2.5L ('98-'01) Oil clearance

[Sonkay ranger00]

I'm rebuilding my first 2.5. In tear down everything looked absolutely great (except for the blown head gasket, reason for tear down). I decided to reassemble with no machine work, just hone and a std, std, std remain kit. I found .003 oil clearance on the new main bearings. Crank journals Mic exactly what the Haines book says but has double the clearance they recommend. Any experienced 2.5 builders that can tell me how critical that specific is on a daily highway driver? I greatly appreciate any input!

 

[tomw]

Where did you get your bearings? Could be they are out of spec. I would not want to take all that time and $$ only to find I had a thudding main bearing. Likely it won't make noise, but if it is .003" clearance, it is out of specification.
FoMoCo used to sell bearing shells, available individually, that were .0015 smaller than 'STD" for use when the journals were in good shape, but just a little smaller than desired. As I remember, there were different sizes available, and you could mix/match to get the clearance closer to spec. I did use several in my 2.3 when it was actually pretty low mileage.
I would not use them if the clearance is out of spec.
tom

 

[Sonkay ranger00]

thanks for the reply I got my bearings from engine Tech they are to spec and the crank Journal is to spec, apparently it seems to be the main caps I really didn't want to do a line bore.

 

[tomw]

You should not need to do a 'line bore' unless you have had problems with overheating or distortion due to running without oil.
OR are blueprinting an engine. The factory done bore should last the life of an engine, even with installation of new inserts, if the block and caps have not been damaged.
The clearance being twice the factory spec indicates something is wrong. I do not see how main bearing caps could affect the clearance that much.
Have you checked using Plastigage? If you do that, you can at least check if the clearance stays out of limit or closes when torqued.
How are you so sure your bearings are to spec? Who is engine Tech? Are they a 'brand' or house branded parts? China?
A quick check would be to get a set of a different brand inserts and check their clearance.
Can you post an image of the new inserts, both sides, and the box/container they came in?
tom

 

[Dirtman]

I'd want to know how you are measuring the clearance and journals. Plastiguage or just a micrometer and a calculator?