Start up w/o coolant, REALLY !

xray zulu

xray zulu

Junior Member
New head gasket, proper torque, all is well...

I have been told to start it up for 1-2 minutes w/o coolant. Then let it cool completely and torque as normal. Theeeeeennnnn add coolant... Comments Please. Thank You...
 
Who is telling you this advice? It may not hurt but 2 minutes might be too long. It definitely would get the head retorted faster.
 
It may not hurt but I have never heard of it. I would just do what everybody else does with their engines: running it with coolant.
 
xray zulu said:
New head gasket, proper torque, all is well...

I have been told to start it up for 1-2 minutes w/o coolant. Then let it cool completely and torque as normal. Theeeeeennnnn add coolant... Comments Please. Thank You...
Click to expand...

Have you ever heard the saying: "Put your money where your mouth is"? It applies here! Have the giver of this "advice" hand you a check for say, $5,000 with the promise you will deposit it a bank for six months. If no engine damage is apparent by then after having run it 2 minutes without coolant, he gets his money back, with any interest it earned.
Running without coolant for a minute or two will result in localized hot spots forming, which may result in distortion of the block or head. Keeping the coolant in the engine results in an equalized warming up of the entire engine, which is healthier for it in my opinion. So what if it takes a little longer to reach operating temperature??
 
Back in the late 50's in the winter I'd come home from school and start the A in the driveway and go back and forth for about a 1/4 hour (I was 15?) with no coolant, never had a problem.
Paul in CT
 
I believe this type of advice arose with the advent of easily postable videos such as youtube. I saw one in which a guy had just finished installing his crate chevy motor in his rust-bucket street rod and filmed its first run. After a hearty "Hold my beer and watch this" it seized hard after a few minutes because he just could not stop goosing the throttle...
 
After putting on a new head gasket I will start an engine without coolant for 20 seconds and only 20 seconds at low idle. Then I shut it down and let the heat saturate through the head. After it saturates I will torque it and let it cool completely and then torque again.
After that I will run it again for 20 seconds and let it cool completely and re-torque.
Only running 20 seconds will not get an engine too hot and allows the head gasket to settle in without the chance of coolant sneaking in between the gasket and the head/block and causing troubles.
Works for me.
 
Rich in Tucson said:
I believe this type of advice arose with the advent of easily postable videos such as youtube. I saw one in which a guy had just finished installing his crate chevy motor in his rust-bucket street rod and filmed its first run. After a hearty "Hold my beer and watch this" it seized hard after a few minutes because he just could not stop goosing the throttle...
Click to expand...


I agree, gotta be careful following info from u-tube. Once tried to repair a shower valve, was following a u-tube video. Something did not seem right, called a plumber in, told me I was lucky I stopped when I did, came close to twisting the water connections off teh back of the valve. Allmost did a Tim Taylor.:)
 
I don't know what you are trying to save. You have to re-torque it several times anyway. Never 2 minutes. Way too long.
 
1crosscut said:
After putting on a new head gasket I will start an engine without coolant for 20 seconds and only 20 seconds at low idle. Then I shut it down and let the heat saturate through the head. After it saturates I will torque it and let it cool completely and then torque again.
After that I will run it again for 20 seconds and let it cool completely and re-torque.
Only running 20 seconds will not get an engine too hot and allows the head gasket to settle in without the chance of coolant sneaking in between the gasket and the head/block and causing troubles.
Works for me.
Click to expand...

So when it is running the intake port is cooled by evaporation of the fuel and airflow, the exhaust port--and seat get HOT, then shut off the heat moves to the intake port----then started a rush of cold hits it ---cast iron is quite tolerant of many stresses, but thermal shock is something it gets all broke up over at times.
I got to take apart 2 engines that had a known history of being run without coolant "just for a min or 2" --both had valve seat cracks
 
This came from a misnomer that some coolant might leak out through the new head but lets remember, we are torquing the new head at 35,45,then 55 lbs....BEFORE we fire it up and before we add coolant. There is a snowballs chance in hell that any coolant will somehow slip by the new head gasket and the torqued head bolts. Also, let her sit over night after torquing (so I'm told) so the head can settle then re torque at 55 lbs, fire her up and take her out, come back and let her cool again and re-torque.
 
I have started the engine dry a few times to check other things but only for a few seconds. re-torquing is important, some gaskets don't move much, others require several torquings before they settle down. I recently put an engine together with Best 509 composition gasket and the nuts barely moved on the second torquing, a few days ago I used a Best 509 copper gasket and they moved a lot on the 2nd round and a little on the 3rd.
 
I just fill it with water, start it up drive around a bit THEN when there are no leaks or problems I let it cool , drain it, pour in one and a half gallons of Ethelene Glycol anti freeze (Prestone) add a small bottle of Coolant conditioner UPG Radiator antirust with water pump lubricant in it then top off with Distilled Water . I have found that the anti rust conditioner with water pump lubricant will greatly reduce water pump problems . :)
 
FWIW

Here are the instructions that come with the head gasket that is used by a reliable engine rebuilder in our club.

The only deviation he recommends is to not put coolant in the cooling system, start the engine and let run until the head is warm to the hand, let cool overnight.

Torque cold and repeat the warm up and cool down retorque until there is no added torque to get to 55 ft. lbs. Typically three warm ups.

Then add water drive and retorque after 500 miles.
 

Attachments

You must log in or register to reply here.
Back
Top