56 oc 3 oliver

ocman · December 09, 2012, 10:08:12 PM

I am having a problem with a rebuilt Hercules motor i installed a new thermostat in the motor it did not have one it runs for a few minutes and gets up to 220 degrees then it starts overflowing out of the top of the radiator i checked the coolant in the drain on the pipe connected to the waterpump it is cold there but the water pump itself is hot along with the head i am wondering if the thermostat is not opening to cycle the coolant I checked the vent in the radiator it is OK also i have the thermostat with the pointed end facing up torward the sky i believe this is right? any thoughts appreciated Wes

1956oc3 · December 09, 2012, 11:36:39 PM

sounds like the stat is not opening, remove it, suspend it in a pan of boiling water and see if it opens, it should.was it a new stat? also is the water pump impeller turning ok? Scottie

ocman · December 10, 2012, 02:25:04 AM

Brand new stat, water pump just rebuilt I will remove stat and try boiling water thanks for info

Blake Malkamaki · December 10, 2012, 03:32:32 AM

See if it cools without the thermostat.

oliverchris · December 10, 2012, 01:57:33 PM

I'd go with Blake. I have hardly ever seen an OC3 WITH a thermostat.

ocman · December 14, 2012, 12:30:13 AM

Well I pulled the thermostat and it did not overheat it ran about 130 degrees i put the stat in hot water and it opened around 180 f so i am not sure i guess my oliver does not like stats it never had one before i had it rebuilt anyway the motor ran good but i wonder if i should leave as is running at 130 f, thanks for your replys

Blake Malkamaki · December 14, 2012, 02:33:28 AM

I doubt if it would hurt to run it without one, though it could cause condensation in the crankcase if you only ran it for a short duration during the winter. But I bet it will be ok. As far as the thermostat goes, could there have been an air pocket under it that was not allowing the water to get to it to open it? There is usually a little hole in the stat along the edge to let air out - maybe your gasket was covering the hole?

hotratz · January 19, 2013, 07:39:06 AM

I had a t-stat on a car that would hang up occasionally while installed (would not close all the way). I did the boiling water test and it worked fine but on closer examination I could see the slug did not travel exactly in line with the seat and there was a slight witness mark on the spring supports were it must have been rubbing. Replaced it and problem went away.