Changing bearings

[Guest]

If I pull the crank bearings off, the bearings should have numbers on them denoting which size they are, right? If the crank shows no visible signs of deterioration (using my magic mic vision), is it safe to assume that slipping in new quality bearings is ok without plasigaugeing the crank? Same with the rod bearings. Just one of the symptoms of shipwrights disorder.

 

[tomshobby]

Bill,

I would definitely plastigage them. I base that on two experiences I have had.

The first was many years ago, late 60's actually. I replaced the main and rod bearings assuming they were the same size. Spun a rod bearing.

The second was last spring. While getting ready to install the rod bearings and checking sizes there happened to be 2 pair that were marked a different size than the rest. Neither myself or my engine shop had ever heard of this before.

 

[vettedog72]

Plastigage the current bearings; if they are ok, you will not be advantaged by replacing them.

 

[Brosky]

Bill,

I just received all of my new parts for my engine. I'm taking everything to the machine shop Monday to be measured with digital micrometers and matched to the block, pistons or crank. That will include each and every main and rod bearing, pistons, the rings and the cam to fit it properly to the cam bearings.

I will even have him check the lifters to the lifter bore.

You can never take too many engine measurements before and during assembly.

 

[Rickc]

Bill
To answer your question, yes the bearings should be stamped with their size. As an example: STD meaning original crank and has not been turned.
I presume you want to do this because there has been a few miles put on the car by you and/or you do not know if OE or have been replaced. I do not think it is a bad idea to plastgauge each replacement set of bearings.
Remember do one main at a time starting from front or back and then going in order. Then do con rods one at a time in order in either direction. This is obviously a good time to check end float and see if you need to replace the thrust washers.
Might I also suggest current equivalent VP2 bearings....the more expensive ones.
Rickc

 

[Opa]

Bill Yes bearings will be marked for size and quite often brand as well(Vandervell,Glacier and a host of others)
That's what I like about the Standard engine in the TR cars, bottem end is a relatively easy rebuild in the car, often called an "in frame" rebuild as is done with large diesel trucks. In fact the engine can be redone in it's entirety with the block left in the car,providing bore measurements are within spec.for taper etc.and no scoring is present,and the crank shaft is good.

The first cap I pull I mic the old shells and the new shells to see what differences in measurement are present.If it is more than .001, I would measure with plasti gauge to make sure it's not too tight.

The hardest bearing to replace is the front one as the timing chain keeps tension on the crank,if the chain is any good.I have tapped a small block of wood between the water pump pulley and crank pulley pushing the crank down a thou or two.Then using the new shell, push the old one round the top half of the crank until you can grab it.I try to stay away from using screwdrivers etc. as the crank is easily burred by the slip of a tool etc.

Make sure you apply bearing assembly lube to bearing face.Keep the back side clean.(the side facing the block or cap)

Similar process with rod bearings.I cut 3inch lengths of fuel line and slip these over rod bolts so that they don't damage the crank if they slide of the journal as you move them, or the crank around to get at the top shell.

The last in frame i did cost about 225.00 incl.tri metal rod and mains,thrust washers,lower gasket set,relief valve and spring and new oil pump.All parts came from British Parts Northwest.

However if your not comfortable doing this yourself, get somebody to help you as it does get a little spendy if it fails.

Warranty is hard to claim for, if work is done by oneself

 

[Guest]

Thanks, guys. All good info. Will go from here, will slow down the rebuild another month what with getting parts and doing it on weekends.

 

[Brosky]

<div class="ubbcode-block"><div class="ubbcode-header">Quote:]try to stay away from using screwdrivers etc. as the crank is easily burred by the slip of a tool etc.[/QUOTE]

That comes from experience and is some of the best advice ever given here.

As well as the measuring procedure that precedes it.

Take your time, Bill and this will be the last time.