Polish connecting rods.?

Question

Hi,

I am replacing rod bearings in my car and I am wondering if it's safe to polish the connecting rods to get rid of the old bearing residue on them using a fine emergy cloth. Is there a risk of making them smaller?

Car = 1989 Camry 3S-F

Cheers

Hey thanks for your replies. To see why I am doing with, see my question here: http://answers.yahoo.com/question/index;_ylt=AtHiGlYqFkfclP0hL1OthmDsy6IX?qid=20070721233230AArdMy6

The rod caps have some minor residue in the form of tiny bumps in some places and the numbers on the bearings got etched into the caps. I can't feel the bumps by hand but I can feel slight irregularities them when dragging a penny across.

Sorry turning the crank is not an option :( I am trying to squeeze the last bit of life out of this car before a used engine / or car. This is not a repair I expect to last 100,000km... 20,000 km max. I can't pull the crank because I am changing the bearings from underneath the car (through the oil pan).

Answer 1

The amount of material you would remove from polishing hardened steel with an emory cloth would be negligible. If it makes you feel better, go ahead.

I'm wondering why you would need to replace the rod bearings? If you have so much wear out of them that they need to be replaced, it's probably a good idea to measure the inside of the rod bearing surface for tolerance. A worn bearing will also create wear on both the rod bearing surface as well as the crank bearing surface. It's common practice to machine down the surfaces and use an oversize bearing. This can only been done by a competent machine shop with experienced engine builders. If you just slap in a new bearing you'll end up trying to mate the new flat bearing surface with the worn surfaces on the crank and the rod. These irregular surfaces surface will create pressure points that will slice right through the new bearing, and you'll end up with the same problem that got you to this point.

If you've disassembled the engine to the point where you can get the rod bearings off, Then you should take the crank and all the rods (rods and caps) to a speed shop, have them turn them down, measure them, and make sure a standard bearing set will still fit. If not, you might have to order an oversize set.

Answer 2

If you'd like to go the extra mile have your connecting rods re-conditioned at a an engine builders shop.
Both ends are completely re-sized to OEM specs. They'll kick out the rod bolts if necessary and refinish the flats so the big ends of the rods will be once again perfectly round.
You can have the crankshaft journals checked for size and finish. Have the cylinder dimensions checked and either honed or worse case bored and honed. After checking the dimensions new rings and pistons may be necessary. While you're at it have the rotating assembly balanced. You'll love it and so will the motor.

You see I like spending your money. I guess my point is, while it's apart go the distance and do everything right!

Answer 3

yes it is ok to polish your rod and main bearing bores. it cleans any residue and it is a fact that a loose bearing is better than I tight bearing. a tight bearing wears faster and ruins the oil with metal shavings. a tight bearing takes more power to turn your crank. I am talking about bearing clearances with in tolerance. a hair behind a bearing can cause a tight clearance, what ever is behind the bearing will likely remain because the back of the bearings don't spin. the internet has its know it alls with no common sense reasoning or experience. not a goat

Answer 4

No, it's not a good idea to polish the connecting rods. It will
make them smaller. Probably Enough to let the bearing spin.