Need Help with Torque Angles

[matthewpetruescu]

I have a 2002 Ford Explorer 4.0 SOHC and I am replacing the head gaskets but the problem i am having is torquing the bolts correctly. I have Haynes manual, it says to torque it to 24 ft lbs, then turn the bolt 80 degrees, and then an additional 80. I turned all the bolts to the first 80 degrees, but it is very very, almost impossible, to turn the bolt another 80 degrees. I am starting to doubt the manual. Has anyone torque the bolts that far?

 

[2000StreetRod]

head bolts

My 2000 Workshop Manual says for the 12 mm bolts: 26 lb-ft, then 90 degrees, then 90 degrees but I've never tried it.

 

[matthewpetruescu]

How far have you torqued it?

 

[2000StreetRod]

2002 shop manual

I've never removed or installed my heads. My 2002 workshop manual agrees with your Haynes manual: tighten to 24 lb-ft, tighten 80 degrees, tighten additional 80 degrees. Have you removed the cam followers so the valves are not extended?

 

[matthewpetruescu]

i never thought about that. do you think i can just take the cam shaft off and continue tightening the bolts?

 

[2000StreetRod]

removing camshaft

Removing the camshaft without first removing the cam followers is dangerous. There is pressure on the camshaft lobes because of the compressed valve springs. When reinstalling the camshaft bearing caps it is difficult to keep the camshaft horizontal to the bearing bore axis. The caps can easily bind when tightening them and break. Since there are no bearing inserts when a cap breaks you have to purchase another head.

If you have been tightening the head bolts with no regard for the interference between the piston and the valves then you may have already bent a valve(s). What is the position of the crankshaft and the camshafts?

 

[matthewpetruescu]

i already tightened it with the camshaft on, i took the camshaft off then tightened it the rest of the way, Do you think i bent the valves, when i had the camshaft in it wasnt timed or anything, at least i don't think it was..

 

[2000StreetRod]

air compressor access?

It would be good to determine if any valves are bent before completely assembling the engine to perform a compression test using the starter. Do you have access to an air compressor and a spark plug hole adapter? If so, and the camshafts are still removed then you can check the valve seal of each cylinder.