Trying to order replacement main (crank) and rod bearings from A&H motorsports. Im having an engine shop rebuild a B18C1 I have, using all stock OEM parts. Andy says both bearing types are color coded for the different sizes.

"The bearing size depends on the block, crank and rods. There are specific numbers on the block and letters on the crank and rods which, when using the chart in the Helm manual, tells you what color should be used.
Andy!"

Im at work right now and the engine is at the Engine shop and my helms is at home. I dont understand how there could be more than one color/size I need for my engine - a '95 B18C1 GSR. A little help and clarification would be appreciated. Why cant he look up the size I need?


[Modified by Muckman, 2:07 PM 3/24/2003]

 

He is exactly right, honda bearing sizes need to be EXACTLY within spec... so there are different bearing colors for different bearing sizes, and are different for EVERY engine.

 

crap what the hell.. who builds engines that arent the same spec? Ahh more delays in my gen2 project.. Thx for the reply!

 

You could have him read the codes off the block and crank to you. The differences, color by color, are mere thousandths.

I went with the one size fits all ACL's. Got them from Earl complete with thrust washers. From testimonials, I've heard nothing but good things about them. my motor is still on the stand so I can't give you my actual thoughts on their wear yet.

 

my engine builder hasnt taken part my entire block yet to see the numbers on the crank, block, and rods. But he told me it would be a big hassle to replace the bearings because even if I ordered new bearings in the proper size according to the numbers they never fit right he said and its better to have all the assorted sizes to match up the proper sizes.

Is replacing the main and rod bearings on a honda engine a simple task (as in matching the right part and installing it) or complicated (as in having to measure everything to the thousandths of an inch just to order the right part and then having it fit worse than stock)???

Does anyone understand this or think its bullshit? I love when I dont know what the hell im doing and neither does my engine builder. Its so confidence inspiring.


[Modified by Muckman, 11:35 PM 3/24/2003]

 

It's really a simple task if you have experience with it. Plastigauge works but it can be done much faster with a quality dial-bore gauge and a mic. Yes, you have to measure everything. Not to the thousanth of an inch but to the ten-thousanth of an inch (1/20th the size of a human hair). I must say that the bearings are a bitch on a Honda. Each color up or down in the sizes is only about .0001" so it can be time consuming. But as far as ordering them and having it not as good as stock, I'd say no way. If you take your time and have some patience, you can get the oil clearances better than stock.


[Modified by BabyDaddy, 2:29 PM 3/25/2003]

 

Thanks for the reply.

My next question would be would I order the exact bearing sizes specified by the numbers stamped on the crank/block/rods? OR would I have my engine builder just measure everything and order the bearings based on what he thinks he needs?

 

If you're going to use stock bearings, yes, you have to follow the color codes. That said, you still want to go back and check the tolerances with Plastiguage after you've seated the bearings. Even if you've taken accurate measurements with a micrometer, you must Plastiguage!!!!!!

The physcial act of changing the bearings is the same on a Honda is it in on any other car. Maybe easier if you compare to a an American V8 with a 4 Bolt main as opposed to ur 2 bolt mains. That's a lot more tourquing! Sounds to me like your engine guy doesn't want to take the time to do it right.

 

It's not that they try to be sloppy, the range of sizes is to account for machining precision (or rather a lack of machining precision). It also tries to account for the wear & tear in the likelihood of a rebuild.

When you're machining to such high tolerances, there's no way you're gonna be perfect every time...so you need something to help parts size matching come into spec.

 

Thanks for all the info. Ive decided to forego replacing the bearings as its unnessecary on a motor with 90k unabused miles.

 

90k miles is still 90k miles. Replace them.

Even if you decide to ignore the advice, at least make sure you put them back in their original places.

 

More machining questions: If the pistons are taken out of the block is it nessecary to replace the rings, and if you replace the rings is it nessecary to hone the cylinder wall? The same pistons are going back into the engine.

In the Helms it says "Only scored or scratched cylinder bores must be honed"