Indiana Jones wrote:Interestinger and more interestinger.
The big end bearings all have 2 extra oil holes in them,so each bearing has 4 oil holes.
I wonder are these modified or are they bearings from another compatible model.
Edit: Single hole bearings are OE, all new bearings have two holes.
I love learning new stuff.

The earlier models all had single oil holes in the big end shells and part numbers to reflect this for front and rear fitments in order to make sure the oil holes lined up on instalation. Later they started putting 2 holes in them so that the same coloured shell could then be used front or rear which stopped a lot of miss fits on engine rebuilds and less part numbers to control. Instead of 2 lots of green (one for front and one for rear) 1 set would do the job on either journal. Makes my job a lot easier mind too

rvfhonda wrote:Hi,
The rear conrods are 2g's heavier than the front. So at speed the gyroscopic or rotating mass will be magnified. Without seeing the engine myself couldn't say that caused the failure but just wanted to say that there is a difference between the front and rear rods but only by weight.
Mike @ BMC Racing.

Thing is that both rods on that crank pin had been swapped,so I'd imagine there shouldn't be any more of an imbalance than if they were used in their correct positions.
The replacement conrod I was going to use has a slightly scored small end and corresponding scoring on the gudgeon pin.
I'm considering using the original conrod and pin as the piston did take a hammering but not for long.
I know it's a gamble.
Unless someone has a good B2 front and B1 rear conrod they are willing to part with.
Might post in the wanted section.

I'll have a look to see what rods I have. And I'm only up the road from you too.

I've B1 rods front and back and rods with no marks from and back.