Is excessive windage the root cause to LSX oiling issues? What makes the LS6 work?
08-10-2012, 03:55 PM
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Is excessive windage the root cause to LSX oiling issues? What makes the LS6 work?
Been doing some homework of late on LSX oiling. I'm one of those who've had great success with my 2001 LS6 with nothing more than a high flow oil pump and an oil cooler. Car has 123k on it now, last 3k all track use.
I'm putting together a 2004 LS1 crate motor to go in my father's Panoz and want to ensure I do everything properly to make it live (2 blown up SBFs prompting the LS1 swap).
I've always heard the batwing pan is part of the "secret sauce" that makes the LS6 work better than the later LS2/LS3/LS7s. The Panoz will have a Kevko baffled pan as shown here.
Everything I've read says the root cause of oil starvation is poor oil return from the top of the motor to the sump during high-G high-rpm cornering. But what is the root cause of this?
1. The LSX oiling circuit - Does our non-priority main oiling push too much oil up in the heads?
Possible fix - restricted pushrods
2. Oil drainback passages/path - Do the cylinder heads just not let enough oil flow down quickly enough?
Possible fixes - Drill lifter cups or install linkbar lifters
3. Insufficient PCV air flow - On LS6s the driver's side valve cover is sealed. On older LS1s the PCV is pulling vacuum from each valve cover. Both would inhibit oil return i.e. "Glub, Glub, Glub" as Geerookie puts it.
Possible fixes - Properly vent each valve cover, remove vacuum sources
4. Excess windage - Does the windage in the sump build up such that the oil has a hard time migrating back into the sump?
Possible fixes - Crank scraper and revised windage tray
The fact that it's sustained left hand turns that hurt these motors (and not right handers) seems to say that the crank flinging oil plays a part in all of it. The g-forces are pushing the oil to the right side of the motor coupled with the crank flinging oil to the right side would really make it hard for oil to drain down to the sump in a sustained turn.
If that's the root cause then wouldn't a crank scraper designed to reduce windage and force that oil into the sump be the fix? Less oil getting flung on the right side of the block would allow that oil in the head to drain back down more rapidly.
I read on the forums over and over that the LS6s are "bullet proof" and the LS6s just work with no explanation as to why. It has to be something about the pan.. is it just the extra capacity?
The LS2 "should" work better:
1. The lifter galleys and valley are much improved over the LS1/LS6 for oil return.
2. The "unwinged" pan should be able to keep oil around the pick-up better on turns; less area for the oil to move away.
So what's the problem?
On the LS3 you've got the re-designed square-port head that changes the shape of the oil returns, but even GM's tech articles said they made a point to keep the passages the same volume.
What's inhibiting oil return there?
I know this is a bunch, but it's been bugging me for a couple of days and most all I can find is thread that just say, "The LS6 is rock solid"... I get that... mine has been too, but why? What makes it work a bit better and how can one implement those aspects on another LS motor?
I'm putting together a 2004 LS1 crate motor to go in my father's Panoz and want to ensure I do everything properly to make it live (2 blown up SBFs prompting the LS1 swap).
I've always heard the batwing pan is part of the "secret sauce" that makes the LS6 work better than the later LS2/LS3/LS7s. The Panoz will have a Kevko baffled pan as shown here.
Everything I've read says the root cause of oil starvation is poor oil return from the top of the motor to the sump during high-G high-rpm cornering. But what is the root cause of this?
1. The LSX oiling circuit - Does our non-priority main oiling push too much oil up in the heads?
Possible fix - restricted pushrods
2. Oil drainback passages/path - Do the cylinder heads just not let enough oil flow down quickly enough?
Possible fixes - Drill lifter cups or install linkbar lifters
3. Insufficient PCV air flow - On LS6s the driver's side valve cover is sealed. On older LS1s the PCV is pulling vacuum from each valve cover. Both would inhibit oil return i.e. "Glub, Glub, Glub" as Geerookie puts it.
Possible fixes - Properly vent each valve cover, remove vacuum sources
4. Excess windage - Does the windage in the sump build up such that the oil has a hard time migrating back into the sump?
Possible fixes - Crank scraper and revised windage tray
The fact that it's sustained left hand turns that hurt these motors (and not right handers) seems to say that the crank flinging oil plays a part in all of it. The g-forces are pushing the oil to the right side of the motor coupled with the crank flinging oil to the right side would really make it hard for oil to drain down to the sump in a sustained turn.
