re-torque head bolts

[1974vette]

I replaced the head gasket on a 54 super w4 mccormick a while back. I want to re-torque the head and have seen on this form to do that after the tractor has been run for a while. the question is do you do this while the tractor has run and is still hot or letting it cool is ok. thanks in advance and I enjoy reading all the post on this forum. I have learned a lot

 

[Red Dave]

When I do them I usually run it until it is up to temperature, shut it down and start re-torque after it has cooled down. I think the idea is to run it through a heat up/cool down cycle before re-torque. I don't think the engine needs to be "Hot" during the re-torque.

Don't forget to re-set the valve lash after the re-torque.

 

[1974vette]

thanks for the info. I will get it done this weekend so we are ready for the summer shows.

 

[CNKS]

It's not that critical, I have done it cold on 5 tractors, no leaks. What you do want to do is reset the valve tappets.

 

[gene bender]

I always do but realy you arent going to move the head a fraction of a thous so it realy isnt that big of a deal

 

[the tractor vet]

You do a retorque with the engine to operating temp and this is done just as soon as you get them running the FIRST TIME . Is this important YES will the head bolt torque change when when HOT yes . You will find that the bolts towards the center of the head will be looser then the ones on the ft. and back of the head .

 

[riverbend]

I did my H after it cooled off and everything shrank back a bit. And then I did it again after 100 hours. And again. It took several times before the bolts all stayed tight.

Greg

 

[Andy Martin]

Trust The tractor vet.

 

[MN Scott]

In its service manuals IH defines hot as any temp over 70 degrees. They also state not to adjust valves on a recently run hot engine because the quality of work will suffer because of the hot engine.

 

[Mark in Upstate]

Always at operating temp. Same with valve adjustment after retorque, operating temp.