16 hp spark plug thread

[squonk 42,740]

12 and 14 HP heads will not work. Not enough bolt holes like Eric said.

[953 nut 58,203]

Clean and lubricate the head bolts and the threads in the block to obtain a true torque reading. When you torque the head bolts follow the sequence shown below. After the engine has been run up to normal operating temperature let it cool down and then retorque the head bolts using the same sequence.

[John2189 515]

On 5/6/2025 at 7:34 AM, 953 nut said:

Clean and lubricate the head bolts and the threads in the block to obtain a true torque reading. When you torque the head bolts follow the sequence shown below. After the engine has been run up to normal operating temperature let it cool down and then retorque the head bolts using the same sequence.

Thanks for the diagram 

[Fordiesel69 268]

I keep forgetting the extra bolts on the K341 / M16.

 

Its the K321 that was the different valve diameters that burned me one time.  

[John2189 515]

Ok I took the head off that I thought the threads pulled again. After checking it, it looks like the outside diameter of the insert is larger than the outside diameter of the spark plug. So IM guessing that after running it , since the plug didn’t have anything to tighten up to, the loctite gave out and came loose. The threads in the head and the insert looks good so I was thinking to loctite the insert back in then take a thin washer drill it to fit the spark plug for something for it to tighten up against.  
I did get a used head and it is installed.