Lifter cup drilling location
05-09-2013, 06:11 PM
#1
Safety Car
Thread Starter
Lifter cup drilling location
How high does one drill the holes in the cups for oil drainback? I have a picture of where from geerookie, is the location critical?
And what size holes?
TIA
And what size holes?
TIA
05-09-2013, 06:39 PM
#2
Drifting
Member Since: Dec 2005
Location: Dayton, OH
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05-09-2013, 07:02 PM
#3
Safety Car
Thread Starter
Sweet...thanks. My searches only turned up some C5tech posts asking if it should be done and people saying they wouldn't risk it...
05-09-2013, 08:08 PM
#4
Drifting
Lifter trays
I have been doing it (drilling lifter trays) for 6 years on LS engines.
No lifter or engine failures with either Accusump or Dry Sump engines.
In reviewing location with engine builder we drilled in lower corners of lifter tray where the oil pools and
we based the size of the hole on viscosity of oil.
I actually heated oil to operating temperature and poured into lifter tray with lifters to observe how much
drainback took place. Note: This is obviously not scientific but the method I used to try to replicate, as
much as possible engine conditions. I used a hole size of approx. .180 in this location.
Also this is done in conjunction with restricted pushrods, so that will effect how much oil pools in the heads.
geerookie"s location and size may work just as well.
Whether the above is the best or only method to minimize the amount of oil that stays in the upper portion of
the engine is debateable. It has worked for me so far and does not appear to have created any issues with LS3 engines.
If you use a 4 gallon dry sump with a 2 stage pump the above may be irrelevant.
No lifter or engine failures with either Accusump or Dry Sump engines.
In reviewing location with engine builder we drilled in lower corners of lifter tray where the oil pools and
we based the size of the hole on viscosity of oil.
I actually heated oil to operating temperature and poured into lifter tray with lifters to observe how much
drainback took place. Note: This is obviously not scientific but the method I used to try to replicate, as
much as possible engine conditions. I used a hole size of approx. .180 in this location.
Also this is done in conjunction with restricted pushrods, so that will effect how much oil pools in the heads.
geerookie"s location and size may work just as well.
Whether the above is the best or only method to minimize the amount of oil that stays in the upper portion of
the engine is debateable. It has worked for me so far and does not appear to have created any issues with LS3 engines.
If you use a 4 gallon dry sump with a 2 stage pump the above may be irrelevant.
Last edited by J.R.; 05-10-2013 at 09:54 AM. Reason: added info
