After installing a new set of Clevite MS 804P std main bearings, I cant get the crank to rotate. Main caps are only snug, I double checked the part numbers and the bearings are supposed to standard. This is a 400 E block. Any suggestions? Thanks to all.

 

Update, the crank will rotate if only cap 1 is snug, if I snug any of the other caps the crank wont rotate. I checked the bearings and they are stamped std. Any help appreciated.

 

Can you measure them and confirm they are the correct size?

 

Are you using a rope rear main seal ? If so try it without the seal and see how it feels. Are you sure you have all of the bearings in the correct positions ?

 

Yes I am using rope seal, is there any alternative? Even with the cap with the seal loose when I snug any other cap the crank wont rotate. The bearings are installed correctly, Thanks

 

I have no way to measure the bearings but they are stamped std. Thx

 

Before you do anything else, remove the rope seal completely then reinstall the crankshaft and torque all the caps and see how it turns. Use 10w30 oil, not the thick sticky assembly lube. That way you will get a feel for how the crankshaft turns with no drag on it.



If it turns fine that way then you can either reinstall the rope seal or get a rubber one. I am pretty sure that BOP has them.


If the crank does not turn freely without the seal in place then you have other problems that are going to be hard to address over the internet

 

are the caps all in the correct location??if it will not turn with just the rear cap snug i would say under size bearings.

 

Why was the motor rebuilt in the first place? Did it have spun main bearings? Did the crank get turned and did the main bearing journals get checked for round and did they get turned? Did the block get align bored? Sounds like it may need it. I had this problem on the first motor i ever rebuilt, it was a 67 E block 400. I had spun the mains in it, didnt know it. When i went to install the crank, just barely tighten the main caps would lock up the crank. Had it alignbored and all was good. But then it needed an under size timing chain.
Just a thought.

 

If the rope seal is causing the problem, suggest you use a neoprene seal from a Ford 460. Your local auto parts store sells them.

 

You are installing the caps the right way round and in the order they came off?.

Roger.

 

 

Rope seals, when installed correctly, put a lot of drag on the crankshaft until they have run some. If you are not familiar with this then you could think you have a bearing problem when actually everything is fine. That is why I suggested trying the crank without the seal first.

 

I will remove the rope seal and see what happens. Thanks everybody

 

The rope seal was the issue, I am going to try the seal from the 460 ford. Thanks everyone.

 

I thought I read that someone suggested a dab of RTV where the seal halves join, when assembling. This was to keep oil from seeping out.

 

Yes, and I remember reading to offset the halves so the ends aren't flush with the bearing cap/block mating surfaces.

 

yup we always put just a dab of rtv on the outer edge of the rope.and had good luck with it.especially if it was done in the car with a sneaky pete.

 

Thanks, I forgot that part.

 

Check out Bill Travado's YouTube videos on putting together an Oldsmobile engine.