Is there any reason other than originality that I can not replace the flywheel cap screws with modern bolts and use lock tight instead of safety wire?
Not highly recommended.
I suppose you could do that throughout the Model T. With safety wire and cotter keys you have hard evidence the connection is secure.
What grade of Loctite would you use? Would you clean all your parts with a Loctite primer? Have you run tests to see that your Loctite technique is reliable?
Is the Loctite product you are going to use reliable in oil at the temperature encountered inside an engine?
It is my personal opinion that I would rather trust hundred year old quality over modern hype. I have been bit a few times. There are several special bolts in a model T that I much prefer to use original bolts if they are available (actually all of them just because they look better). But wrist-pin bolts, rod bearing bolts, and flywheel bolts top the list. Several years ago, I was OUT of wrist-pin bolts and used four supposedly top quality grade eight modern bolts. Not just one, but TWO of them stripped within 400 miles.
I have never had any of those original fail me.
That is my opinion. (And oh boy am I opinionated!)
Drive carefully, and enjoy, W2
So don't put the wire in. The later engines didn't use it and used the same bolts without the hole for the safety wire. Lots of engines that don't use Loctite in that location ether.
It's hard to beat original.
I personally don't like using grade 8 bolts against cast iron. Otherwise I don't see a problem.
There is a reason that safety wire is still used on aircraft today, and locking compounds are very seldom used. Simply put; safety wire is more reliable.
I have disassembled many T engines and rear axles where safety wire was the only thing that prevented devastating carnage. Often the bolt heads are hanging by the wire, completely severed from the bolt. No way Loctite is going to do the same job.
Especially true with those darn ring gear bolts. Seems they always work loose.
Safety wire when done right per aviation spec's looks good. Not that you will ever see it inside the transmission but it just looks good and makes me smile just knowing it is there.
Good safety wiring is a matter of pride in the right circles.
Are you asking about the magnet cap screws or the 4 that hold the flywheel to the crankshaft?
If you are talking about the ones that hold the flywheel on, then yes use the original and safety wire, for sure.
If you are asking about the cap screws that hold the magnets...then;
Are not the flywheel magnet cap screws/washers and the differential ring gear cap screws under two completely different load/stresses. Ford at some point around late teens early 20's dropped the safety wire on the magnet cap screws but kept the wire on the differential ring gear cap screws. There must be a reason beyond cost for that.
(Message edited by redmodelt on June 10, 2016)
The result is the same if the bolt falls out Mark. Expensive carnage.
There is no substitute for taking the few minutes to do the job right versus applying a compound that is not going to hold long term.
I didn't even think about the 4 cap screws holding the flywheel on. Not using them and safety wire is so far out of the box that it did not even enter my mind that might be what he was asking about.
If you used loctite how would remove the bolts?
I hear heating is best, but I would not want to heat the cast iron flywheel...
Why change a good reliable method? The Ford method is the best, and always has been.
I like a torque wrench and Loktite. I've used it for 20-30 years on rods, mains, flywheel, clutch housing. Standard grade "red". No problems on disassembly. I do wire ring gears and cotter pin axles. And of course wire wishbone to pan
Now that I am on the same page! Another reason to use the original bolts; modern bolts in that size are fully threaded along their length, the originals have a non threaded shank that that is just a bit larger in diameter then the thread and helps lock the crankshaft to the flywheel. If you used the modern bolts you would be relying entirely on the dowel pins and tightness of the bolts to keep the flywheel from trying to move because the threaded part is smaller in diameter then the hole it fits in the crankshaft flange.
Considering that the torque is transmitted by the clamping friction I will take strong exception to your "engineering "
I will stick to original bolts even if the clamping friction using modern bolts is in place for the reasons I gave. I want as much metal filling the hole(s) as I can have, that's what the shoulder on the cap screw does. I do not disagree with your line of reason but prefer my thoughts on the subject for me.
I use original bolts if I can because I'm cheap. Sometimes I don't have them. Sometimes (with a converted A crank) they don't fit anymore. So I use the best bolts I have handy.
As far as connecting rod bolts go, so many of them have been "stretched " by people over torquing them to try and line up cotter pins, that now replace them with new grade 8 fine thread bolts and nuts along with grade 8 SAE flat washers as standard practice. Then assembly with Loktite and a torque wrench. Going on for more than 20 years and no regrets
RE connecting rod bolt, yes or the Chevrolet bolts.
52 years we have used new lock washers, and never wire.
Use only Original bolts.
I doubt if you could find a new flywheel bolt with the correct 11/16" head anyway! I've never tried this, but I think a Model A flywheel bolt would work, and has a 5/8" head which is easier to use. I think they are only 1/8" longer than a T. Has anyone ever tried this?
Hi Larry- Model A/B flywheel bolts are much shorter than the T bolts and won't work on a T. I've used good quality (Holochrome etc) socket head cap screws with a hard head bolt washer with good success in the past. Of course the head were drilled for safety wire. For the most part, absolutely noting wrong with the stock bolt and safety wire. Having a Ford flywheel bolt wrench helps a lot though. Just my opinion, but I've installed a fair number of flywheels in 45 years and none of them have ever come loose.