Well here is my problem. I removed pistons to replace piston rings and do a valve job on a low compression 1924 Model T engine. As usual, very impressed by Ford engineering how EASY it was to get to all the parts!
I was careful to 1. Match the piston to the cylinder, match the direction of the piston to the cylinder and to match the cap to the rod facing the correct way.
My problem seems to be the re-installation of the rod caps.
I cannot tighten the rod cap nuts sufficient to insert the cotter pins to retain the nuts without, it appears, binding the rotation of the engine. The engine would turn over freely just low compression before I started. Now it is jammed tight
I consider myself a careful but amateur mechanic still after 40 years so any advice no matter how simple an item I may have overlooked is appreciated. Also I did buy shim spacers for the rods not installed.
You may have left out rod shims. The rod bolts have a flat sided head that must face the con rod and if not inserted right may not allow the cap to seat correctly.
Try plasti-gauge to check clearance to specs.
Ditto on everything David said. If it is binding you'll need to add more shims. When you do shim the rods, do one rod at a time so a binding rod does not give you a false reading. Add the same number of shims to each side of the cap and remove one sliver from each side until the cap binds a little, then add one shim to one side. If it still binds, add a shim sliver to the other side. Jim Patrick
If you got even one cap on backwards it will bind the rod. I always take a rattle can and mark on side of each rod and cap to make sure I match them when putting them back together including the mains. Use some prussion blue and see if you have a cap that is not matching.
Another thing I do is always use all metal aircraft style nuts so I don't have to worry about lining up any cotter pin holes.
Another thing you can do is tighten ONE cap at a time and then loosen it this always tell you which rod is binding. I also do the mains the same way. Have ALL your rods and mains slightly loose except the rod you are working on. then loosen that rod when it is just right and go on to the next one.
SIDE BAR; If I understand you correctly your rods were the same ones that were in the motor. Most old timers that I know like to with some minor force move or slide the rod along the crank shaft. unless the rod or cap is too wide you should be able to move it slightly. This does not mean sideways but along the crankshaft.
I agree with David.
You say you cannot line up the cotter pin hole, is the head end of the bolt sitting in the correct position?
Once that is correct, the nut should fit correctly, then you look into the shims and measuring with plasti-guage.
David (original poster, wow there's a lot of Daves on here including me), my situation is identical to yours in every respect. I set my mains and rods to 0.015 and I found that the # 2 rod is binding. I might resort to resetting that one rod to 0.020 to see if that helps and then run the motor in a bit. It would be easy to readjust later from under the car if need be.
Obviously, it would be harder to turn the crank be hand like this as opposed to doing so using the extra leverage with the transmission and flywheel attached. It should be even easier for the starter motor to turn it. My only worry would be having it so tight that it can't be rotated at all once in the car. Any thoughts on all this?
I left out SELF LOCKING NUTS that I use on the rod bolts . These are all metal, I would be afraid of the plastic self locking nuts. The air craft style self locking nuts are longer and I suspect lock better.
Are you sure your mains are not binding up? If you inadvertently forgot the shims on your rods, it is possible you forgot them on your mains as well, that is, if you removed the main caps. Jim Patrick
Two other possible thoughts. Maybe a couple shims slipped away when you weren't looking. OR, maybe who ever put it together before only tightened the nuts till the rod was snug, but it didn't have enough shims in it? That one can fool you and I have run into it a couple times.
Drive carefully, and enjoy, W2
Wow thank you all for the great advice.
I MAY (actually did) drop one rod cap and MAY (probably) put it on reversed.
Next week I will
take off all rod caps carefully marking the front
buy rod shims again
do ONE rod cap at a time working from front to back
I do have a question on buying self locking rod cap nuts sounds like a great idea source for these nuts?
It will be wonderful hearing another engine come to life after YEARS this one sat in Florida for over 25 years before I brought it up to Indiana to repair last year. My biggest thrill is hearing an engine come back to life and getting another dead Model T back as a safe driver
David, your rods and caps should be numbered,(file marks) as per factory specs on the small end bolt side of the big end and as a rule the numbers would face the cam shaft side when assembled.
But what's been done over the years is always another story.
If you have a small airport nearby you may be able to talk a mechanic out of 8 of those lock nuts...otherwise they'll probably sell you some.
David, I had to laugh when you said you dropped one of the caps. My wife came in the garage to talk to me and guess what, one of the oily buggers slipped from my hand and bounced across the table, forever concealing it's proper orientation. The good news? I just read the posting from Kerry from Austrailia regarding factory file marks. I remembered seeing some deep dings on my rod caps which I assumed was from careless tool handling. I dashed to the engine to check. Sure enough, the #1 rod had one mark, # 2 had two marks and so on, all on the camshaft side. The caps had matching marks, again all in correct order EXCEPT, the #2 and #3 cap marks were facing the wrong side and need to be turned around. This has got to help the situation. Thanks again Kerry. I've always found the guys down under to be the most helpful of all on any forum. One day, I have to visit there. Here is a pic of the marks on my #4 cap.
WOW thanks for all the great info. This message board, when properly used, is such a wealth of great info, keeping these cars running instead of sitting unused in a shed.
David, I was wondering how things are going with your engine? Do you have the factory file marks on your rods and caps? I turned around the two caps on mine that were facing the wrong way. That solved the whole problem. Before, the engine was locking up even with shims in place. By turning the caps so that they match the rods, it made for a perfect fit and clearance even with no shims and now it rotates perfectly. It appears to be very important to keep the caps lined up exactly as they were before.
Wow thanks for all the advice. In summary. last fall I had to stop working on the car due to an old military injury limiting my walking lifting ability. The car has been up in the drive way covered on jack stands since them. Just got the driveway scrubbed clean of leaves and debris today underneath the car. . Will order plasticgate, shims etc tomorrow from Snyders and hopefully, hear the engine running next Sunday! Enjoy your youth and mobility while you have it! I can get stusff done just takes 20 times longer!!
FYI, I don't think the file marks were done by Ford at the factory. That's an old time rebuilder's way of marking rod caps. You see that on any brand of engine. Original Ford rods didn't come that way from the factory.
Are you sure Royce?
Ford Service Book, page 97, par 383,
'When connecting rods and caps are assembled in NEW engines, they are marked with file mark which corresponds to the number of cylinder into which they are fitted'
You must be right Kerry. I just looked at the very page you mentioned in the manual. Those marks in the photo are exactly what I saw on my factory Ford script rods. I would think rebuilders would do it too but, what need would there be in this case when the marks are already there? It would be nice to hear from a few more people here as I know there are engines and rods laying around everywhere and the file marks are easy to find.
I got you email and tried to answer but I am having so much trouble with my email I doubt you got it so I will answer on here.
The self locking nuts that use are 3/8" inside and 9/16" outside.
DO NOT use a self locking nut to fit the rod only an every day 3/8'. Then when you get the rod fit to your satisfaction take the regular nut off and install the self locking nut. Remember to leave that nut loose until you have fit the other rods and mains then tighten them all up.
Take lots of time fitting ;the rods and mains. I think it the most critical part of rebuilding a motor.
You asked me where I got the aircraft style nuts. I used to have a salesman come to the shop and I would order a hundred of what ever I needed and she would deliver them. I would bet there are some aircraft guys on this Forum that can tell you where to get them or you could maybe go out to an airport and ask them
Self Locking Heat treated Nuts "Chevy's"