Rover 4.6 rebuild

[huebnerd]

I have bought another discovery 2 rover 4.6 that the oil pump failed.
The shop I bought it from attempted to repair the engine and install 0.01 oversized bearings but could not get the crank to turn.

After inspection I found they had the crank polished and not turned to 0.01 oversized. I measured the crank and it is 0.005 undersized from spec. So I have two choices. Use standard bearings and hope for the best on oil pressure. or turn the crank another 0.005.

Anyone have any experience on 4.6 or 4.0 rebuilds? Can I go out of spec by 0.005 and still be okay?

[punkinracer]

You need to find out what the factory tolerances are, like in a Haynes manual or the like. the best way to measure your clearance is with plasti-gauge, any place like Lordco will have that. Clearance should be somewhere like 2-4 thou on a crank, so if you have +10 bearings and the crank is only -5 there is no way it will turn. Check the crank with standard bearing caps if you have them with the plasti-gauge, if you are in the ballpark then bang it together. if not then you will have to get the crank properly ground and use the +10 caps. Grinding the cranks is only about $120 these days anyway so it is worth it. hope that helps,

Pat

[huebnerd]

I figured plasi-gauge was the best way. The rover 4.0 − 4.6 rebuild manual just gives a measurement of the crank for standard, then oversized, and double oversized.

I should give it a try using the specs you gave me.

However if crank regrind is only 120.00 then you answered my question for sure. Because to regrind the crank to 0.01 oversized (which is the new bearings I have) is less than buying standard bearings and hoping for the best.
I am going to take the crank to a machine shop Wednesday.
Just hope they don't mess it up.... I do not believe 4.6 cranks are easy to come by.

Thank you