What is the correct torque for head bolts for 1915 T?
About 45 FP. Just use the Ford wrench. The length of the wrench only allows you to pull so much and so far. They didn't have values or torque wrenches (in general use) in the day so wrenches were designed by their length to give the needed tightness/torque to bolts and nuts.
Agreed. Some go crazy on torque. Accounts for many stripped threads in the block.
You need to be really careful unless the holes are all helicoiled on early blocks. Use the Ford spark plug / head bolt wrench and there is no way you will over tighten them.
More importantly you need to be sure the surfaces are utterly clean and dry. And you need to get the engine warm, let it cool completely, and re - torque before you go driving.
And be sure the thread holes are clean and free of debris in the bottom of the hole. Use an undersized drill bit to twist down and get all the gunk out, and use compressed air too, get that hole clear to the base. Otherwise the bolt could stall above being jammed on debris and torquing won't be effective as the bolt can't seat on the top of the cylinder head.
Of course you could use the magnetic means of cleaning out debris
Wear eye protection if you use compressed air to clean out the crud from the head bolt holes or you'll end up with eyefulls of debris!
My 1915 sealed perfectly at 35 ft/lbs.
Royce, cast iron heads are re-torqued hot, aluminium is done cold.
As I remember, and the memory is not what it was, the Prus head recommended 55 pounds feet. I agree this is a little high and go for a 50....
I'm with Royce. In 50+ years of being around things mechanical, I have never heard that cast iron heads should be torqued hot. What good would that do? JMHO. Dave
Fitting instructions usually are on the gasket sets, at this end of the world anyway, if that fails there's always the manual.
Being old school and copper head gaskets are too, I fit by the book.
This is from a gasket manufacture. note, some modern gaskets do not require a re-torque.
Dave - On the other hand, what harm would it do?
OK - I got to do it this weekend --
Standard cast iron head with copper gasket
40-45 ft pounds hot!
Mark - I understand your point but a 100 pound weakling and 250 pound guy will produce different torque without the correct equipment.
We told our assemblers in China that they needed to make sure the nuts were tight on our equipment and found that after heating we couldn't get them off without breaking the studs.
We now have "work instruction" that requires them to use a torque wrench.
I won't go into the other horror stories but we have work instructions that describe how to use work instructions.
We are also considering a work instruction on how to read a work instruction
This is the first time I've ever seen hot re-torquing in print. Have absolutely never done it myself as it goes against all I've learned plus it would definitely alter the tightening of the bolts. Everything's expanded when hot. Has to change things. How old is that chart?
Hot or cold?
at least we have 40-45 ft pounds!
The shade tree knuckle color gauge for torque works. When your knuckles turn the proper shade of white the bolts are torqued right
Interesting Frank. I don't have anything to show, but all of the car magazines, manuals, auto and heavy equipment mechanics that I have seen over the years have always said to torque when cold. Is that the only place you've seen that example in print? Not trying to start another pxxxxxg contest here, just trying to learn(or unlearn)something. What do the engine builders on here do? Dave
Page 289 of the ford service bulletins from October 1928 clearly state hot. I will try and post a scan of it. Might have to wait for help with that.
The Ford Service doesn't mention first tightening on a warm engine, the head goes on a cold engine.
Ford Service Bulletin June 2, 1919 says the same,
Good shop practice has been to 'check' for any leakage after running the engine, so a re-tightening or re-torque after the motor is warm is done.
Article from Ford Owner Dealer Magazine, (M. Fahnestock)
So always check after the motor is warm (10 min running for garage work) or maybe even after a few hours of running, or 50 miles or whatever, then tighten back to torque spec initial, for any loosening. Allow engine to become cool for re-torque for aluminum heads, that is for the contraction difference of the alum. material.
IMHO it doesn't make a hoot whether you re-tighten the bolts hot or cold on a cast iron head as long as you re-tighten them.
Ted - Thanks for that! I've never really been too sure (on a stock Model "T") whether to torque the head bolts hot or cold, so I do both. Always figured it wouldn't hurt anything either way, and no matter which is correct (hot or cold) somewhere along the line, I've done it right, and as many have mentioned, it's a good idea to re-check once or twice anyway, and my "hot & cold" method, while it might seem silly to some that seem to wanna' argue about it, I'm gonna' continue this same way I've been doing it since I rebuilt a Model A engine when I was 14 years old! (.....haven't had any trouble that way yet,.....)......harold