I have a 24 Touring Car that my grandfater bought new in 1924 from a dealer in Kerville, Texas. My dad got he car in "48" and restored most of the car. I got the "T" in "85" and have only had to do minor things over the years. Although it is time to begin restoration of the paint, top and interior again.
Even as a kid I remember inside my grandfathers barn in Fredericksburg, Texas head gaskets all over the walls. My dad had problems as well keeping new gaskets working for very long. I have replaced at least 8. We have had the head machined and the block checked for truness. The only thing we found was as I was tourquing the head bolt right rear, the head of the bolt twisted back. I found that the bolt hole was not tapped as deep as the other holes in the block. Rather than remove the engine to redrill and tap the hole I shortened the bolt 1/8". Not much but enough to allow for tourque on the head and not just the bolt. Knowing that I was loosing thread depth also meant more stress on the existing threads. Well it finally happened the threads stripped out in the block.
Any suggestions on a cure for the blowing of head gaskets or solution to getting a Heli-coil in a spot so close to the firewall? Engine still has good compression so I hate to pull it out just for one bolt hole.
Helicoils recuire that the hole be enlarged to accept the special Helicoil tap. You can pull the firewall a lot easier than pulling the engine.
To keep the head gasket from blowing is likely a matter of technique, preparation or cleanliness. The surfaces should be clean and dry. Then apply a coat of KW Copper Coat to the block and the head surface. Let it dry till it is tacky, then install the head.
The bolts should also be installed dry and clean to avoid over torqueing or cutting / pulling threads. You need to check all the holes and install helicoils on any that look excessively worn. Check every bolt to be sure it does not bottom out in a hole.
The bolts can be installed using a torque wrench, although one is not mandatory for an experienced mechanic. Ford did not give any torque specs. The mechanic was expected to use the supplied 5/8" wrench and tighten the bolts evenly. This sort of technique is lost to many of today's T owners, so in the case of those who do not trust the original method you can torque all the bolts to 30 ft - lb, then 45 ft - lb for pre - 1917 engines.
Later engines can go to 55 ft - lb. After the engine has been run hot once you should let it cool completely then check the torque ONCE and ONCE ONLY. You should never retorque more than once.
I have a 26 touring and one of the rear block threads stripped. I took off the radiator and loosened all the motor mounts and u joint bolts and fuel line wires etc and pulled the engine forward far enough to get the drill over the affected thread and drilled tapped and placed a helicoil. Then pushed everything back into place and re installed the radiator. It was a bit of a job, but didn't have to pull the entire engine.
Royce covered all the important stuff to get the gasket and head on right. And use the better copper sandwich gasket, these are better than the steel sandwich or the non sandwich fiber head gaskets.
One more is if the old gaskets shows were it is blown, check those areas first. Or if you mean leaks coolant, the normal spot is the front water outlet.
The block and head openings at the front outlet are often pitted can leak there, as the gasket can't get into those pits. So lay a thin line of silicone sealer at the leading edge of the block and head at that opening, that will fix those leaks at the front of the head.
But....do be sure to bolt down and tighten each bolt in sequence, that will make the gasket lay flat as the head is squeezed down.
Welcome aboard. From your profile page it appears this is your first posting to the forum although you may have posted sometime in the past under a different registration or name.
The information provided above is great. There will always be some different opinions. In my own case – I often recheck the torque several times after I have reinstalled the head. I use a torque wrench and apply the same 55 #s. Normally none of the bolts will turn with 55# but sometimes I have found one or two the turned just a little. Once I check them a couple of times and they do not move at 55# then I don’t check them again. Royce is probably correct – as I don’t have any reference for that one – other than that is what my Dad taught me and it has worked well for me over the years. I may be doing it wrong and just got lucky? Royce – I’m sure your method has worked well for you and others over the years also. If you or someone else has a reference concerning that procedure of “After the engine has been run hot once you should let it cool completely then check the torque ONCE and ONCE ONLY. You should never retorque more than once.” Please let me know, I like to add that sort of information to my “engine head torque” file – and so far I’ve never been too old to learn a better way to do something.
Burt, you mentioned the car has had a history of blowing head gaskets. You said, “My dad had problems as well keeping new gaskets working for very long. I have replaced at least 8. We have had the head machined and the block checked for trueness.” Based on that it sounds like something has been wrong in the past and if it is not corrected it will continue to be wrong and cause problems in the future.
