Anyone know if it is best to use thread sealant on head bolts? I've built several Ford flatheads and it is common to use thread sealant with them since the bolts extend into the water jackets, but this is my first rodeo with a Model T engine.
Appreciate the advice.
Unless there is a defect, Model T head bolts do not extend into the water jacket. Some do use something (oil, grease, anti-seize or sealer) on head bolts and what you use may effect the suggested torque.
Let the dry versus oiled torque argument begin!
By the book you torque the bolts cold. Start and run engine to operating temp. Final torque is hot. Thus you can't apply Loctite prior to final torque. Plus I have seen threads ripped out later because of a heavy loctite useage.
Was always told to torque head bolts dry. Oiled threads will effect torque. A wet bolt will not hold a torque. Bolt holes are dry holes. At Most I would use the correct anti-sieze and sparingly so.
Chances are, you taking the bolts out once, cleaning the treads, will be the first and last time you will ever have to do that in your life time. Chances are your car will be garaged out of the rain most of your life. Chances are your car will recieve greater care than it has in its life. Don't worry and just drive it.
I vote OILED after you clean out the bolt holes no rhyme or reason other than that's the way I've always done it!
I use never seize.
To avoid "using the correct oiled or dry torque", tighten them from the center out using a 1/2 inch ratchet or long box end in two steps.
While we're on the subject, what is the correct torque specs for head bolts...55 ft/lbs? I understand about torquing in stages and re-torquing after warm-up.
I use 50 - 55 ft-lbs.
50 pounds cold, 55 pounds hot, torque in sequence.
Cold engine, in sequence I go around first at 35 pounds, then around with 50 pounds, heat engine, go around at 55 pounds, done.
I would only use sealant if the bolt extends into the water jacket. They shouldn't extend that far, but sometimes someone might have drilled it out and installed a helicoil and accidently drilled through. Or perhaps it rusted through to the water jacket.
Be sure to clean the threads with a bottoming tap and blow out any carbon or dirt. Oil won't hurt anything. Be sure the new bolts do not bottom out before it pulls the head down. Try them without the gasket first. If they bottom out, grind off some. This problem can exist when you put in new bolts, or if either or both the head or block is decked.
One reasons against oil.
Once you have torque your cleaned bolts and hopefully clean block threads, you want the metal on metal friction to bind the two from turning loose.
I still say wipe on a sparing coat of silver anti-sieze, torque and forget it.
I don't understand why you would retorque when the engine is still hot. To me, that seems like a wasted effort. I was always taught to retorque after the engine has cooled down. That lets the gasket, head and bolts"take a set" so to speak. Then, when cool, retorque to whatever spec's you are using. I've never retorqued anything when hot, but if you do, try it again after it has cooled down and see if there is a difference. JMHO. Dave
I re - torque the bolts once after the first time the engine has come up to operating temperature. I torque the bolts after the engine has cooled.
If you torque the bolts in a pre - 1916 block to 55 Lb-ft you will likely strip several of them, especially if you oil the bolts.
By whose book do you torque the bolts cold. The "book" does not say anything about torque settings.
It just says to tighten them.
45 lbs. is enough. It has less than 4:1 compression. Do it at least three times in the first 200 miles, after cooling down.
The Ford book says nothing about oiling the threads, nor torquing the bolts!
I used the term "torque" loosely also meaning to "tighten". Same result, just different methods. I also think that using torque wrench is important on any engine not only for overall tightness, but for overall evenness. Again, JMHO. Dave