Bearing thickness?

[tntprocomp]

Ok..Are mid 90`s 3.1 main and rod bearings thinner than 85 or 86 2.8 bearings..I put a 3.1 crank in my 2.8 block and when you torque the rod and mains, the motor is locked..I used bearings for an 86 2.8..If not fully torqued, the crank turns smooth and nothing is hitting the block..It is a crank sensor type crankshaft but the crank fully clears the block..

[SappySE107]

should be the same. Sounds like .010 bearings on std journal or just incorrect clearance on a machined crank with matching bearings. The 80 to 84 are small, and sometime in 85 or 86 they changed to larger mains but I am not familiar with their actual size back then. Could also be the caps are not in the right spots. tighten one down and see if it spins.

[tntprocomp]

I did some checking and the part numbers for 86 bearings is different than 97 3.1 bearings...Out of curiosity, I looked up bearings for an 87 2.8..Same part number as the 97 3.1..It would seem that the 86 is different..The bearings I put in are std size and the crank has not been worked on..What I really need to know is, if the journals are different..Did they just increase the diameter of the journals on the crank or did they increase the main size on the block as well..I think they just increased the journal size on the crank and not the block = thinner bearings..

[SappySE107]

really don't know, or care to know about the old small journal iron blocks so maybe someone that does will post. At least you know which bearings to get.

[tntprocomp]

Well, I do have the 3.1 main bearings..Now I get to pull the caps and mic the journals..Im not even 100% sure which block this is..I do know that the 3.1 crank rotates without hitting n e thing.

[SappySE107]

1980 2.8 Main journal diameter is 2.494".
1991 3.1 is 2.647"

Thats all I got from a quick search on main journal sizes. I don't know anything about the block casting changes if any.

[Purple pit]

Damn I use to have a link to a site that was all about rebuilding the 60*. It had good tips and info, but I can't find it.

[Syndicated]

This happened to me once re-building a 305.
I don't really know what the problem was, but I took all the bearings out, cleaned and relubed, and it all worked fine.

[tntprocomp]

Well I mic`d the worn 2.8 crank that I pulled out and it is the larger journal crank..So, they had an over size bearing in the pack of standard bearings or I put a cap or something on wrong..Im gonna pull the pan and all the caps and check it out..