main bearing clearance

[rayc3045]

I would like your opinion on main bearing clearance.
I am in the process of rebuilding the bottom end of my 88 7MGTE, because of a rod knock on the #4 cylinder.
I have disassembled the block and had the block and crank to the machine shop. The machinist milled the deck of the block, cleaned and balanced the crank and replaced the oil pump drive shaft bearings.
He said that the main and rod journal were were ok and to use standard after market bearings. I installed new King bearings and tested the clearance with plastigage below are the results i got.

Main
#1=.0020 #2=.0175 #3=.0020 #4=.0020 #5=.0025 #6=.00275 #7=.0020

Rod
#1-#6 all .0015

The rod bearing clearance spec are 0.0008-0.0021, this shows the rods are good to go.

The main bearing clearance spec are 0.0012-0.0019 with a max clearance of 0.0028, this shows that the mains are out of the spec range, but not past the maximum clearance

My current bearings have a wall thickness of 0.0787.

If I use what I currently have will this give me good oil pressure for the life of the engine or should i look for other bearings.

Need your opinion
Thanks
Rayc

 

[IJ.]

Which King bearings did they supply?

For a sustained high rpm/output motor those main clearences are fine, I found going tight on a 7M produced some really funky wear patterns due to crank and block flex, opened it up a little and the wear went away.

 

[rayc3045]

I have King bearings # MB 787AM STD
#1 bearing stamped M787/1U AM STD, #2-7 BEARING STAMPED M787/2U AM STD.
This is going to be a daily driver car, and wont see much high RPM

Thanks
Rayc

 

[IJ.]

They Bi metal or Tri metal bearings Ray?

 

[rayc3045]

I cheched with King and they said the bearings are Bi metal

 

[IJ.]

Personally I wouldn't use them after seeing a set at my crank shop that had splooged under pressure.

I'm hard on engines though so always take worst case scenario's with any product as "this WILL happen to me"