It could be a number of things. But you said the head had been milled and the block was checked for straightness. When you pull the head to fix the rear head bolt I would recommend again having the head and the blocked checked by a knowledgeable person. I remember once when my Dad had a machine shop mill an non-T exhaust manifold. They had “trued it up.” But when Dad got home he routinely checked things for straightness. He could easily slip a feeler gage blade between his straight edge and the manifold. He took it back and they laughed at the idea that he could check for straightness with out a more professional straight edge. But when they rechecked the manifold – it was not milled properly/straight. They corrected the problem and the manifold worked great. The reason I share that – is anyone can make a mistake. I would recommend have someone new check that the block and head are level.
If they were level in the past then clearly something else was causing the problem. I would guess based on your comment “The only thing we found was as I was tourquing the head bolt right rear, the head of the bolt twisted back. I found that the bolt hole was not tapped as deep as the other holes in the block.” You were not aware that it is important to always check to make sure the bolts will go all the way down on the head before they impact the dirt and/or bottom of the hole. One relatively easy way to check that is to remove the head gasket and place the head back on the block. Insert the bolts and make sure they all turn down and touch the head before they bottom out. I recommend if they don’t clean the hole and use a bottoming tap so they will. If they still won’t I would recommend shorten the bolt but not just the one – all of them. So if later the head is pulled a long bolt will not accidently be placed in the short hole. If you did not do that in the past, there is a good chance that one or more of the other bolts was partially bottoming out and giving you a false torque value (or feel if done by hand). When the head is milled and especially if it has been milled before it is not uncommon to have to shorten the bolts and/or use a bottom tap to clean the threads/hole.
Do you have a stock 1918-1927 Model T High head or are you using an earlier low head or a high compression head?
I’m sure you will be able to sort things out and have a reliable Model T that doesn’t blow the head gasket and that you won’t need to pull the head again until you need to do a valve job and/or clean the carbon off the pistons and head. You are in a great location – there should be lots of T folks near you. From memory it seems like there is a nice Model T restoration shop within 2 to 4 hours driving time of you. You probably won’t need to use them – but if you don’t figure out what was causing the problem in the past and it reoccurs once again – I would strongly recommend you have a knowledgeable Model T repairman work on it, as I believe the Model Ts are much more reliable than your experience.
Again, welcome aboard.
Hap Tucker l9l5 Model T Ford touring cut off and made into a pickup truck and l907 Model S Runabout (no head bolts, no removable head, no head gasket). Sumter SC.
I could only remember that when I first reinstalled the head on the '27 I had a devil of a weeping leak at the front of the head, no matter what I tried all the bolts tight and in sequence..copper head gasket, sealant etc...no luck.
Ended up that the engine shop decked the head and block and had shaved just enough off that the old head bolts were bottoming out. (I had to break one off to discover that was the problem. New bolts and the problem was solved.
Anyway, my thought after reading this is maybe that one bolt hole was not drilled and tapped deep enough way back in the day (from the factory) and that (even though everyone throughout the years has thought they had it tight) it allowed the gasket to blow out at that spot.
It would only take a little bit.
It's a possibilty.
Larry Bohlen, '27 touring
Torqueing a third time - why would you do that? If it is not leaking, you would not attempt a second retorque.
If it is leaking after the retorque, a third attempt is normally going to result in a stripped head bolt hole, a broken head bolt or no improvement in the status of the leak.
How would re-torquing the head bolts lead to a failure if a torque wrench is used, and the bolts tightened to the same torque as previously?
My understanding is re-torquing head bolts is recommended because the head gasket may take a set which reduces the tension in the head bolts and can lead to a leak in the future.
