My 93 GTS uses more oil than yours!
03-19-2014, 02:04 PM
#16
I just read the post about the SWEPCO 502... interesting. I go along with the leakdown test. Harbor freight sells a tester. The oil control ring could be stuck. I would consider squirting in a goodly amount of PB Blaster and hand cranking it a few times then letting it soak for a few hours. I would change the oil afterward as I don't think PBB is much of a lubricant.
03-19-2014, 02:24 PM
#17
Rennlist Member
Phil,
I am intrigued by your compression reading- I typically get 185 psig even across all cylinders but I am not too concerned about that unless and until I can verify calibration.
Also interesting that you are predominently see pinging on 7 & 8, most folks tend to report this happens on 2/6 as on my S4 motor.
Like yourself I collect very little oil in the Pro vent but then I suspect my baffle may be catching too much. I assume my oil consumption is going up through the rings but that is supposition. for sure it is not going through the inlet manifold as I am currently venting to atmosphere. So either my separator is very efficent or it is preventing venting.
I am not aware of any test that can verify the integrity of the oil control rings absolutely. Try a leak down test. I am going to do one on mine shortly when everything is back together again-hopefully this weekend.
Fred
I am intrigued by your compression reading- I typically get 185 psig even across all cylinders but I am not too concerned about that unless and until I can verify calibration.
Also interesting that you are predominently see pinging on 7 & 8, most folks tend to report this happens on 2/6 as on my S4 motor.
Like yourself I collect very little oil in the Pro vent but then I suspect my baffle may be catching too much. I assume my oil consumption is going up through the rings but that is supposition. for sure it is not going through the inlet manifold as I am currently venting to atmosphere. So either my separator is very efficent or it is preventing venting.
I am not aware of any test that can verify the integrity of the oil control rings absolutely. Try a leak down test. I am going to do one on mine shortly when everything is back together again-hopefully this weekend.
Fred
03-19-2014, 03:22 PM
#18
Nordschleife Master
Fred,
Don't worry about his seeing 210 while yours sees 185 in a compression test.
Compression testers (especially the cheaper ones) vary wildly.
Additionally there is cam timing will affect the results as will carbon build up.
So long as the figures are even across the board you're fine. The leakdown shows much more real world data for condition of engine health.
Don't worry about his seeing 210 while yours sees 185 in a compression test.
Compression testers (especially the cheaper ones) vary wildly.
Additionally there is cam timing will affect the results as will carbon build up.
So long as the figures are even across the board you're fine. The leakdown shows much more real world data for condition of engine health.
03-19-2014, 03:34 PM
#19
Former Vendor
Both on this thread and the other thread there has been some discussion about compression and leakdown testing to determine where the oil is coming from.
One of the things that mechanics are taught is to put oil into a cylinder and then recheck compression/leakdown to help determine if the problem is rings.
If there is oil already present, neither of these checks are going to tell anyone much....
One of the things that mechanics are taught is to put oil into a cylinder and then recheck compression/leakdown to help determine if the problem is rings.
If there is oil already present, neither of these checks are going to tell anyone much....
03-19-2014, 04:11 PM
#20
Nordschleife Master
Both on this thread and the other thread there has been some discussion about compression and leakdown testing to determine where the oil is coming from.
One of the things that mechanics are taught is to put oil into a cylinder and then recheck compression/leakdown to help determine if the problem is rings.
If there is oil already present, neither of these checks are going to tell anyone much....
One of the things that mechanics are taught is to put oil into a cylinder and then recheck compression/leakdown to help determine if the problem is rings.
If there is oil already present, neither of these checks are going to tell anyone much....
It was my impression, possibly incorrect, that the most of the leakdown test air flow will go thru the ring end gap. In a fresh engine that seals well when running, if the ring end gap is set to be large, the leakdown number is high. If it is set to be small then the leakdown number is low. There are many good reasons to set the ring end gap to be pretty large, yet that doesn't mean that the engine isn't working as the builder intended. My understanding was that the leakdown is ideally used as a relative measure. The leakdown numbers are recorded for a new engine, and then as the bore and rings wear the ring end gap increases. The ring end gap increase leads to worse leakdown numbers, and the engine builder can infer the ring and bore wear from the leakdown number. Is this correct?
