The Stovebolt Site Forums The Shop Area Engine Shop 216 Chevy main bearings-

Hello, I'm starting the assembly of my 216. My car is a '48 Fleetline with the original block different head. I'm having a few issues but try this one out-
I had a 10 10 grind done on the crank. I have put in the bearings with assembly lube but I noticed that when my bearings are placed in (nothing has been torqued or shimmed at all) I can see that the bearings come up above the deck of the block as well as past the bearing caps about 1/32" or so... is this normal? I haven't done anything else but lay the crank in in the bearings and then bearings in the caps and loosely bolted the caps in place, no shims, no torquing. Before going forward on this any more I thought to get some input. Whacha think am I screwed or is this okay? I have no idea, lol. I'm at a standstill on that please help
Be cool, freezerburn

This might sound a stupid response, but your machinist provided you with the correct size new bearings for your grind?

They are 10 under bearings and 10 under grind... but does my above question seem alarming to you? Have you done 216 bearings before? It just seemed odd to me that they come up passed the deck etc... half of a circle isn't going to come past half of a circle, lol. I've never don a shimmed type bearing before though. Thanks for the comment and good question, any one else any input? -freezerburn

Did the crank bind when you tightened it? I would leave the rear main seal out and use plenty of assembly lube on the bearings. Slowly tighten the main caps and make sure the crank turns free. If you get things tightened to the recommended torque spec and it is still free I would then plasti gauge and see if you are going to need shims.

When I had my rods converted the bearings did not meet at the rod parting line but were offset. Is there a chance that the dowel in each bearing is not fitting into the block?

Put the main bearings into the right places in the block and the corresponding caps, and snug the bolts down without the crankshaft in place. Since each bearing is a different diameter, it's virtually impossible to get them in wrong. Remember to install the doweled bearing shells in the right place- - - -the upper and lower bearing shells are NOT identical. The cap should meet the block with little or no torque applied to the bolts. If there's a noticeable gap between the caps and the block surface that would require a lot of torque to close it up, something's wrong. If necessary, a few thousandths of shim can be added between the cap and the block to adjust the oil clearance, so if the crankshaft gets difficult to turn after it's installed, adjust the clearance one bearing at a time. Do this BEFORE installing the rope oil seal at the rear. I like to see about .002" clearance on the main bearings. The Federal-Mogul bearing specification manual lists main bearing clearance at .0005" to .0031", but .0015"-.002" has been the rule of thumb for most of the engine builders I've known for the past 60-something years.
Jerry

Thanks folks, I had a rough day yesterday and I decided to starve myself away from the engine for a day to recoup'. I'll post up any updates or progress. -freezerburn

Thanks folks, the bearings did seat down well enough by just tightening down the caps to right about snug. Now everything looks much more do-able. I am now cutting up some .002" brass shim stock and using the thick shims from the kit as templates. The kit ones are huge thick! Be cool -freezerburn

Check the kit shims closely- - - -I think you'll find that they're actually several layers of .0005" or maybe .001" thick metal stacked together, like the rod shims. Sometimes it takes a lot of effort to separate the layers. Peel off a layer at a time until the clearance is right.
Jerry

I was fooled by shims like that. I sent a sample to Dave and he showed me that they peeled apart. I then was able to do so using a small utility knife, the kind with the 1/2" wide blade that you break off a piece to get a new tip. I used the knife on the edge of the shim pack to separate them.

Sometimes you can cut the very corner off of the stack and it deforms them slightly so that you can peel off what you need.

before you get too excited about the shims, measure your clearances first. Given the precision of the modern insert bearing there is a good chance you won't need them. This is all assuming the block was held to the correct tolerances of course. The only reason I can think of they would have ever used shims in the first place is they hadn't figured out how to make the "precision" aspect of the bearing insert consistently back then.

I shall look into that guys, S**t I already bought .002" shim material and made a hole cutter but what the heck, live a little right? I will try as you say regardless -freezerburn

Yeah no luck guys, the shims are not in layers:( I have one size of thick shims and that's it. I guess I'll have to make some out of .002" stock to get what the book is calling for. fb

I usually get soundly thrashed by the resident "experts" for suggesting it, but soft drink cans make excellent shim material. Beer cans are the same thickness, but for some reason I end up with some sloppy-looking shims when I start emptying cans of Budweiser during an engine build! Dunno why!
Jerry

That's funny hotrod, I did make a nice set using the kit for templates though. .002" brass x4 each for everywhere under the caps. Hey it was available close by and cheap so heck with it... I had to give up the beer and the soda pop years ago dangit, lol -fb