How difficult should it be to turn over by hand??

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xLURKxDOGx

xLURKxDOGx

"An angel fat, at satan's feast"
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I finally had the chance to put my 273 complete rebuild together over the last week and went through the steps in a mopar book as far as assembling pisotns, rods, bearings. I had the rods and crank turned 10/10 and it seamed fine when i installed the crank, turned pretty easy by hand without any wrenches (is that normal?) I gaped the rings to specs and now that its completely assembled without the heads on its really hard to turn over with a huge crescent wrench, but once it gets started its a bit easier to move. I noticed after leaving it alone for an hr that when i came back to turn it i nearly tipped to engine off the stand to get it to turn, is this normal?


Thanks,

Jake
 
Check your rod caps and make sure they are aligned correctly. The numbers stamped should be on the same side, and the oilers pointing in. I had 3 and 8 swapped (light stampings) and it took a breaker bar to turn..WTF? 5 months later I went at it again and found my mistake. turns by 3/8 ratchet now. Still stiff but crankeable with a starter no prob. you got the cylinders oiled down and Assembly lube in the bearings? Oh yeah, if you went with an aftermarket crank, your OEM bearings might need clearancing for the new crank fillets.
 
Once the piston/ring assemblies are in, yes it gets harder. Those cast rings put a lot of drag on the cylinder walls. And you are right; the break-away torque is quite a bit more than the turning torque after break-away. If you were paying attention during the piston install, you would have noticed the incremental increase as each next piston went in.
check also post 2.
 
As you install more pistons, there should be some more drag when you turn the crank.

When they are all in, it should still be able to turn.

Were you diligent to keep all of the rods and caps together and in the proper orientation. One wrong cap can have enough mis-alignment to lock up the crank.

Try loosening one cap at a time and then turning the crank until it gets free to turn. Try to isolate which caps are giving you the most resistance to turn. Then closely look at the rod and cap to see if there are any chamfers on the sides of the crank bore and if they match between the cap and rod. That could indicate a cap that was mixed from its original rod.


It sounds like there is too much resistance for your crank to turn with all of the pistons in....
 
hi, the truest way is to rotate it with a beam torque wrench, it will tell you how much torque it takes, lot more accurate!! also, I assume you oiled bearings and cylinder bores?
also, what kind of rear main seal did you use? rope or lip seal?? just curious
 
Did you plastiguage the bearings? I bought a ".010, .010" crank years ago that had one rod journal that wasn't cut down and would lock up every time I torqued the rod cap down. Checked it and it was standard on one journal.
 
are these all stock parts?

Do the rods have side clearance?
rods and rod bearings installed correctly (chamfer, toward the crank)
what about the thrust bearing clearance ?
Since the crank was ground, does it still have a correct radius, on the journals
Cast rings? What kind of cylinder finish?

crank should spin easy
without pistons


[ame]http://vid267.photobucket.com/albums/ii313/draginmopars/why/002_zpsgt0tgx82.mp4[/ame]
 
Thanks everyone for all the helpful responses!!! One thing i forgot to mention is that i bought a set of 340 rods that had been balanced and had ARP studs in the off Ebay, when i got them i looked at the caps stamps and a few i couldnt make out a numbers so i kept them on the rod they were on when they arrived to me. I havent tried the plastigauge, i could turn the crank over using my hand when it was torqued to spec so i figured it was acceptable?

Im going to try to loosen some of the caps like mentioned and start from there. How many times can you torque and retorque cap/main bearings before you need another set?


Thanks a million!

Jake
 
I got a set of main bearings from summit one time that were supposed to be 10 under, but they were actually 20 under and put in the wrong box. the crank got pretty tight but I discovered it as I was rotating the crank and tightening the mains down. I always plastigauge them just to be sure. same with rod bearings. cheap insurance. if the crank will turn by hand without the rods, and they are torqued down, I doubt that's the problem. if the pan isn't on yet, I would plastigauge everything anyway. use plenty of assembly lube
 
xLURKxDOGx said:
Thanks everyone for all the helpful responses!!! One thing i forgot to mention is that i bought a set of 340 rods that had been balanced and had ARP studs in the off Ebay, when i got them i looked at the caps stamps and a few i couldnt make out a numbers so i kept them on the rod they were on when they arrived to me. I havent tried the plastigauge, i could turn the crank over using my hand when it was torqued to spec so i figured it was acceptable?

