07-12-2020, 09:42 PM
The supercharged engine in our new build single seater is splash fed, there are 2 very good reasons for that, firstly the job lot of bits we bought included a new splash fed 1.5/16 crank & rods and secondly we chose to drive the MAG blower directly off the nose of the crank, so the drive screws in where the original starter dog screwed in.
We are running an over-bored oil pump with new vanes and springs, carefully fettled to be as smooth as possible, thus absorbing minimum power losses. The edges of all the entry & exit angles are all radiused & dressed smooth & the pressure relief valve was shimmed up. The pockets in the Phoenix were cleaned up and the holes opened up to be a bigger entry with a pronounced entry radius to facilitate oil flowing into the holes from the pockets. The crank, rods, flywheel & pressure plate were then balanced.
Lastly a Forrest double oil jet conversion was made & installed & by pumping paraffin through the oil pump via the pick-up we could adjust each of the 4 oil jets to spray the maximum amount for the maximum duration into the respective pockets. I simply capped 3 jets & focused on aiming one jet at a time. There's almost 80* of arc on each oil jet now, so top & bottom means the crank is getting a steady supply for 160*rotation per pair of crank pins. The original direct down single oil feed was an arc of about 15* and they seem to have lasted a goodly while.
I'm off the 10lbs gauge when cold and after several good runs it's holding 6lbs at 6000rpm at the top of the hill. 1 gallon pan sports pan so the oil probably hasn't got enough hot enough to get really thin, but even if it drops to 2 or 3lbs, that's plenty on 4 oil jets. The hill climbs here are 2kms each or 1.25 miles
The blower is on sealed bearings and I run a dollop of Castrol R in the gear case - so far so good.
Ciao
Greig
We are running an over-bored oil pump with new vanes and springs, carefully fettled to be as smooth as possible, thus absorbing minimum power losses. The edges of all the entry & exit angles are all radiused & dressed smooth & the pressure relief valve was shimmed up. The pockets in the Phoenix were cleaned up and the holes opened up to be a bigger entry with a pronounced entry radius to facilitate oil flowing into the holes from the pockets. The crank, rods, flywheel & pressure plate were then balanced.
Lastly a Forrest double oil jet conversion was made & installed & by pumping paraffin through the oil pump via the pick-up we could adjust each of the 4 oil jets to spray the maximum amount for the maximum duration into the respective pockets. I simply capped 3 jets & focused on aiming one jet at a time. There's almost 80* of arc on each oil jet now, so top & bottom means the crank is getting a steady supply for 160*rotation per pair of crank pins. The original direct down single oil feed was an arc of about 15* and they seem to have lasted a goodly while.
I'm off the 10lbs gauge when cold and after several good runs it's holding 6lbs at 6000rpm at the top of the hill. 1 gallon pan sports pan so the oil probably hasn't got enough hot enough to get really thin, but even if it drops to 2 or 3lbs, that's plenty on 4 oil jets. The hill climbs here are 2kms each or 1.25 miles
The blower is on sealed bearings and I run a dollop of Castrol R in the gear case - so far so good.
Ciao
Greig