New pistons and sleeves too tight for starter to turn

jd36a

Member
Have a friend who purchased a 1961 AC gas (not sure of model). It had one cylinder stuck when he got it. He removed the sleeves and pistons and ordered a new set. When replacing them cylinder # 1 was fine but as he got # 2 in was very hard to move and when 3 and 4 were put in it was so tight you could not move them at all. He jacked tractor up and put in gear but could not move them at all. What are some things he should be looking at. He said he numbered them as he removed them to get the (rods I think) matched to the cylinder they were originally in. Not in backwards he said as they will fit only one way and the arrow on top of pistons pointing in correct direction. Wish I could be more exact but not versed in this at all. Will relay any ideas anyone may have and thank you in advance for your time.
 
Either he didn't get the rods offset in the pistons, or he needs to buy some plastigage and start checking rod bores.
AaronSEIA
 
Did her put in new rod and main bearings?? If he did does he have the correct ones for how ever the crank has been turned to if it has been turned. Did he maybe tighten them to much. Or maybe he did not prelube them as one should any or all of those can cause the problems
 
When he put in #2 & it was tight, it was time to find out why? Not after putting 3 & 4 in. All new parts or using the old pistons without cleaning the grooves? Ring gap checked? Bearings plastigaged? Using lube or dry?
 
His rods are not correctly installed on the Pistons. They are offset if pistons and rods are assembles incorrectly you can't turn the engine over without destroying them.
 
He ordered a new set that includes what? What all new parts does he have? Has he tried to turn it with rod caps loose? so many little details to guess with the information provided. If the rings were new did he place the rings down in the cylinder square and check the end gap. If the rod bearings were new and placed on the crankshaft that wasn't ground. If the crankshaft was not ground was it measured to see how far out of round it was. The arrows on the pistons are not what you go by if you have an engine with off set rods. With off set rods you can check in assembly if they are correct by making sure the rod is centered in the piston on the wrist pin. When sliding the piston with rod down in the cylinder it must then be centered on the crankshaft journal. That means you have to be (looking) at the rod starting to go over the crankshaft journal. If it is not centered it needs to be turned the opposite way. Checking this way there is no need to try to remember which way they should go and get all mixed up.
 
basically no info of any use here. need measurement details and every little thing that was done. dont even know if your talking about pistons in the cyl's or once the rod is torqued to the crank.
 
OK got a little more info. Only new parts were the sleeves, pistons, rings and gasket set. Ran some of the answers by him and said ring gaps were ok as the pistons moved fine until corrected to the shaft. did not plastigauge anything but going to take back apart and try that. Thinks a couple the rods may not be exactly centered as mentioned in a response so i guess he just starts over, Thanks for the responses
 
If he reused the rod bearings, I wonder if he mixed up rods and got the bearings in the wrong journals or put a bearing in backwards from original.
AaronSEIA
 
All the above and check the toque specification. A buddy and I did mains and rod bearings on a WD back in 1974 and it wound not turn over,the book we used had the wrong rod toque specs.
 
STILL DON'T KNOW WHAT MODEL OF TRACTOR OR ENGINE !! There is a chance he has something not SHIMMED correctly on a rod or main cap !!
 
Not if it is truly a 1961 model, but we can't assume that claim is accurate when we haven't been told what MODEL it is.
 
Bingo ! so he knew about plastiguage and did not even check the brg's? wow , and asks us what the problem could be ,as if we are magician's. new brgs or old brgs need to be checked to know how much wear you have and to see if clearances are in spec.
 
Dick L. I heard you are familiar with the model b. I recently purchased a 49 with a CE low octane motor that was rebuilt. It runs well with 99lbs compression across all cylinders. Any tips on improving performance for tractor pulling? Also any tips on tire pressure for different tracks?

Thanks
 
Do the pistons move freely in the cylinders? I once tried to assemble an engine and found the block had been bored to EXACTLY the cylinder specs with no allowance for piston clearance. I had to hone the cylinders myself to get a couple of thousands clearance, whatever the spec was.

That being said, and without even knowing the model of tractor or other information, there are so many possible errors it's impossible to know where to start. I would assume everything has been lubed with assembly lube while it's being assemble.
 
My two cents: My brother and I overhauled his 1956 ford 223 6 engine in car. We were working in a not well lit garage. When we started putting the rod caps back on, it was a lot easier to see the fomoco stamp on the bearings than the finely stamped numbers. So after we put in two we noticed the fomoco stamps were on one side of the bearing cap so we used that as our guide to replace the rest as it was easier to see. Well even before we put the head on we tried to turn it and we could not turn it even with a breaker bar. Took bearing caps off only to find the fomoco stamps were not all stamped on the same side of the cap. (Not even sure how or why that was possible) Got a flashlight and reading glasses (which I should have had on from the start) and put them back with the numbers aligned and it spun right over.
 
If you are using used bearings over that had no problems WHY SHOULD YOU HAVE TO CHECK CLEARANCE? They should have same clearance as when taken out and everything was good. So why measure?
 
Checked with him and I was off by 1 year as it is a 1962 version. The model is a D14 and he said the size was a 149.
 

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