top end rebuild mystery

[prosport]

what could this be? R400 race car raced Pembrey missed gear. head removed 4 inlet valves minuteley bent.engine otherwise perfect great oil pressure no leaks.Head rebuilt by specialist company,having previously done same with no problems.Head refitted. Car started instantly smooth tickover, within few secs oil leak at rear cam cover,switched off. topped up dry sump resevoir,restarted.fine for few secs then oil press dropping more leaks. Resevoir low again, top up, restart, huge amount of oil from every orrifice. Evidently dry sump and crankcase completly full of oil and pressurised. gold pump is turning, and oil is returning from pipe into top of resevoir although maybe not at fast enough rate.Seems much too coincidental that scavenge pump may have fault instantly cyl head replaced.Can anyone think of possible reason how rebuild and replacement of cyl head can in any way be linked to oil feed problem resulting in dry sump filling eg possible blocked oilway.

 

 

 

 

 

 

 

[CageyH]

Head gasket not sealing properly?

Try a compression test.

[Rob Walker]

Some debris may have got into the dry sump pan and blocked the wire gauze filter at the scavenge pick up. Remove the scavenge pickup and clean the filter. The drop in oil pressure could be either the level in the bulk tank dropped below the outlet as insufficient oil was being returned or the pressure build up within the engine due to flooding with oil worked against that being produced by the oil pump.