The ring end gap is so large that it's not likely that slight amounts of oil in the cylinder can permanently block the ring end gap. Pressurized air running thru the gap should blow it our. (Oil in the cylinder should improve the seal if the rings have not bedded to the cylinder wall well, but I don't know how relevant this is for our alusil bores.) In the end, I wouldn't guess that the leakdown number is very sensitive to some oil in the cylinder, but that's nothing but a guess.
If I am thinking about this correctly, in the compression test where engine is cranked and peak pressure is measured, the oil impact can be much larger because the oil is not blown away by continuous air flow in one direction. So I wouldn't be shocked if in the compression test oil in the cylinder would change the results quite meaningfully.
This with the caveat that I've never done a compression test and even the leakdown test just a couple of times. I am planning to do the leakdown regularly when the new engine goes into my car. This post is a verbose question, I am asking and not telling what's going on.
03-19-2014, 04:29 PM
#21
Former Vendor
Greg,
Give it a damn rest.
That's priceless. You come here, attack my product and my research, promote your own engine killing product, Want me to do all your research for you, threaten to release some of my proprietary information, proceed to release that information.....and you want me to "give it a damn rest?" That is really priceless!
Phil,
I would firstly be ensuring that there is no cylinder bore scoring. As well, do a leakdown and compression test to ensure that there are not larger problems!
I also couldn't see the stem seals allowing that much oil to get past them.
(Even though Colin "sold" this job to another GTS owner.) The pooled oil is getting past the rings. You can remove the fuel injectors and be able to see all the intake stems which will show if any are leaking. The stem seal material does wear, and does harden over time/miles which does reduce their effectiveness.
Don't use the ProVent, it is a crap separator which is easily overwhelmed.
As I've said, I've got literally a hundred of these things out there running. ONE of which was apparently "overwhelmed" (or sabotaged!)
Colin: I'll pass your quote on to the MANN people and see what they think of your comment....you might find that you want to preface things like this with "In my opinion."
Run a good oil which has good detergents in it to help free any crud from the ring lands. Swepco 502 is a good product for this.
Give it a damn rest.
That's priceless. You come here, attack my product and my research, promote your own engine killing product, Want me to do all your research for you, threaten to release some of my proprietary information, proceed to release that information.....and you want me to "give it a damn rest?" That is really priceless!
Phil,
I would firstly be ensuring that there is no cylinder bore scoring. As well, do a leakdown and compression test to ensure that there are not larger problems!
I also couldn't see the stem seals allowing that much oil to get past them.
(Even though Colin "sold" this job to another GTS owner.) The pooled oil is getting past the rings. You can remove the fuel injectors and be able to see all the intake stems which will show if any are leaking. The stem seal material does wear, and does harden over time/miles which does reduce their effectiveness.
Don't use the ProVent, it is a crap separator which is easily overwhelmed.
As I've said, I've got literally a hundred of these things out there running. ONE of which was apparently "overwhelmed" (or sabotaged!)
Colin: I'll pass your quote on to the MANN people and see what they think of your comment....you might find that you want to preface things like this with "In my opinion."
Run a good oil which has good detergents in it to help free any crud from the ring lands. Swepco 502 is a good product for this.
03-19-2014, 07:20 PM
#22
Pro
Thread Starter
Fred,
The GTS engine has a slightly higher compression ratio compared to the S4 engines. So I would think that 185 is about right for an S4.
I will report back on the swepco once I've run it for a while!
The GTS engine has a slightly higher compression ratio compared to the S4 engines. So I would think that 185 is about right for an S4.
I will report back on the swepco once I've run it for a while!
03-19-2014, 07:21 PM
#23
Nordschleife Master
Why is that? An honest question, I'd love to know.
