James187

Hi,

My cars has 110k miles, slightly low oil pressure and some copper & lead in the oil after analysis. So as a preventative measure I want to change the rod bearings.

I really only want to take the sump off once but as far as I am aware the only way to find out the bearing size is to take off the sump and check the numbers on the crank webbing.

The only place I can find them is www.parts-honda.uk, but they are £32 and if I wanted to get 4 lots of each of the 7 sizes that would be just under £1800. I'm not sure if they'd let me return the others...Even still with just the 8 I need is £256, sounds quite steep!

noodels

Suggest borrow a car if needed while you wait for correct size

CHIPPO

I presume we are talking about crank shaft bearings ? Not rod , as in Conrod Bearings?

wouldn’t fancy doing those even with car on lift and engine in. You need to be scrupulously clean as the limits are small I think we landed up with less that .0015 “ clearance over the entire 5 main bearings when we plastic gauged them , it really is an on the bench job.

the Honda ones come in a variety of sizes , as said to match the codes on the block and crank , I wonder do aftermarket ones have these variations ? And this presumes the crank journals are in good condition, not oval ect, or scratched.

danwebster

I’m afraid that main bearings have a much bigger ‘bearing’ on your oil pressure than rod bearings so if wear is indeed the cause then it’s unlikely new big ends will help you.

Also, after 110k miles you can’t rely on the codes to pick your bearings as there will be enough wear on the components to make a difference.

Each bearing shell is two tenths of a thou different in size to the next so we are dealing with extremely fine margins here. When I build engines (which I do for a living) I pick a point in the tolerance and I hit it with every bearing by swapping and changing. It’s the difference between having 40 psi oil pressure at idle when hot and 5psi.

I don’t think I’ve ever had more than 2 or 3 bearings come up the right size just by using the codes.

sorry to be the ‘bearer’ of bad news.

CHIPPO

The crank journals on the engine we rebuilt, had not worn at all it seemed, so the coded shells for both mains and big ends all were correct. We measured the journals for OD , oval and parallel to , all were good.