Engine seize after assembly

[Husker]

So I torqued everything to spec do you think my torque wrench is trash or I didn't put enough oil on the bearings

[Fil Bonica]

Did you lube the bearings during assembly?

Fil Bonica

[m3a1]

Oh man! Sorry to hear that!

[Husker]

I did it in accordance with the -34 but idk if my level of light was supposed to be dipping them in oil. I poured in a quart of cheap stuff in an effort to loosen things up and will try tomorow I'm spinning the engine via the bolted on flywheel with no other aid may try a breaker or something tomorrow. Or adding more oil and hoping it gets in the bearings idk any aid would be appreciated

[rickf]

If it will not turn do not keep trying, you will just do more damage. Over torquing the bearing will not cause it to seize because you are torquing the bearing cap against the block, not the bearing. Did you try turning it a bit as you tightened up the main caps? If it started to get tight then the bearings are the wrong size. Did you measure the crank and bearings to be sure you had the right sizes? Or check the sizes on the old bearings that came out.
Is this motor completely assembled or is it just the crankshaft? No matter what do NOT keep trying to turn it!

[Husker]

Crankshaft turned fine when the main bearings where installed and continued to spin freely until intorwued down the connecting rod bearings (I had to loosen them to alin for the intalation of the oil pump gear) engine is almost full assembled head is on oil pan is sealed etc. the bearings are the correct size same as the old ones I must not have put enough oil on during install unless I was supposed to use gaa grease.

[rickf]

It sounds to me like the rod bearings are the problem. The only solution here is to pull the pan and take the rod caps loose a half turn on each nut and see if it loosens up. If it does then the bearings are the problem. If you put any oil on them at all then this will not happen with the correct bearings. Even dry they will not bind up like that. You can put a gallon of oil on them but when you tighten them down it all comes out except for the .002- .003 thousandths clearance in the bearing. Did you plastigauge the bearings before assembly? If it does turn out to be the rod bearings that are to tight then you need to check the sizes on the bearings and get some plastigauge. I am not trying to beat a dead horse but what size bearings did you get? And did you actually look at the sizes of both the old rod and mains? Sometimes you will have undersize mains and standard rods. I strongly suggest checking both the old rods and mains to see what size is marked on them and if you no longer have them then you will need to mike the crankshaft. Especially use plastigauge on the mains to be sure they are correct. I use it on every bearing in every engine I build. Cheap insurance and it has saved my butt on several occasions.

[Husker]

I'm reusing the original rod bearings only thing that I could have done was reverse the order of the pistons unless the bearings were the wrong size to start with from the military/PO all bearings were in exellent shape limited wear and clean.

[muttguru]

Husker...
did you make sure that the timing marks on the front timing gears were aligned? If not you could have a valve opened while the piston is rising.
Ken

[halftracknut]

mix up rod caps?....dry piston hole... bolt in cyl?...could be alot of things....

[rickf]

Ok, I am going to go out on a limb here and probably become kind of unpopular. Ken, there is nowhere near enough valve lift nor piston height to have a valve to piston interference, even if the valve was all the way open and piston at TDC.

Husker, You say you rebuilt the engine according to the manual but you reversed the piston order. The rods and cap are numbered from 1-4. Each cap has a matching number to the rod and the numbers have to be on the same side. Sometimes cylinders are not all bored the same, this is not a likely scenario on a contract engine but something you need to know. Whenever replacing the old parts back in an engine they ALWAYS go back in the same place. Why in the world would you not replace the rod bearings during a rebuild?

So here is the bottom line, you have a problem and the only way to fix it is to tear the engine apart again. Consider this a learning experience. You obviously did not follow the manual because it would not tell you to do most of the things you did. We could sit here and guess for weeks what the problem is and never know for sure because there are quite a few possibilities. You did several things wrong and any one of them could be the cause. It all has to come apart and everything needs to be put in the order that it came apart. Be aware that the pistons have a front and back also. Get yourself some plastigauge, you are going to need it. If you tried to force the engine to turn then there is going to be damage somewhere, you need to find it.

Once you get it all apart get some pictures and then ask questions!!! It will save you time and money. Sorry if you do not like the way I came across but sometimes it is best to just say it as it is.

[Husker]

I understand I'll be doing it over again on Saturday. The pistons rods and connections are all matched to each other I bagged and marked them with number some when I took them apart. At the top of the head there were letters but all my pistons had the same letter on each one.......

The head wasn't attached when I first had the issue so it isn't a valve

I'll buy replacement rod bearings then if I do should I have the camshaft ground again?

[rickf]

Do not try to do this all on Saturday! You had the camshaft ground?! The cams in these almost never go bad and regrinding a bad cam back to stock is super expensive. Did you put cam bearings in this? You can buy NOS camshafts fairly cheap, regrinding a cam is usually done for performance purposes and even then pretty much only on very hard to find antiques and exotics. Let's start from the top, what exactly have you done to this engine?

Here is a NOS camshaft

http://www.tnjmurray.com/militaryvehicl ... 350B3E0003

[Husker]

I have only cleaned and repainted parts and replaced the main bearings with a the same size new old stock. I have spare is camshaft already it has not been ground unless it was by a previous owner

That's it
I spent about 6 hours one day installing the cam pistons and oil pump and then the week after another day puting the oil pan engine head, side panel cover on
That's all. I also poured a quart 10W30 oil in it in an attempt lube it

[Husker]

I also used the wroung terminology I mean the lobs of the main crankshaft not camshaft

But I didn't move the bearing of the camshaft at all it is still in its original bearings and is aligned with the timing mark of the crankshaft