This section exists
to help give back to the community by explaining some of the technical
challenges we've faced along with their solutions.
Oil Pumps
Oil pump failure is a common 4g63 ailment when combining high
rpm, stock oil systems, and high acceleration.
Oil Pickup and Starvation at Launch - the
normal root of the oil pump problems are oil starvation to the
pump because the oil pickup tube gets uncovered during launch.
This can start happening even in the 1.6-1.7 second 60' time
range. Covering the leading edge of the oil pickup by tig welding
on a simple piece of thin sheet metal like shown below can fix
the oil starvation problem down into the mid-1.3's. Beyond this,
a higher capacity pan is the next step. The best way to go is
a deeper pan with the sump and pickup both extended down, put
the pickup about 5mm from the bottom of the pan.
Oil Starvation at Extended High RPM Use -
the 4g63 does a poor job of returning oil to the pan where it
needs to be. The oil gets both stacked up in the head and suspended
in a slurry in the crankcase. The longer the engine lives at
high rpm, the worse the problem becomes. If you see pressure
drop down off more than 20-30psi during any event (end of a
1/4mi pass for me), it is a time bomb toward destroying rod
bearings and oil pumps. The more blowby an engine has, the worse
this situation becomes. The HLA
regulator was developed to help with the cylinder head oil
stackup situation. The wider bearing clearances that need to
be run to keep bearings alive at high power levels (0.0035")
also exaggerate this problem. Again, a deeper sump can help
with this scenario as well as a windage tray (custom) or just
simply decreasing blowby. If your oil pressure datalog looks
like the worse of these below, you will eventually start having
pump or bearing problems.
Oil Type - running a high zinc content oil
is necessary to protect the oil pump during high performance
usage. SAE specifications for SN and modern oils limit the street-legal
zinc content to 1200ppm, which isn't optimum for protecting
engine components. A specific racing oil will have higher zinc
content plus potentially also add other protective oil additives
like moly. I've had the best results with Pennzoil GT Racing
25w50. I've also run Royal Purple in a similar weight with good
results. I did not have good oil pump life with Mobil 1 and
even Brad Penn 20w50 didn't work well in my application. I know
others have had great results with Brad Penn, but it didn't
work well for me. In general, it is probably best to reference
the oil type guide Forced
Performance has on their website for turbocharger bearing
durability. Everything applies the same for oil pumps. I have
not run lighter weight oils in my setup due to the large bearing
clearances I run, but they may be appropriate in other applications.
©2011 Kiggly Racing, LLC
