Measuring bearing clearance

[Cobra52898]

Looking for anyone with experience rebuilding a 4.6L aluminum Teksid block. And what method(s) they used to check main and rod bearing clearances during assembly.

I’m leaning towards the older method of using a micrometer and lead impression wire to check clearance. This method is still considered the standard for measuring journal bearing clearances. But I’d like hear what others have done.

I also understand that it’s not uncommon for “Select fit bearings” being needed to obtain proper clearances with a 4.6L Teksid block. Has anybody run to this?

I’d appreciate any thoughts and recommendations anyone has.
Thanks

 

[Cobra52898]

Surely there’s someone here with experience installing bearings in a “Teksid” aluminum alloy block?!

 

[blkGT500nCA]

Never done it myself but I’ve seen a lot of guys use plastigauge.

 

[tomshep]

Never built a teksid block but I have used plastigauge on Windsor and FE motors. You can't measure the journals all at once. There is a method to using plastigauge. It saved me from ruining an FE with tight rod journals. I would have spun a bearing if I hadn't checked it and the machine shop told me it was ready to assemble. I had to get undersize bearings and it specd out perfectly.

Tom

 

[chao5.0]

Forget plastigauge, you need a dial bore gauge which isn't cheap, its best to let a machine shop measure and setup the oil clearances. But if you are curious you can download Clevite's bearing book online, just google Clevite bearing book and start looking. The aluminum blocks will get setup a little tighter than iron because of the expansion properties of aluminum.

Also the use of inside micrometers usually only measure down to .0005", oil clearances are measured in .0001".

 

[Cobra52898]

Forget plastigauge, you need a dial bore gauge which isn't cheap, its best to let a machine shop measure and setup the oil clearances. But if you are curious you can download Clevite's bearing book online, just google Clevite bearing book and start looking. The aluminum blocks will get setup a little tighter than iron because of the expansion properties of aluminum.

Also the use of inside micrometers usually only measure down to .0005", oil clearances are measured in .0001".

Thank y’all for your input. I back burnered the engine portion of this project while working on the front suspension. With the summer heat here in Texas, it’s time to refocus back on the engine.
Anyway I had a well known engine shop in the area prep the block, balance the rotating assembly and record the clearances for reassembly and my records. Going through the paperwork later on is when I realized that none of the measurements I asked for were documented! Not even how much the cylinder bores changed after being honed. I believe the work was done, but without clearances I have no way of ensuring everything will be in spec upon reassembly. So that’s where I am right now. Trying to figure out the best course action. I appreciate everyone’s input! Thank you!