case 3/4? to hot). Take off the radiator cap SLOWLY and with a rag and then stick the thermometer in it. This will tell you what the water temp is.

Ford gauges are known for proving inaccurate reading. You might have a bad gauge or a bad temp sending unit (or the wrong one)
 
I have the same problem with my 292 did the shroud 6 blade steel flexfan new rad and gauge still reads h shot with a infra red thermal therometer { harbor freight ] reading 185 at the stat go figure
 
Thanks for the reply on this heating problem. I put a mechanical water temp gage on it today and it looks like I must have a sending unit or dash gauge that's bad.....the engine is running at 180-190 degrees, which is no problem. That's the good news! Now I need to find a good sending unit and switch back to the stock set-up. Anybody have a new or good used one for sale???? Must be 6 volt, 54 or 55 Ford/Merc, y-block.
Thanks again!
Steve
 
I just rebuilt a Y block and had the same issue with a sending unit from Sac Vintage Ford. They wouldn't replace it, so I just put the old one back in and voila it works great.
 
I really prefer mechanical gages much more than the ones in the dash . They are much more accurate ! I know you can get replacement gages from many places or they can be rebuilt .
If you don't like the look of the aftermarket gages you get at the parts stores when you show your car at a show or places like that , here is what you can do . Use the gages from the parts store and put small hinges on the chrome frame that the gage kit comes with . Attach the frame under the dash and what you end up with is a set of gages that are hinged so when you don't want to see them just push them up under the dash . Sort of a door set up . Then when you drive and want to see the gages just swing them back down .
That way no one will know you have the gages !
Another one I have seen is you take your speaker grill and hinge them on one side so the grill pops up with the gages attached to the bottom of the grill . When you are at a show , just push the grill down and the gages are out of site !
Just some ideas if you want modern gages that you don't want anyone to see !

Jim
 
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