Connecting rod siezing the motor

[sdc eastern ia]

Well today I made a set of shims from a pop can. Actually I'm kind of proud at myself even though it didn't change a thing. .005 shims hand tightened the nuts pretty snug and the crank won't spin. Back them off just a little and it spins. I've taken all your advise ie. backwards cap, wrong end caps (a possibility although the rest are fine) used plastiguage and had satisfactory clearence before the shims. At this point I'm just trying to get the correct answer. I will not be using this motor as of now.
 

[Gary Spitznogle]

Check and make sure the 2 digit # on the cap and rod match. This is not the Cyl# But a # like 32, 54 it will have 2 digits. If this is ok with the rod tight take a flashlight and look at the wrist pin and see if the rod is pushed to one side or the other of the piston if it is the rod needs turned a half turn as it is offset. If this is all ok you probaly have a bent rod which is binding.
 

[RWT]

I had a 1750 once that didn't feel right when torqued even thought the rod was good and the clearance was good.

I put different inserts in and the problem went away. I still have those inserts and still don't know what was wrong with them.

RT (my 2 cents)
 

[sdc eastern ia]

Monday I will look for numbers and even turn the rod around. I used 4 .005 shims on each side and still have .003 clearence. I've never seen such a thing.
 

[el6147]

if you are confused as to why your plastigage always shows as being .003 its because it will only crush so far, as to what your problem is I don't know but one thing to check is the size of the rod with no bearing insert installed , the rod bore may be under size . I had a machine shop resize four rods for me for a 1010 John Deere and every one of them was .010 under and the first one that I installed showed that there was .003 clearance with plastigage also, first one I installed and torqued down locked the crank up , the shop tried to convince me over the phone that my bearings were not correct for the application. Shop tech doing the work read the mic incorrectly when he honed them .
I purchased a bare block for a 1650 from a salvage yard about 10 years ago and when I installed all the bearings and the crank and torqued the mains the crank would not turn . one by one I loosened each of the mains until the crank would spin , turns out that one main journal was under size from all the rest and I had to have the block line bored to fit the bearings properly . I have no idea why one was smaller than the rest but if I would Have to guess I would assume Waukesha had some bearings that weren't sized correctly and rather than scrap them they just under bored the block and used them up .
 

[PORKY B]

you will find your rods big end is out of round have it resized
 

[e]

Sounds like it's time to buy a calipers or better yet, a micrometer. If you continue down this path of just guessing at what to do, you'll end up with a rod hanging out of the block plain and simple.
 

[Dick L]

If you put new bearing inserts in without grinding the crankshaft and having the bearing inserts matched to the crankshaft you can have the new inserts pinch in on the crankshaft. If there is not enough room the rod is not going to expand. (If) that is the problem the bearing inserts need to be measured and the ends filed to fit.
Pictures Of How I Measure and File

 

[roy drewis]

Are you sure all the rods were installed the correct way and one isn't backwards. Don't know if you replaced the pistons on the rods and maybe installed it wrong. I have come across some rods where someone in the past stamped the rods on wrong side. Rule of thumb is that the numbers on the rod should be stamped to the camshaft side. I'd check each cylinder seperately by loosening each one and re-torque to see which one or if all are causing the problem. If all are causing it you could have mis-labled bearings also. plasti gauge will help you also once you find the bad one. If they all gauge the same then your crank; if reground could be ground wrong or the bearings are incorrectly fitted. I usually ask to have the machine shop fit the bearings to the crank if I'm regrinding a crankshaft. I had one reground once and they then could not get the bearings so the monkey was on their back,they didn't charge me for the grind. But I still ended up then with crank I couldn't use and had to locate another to replace it.
 

[mattwillson]

I had a crank ground 10 under once that the cheeks were interfering with rod bearings. Not cool, big block dodge cranks are hard to find. Ended scrapping it and getting another crank done up.