I've been talking to a guy about some racing bearings for ITR/GSR etc. He said that they are all the same size and are not colour coded like the stock Honda ones. He assures me that there is no align honing or anything that needs to be done... I've never heard of such a thing, and thought that I would see if any of you have. I guess they are stronger and have higher tolerances... any thoughts or heresay?

 

well they need to be different sizes cuz the space between the rod and the crank is different for every rod. not to mention higher tolerances? i think honda bearings have enough tolerance.

 

He might be talking about the acl bearings, i heard some good stuff about them. I couldnt tell you personally about them since my motor is still in the stand.

 

I wouldn't trust "race" bearings. In my opinion, the only thing you could do to bearings to make them "stronger" is making them wider or something. The very function of the bearing is to be very soft so that they wear instead of the crank, and so that particles get embedded into them instead of messing up the crank.

Besides, there's not supposed to be any metal to metal contact in bearings anyways. All they do is provide a smooth surface and are designed to wear first instead of more expensive things, in case metal to metal contact does occur.

What I'm trying to say is that I don;t think you could do better than Honda bearings, unless you have something other than overall engine durability in mind.

 

They're likely using standard sized bearings like ACL. I'm using them currently, but I checked clearances prior to installation to be certain all were within spec with them.

 

Road race engines use loose tolerances than a motor built by "book specs"
They use clearances around .020 when the book calls for .009-.015 depenging on which main cap it is. Some main caps (#3) are as loose as .017 by "the book".
Looser tolerances will allow the engine to spin quicker with the less resistance. A little road race engine building knowledge.

 

I like to get around .0017"-.0018" on the #3 main and around .0012-.0016 on the others.

 

Race engines are usually buildt with looser clearances to quicken the break-in period. Such an engine is usually built and expected to be ready to go right away.....waiting for a 1000mile break-in period is not desirable. Looser clearance engines also need other steps to ensure proper oil film between the larger clearances...like increasing oil flow.

I'd use only Honda bearings or ACL bearings, but it is still very important to take time and measure things like oil clearance, line bore, crank endplay, etc. Why hurry past some important steps and possibly cause yourself more problems later on???


[Modified by SLPR, 5:34 AM 3/26/2003]

 

OEM bearings are all you will ever need.

 

I find it interesting that one could use standard non uniform bearings on the crank. In theory then, could a person get all one colour bearing from Honda and run those? wouldn't that be basically the same thing that the race bearings do? Sorry about being so naiev about this.. it's just something I didn't know...

 

Again all the more important to check the oil clearances with (at least) plastiguage.

 

You can use all one size bearing under two circumstances with the same outcome. One is that you are lucky enough to have a crank that already uses the same size/color bearings straight from Honda (not likely but non the less not all that uncommon). Secondly have your machine shop grind the journals down so that they all except the same oversized bearing. I guess the third way would be to buy an aftermarket crank but you are refering to the stock one so we shal leave it at that. I too have heard good things about ACL bearings but have no experience with them to back up what I have heard. From what a few members have poitned out on this subject I would be inclined to say that "race" bearings would have faster wear charecteristics than that of others. Most people in this type of industry rebuild thier engines on a fairly regular basis so the trade off is worth it to them.

 

I think the guys is referring to ACL Bearings. Thats what I use in my motor builds. They are real good bearings. Lots of people use them because they tend to "loosen" the motor up. (oil clearance) Honda uses color codes on their bearings for "oil control" of the bearings. Everyone knows that "black" color code is for tight (less clearance) and "green" color code is lose (more clearance). The ACL tends to put your clearance in line with honda "Green" bearings. Use should use plastigage to confirm yours. Most honda's run the black bearing on the 3rd main and looser on the rest.
Hope this helps you out...I recommend ACL Bearings.