Intermediate Timing cover inspection

[adamnreeves]

My EBAY purchased RV8 intermediate timing cover turned up today.

It is used and it needs a good clean. Started to take it apart for inspection and cleaning. I have takled the oil pump gears (I have a new set) I have not measured the tolerances but I am thinking I shall jsut replace anyway. However I noticed some fine scoring marks on the little cover plate, nothing to be concerned with maybe? But I am more concerned with the gear housing once I removed the gears. There appears to be a grove in the front of the gear housing it kind of looks machined, is this by design or should I be very concerned with my purchase!



High res one here



High res one here

[russell_ram]

That little V shape groove is designed in mate. It reduces oil pump whine.

Because it's a constant volume oil pump, as each volume of (low pressure) oil that has been transported round to the high pressure side opens to the bulk HP volume it induces a small sudden change in the bulk oil pressure (particualrly local to the pump). This becomes apparent as oil pump whine. This small V groove allows the pressure equalisation to occur over a much longer crank angle than otherwise, removing the sharp pressure spike - less whine.

As for the scoring on back of the plate, difficult to see quite how deep they are but personally I wouldn't worry about it - the concentric pump has plenty enough volume capacity to allow some leakage - it has some built in (fit tolerances) anyway otherwise it would seize!

Russ

[ihatesissycars]

Mine was exactly the same when i took my pump gears apart.

Just make sure that when you reassemble it that theres zero binding when you turn the pump gears by hand. They should turn freely but feel heavy and slick assuming you've oiled them during reassembly but nothing that feelds like grinding or metal on metal.

[adamnreeves]

Thanks guys you've put my mind at rest. Better to be careful than assume I guess.