If that's the root cause then wouldn't a crank scraper designed to reduce windage and force that oil into the sump be the fix? Less oil getting flung on the right side of the block would allow that oil in the head to drain back down more rapidly.
I read on the forums over and over that the LS6s are "bullet proof" and the LS6s just work with no explanation as to why. It has to be something about the pan.. is it just the extra capacity?
The LS2 "should" work better:
1. The lifter galleys and valley are much improved over the LS1/LS6 for oil return.
2. The "unwinged" pan should be able to keep oil around the pick-up better on turns; less area for the oil to move away.
So what's the problem?
On the LS3 you've got the re-designed square-port head that changes the shape of the oil returns, but even GM's tech articles said they made a point to keep the passages the same volume.
What's inhibiting oil return there?
I know this is a bunch, but it's been bugging me for a couple of days and most all I can find is thread that just say, "The LS6 is rock solid"... I get that... mine has been too, but why? What makes it work a bit better and how can one implement those aspects on another LS motor?
08-10-2012, 04:39 PM
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Melting Slicks
08-10-2012, 05:43 PM
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Safety Car
I have a #4 if you want. Seems like a great idea. I haven't had the change to put it on and not sure when I will.
I read, when looking up aftermarket blocks recently, the windage was the problem, but not from the crank but from oil getting "pissed away" up top. Apparently windage means whenever the oil gets shot into the air, and it happens a lot on LSx blocks that are not priority main oiling (eg all OEM blocks, even the C5R). There is an article on-line somewhere about the Warhawk or RHS block that describes this in more detail.
I have also heard that the head design on the LS2 and 3 causes problems with oil pooling.
I read, when looking up aftermarket blocks recently, the windage was the problem, but not from the crank but from oil getting "pissed away" up top. Apparently windage means whenever the oil gets shot into the air, and it happens a lot on LSx blocks that are not priority main oiling (eg all OEM blocks, even the C5R). There is an article on-line somewhere about the Warhawk or RHS block that describes this in more detail.
I have also heard that the head design on the LS2 and 3 causes problems with oil pooling.
08-10-2012, 06:33 PM
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The problem is the LS engines are essentially SBFs
Chevy guys hate when I make this statement, but the LS engines are GM taking the SBF 302/351W and copying the bottom end and finally bolting really good heads onto that design. They are nothing like an old school SBC. You mention you are switching from SBFs to the LS due to blow ups; the LS engines may have the same problem.
SBFs with Hi Vol oil pumps will fill the valve covers up with oil because the drainbacks in those heads are so small. When GM did the LS3s for instance with the large ports spaced out like a SBF, the drainbacks essentailly were copied as well, so they pump oil to the top and in a long sweeper turn the oil just keeps filling up in the valve covers.
So switching from an SBF to an LSx won't necessarily solve the problem, they both have the exact same problem! If you know Fords, then look at the head bolt pattern and overall design v. an LS and you might be blown away - they are nearly identical right down to them accidentally copying the bad things like oil drain back sizing. The pattern is off by about .020" at the bolt holes or you could essentially bolt a ford head to an LS block. Indeed, there are head mfrs out there that are making one head that bolts onto either a SBF or an LS
On road race SBFs we run external drainbacks from the valley area down to the oil pan along the outside valve cover rail. then in a sweeper you are essentially forcing the oil into the drainbacks. that is the same thing to do on an LS engine.
Oh, and the drain backs on an early LS like the LS6 aren't as bad as the LS3s, that is why they work better and don't exhibit the same issues as the LS3s for example.
SBFs with Hi Vol oil pumps will fill the valve covers up with oil because the drainbacks in those heads are so small. When GM did the LS3s for instance with the large ports spaced out like a SBF, the drainbacks essentailly were copied as well, so they pump oil to the top and in a long sweeper turn the oil just keeps filling up in the valve covers.
So switching from an SBF to an LSx won't necessarily solve the problem, they both have the exact same problem! If you know Fords, then look at the head bolt pattern and overall design v. an LS and you might be blown away - they are nearly identical right down to them accidentally copying the bad things like oil drain back sizing. The pattern is off by about .020" at the bolt holes or you could essentially bolt a ford head to an LS block. Indeed, there are head mfrs out there that are making one head that bolts onto either a SBF or an LS
On road race SBFs we run external drainbacks from the valley area down to the oil pan along the outside valve cover rail. then in a sweeper you are essentially forcing the oil into the drainbacks. that is the same thing to do on an LS engine.