I actually torque my T heads at least 5 times! When I install the head I use a click type torque wrench and start by torquing the head by the Ford service manual sequence to 30 Ft Lbs with the bolts lubricated with anti-seize. Then I go back and torque them to 40 Ft Lbs. Then I go back and torque them to 50 Ft Lbs. I then start the engine and let it run until the motor gets to operating temperature. I let the engine cool and then I then re-torque to 50 Ft Lbs. I find that most of the head bolts tighten just a little bit. Then after I drive the car I recheck the torque to 50 Ft Lbs and find that 20 to 30% of the bolts tighten a smidge. I have been doing this for about 40 years and have not blown a head gasket on any engine that I have overhauled. This method was passed down to me by a guy that spent his whole life as a professional automotive mechanic and who built many T motors. I also find that you should check the exhaust/intake stud nuts a couple of more times after that if you are using gland gaskets. It is cold here in Denver and I do not want to walk out to the shop and check my notes but I think I torque the exhaust/intake nuts to 25 or 30 Ft Lbs. It works for me and I am not going to stop. Just my .02
I'm with Paul on the anti-seize. I was taught that dry thread give a false torque reading. I also know how much of a pain it is to loosen bolts/studs rusted into the block!
I work in an industry where bolt torque is very important. Most building/erection torque speciations are clearly listed and the lubricant of choice is spelled out. Then the bolts are secured with a device that is verified daily. Dry thread torque will give very accurate results. The problem is that to achieve dry torque you must chemically remove all traces of lubricants from the male and female threads of the fastener. Dry torque is NASA type stuff. If you were to handle a "dry bolt" the oil in your fingers would screw up the torque settings. If you get into this you would find that that there are multiple torque charts for each bolt size allowing for each type of lubricant that might be used. Also the oils used to manufacture new bolts will generally make the bolts qualify as "lubricated" right from the box.
On Model T's I use "wet torque" specification charts and de-value them a bit as to allow for 80 to 100 years of use. I am quite sure that some of the forum members will disagree with this information. I deal with this on a daily basis and have engineers on our staff that verify the torgue on structural fasteners when needed.
One of my favorite fasteners is a about a 2 1/2 inch vertical fastener pin that must be removed yearly and be NDT tested. When you re-assemble it you apply the correct lubricant and then use a torque wrench to tighten the nut to 250 Ft lbs. You then mark the nut position and make a second mark 120 degrees from that mark. Then you find some way to tighten the nut to the second mark. (Large impact wrenches and sweat will be liberally used in this process) You then have applied the 1500 Ft Lbs required for the fastener! Believe it or not this is a very accurate way to achieve high torque settings.
Royce -- I did some more checking hoping to find something written about "do" or "do not" retorque the head bolts again even after running the engine and then torquing the head bolts back down the first time. I looked in the “Tinker Tips” in the “Vintage Ford” and several other places. I did not find any place that recommended to check the torque after it was once checked after the engine run. But I didn’t find any place that said “don’t check it” either. The closest “do not” I located was in the “Model T Ford Owner” which said, “The final tightening should be done after the engine ahs been run a few hours and has had a chance to thoroughly warm up. Then it will often be found that a half or full turn can be taken on each bolt.” In that case you could read “final tightening” as “do not tighten again after that.” But so far I have not found anything written that says checking the torque (does that sound better?) until it no longer changes will cause a problem. So it may be one of the many areas where there is more than one acceptable way to accomplish the task. In my own case – that is how I was taught is why I do it that way. It doesn’t mean I was taught correctly or that a better way wasn’t discovered later (the Air Force often publishes emergency changes to procedures when they find out the current procedure has a problem). I’ve had good success with it so far. And as originally shared – I use a torque wrench so I am not applying more torque – just making sure that the final torque is still there and if not – turning the bolt to obtain the desire torque. But if anyone has some written guidance – I would love to file it away for future use.
Paul – 1500 torque pounds – I’m glad I don’t have to work with that part!
Burt – please let us know if you find anything causing the frequent head gasket problem or not.
Hap Tucker l9l5 Model T Ford touring cut off and made into a pickup truck and l907 Model S Runabout. Sumter SC.
I too believe in re-torquing. I have a '33 Ford V8 with the 21 stud engine. It needs about 4 re-torquing's before things stop moving and the head gasket then lives a long time, otherwise look out.
If nothing moves then that is great. If you have a compression seepage into the combustion chamber you will not know it until the gasket is ruined and you are broken down by the side of the road.
I can't see how you will break anything. I am not talking about making it tighter just resetting it to the original tightness. Of course this assumes that you cleaned out the threads and bolt holes and confirmed that you had good bolts and threads in the block and that the bolts are not bottoming out. Easy way to check this is set the head on without the gasket and spin the bolts down. If they all turn down cleanly to the head you will be OK. If not you know what to do.