I got a new yb 0852 pump, from Cosworth, and a new original driveshaft from Ford, but when i test it in the oilpump, it`s more clearance on the new pump, than on the original pump, what do people do in case like this ?

 

Anyone ?

 

do you mean the oil pump drive (that fits in the bottom of the dizzy) is loose?

 

This is on not monted on an engine, it`s fore my rebuild. When i turn driveshaft in rotor of oilpump, it`s more clearance in the new pump and shaft, then on the original pump. Jeremy Scott at Cosworth told me that it is the same rotors in bougth, but it dosen`t look like it. Bit worry to use this

 

have you got any pictures i am a bit confused as to what parts you are describing

 

This is the new pump, and when i turn the driveshaft in the rotor, it seems like the hole in the rotor is to big


This is the original pump, and the driveshaft fits better in this one

 

it appears in the pictures that the shaft diameter is better in the old pump, but the most important thing is how it fits in the hexogon drive of the new oil pump and not the diameter,
check that the hexogon drive is the same in each pump. and measure the old and new shafts.
if the shaft fits good in the new pump hex part then it is ok to use.
be sure that you transfer the washer on the old shaft and make sure the washer is in the same place. and fit the shorter side to the oil pump

 

On the pictures, it is the new shaft on both pumps, the clearance is bigger on the hexagon on the new pump, then the old one. You don`t have to use the washer, it`s never been a problem.