It was my impression, possibly incorrect, that the most of the leakdown test air flow will go thru the ring end gap. In a fresh engine that seals well when running, if the ring end gap is set to be large, the leakdown number is high. If it is set to be small then the leakdown number is low. There are many good reasons to set the ring end gap to be pretty large, yet that doesn't mean that the engine isn't working as the builder intended. My understanding was that the leakdown is ideally used as a relative measure. The leakdown numbers are recorded for a new engine, and then as the bore and rings wear the ring end gap increases. The ring end gap increase leads to worse leakdown numbers, and the engine builder can infer the ring and bore wear from the leakdown number. Is this correct?
The ring end gap is so large that it's not likely that slight amounts of oil in the cylinder can permanently block the ring end gap. Pressurized air running thru the gap should blow it our. (Oil in the cylinder should improve the seal if the rings have not bedded to the cylinder wall well, but I don't know how relevant this is for our alusil bores.) In the end, I wouldn't guess that the leakdown number is very sensitive to some oil in the cylinder, but that's nothing but a guess.
If I am thinking about this correctly, in the compression test where engine is cranked and peak pressure is measured, the oil impact can be much larger because the oil is not blown away by continuous air flow in one direction. So I wouldn't be shocked if in the compression test oil in the cylinder would change the results quite meaningfully.
This with the caveat that I've never done a compression test and even the leakdown test just a couple of times. I am planning to do the leakdown regularly when the new engine goes into my car. This post is a verbose question, I am asking and not telling what's going on.
It was my impression, possibly incorrect, that the most of the leakdown test air flow will go thru the ring end gap. In a fresh engine that seals well when running, if the ring end gap is set to be large, the leakdown number is high. If it is set to be small then the leakdown number is low. There are many good reasons to set the ring end gap to be pretty large, yet that doesn't mean that the engine isn't working as the builder intended. My understanding was that the leakdown is ideally used as a relative measure. The leakdown numbers are recorded for a new engine, and then as the bore and rings wear the ring end gap increases. The ring end gap increase leads to worse leakdown numbers, and the engine builder can infer the ring and bore wear from the leakdown number. Is this correct?
The ring end gap is so large that it's not likely that slight amounts of oil in the cylinder can permanently block the ring end gap. Pressurized air running thru the gap should blow it our. (Oil in the cylinder should improve the seal if the rings have not bedded to the cylinder wall well, but I don't know how relevant this is for our alusil bores.) In the end, I wouldn't guess that the leakdown number is very sensitive to some oil in the cylinder, but that's nothing but a guess.
If I am thinking about this correctly, in the compression test where engine is cranked and peak pressure is measured, the oil impact can be much larger because the oil is not blown away by continuous air flow in one direction. So I wouldn't be shocked if in the compression test oil in the cylinder would change the results quite meaningfully.
This with the caveat that I've never done a compression test and even the leakdown test just a couple of times. I am planning to do the leakdown regularly when the new engine goes into my car. This post is a verbose question, I am asking and not telling what's going on.
You understand it correctly. The oil in the cylinder has no meaningful effect on a leakdown test.
The leakdown test will be able to help you determine the wear of the liner at the top/bottom of the bore as well. But be careful when doing this as 100 PSI on a cylinder with good rings can do some real damage. So set the gauge at 20 PSI or so and rotate the engine through the cycle to get an accurate gauge of the cylinder wall wear, and how the rings are sealing. If you do have a scored cylinder wall, this test will make this very obvious.
As a side note, pull off the oil fill cap when doing this, and preferably prop the throttle body open so that you can hear/see/feel where the bypassing air is coming from.
03-19-2014, 07:47 PM
#24
Former Vendor
Why is that? An honest question, I'd love to know.
It was my impression, possibly incorrect, that the most of the leakdown test air flow will go thru the ring end gap. In a fresh engine that seals well when running, if the ring end gap is set to be large, the leakdown number is high. If it is set to be small then the leakdown number is low. There are many good reasons to set the ring end gap to be pretty large, yet that doesn't mean that the engine isn't working as the builder intended. My understanding was that the leakdown is ideally used as a relative measure. The leakdown numbers are recorded for a new engine, and then as the bore and rings wear the ring end gap increases. The ring end gap increase leads to worse leakdown numbers, and the engine builder can infer the ring and bore wear from the leakdown number. Is this correct?
