tried to rotate the crank and it wouldn't budge

[92talontsibryce]

Ok I finally got my block and crank back from the machine shop. I cleaned it all, installed my new main bearings, plastigauged all of them and came out to be around .025mm for all of them, then used lucas assembly lube, torqued down to 48 ft/lbs and everything looked great untill I tried to rotate the crank and it wouldnt budge. What could possibly be wrong with this?

Thanks,
Bryce

 

[DSMN]

Did you install new arp main studs or use the factory bolts? cause if you didn't provide the machinist with the studs (thats if you used them) then the line bore could be out. Meaning when you tightened down the mains instead of having a true round bearing surface for the crank to ride on, the area is now football shaped causing a bind up. the only way to fix this is to have it line bored with the mains on and torqued down without the crank in.

 

[92talontsibryce]

Im using the stock main bolts and the shop said they aligned honed the mains. Is there anything else that could be causing this or did the machine shop screw me over? and what can i do to check there work?

Bryce

 

[adrian2627]

double check your measurements. Also did the shop check your crankshaft for straightness?

 

[ptownracer]

be sure and check the main caps make sure u didnt mix one up they should be stamped if the machine shop is worth a shit.... get back to us on this....



"BOOSTIN"
p_townracer

 

[92talontsibryce]

I have double and triple check the main caps and they keep comin up .025mm. And i do not have the rods and pistons in the block yet its just the crankshaft so it should be able to turn it easily. Anything else?

Bryce

 

[joe sobo]

yes, you are correct. if just the crank is in, and it does not spin over fairly easy, don't continue to force it. just take it back apart, and look at all the main bearings. see if you can locate a shiney spot on them in the journal area, or where the two bearings meet each other.this would tell/show you where it is binding up. also check to see what your cank is cut on the mains and make sure the box for the new mains say the same size.

 

[corsair231]

You may be able to pinpoint the problem area by first tightening the assembly to specs. If resistance is felt then back off of one main a little. If it turns freely then you know it is the problem area. If it still has resistance, tighen that one back to specs and loosen the next one and so on until the problem is found. If it does not track down to one main being the problem then my guess is that you may have the wrong bearings.

 

[96eclipzGsT]

some engines are tight enough to the point that they wont turn by hand. The rings havent seated and the cylinder bore is fresh. Bolt on a crank pulley for leverage and give it a good crank. Lube up the cylinder walls with something thin and try again.

Wrong!!! When you complete assemble a motor always set a torque wrench to 14.5lbs and put it on the front of the crank. If you cannot spin the motor without the wrench clicking then you HAVE A PROBLEM! Simple as that.

Do this without the spark plugs in.

Forget the plastigauge it seems its not working right, if you just have the crank in it should be easy to turn it when it is torqued down. You either have a bearing in wrong, caps backwards, or someone just completely messed up the line hone or maybe you need to get it line honed. Wrong crank?

 

[cbrfrenzie]

I know this sounds stupid, but it happened to me... Check your main bearings to be SURE they are not undersized, and are in fact standard size. I ordered some parts from a reputable vendor on here, and get shipped undersized rod bearings by accident. 2 years later when I went to assemble the engine.... it would not turn just as you are stating and BINGO, wrong bearings! Loosen the main caps SLIGHTLY and see if it turns. If so, sounds like wrong bearings....

Also, plasti-gauge is only REALLY useful when checking clearances greater then 0.002", or at least that's my experience with it. Anything tighter I use the micrometer, as the plasti-gauge isn't precision enough for my liking.

 

[Defiant]

if you just have the crank in it should be easy to turn it when it is torqued down. You either have a bearing in wrong, caps backwards,

Those would be my first suspicion.

 

[92talontsibryce]

Thanks guys for all the help. I finally figured out what the problem was. When i got my block back from the machine shop they put one of the main caps on backwards but not tightened down and i thought that was the way the main cap was suppost to face. But then i did some research and found out the all the arrows are suppost to face the same way. So i flipped the main cap around and all is good now.

check out my build http://www.dsmtuners.com/forums/hangout/333311-my-engine-build-pics.html

Thanks,
Bryce

 

[BrokenTsi]

Wrong!!! When you complete assemble a motor always set a torque wrench to 14.5lbs and put it on the front of the crank. If you cannot spin the motor without the wrench clicking then you HAVE A PROBLEM! Simple as that.

Do this without the spark plugs in.

Forget the plastigauge it seems its not working right, if you just have the crank in it should be easy to turn it when it is torqued down. You either have a bearing in wrong, caps backwards, or someone just completely messed up the line hone or maybe you need to get it line honed. Wrong crank?

I was talking about just the block. Not an entire long block assembled with head and timing belt. I have a fresh block sitting here in my living room. Crank/rods/pistons are the only thing that are on it. Its pretty much bare.

I cant turn the crank by hand because I have nothing to grab on to. There is no crank pulley or anything like that. I just flip the block over and push it with my hand to make sure the crank rotates.