G2 CSR Big end bearing

[ballard berkley]

Can anyone help me with identify the correct big end / crank pin for my G2 CSR ?

I have stripped the engine and the crank pin has sheared, the big end on the con rod is fitted with a sleeve and has sixteen rollers.
During the stripping down of the engine I found that the drive side crank casing had been welded around the bearing housing, the main bearings had also been fitted incorrectly, the roller bearing fitted where the ball bearing should be and vice versa, and a host of other things.

I have purchased a second hand CSR engine and stripped down, this seems to have been a good buy, the crank is complete,however it has lift in the big end and the oil pump side axle is worn.

The casting number on the con rod is 042225, it also has "alpha" cast on the opposite side to the number.

I purchased a con rod with crank pin with the same casting numbers from the states, this has a cage roller with twelve rollers.
Is this the later/modifided version big end bearing ?

Both crank pins are the same diameter

Any help and information would be greatly appreciated

[cbranni]

Hi there, the conrod with 12 rollers is an Alpha after market replacement unit, AMC 250 engines have 20 rollers while the 250csr and 350 have 28 rollers. Thats only my interpretation of it, I could be talking a load of bollox, but at least it will make someone who knows reply to you.

The welding on the drive side bearing case is quite common, I have welded two crankcases like that, its where the bearings have been pressed in without warming the casing, you can't tell when the bearing is home and you reach the bottom and hammer off the alloy casing.

The ball bearing goes in first then the stator and rotor and finally the roller bearing, club spares have replacement big end assemblies, but it depends how good your con rod is....................all good fun.

Colin

[ballard berkley]

Hello Colin

Thank you for the information,
I will recon the flywheel from the second engine with the new con rod and oil pump side crank axle, I am going to use the crancases from the second engine (doesn't look like this had ever been split before) and rebuild the original later.

The con rod I purchased is complete with the pin, all the other parts purchased through the excellent club spares scheme.

Onwards and upwards now

Paul