The ring end gap is so large that it's not likely that slight amounts of oil in the cylinder can permanently block the ring end gap. Pressurized air running thru the gap should blow it our. (Oil in the cylinder should improve the seal if the rings have not bedded to the cylinder wall well, but I don't know how relevant this is for our alusil bores.) In the end, I wouldn't guess that the leakdown number is very sensitive to some oil in the cylinder, but that's nothing but a guess.
If I am thinking about this correctly, in the compression test where engine is cranked and peak pressure is measured, the oil impact can be much larger because the oil is not blown away by continuous air flow in one direction. So I wouldn't be shocked if in the compression test oil in the cylinder would change the results quite meaningfully.
This with the caveat that I've never done a compression test and even the leakdown test just a couple of times. I am planning to do the leakdown regularly when the new engine goes into my car. This post is a verbose question, I am asking and not telling what's going on.
It was my impression, possibly incorrect, that the most of the leakdown test air flow will go thru the ring end gap. In a fresh engine that seals well when running, if the ring end gap is set to be large, the leakdown number is high. If it is set to be small then the leakdown number is low. There are many good reasons to set the ring end gap to be pretty large, yet that doesn't mean that the engine isn't working as the builder intended. My understanding was that the leakdown is ideally used as a relative measure. The leakdown numbers are recorded for a new engine, and then as the bore and rings wear the ring end gap increases. The ring end gap increase leads to worse leakdown numbers, and the engine builder can infer the ring and bore wear from the leakdown number. Is this correct?
The ring end gap is so large that it's not likely that slight amounts of oil in the cylinder can permanently block the ring end gap. Pressurized air running thru the gap should blow it our. (Oil in the cylinder should improve the seal if the rings have not bedded to the cylinder wall well, but I don't know how relevant this is for our alusil bores.) In the end, I wouldn't guess that the leakdown number is very sensitive to some oil in the cylinder, but that's nothing but a guess.
If I am thinking about this correctly, in the compression test where engine is cranked and peak pressure is measured, the oil impact can be much larger because the oil is not blown away by continuous air flow in one direction. So I wouldn't be shocked if in the compression test oil in the cylinder would change the results quite meaningfully.
This with the caveat that I've never done a compression test and even the leakdown test just a couple of times. I am planning to do the leakdown regularly when the new engine goes into my car. This post is a verbose question, I am asking and not telling what's going on.
The problem in a GTS engine is that the rings get so gunked up, because of the lack of oil return holes in the pistons, that the rings do not seal well against the cylinders. This is, obviously, why the rings are passing oil, in the first place....and one of the reasons they burn so much oil.
Liquid oil, in the ring area, acts as a sealant, reducing the leakdown percentage.....and if the GTS engine is stock....there is always liquid oil present, when the engine is shut off.
Pretty common knowledge among mechanics. Almost no one does either a compression test or a leakdown test without a squirt can of oil to put into the cylinder (a bad valve is never sealed by a dose of liquid oil.) Of course, in the stock GTS engine, you will never need the squirt can of oil!
I have no idea where you can find this, on the Internet. I'm not going to go look, either.
But if you don't believe me....do a real life test. Run your GTS engine. drive it. Get it hot. Shut it off and let it sit. Pull out a spark plug. Bring a piston up in the bore. Put a camera on the bore. Turn the engine over by hand, moving the piston down in the bore. You will then see the residual oil running down the cylinder walls.
This is why the GTS engines that use oil blow a cloud of blue smoke, when you start them!
03-19-2014, 09:53 PM
#26
Electron Wrangler
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Seems throughout these threads there is a mix of assumptions of ring consumption vs intake consumption - they are clearly very different things, maybe some cars even have both, its clear to me I have very little ring losses.
Seems there must be different explanations for each case since they don't (always?) occur together. I'm not into lumping it all together - if its different lets understand the individual items and root causes.
Alan