Oh, and the drain backs on an early LS like the LS6 aren't as bad as the LS3s, that is why they work better and don't exhibit the same issues as the LS3s for example.
08-10-2012, 07:01 PM
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sorry, don't have any exact pics, but I can describe what you do. You go into the valve cover rail and drill and tap an 1/8" NPT hole at the front and rear corners of the head, outside edge (exhaust side) on both heads. They don't have to be big, they just have to be there. Then you weld a return bung into the oil pan on each side. You run -6 line in between them and T into the pan bung.
Attached is an image of the Arias heads that can go on either an LS or SBF, he has oil returns cast in down low. Think of moving this up to the valve cover rail (the lip that the valve cover sits on) and that is what I mean. It is hard to see in the image but there are rear drainbacks and they T into the pan return
then when you are rolling thru a long turn, the oil has somewhere to go. the LSs IMO get by heavily on drainback through the pushrod holes which are exactly opposite in location they need to be in a long, sweeping turn. Good enough for the street and drag racing...
Attached is an image of the Arias heads that can go on either an LS or SBF, he has oil returns cast in down low. Think of moving this up to the valve cover rail (the lip that the valve cover sits on) and that is what I mean. It is hard to see in the image but there are rear drainbacks and they T into the pan return
then when you are rolling thru a long turn, the oil has somewhere to go. the LSs IMO get by heavily on drainback through the pushrod holes which are exactly opposite in location they need to be in a long, sweeping turn. Good enough for the street and drag racing...
08-10-2012, 07:10 PM
#9
Le Mans Master
Cobra,
Check out this thread on my LS1 adventures in my Miata with a custom pan similar to what you're thinking:
http://forum.miata.net/vb/showthread.php?t=443723
I'm using an essentially stock LS1 windage tray, but did, on recommendation (actually insistance) from my machinist, drill 1/2" holes in each of the lifter trays to assist in drainback.
HTH, and have a good one,
Mike
Check out this thread on my LS1 adventures in my Miata with a custom pan similar to what you're thinking:
http://forum.miata.net/vb/showthread.php?t=443723
I'm using an essentially stock LS1 windage tray, but did, on recommendation (actually insistance) from my machinist, drill 1/2" holes in each of the lifter trays to assist in drainback.
HTH, and have a good one,
Mike
08-10-2012, 07:28 PM
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08-10-2012, 07:56 PM
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Snapped 2 cranks in two SBFs in this Panoz. For $3000 a LS1 gets you way more motor than any Ford. You have to spend $7500 to get something comparable and then it's still an iron block, 4-bolt main vs. 6, and the heads just don't have the same ultimate power potential.
Plus, I know LSXs far better and have all the right tools and spare bits around the garage to make things easier. It's easier to maintain two cars when they share the same power plant.
SBFs with Hi Vol oil pumps will fill the valve covers up with oil because the drainbacks in those heads are so small. When GM did the LS3s for instance with the large ports spaced out like a SBF, the drainbacks essentailly were copied as well, so they pump oil to the top and in a long sweeper turn the oil just keeps filling up in the valve covers.
LS1/2/3/7 heads have the oil drains over each bolt head under the valve cover. Each drains back to the lifter galley and down into the crankcase. They are very different... there are 5 in all.
Originally Posted by CyberGS
On road race SBFs we run external drainbacks from the valley area down to the oil pan along the outside valve cover rail. then in a sweeper you are essentially forcing the oil into the drainbacks. that is the same thing to do on an LS engine.
Oh, and the drain backs on an early LS like the LS6 aren't as bad as the LS3s, that is why they work better and don't exhibit the same issues as the LS3s for example.
Oh, and the drain backs on an early LS like the LS6 aren't as bad as the LS3s, that is why they work better and don't exhibit the same issues as the LS3s for example.
Last edited by Cobra4B; 08-10-2012 at 08:00 PM.
08-10-2012, 08:58 PM
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sorry, I see how I said the drainbacks were essentially copied being misunderstood - I didn't mean exactly, I meant they have poor drainage like the SBFs so they essentially copied a bad idea. No biggie. Looking at how I said it I can see where you thought I meant the same. The Fords are really bad with only the two holes at each end.
