By popular request (1), I have been asked for help in finding good studs for a low head. I use Model A studs on the Fronty, and they're the long ones that go next to the water outlet on the A head. Are the short A studs the right length for the T low head?
I'm pretty sure grade 5 studs are correct for the application, 55 lb is the modern standard for 7/16-14 bolts.
rdr
Coburg b&b with incoming, but no outgoing email.
Here is a chart with non-dry bolts. For grade 5 7/16-14 it is 35 ft-lbs. For dry it lists 50 ft-lbs.
It seems to me that switching to studs would be a good idea on any engine.
Royce, would it be acceptable to change to these studs or do you think they may lead to a failure sometime and be stranded down the road? They would be noticable when the hood is open.
I would have to remove the back studs in order to get the head to slide out under the firewall.
Wow, I should have read this earlier. I ordered material to make a set of grade 5 studs for my T today. I should have the material in about a week and can make a report on what I find.
I spent a couple of days searching out sources and have found what I think is the best way to go.
TH
I use studs on my RAJO. They were purchased from an after-market company (name fails me right now). What I liked about them was they had a hex head recess in the top that makes it easy to remove/loosen, especially for those studs near the firewall.
What is the advantage of studs? As mentioned above, it looks like it would be hard to get the head over the rear ones. My experience with head studs (Model A) was difficulty removing the head because of rust and corrosion between the stud and head. Nuts came off fine, but pulling the head proved to be a nightmare. Just curious why you would use studs rather than bolts.
The advantage of studs is that you are not stressing the threads on the block every time you torque the head. problem is with many T's the firewall overhangs the head so you cannot lift the head straight up over studs, you first have to remove the studs by double nutting and unscrewing them to allow the head to move forward as it is lifted off the block, and having to remove the studs every time defeats the purpose of having studs in the first place. I had a model A which has studs and found removing and installing the head to be way more difficult than a T with head bolts. Those with special OHV heads may have other reasons, but with a stock T I would not recommend studs.
It is fairly common to strip head bolt threads in the block.. With studs you can make sure you use the full length of the coarse threads in the block while you tighten the head with finer threaded nuts on the upper end of the studs. Less wear and tear on the block threads together with a potentially better clamping force holding the head. Some copper or aluminum paste on the studs should keep them from getting stuck even with an aluminum head.
Mac's catalog says high head bolts are 3.5" long while low head bolts are 3" - a difference of 1/2". Short Model A studs are 3-15/32" in length while the long A studs are 5-23/32"
It may be possible to use 3-15/32" studs for a low head - I have purchased short A studs intending to use them on my current high head engine, but when I got them and checked the fit, they're too short for a high head. The thread holes in the block are 0.82" deep while the full threads maybe goes 0.75" deep. The model A studs from Snyder's has .75" inch of coarse threads for the block, so the full block thread can be used. Original high head T bolts typically only uses 0.63" of the block thread and only 0.59" if using a hardened washer (as you should with an alloy head)
Now with 2.74 of the stud sticking out of the block, the head gasket builds about 0.05", the low head about 2.19"(?) and a washer 0.04" = 2.28" giving 0.46" room for the nut. Snyder's model A head nuts are 0.435" thick, making it a perfect fit if my low head thickness estimation is correct.
A perfect stud for the high head should be about 4" long, the long model A studs at 5-23/32 are much too long if the upper fine thread length of 0.87 is the same as the shorter bolts. Now it may be possible to continue the threads down the studs with a die, but the threads are rolled and cut threads would weaken the studs. Anybody know of a source for 4" long 7/16 studs threaded with 14 tpi minimum 0.75" in one end and 20 tpi minimum 0.85" in the other end?
Roger, I am doing this now. I am finding that my 1913 block has 3/8"-24 thread (fine not coarse thread). So I am going to make up some studs out of grade 5 threaded rod and see how I go.
TH
I have used model A studs on T blocks.
You can run the studs in with the head and a head gasket on the block, screw on the nut and file the prodruding stud so it is flat on one side.
Next remove the studs and cut of the filed portion of the stud.
The two rear studs you can leave a slight bit longer and cut a screwdriver slot in the top so you can install them after the head is on.
I seal them with the special stud sealer or use Permatex #3 or RTV.
Torque the fine thread nuts to 37 ft.lbs, that is the same as 50 lbs. on the coarse stock bolts.
Thanks for the excellent explanation, Roger. You are the kind of T guy who does us all proud.
rdr
Yreka
My grade 5 all thread just arrived and I am preparing to break it up into a set of studs. I had it all planned out in my mind, but while preparing to start I had second thoughts.
My plan was to make all the studs long enough to bottom in the block, pass up through the 1913 low head, pass through a lock washer and then a nut. The two studs at the firewall would be cut long enough to accept two nuts (either two full size nuts or one full size and one jam nut) so I can double the nuts to pull those two studs out when I want to remove the head since the firewall is in the way of the studs.
Suddenly the light goes on in my little cephalic lump... that is dumb! I can't pull the head off of the engine with the firewall in place on a 1913 unless I pull out ALL of the studs! I'm glad I thought of this before cutting the studs, since it is difficult stretching them a bit longer once they are cut. Just not running them all the way down inside the block is contrary to the whole reason for using studs.
So now I plan on cutting all the studs long enough for double nuts. I will also drill two just in case the Montana guys let me come and play.
TH
Ok, I've had my comeuppance on this. I measured my block with bolts. The 3/8-24 went so that is what I got. Made a few studs and tried them in... what??? They don't tighten, they strip.
I admit that I messed up. It seems that my block has been butchered up and messed with over the years. Based on two heli-coils I found in there I really should be using 7/16-14 studs. So now I see that my job is to run in a few more heli-coils and then procure the proper studs.
Good thing I got a great deal on that all thread and that I have another project which can use them right away!
So, my findings remain... when you switch to studs you should go with all 11 and make sure you can run two nuts down above the top surface of the head.
TH
If you use all thread you are going to have to use coarse threaded nuts. To me there are two good reasons to use model A type studs, One is that you can run the stud down to the very last thread in the block and when you tighten the nut you are not turning the stud in the block.
The other reason is that you will use fine thread nuts.
I just rebuilt the engine in an MGB two months ago and they have 3/8" studs but this engine had studs that had an allen hole in the top for easy removal.
Thats the type I would like to find for the model T.
If you use all thread you are going to have to use coarse threaded nuts. To me there are two good reasons to use model A type studs, One is that you can run the stud down to the very last thread in the block and when you tighten the nut you are not turning the stud in the block.
The other reason is that you will use fine thread nuts.
I just rebuilt the engine in an MGB two months ago and they have 3/8" studs but this engine had studs that had an allen hole in the top for easy removal.
That's the type I would like to find for the model T.
Terry, IMHO studs are an un-necessary complication. If, after 90 or so years, the threads in the block are pulling, they need fixing. Just helicoil the lot and be done with it. In Australia, we are lucky to be able to use modern head bolts from a GM Holden six. To use them I first clean out the bolt holes in the block by running a bottoming tap down each hole and cleaning them right out. In some holes it is necessary to cut one or two threads off the bolts so they don't bottom out. These bolts give maximum thread engagement and I have never had one of them break or pull a good thread.
By the way, if you do go ahead and make your 11 new studs, make 4 more for spares, just in case.
Forever helpful,
Allan from down under.
Aaron, you lost me when you said "If you use all thread you are going to have to use coarse threaded nuts".
Threaded rod is readily available in both coarse and fine threads and in grades equivalent to grade 8 and even stronger. So are studs as far as that goes.
McMaster-Carr has it all. A few clicks and it'll be on your doorstep.......