Main and Rod bearing question

[rlpete01]

Putting main and rod bearings in a 98 4.0 SOHC and the Haynes manual is giving me oil clearance spec of:

rods
desired 0.0003 to 0.0024inch
allowable 0.0005 to 0.002 inch

mains
desired 0.0008 to 0.0015 inch
allowable 0.0005 to 0.002 inch

The part store only has plasti gage starting at 0.002 and larger. I have already found some incorrect information in this manual so I would like to see if anyone could verify these. And if they are correct what to use to check them if i can not get the proper size plasti gage.

 

[2000StreetRod]

two ranges

Advance Auto sells a plastigage equivalent with two ranges - red: .002 to .006 inches and green: .001 to .003 inches. You need the one with the smaller range.

I checked one of my main bearings and it was slightly less than .002 inches with more than 150,000 miles of wear. I think the tolerances listed in your Haynes manual are reasonable.

 

[imp]

......... I think the tolerances listed in your Haynes manual are reasonable.

They are consistent with just about every Ford engine I recall checking specs on, always taken from Ford Shop Manuals.

Bearing clearances are usually preferred to be on the looser side for high-speed heavy duty use. Clearances for High-Performance engines are always on the looser side. imp