Im going to try to loosen some of the caps like mentioned and start from there. How many times can you torque and retorque cap/main bearings before you need another set?


Thanks a million!

Jake
Click to expand...


3 times max after it's out of the factory.

If you have to replace the rod bolts, you should have the crank bore on the rod refinished as the bolts locate the cap and the new bolts will locate the cap differently. It will need to be re-machined when you change the bolts...

Here's a link to some replacement bolts:

http://www.manciniracing.com/rodbolts.html
 
There is also a process for seating the thrust washers on the main bearing, I don't remember the exact process but it has been discussed here before.
 
krazykuda said:
3 times max after it's out of the factory.

If you have to replace the rod bolts, you should have the crank bore on the rod refinished as the bolts locate the cap and the new bolts will locate the cap differently. It will need to be re-machined when you change the bolts...

Here's a link to some replacement bolts:

http://www.manciniracing.com/rodbolts.html
Click to expand...

Not with ARP bolts they are not torque to yield.
 
xLURKxDOGx said:
I finally had the chance to put my 273 complete rebuild together over the last week and went through the steps in a mopar book as far as assembling pisotns, rods, bearings. I had the rods and crank turned 10/10 and it seamed fine when i installed the crank, turned pretty easy by hand without any wrenches (is that normal?) I gaped the rings to specs and now that its completely assembled without the heads on its really hard to turn over with a huge crescent wrench, but once it gets started its a bit easier to move. I noticed after leaving it alone for an hr that when i came back to turn it i nearly tipped to engine off the stand to get it to turn, is this normal?


Thanks,

Jake
Click to expand...

Did you rotate it after each piston and rod assembly? Do the cylinders bearings and rings have a plenty of oil? If you have all good parts and machine work it should not be that hard to turn without heads.
 
krazykuda said:
3 times max after it's out of the factory.

If you have to replace the rod bolts, you should have the crank bore on the rod refinished as the bolts locate the cap and the new bolts will locate the cap differently. It will need to be re-machined when you change the bolts...

Here's a link to some replacement bolts:

http://www.manciniracing.com/rodbolts.html
Click to expand...

Thanks krazykuda! I actually went through and loosened the caps and it made a massive difference, i noticed that a few of them looked really beatup to the point where i had to knock out the rod bolts to get the caps off. Im considering going with the eagle rods, i feel like if i try to reuse these that it is going to be a shortcut and i dont want to compromise this build in any way.



66fs said:
Did you rotate it after each piston and rod assembly? Do the cylinders bearings and rings have a plenty of oil? If you have all good parts and machine work it should not be that hard to turn without heads.
Click to expand...

66fs, i did rotate them after i installed them, the odd sides were fine but when i got into the even sides especially 6 and 8 thats where it all went south.


Thanks!

Jake
 
xLURKxDOGx said:
Thanks krazykuda! I actually went through and loosened the caps and it made a massive difference, i noticed that a few of them looked really beatup to the point where i had to knock out the rod bolts to get the caps off. Im considering going with the eagle rods, i feel like if i try to reuse these that it is going to be a shortcut and i dont want to compromise this build in any way.





66fs, i did rotate them after i installed them, the odd sides were fine but when i got into the even sides especially 6 and 8 thats where it all went south.


Thanks!

Jake
Click to expand...


You can buy some eagle rods cheaper than re-machining the old rods (by about $40). However, you may have to get it re-balanced as the eagle rods are lighter than the stock ones.

Just something to consider..
 
66fs said:
Not with ARP bolts they are not torque to yield.
Click to expand...


I was talking factory rod bolts. I would not trust them after three clamp cycles after the assembly plant. Anything more than that, and you are taking a chance of them breaking...
 
Yeah, there are a lot of bad stuff out there. People wonder why almost no one touches my cars let alone the engines... If 2 are suspect, I would not have a good feeling about the rest. I usually just recondition my rods, but have a good machine shop, and my own dial bore gage and setting rings. The big end of the rods are the most important part of the engine. Good Idea, KrazyKuda, to rebalance if you swap rods.
 
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