Tap L&S Inserts?

[jerry598]

Just checked my main bearing clearances on my 95 6.5 TD w/plastiguage, all were good at .004-.006"

But, the bolts did not thread easily into a couple of the new L&S (Full-torque) inserts that were installed by the machine shop 150 miles from here. By easily, I mean I could not get them to snug up by hand in the last 1/4-1/2 inch of threading. Had to use a rachet on them to get them all the way in, probably using 10-20 lbs of torque in the process.

I'm a novice at this. Do I need to tap them? I was planning to tap the head bolt holes during reassembly since I don't know if the machine shop tapped them when they preped the block.

Also, is there anything that should be used on the crankshaft or rod bolt threads to get them properly torqued? Should they just be cleaned with a solvent like gasoline and dryed first?

I'm a little paranoid about this because I did a rod bearing and ring job on a 1954 324 cid Olds engine back in my younger days, and it threw a rod after about 500 miles.

[john8662]

The main bearing clearance is too wide IMHO, I'd like to see .002-.004. I'd purchase a set of .001" OS bearings to tighten that up a bit.

The main bearing cap bolts should all hand thread into the block with the cap properly aligned on the block and the cap fully inserted onto the block in between the registers (tap in place with a copper hammer). If the bolt or insert isn't going straight, or if the cap isn't aligned it's hard to get the bolt to bottom. Shouldn't need to tap the main bearing threads.

The fasteners for the mains are to be installed WITH engine oil to achieve proper torque, and start on the middle main cap then work your way out to the ends.

The rod bolt buts must be installed onto oiled threads to achieve the 50 Ft. Lbs torque requirement.

Tap the head bolt holes with a bottoming tap, or a thread-chasing tap, there is a difference, although I've always just used the bottoming tap (non taper).

Clean everything thourally with solvent before assembly.

J

[jerry598]

Thanks for the all the good advise. I rechecked the manual and you're right about the bearing clearance.

The machine shop supplied the bearings and I didn't measure the crank myself.

Should the machine shop be responsible to supply the OS bearings in exchange for the std ones?

[Robyn]

Get your clearances right for sure. .002-.003 is usually about where these will be very happy.

The L&S inserts should not have any issues at all , BUTTTTTT if the bolts get snug at the bottom, lightly run a tap through the threads. Be sure to catch any crap that comes out the bottom as you dont want this in the engine

I have installed many sets of these inserts and never had an issue with the threads inside the insert.

Be clean, be careful and all will be well.

Robyn