Interesting that you were snapping cranks - unless were they late model 5.0L cranks from the 80s/90s - those are weak. Blocks sucked too. Early 302 stuff is pretty stout. Nonetheless, I agree, the LS stuff is awesome bang for the buck, especially in the cylinder head dept as I mentioned in my first post.
good luck!
Interesting that you were snapping cranks - unless were they late model 5.0L cranks from the 80s/90s - those are weak. Blocks sucked too. Early 302 stuff is pretty stout. Nonetheless, I agree, the LS stuff is awesome bang for the buck, especially in the cylinder head dept as I mentioned in my first post.
good luck!
08-10-2012, 10:20 PM
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Blocks suck apparently... here's the latest 347 filled with all high end guts. Scat 4340 forged crank, fancy rods, $800 pistons. Unfortunately it was all put in a 2-bolt main block vs. a Boss 4-bolt main one due to ignorance and following poor guidance from the shop that built it.
Snap goes the crankshaft. The mains are all intact, rods banged up but all intact as well.
The first 302 was the original one that came in the car. It was an ex driving school car from the Panoz Driving School @ Sebring. We took off the fuel injection and did heads/cam/carb and knew it'd eventually fail. I was spinning it to 6800 rpms coming out of Hog's Pen to make the 3.89 gear we put in it work... it actually failed at the GRM UTCC at VIR in summer 2010.
Because of that experience the 347 was built to turn 6000 rpms max and we went back to a 3.50 rear end. But I digress... trying to figure out what tricks to do to this LS1 crate motor I'm prepping for the car.
Current plan is:
*LS4 high volume oil pump with 42psi relief (same as I have in my current Z06 racecar and my old Z06 street/trackday car)
*Kevko road race pan with 4-way trap door setup
*Restricted pushrods
Since I have to swap the pan I'm considering the crank scraper and modified windage tray I've seen from I-J. But all of this stuff ads up quickly and I'm trying to stay to a budget.
LS1 I'm setting up
Snap goes the crankshaft. The mains are all intact, rods banged up but all intact as well.
The first 302 was the original one that came in the car. It was an ex driving school car from the Panoz Driving School @ Sebring. We took off the fuel injection and did heads/cam/carb and knew it'd eventually fail. I was spinning it to 6800 rpms coming out of Hog's Pen to make the 3.89 gear we put in it work... it actually failed at the GRM UTCC at VIR in summer 2010.
Because of that experience the 347 was built to turn 6000 rpms max and we went back to a 3.50 rear end. But I digress... trying to figure out what tricks to do to this LS1 crate motor I'm prepping for the car.
Current plan is:
*LS4 high volume oil pump with 42psi relief (same as I have in my current Z06 racecar and my old Z06 street/trackday car)
*Kevko road race pan with 4-way trap door setup
*Restricted pushrods
Since I have to swap the pan I'm considering the crank scraper and modified windage tray I've seen from I-J. But all of this stuff ads up quickly and I'm trying to stay to a budget.
LS1 I'm setting up
08-11-2012, 11:13 AM
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I know... but lets not get distracted on the Ford carnage. I'd really like a discussion of why the LS6 oiling system seems to work better vs. the LS2/3/7 in a wet sump application and how those things can be applied to other LSXs.
I haven't seen a definitive answer on the subject. We've got a long thread on LS3s blowing up with the gist of it being "LS3s suck because they blow up LS6s are great, I know LS3s blow up a bunch because I blew a bunch up."
I want to know exactly what makes the LS6 > than the LS2/3. What is the root problem in the motors preventing oil migration, and what bit about the LS6 allows it to work that much better? They're all the same basic engine once you get past the earlier Pre-2000 LS1 blocks.
I haven't seen a definitive answer on the subject. We've got a long thread on LS3s blowing up with the gist of it being "LS3s suck because they blow up LS6s are great, I know LS3s blow up a bunch because I blew a bunch up."
I want to know exactly what makes the LS6 > than the LS2/3. What is the root problem in the motors preventing oil migration, and what bit about the LS6 allows it to work that much better? They're all the same basic engine once you get past the earlier Pre-2000 LS1 blocks.
08-11-2012, 11:41 AM
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Still, the external drains seem to make a lot of sense and could likely cure the problem. Not sure a 1/8" drain back is sufficient but I like the external suggestion.
08-11-2012, 11:44 AM
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True... they would be less susceptible to windage and crank case pressure. But I don't think I'm going to go tapping my heads just yet.