I got a set of Dura-bond LR-1 cam bearings from roverparts and no one seems to know ow the front one goes in. As you can see in the picture the new bearing has oil channels on one side and dimples on the other. So I have 2 questions. Which side goes to the front of the engine, the dimple or oil channel side? The dimples and channel only cover 90 degrees of the bearing. So what position should the oil hole be placed? If I place the oil hole at 12 o'clock then the dimples and channels are in the 3-6 o'clock position. I talked to Dura-bond technical support and they said they have never seen them installed, they just reverse engineered them after they were removed. AtlanticBritish didn't know either but they sell a short block with that bearing installed. Any suggestions would be appreciated.

 

The oil hole aligns with the oil hole in the block.

 

Great, thanks. That solves the clock orientation. Now which side of the bearing goes to the front of the engine block?

 

Towards the front of the engine, puts a little more oil on the timing chain and thrust surface.

 

Extinct, thanks for you help but I'm not sure I understand your answer. I don't think you can see it in the picture. I got the picture from atlanticbritish.com's long block listing. On one side there are the oil channels you can see in the picture. What may not be clear is next to them on the opposite side of the bearing are dimples at the edge. Both of them could send oil out of the side of the bearing. The oil would be going in opposite directions.

 

Sorry for less than detailed answer.


Looking at the block from the front, the oil feed hole is at 8 oclock, this photo shows the bearings in the their installed positions looking at it from the front. Positioning the large grooves at the top where the oil is needed least bleeds the oil to the front cam chain and thrust bearing surface.

This design is less than optimal. On high performance engines the bearing or block is grooved to put the oil feed hole at the 4 o'clock position, with the oil wedge buildng up at the 6 o'clock position where the load is concentrated. I can find no documentation on this design and why AB thinks it is better. I have pulled apart a dozen LR engines and have not found one yet with a bad timing chain, worn out cam bearings, or worn out cam. The factory oiling system and bearings are not optimal for an 8000 rpm race engine, but it is fine for 200-300k Rover usage.

 

Many thanks for the details. I am a little surprised the feed hole is at 8 o'clock for exactly the reasons you described. For the community's information I have attached a picture of both sides of the bearing.