I put another rod in my Model T. One of the old bolts threads went bad. I use a new bolt I bought from Langs and used the old bolt on the other side with a castle nut. The new bolt does not have a castle nut it uses a lock nut. Will that hurt anything?
The lock nut will work, but only use it once.
Interesting, I never knew that,I think I might order a couple more. Thanks for the advice
What I would do is use a regular nut to tighten while you are adjusting the bearing, and then when you get it where you want, put the locking nut in place.
What would you suggest torque for rods?
I like the Seth Harbuck idea of bending the sheet metal of the rod dipper along side one edge of the rod nut. Fast, effective, and bulletproof. You just need the dippers that have some overlap around the bolt hole area.
That method works best with "modern" SAE nuts that have a smaller 9/16" hex. They are also considerably lighter than the 19/32" castle nuts that came with the car and there are no cotters to deal with or come loose.
25-30 lb-ft is plenty.
The Chev 350 rod bolts w/self-locking nuts fit just right. You just have to file the knurling off the bolt.
The price is good too, we get used ones free from our local automotive machine shop.
When I took up clearance on my recent rebuild after about 1000 miles, I found the rebuilder had re-used the original bolts and nuts. 3 of them stripped as I was torqueing them down at less than 15 ft lbs. I now believe in replacing them with new, or the Ch*&y rod bolts as mentioned above, if there is any question. Imagine one not holding at 45mph.
Larry, Rod bolt torque should be 35 foot pounds according to the instructions that come with most T rods.
Noel, where did you have your rebuild done, and was it re-babbitted, or just old rods and bearings re-worked? There is no reason there should be any "clearance to take up" on a properly "rebuilt" engine for a darn long time!
Adam, I had it rebabbited and bored in Watertown, SD by a gentleman recommended by others with babbit engines redone by him in the past. I had some frustrations and wonder if he'd gotten "past his prime" but have been generally satisfied. I had read in several places, either here or on the other forum, about checking clearance after breaking in and running. I believe others talked about 1000 miles. I pulled the pan and was able to remove a .002 shim on one side of #1,2, and 3 rods. The center main was still at .001. Being a 23 with a 3 dip pan, I didn't check the front or rear main at that time. I rechecked again last year when I pulled the engine to replace the cam with a new Stipe .280 and align the tranny according to the Tulsa club's recommendation. I was unaware of that discussion when I first had the engine rebuilt. All the tolerances on the rods and mains were still at .001.
I see why you had to adjust them. .001" clearance is a little on the tight side and just due to irregularities in the re-ground crankshaft could wear a bearing to the point that it would warrant removal of a shim here and there after an initial break in. Now that you have done that, the bearings should not need any further adjusting. Clearance of .0015" or a little more, but less than .002 is what will allow the strongest oil film between bearings and journals to form. If the bearings have more or less clearance, the oil film formed when they rotate will not be as durable as it could be. Bearing to journal clearance on a "splash-lubrication" engine is figured as .0012" clearance per 1.0" of journal diameter, therefore a stock T crank should have a journal to bearing clearance of .0015".
If you have an opportunity to adjust your bearings again and you use plastiguage and find clearances of between .0015" but less than .002", then leave it be, but check it again in 1000 miles. If it has not changed, you can leave it be and likely don't have to worry about it anymore.
Adam, I rechecked it last year, about 1 1/2 years after the first take up and they were unchanged. I pulled the engine to put on a Z head and Stipe .280 cam, and align the tranny. Now it is more fun to drive!
I think the using of self locking nuts only one time went out when they quit using fiber self locking nuts. If you could only use a steel self locking nut one time when you got your new rod from the suppliern you would have to throw the nuts away. In the aircraft industry they reuse steel self locking nuts over(Nas679) is one example. Also they use steel anchor nuts all over the aircraft. They install & remove inspection panels using steel a/nuts. Also I have never seen a cotter pin that was installed correctly break or come out. If we are nervous about rod nuts coming loose why not use plain nuts with pal nuts like C***y did. Nelson
C***y wasn't the only one to use pal nuts, Ford used them on millions of flathead V-8s.