Bought a HOT Oliver Hart Parr 70-need help

[Welding man]

I bought an Oliver Hart Parr 70 a couple of weeks ago from a friend. It had been in his family for several years and he and his brother had pulled it in antique pulls for several years. They both had lost interest in pulling so I bought it. Got it started fairly easy , cleaned fuel tank and carb and it started right up but right out of the box it had a heating problem. It runs good, no oil in water or water in the oil but, if runs 10 minutes it will start blowing the water out of the overflow on the radiator. I have drained the radiator and block, flushed them out, installed a new water pump and an electric fan, nothing has helped .Original owner said it would get pretty warm but, nothing like I am experiencing. It seems to be circulating Ok but it gets red hot in one pull. I'm stumped. Anyone have any suggestions? Thank you in advance.

 

[rrlund]

Are you sure it's hot and not just a bad head gasket building pressure in the cooling system so it blows out the overflow?

 

[J.Wondergem]

Sounds like a head gasket to me.

 

[Welding man]

It's hot. It has a temperature gauge at the rear of the block below the head. it gets to over 225 real fast and boils when you shut it off. Runs as smooth as silk, no indication of anti-freeze in the exhaust or oil pan. Spark plugs are all burning clean. Could be a head gasket but for what they cost ,I hope not.

 

[oliver90owner]

(quoted from post at 01:17:42 08/23/21) It's hot. It has a temperature gauge at the rear of the block below the head. it gets to over 225 real fast and boils when you shut it off. Runs as smooth as silk, no indication of anti-freeze in the exhaust or oil pan. Spark plugs are all burning clean. Could be a head gasket but for what they cost ,I hope not.

For what it costs, a compression check would be a cheap alternative to simply changing the head gasket!

 

[Dieseltech]

Sure sounds like the radiator has some plugged tubes to me, IF all else looks OK. Did you try pulling the thermostat for testing? Also with the cap off, and fan belt loose so the water pump does not turn look closely right after a cold start for bubbles in the radiator. That would be a sign there's a compression leak for sure into the cooling system. VERY LATE ignition timing will make things hot faster too, but engine would not pull very well then either. Let us know what you find..

 

[Welding man]

Rich 70 does not have a thermostat. Non pressure system. The manual states that the head is cooled by the radiator and circulated by the water pump and the block is cooled by the thermosyphon method and will likely be hotter than the head. I'm going to pull the plugs and do a pressure check on the system. Leak down test may show something also. I just can't figure out why it gets so hot so quick and still runs so good. I pulled second place out of 9 tractors the first time I pulled it. One was another Oliver 70 that rarely gets beat. We will figure it out sooner or later, if not I'll go back to the Cockshutts.

 

[craigco]

Do you still have the engine driven fan on or did it get replaced with an electric fan? I have a later 70 that I pull with, thought I would replace the engine driven fan with electric fan. Same results would over heat after one pull. Had radiator cleaned but washers in radiator hose to act like a thermostat to slow the water. Electric fan would hold a shirt against the radiator every thing seemed like it was fine. Put the engine fan back on stopped over heating.

 

[Traditional Farmer]

Was the other 70 owned by Roger Shivley? Could the motor be bored out and block filled in so water only runs thru the head?

 

[Welding man]

No to both questions. 99% sure it has not been hard blocked. Old tractor is pretty much stock, according to previous owner.

 

[Welding man]

I do still have the original fan, but I don't have any side covers or fan shroud. I could not detect any air flow through the radiator with the original fan. I have considered the washer trick. We did that many years ago on a race car we had and it did cure the problem.

 

[ss55]

A fan shroud helps the fan move a lot more air. If the previous owner added a lot of horsepower, there could be more heat than the coolant can move without a water pump. Do the radiator hoses get hot as the temperature gauge rises? The thermosiphon cooling system might just be slow to respond. Some pullers will block off some of the coolant in the engine block and only run coolant through the cylinder head.

 

[LandonT]

couple suggestions for what its worth...
1. read the manual for how full the radiator should be, low enough to allow movement but high enough that the liquid in the syphoning path is continuous.
2. See if you can feel a difference in temperature (measure?) at inlet and outlet of the radiator. If there is little to none, then radiator is a problem, and sounds like previous owner was living with it this way.
3. I bought a flexible snake from the home depot plumbing section, plastic with a handle on one end to turn(cheap), and ran it into the drains and from the water pump housing in. This dislodged quite a bit of stuff.
4. After dislodging as much material as possible, warm the tractor and hold some old fuel line over open drain holes. Back flush with low pressure compressed air or your lung power.
5. Tractor is old enough(and pre-coolant) that cooling passages are covered with a coating that insulates. 'Thermocure' is a coolant flush that works to remove this coating. Walmart has it.

 

[rrlund]

I think you're on to something with the fan shroud. I built a new greenhouse this spring. When I installed the ventilation fan, it wouldn't even push the louvers open. I built a shroud for it and it immediately pushed the louvers straight out. The air just moves in the direction of least resistance without something to control the flow. You're just going to suck air in from the sides easier than it'll suck it through a radiator core.

 

[Welding man]

Thanks to every one for trying to help with my problem. I am off from work tomorrow and am going to try my best to find the problem. I am going to start with a pressure test on the cooling system, flow check the radiator and go from there. The tractor runs too good for me to be convinced that it has a head or head gasket problem. Will keep you posted.