I'm in the middle of installing new bearings in the bottom end of a stock ls1. My question is once the crank is installed (torqued) and lubed with bearing guard how many ft lbs does it take to turn just the crank in a bare block?

It's taking 20 ft lbs to get the crank to spin once the mains are torqued. Seems kinda hard to me but this is the first ls1 i've taken on.

What should it be or am i in the ball park?
Thanks Shawn

 

If rods and pistons are not installed it shouldnt take any torque to rotate engine. Take it back apart and inspect wear pattern on bearings to see why and where it is so tight.

 

No rods and pistons installed yet. I've taken it apart a few times now and i don't see any thing wrong with the bearings or any sign of wear. It is cold out in the garage (40*) and that bearing guard is kinda sticky, not slick like oil.
Anyone else every take a TQ wrench to the crank and see how ft lbs it takes to spin it over?

 

Sounds like it has to be rubbing on something in there. See if any part of the crank is touching the block besides the bearings. You need to get it in there just right for it to spin freely.

 

The last few motors we assembled it took 15lb-ft to turn the motor over AFTER the crank and pistons/rods were installed. You should be able to spin the crank over with your hand with no pistons/rods installed.

Make sure you are installing the correct size bearings. I have heard of bearings being mispacked, so checked the backside of the bearing to make sure it was boxed as advertised. Was the cranked turned at the machine shop?

 

I'm going back out in the garage now. I'll take out the crank again for the 4th time and recheck the bearings. Everything is standard size. Be back in a few.

 

Mic the crank and main bores (with bearings), look for .0025. Lay crank in without caps, use dial indicator to chek runout. Be sure bearing locks are correctly oriented and that caps face the proper direction. This can lock up a standard block, though the ls-1 may be different. You should be able to spin the crank by hand and have it coast.

 

Is this motor in the car or on a stand? if you can, try to spin in each time you torque a main bearing down. Maybe you can pinpoint the one that could be causing a problem. Also do you have any plastigage? Check clearances!

 

I had the same problem on an engine I rebuilt a few years back. I don't know if the bearing caps only fit one specific way on an LS1, but on this mopar engine we rebuilt, a bearing cap was on backwards.

 

Thanks everyone, I didnt have the first four caps on the right way. I had all the feet on the caps pointing forward <img border="0" alt="[Banging Head]" title="" src="graemlins/gr_banghead.gif" /> <img border="0" alt="[Banging Head]" title="" src="graemlins/gr_banghead.gif" />

 

BTW the crank spins very easily now <img border="0" title="" alt="[Razz]" src="gr_tounge.gif" />

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by TA2SLOW346:
<strong>BTW the crank spins very easily now <img border="0" title="" alt="[Razz]" src="gr_tounge.gif" /> </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif"><img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />

 

You might want to take a look at the bearings again after that. Check for any wear.

 

They looked brand new <img border="0" title="" alt="[Roll Eyes]" src="images/icons/rolleyes.gif" />

 

Easy enough. Good to hear it isn't scuffed.

I'm having a similar problem on a 302 I'm building--cam bearings though.

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by 9D9LS:
<strong>Is this motor in the car or on a stand? if you can, try to spin in each time you torque a main bearing down. Maybe you can pinpoint the one that could be causing a problem. Also do you have any plastigage? Check clearances!</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Not to be an ***, but have you ever pulled a crank out of an LS1 with it still in the car?

 

Well I got it all together lastnight and with the crank, rods, pistons, rings, all torqued down I'm at 18ft lbs to turn it over. How does that sound?

 

Should be great.

 

Sounds GREAT!! Good thing you caught it now. it IS odd how the feet for number 5 points forward and the rest go to the rear. Good to hear you found the prob!

 

[QUOTE]Originally posted by DenzSS:
[QB]Easy enough. Good to hear it isn't scuffed.

Fords are known for line bore problems with cam bores. I think Ford used select fit cam bearings to assemble motors origonally. <img border="0" title="" alt="[Cool]" src="gr_images/icons/cool.gif" />