Bearing Notch Orientation

[99hjhm]

Two questions for Dave, Peter etc...

I'm getting confused with leading and trailing so will describe it like this... When looking at the front of an normal type inline 4 cylinder engine the correct way up, should the big end bearing tags be on the left of the engine or the right.

Question two... Does it matter?

[99hjhm]

I did say normal type four cylinder trying to be generic as possible but I guess this is PistonHeads. lol

Aware of how the notches work and lack of them in recent engine design.

Reason I ask is I have a engine spec sheet from a Hyundai WRC engine and it states bearing notches leading. Yet A former engine designer at Judd says trailing yet couldn’t provide an answer. I have always fitted them on the right side of the engine which i guess is the leading side.

Edited by 99hjhm on Tuesday 18th September 22:55

[99hjhm]

Yes had the same with an engine last year, lack of main bearing clearance (Which was known about on the build, another story) and very high oil temperatures, slight drop in oil pressure, split the filter and FULL of bearing material!

Stripped engine, crank was perfectly reusable, infact, after the extra .001" was ground from it to correct the bearing clearance there were no signs of any damage, even the big ends had not suffered, but were changed, oil pump also fine. Many of the main shells were down to the steel backings. This was with King race bearings. Done a fair few hours and the customer didn't want to stop using it.

Also stripped an MGB race engine last year, one of the intermediate mains that don't feed a rod bering had spun a shell, shell had blanked off the oil hole and survived for god knows how long like it. Again, crank wasn't too bad.