well after getting to talk with Bob for a few minutes (while he was here picking up that oil cap finally 
) i realized that some of you may be interested in what i have uncovered in regards to the 3800 oiling system other than Deek (aka OZ38) in australia.
first lets start with this:
the 3800 oiling system is VERY similar to the GN 3.8's in many ways, the major difference being a crank driven gerotor pump instead of the 3.8 (and 4.1) cam driven spur gear pump.
the nut doesnt fall too far from the tree :lolsign:
also the SII has a lower volume pump (narrower scroll) than the SI (EV6) engines so the SII needs more attention paid to minimize passage restrictions (on both the suction and pressure sides) and to make sure that the bearing and rod side clearances are the only restrictions to oil flow (the way it should be).
and while Oil Restricting pushrods can help, they arent enough...
Issues:
oil pump passages NEED to be ported, there is factory casting flash that needs to be ground away from the inlets and outlets to the pump scroll section, as well as cleaning upp the oil filter passages
#2 and #3 main bearing oil passages, in the GN 3.8 the factory drilled these as 1/4 inch holes, the SII is a little better at ~7mm, while this should be adequate...there is a problem, the cam bearings intrude into these passages and end up with an area equivalent to a ~4.5mm hole...NOT good when this passage has to flow enough oil to feed the main bearing as well as the two connecting rod bearings on either side of the main.
Fortunatly there is sufficient meat in the main webbing to allow the passage to be drilled out to 3/8ths of an inch which aleviates the restriction at the cam bearing OD where it intrudes into the passage, and still leaves a bit over 2.5mm from the web surface facing the front of the engine.
main galley crossover passage, the early SII engines have a fairly small groove in the rear block cover to transfer oil from the main oil galley in the rear bank (cyl'rs 2,4,6) to the front lifter galley (1,3,5) the 98+ covers have a deeper groove, so if you have the early engines it would be a good idea to swap to the newer rear cover or mill the passage larger at the same time as the balance shaft delete is performed and the balance shaft oil hole is deleted.
bearing and rod side clearances, these engines are very sensitive to the bearing clearances... much more so than say a sbc, suffice it to say you should be on the tight side of spec, even so far as getting extra rods to tailor the rod side clearances as well, when i pulled the 98 L36 apart that will be going into the 442 i found as much as .004 variances from one rod/journal pairing to the next pair.
a side benifit from having tighter rod side clearances is that there is less oil windage and les oil thrown onto the cylinder walls which means that the already minimal oil scrapper ring doesnt get overloaded and let oil pass into the cylinder which can contribute to engine and bearing killing detonation.
these are the major issues that i have found and should greatly inprove the 3800's reliability at high power and rpm's, and should be sufficient for most engine buildups but it can be improved upon further...
by improving the oil supply to the pump, the pump draws the oil through the 5/8ths pickup to the block where it makes a 90* bend and heads for the block face where it makes another 90* bend to enter the pump by fabricating an external sump line into the pan with a larger ID you can make a gradual bend and go straight into the pump housing, removing two sharp 90* turns that at high rpm's would seem likely to cause cavitation and pressure loss especially in the case of improvements to flow on the pressure side.
I wont get into the cylinder 1 cooling issues just yet but improvements can be had in this area as well
anyways check my thread at 3800Pro.com if your interesting in reading more
http://www.3800pro.com/forum/showthread.php?t=9384
) i realized that some of you may be interested in what i have uncovered in regards to the 3800 oiling system other than Deek (aka OZ38) in australia.first lets start with this:
the 3800 oiling system is VERY similar to the GN 3.8's in many ways, the major difference being a crank driven gerotor pump instead of the 3.8 (and 4.1) cam driven spur gear pump.
the nut doesnt fall too far from the tree :lolsign:
also the SII has a lower volume pump (narrower scroll) than the SI (EV6) engines so the SII needs more attention paid to minimize passage restrictions (on both the suction and pressure sides) and to make sure that the bearing and rod side clearances are the only restrictions to oil flow (the way it should be).
and while Oil Restricting pushrods can help, they arent enough...
Issues:
oil pump passages NEED to be ported, there is factory casting flash that needs to be ground away from the inlets and outlets to the pump scroll section, as well as cleaning upp the oil filter passages
#2 and #3 main bearing oil passages, in the GN 3.8 the factory drilled these as 1/4 inch holes, the SII is a little better at ~7mm, while this should be adequate...there is a problem, the cam bearings intrude into these passages and end up with an area equivalent to a ~4.5mm hole...NOT good when this passage has to flow enough oil to feed the main bearing as well as the two connecting rod bearings on either side of the main.
Fortunatly there is sufficient meat in the main webbing to allow the passage to be drilled out to 3/8ths of an inch which aleviates the restriction at the cam bearing OD where it intrudes into the passage, and still leaves a bit over 2.5mm from the web surface facing the front of the engine.
main galley crossover passage, the early SII engines have a fairly small groove in the rear block cover to transfer oil from the main oil galley in the rear bank (cyl'rs 2,4,6) to the front lifter galley (1,3,5) the 98+ covers have a deeper groove, so if you have the early engines it would be a good idea to swap to the newer rear cover or mill the passage larger at the same time as the balance shaft delete is performed and the balance shaft oil hole is deleted.
bearing and rod side clearances, these engines are very sensitive to the bearing clearances... much more so than say a sbc, suffice it to say you should be on the tight side of spec, even so far as getting extra rods to tailor the rod side clearances as well, when i pulled the 98 L36 apart that will be going into the 442 i found as much as .004 variances from one rod/journal pairing to the next pair.
a side benifit from having tighter rod side clearances is that there is less oil windage and les oil thrown onto the cylinder walls which means that the already minimal oil scrapper ring doesnt get overloaded and let oil pass into the cylinder which can contribute to engine and bearing killing detonation.
these are the major issues that i have found and should greatly inprove the 3800's reliability at high power and rpm's, and should be sufficient for most engine buildups but it can be improved upon further...
by improving the oil supply to the pump, the pump draws the oil through the 5/8ths pickup to the block where it makes a 90* bend and heads for the block face where it makes another 90* bend to enter the pump by fabricating an external sump line into the pan with a larger ID you can make a gradual bend and go straight into the pump housing, removing two sharp 90* turns that at high rpm's would seem likely to cause cavitation and pressure loss especially in the case of improvements to flow on the pressure side.
I wont get into the cylinder 1 cooling issues just yet but improvements can be had in this area as well
anyways check my thread at 3800Pro.com if your interesting in reading more
http://www.3800pro.com/forum/showthread.php?t=9384
