Excessive Oil Use Question
02-10-2015, 04:15 PM
#21
Moderator
Thread Starter
I was using an Edelbrock Performer manifold with the World Product heads. I spoke to a local machine shop about what I found, and asked if the manifold could be milled somewhat to correct the problem. Rather than that he recommended checking with Edelbrock regarding what gasket to use. I went to the Edelbrock website to see what gaskets they recommended, and used whatever Felpro they recommended and was extra careful about torquing the intake. It didn't completely solve the problem, but it cut consumption by a significant amount. Edelbrock also recommended Gasgacinch.
I have since replaced the Performer intake with a TPI; still using the World Product heads. Again, I was very careful torqueing the base plate down (don't remember exactly which Felpro gasket I'm using). I also used sealer around the ports. Consumption is now 1 quart every 2500 miles.
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I have since replaced the Performer intake with a TPI; still using the World Product heads. Again, I was very careful torqueing the base plate down (don't remember exactly which Felpro gasket I'm using). I also used sealer around the ports. Consumption is now 1 quart every 2500 miles.
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02-10-2015, 09:34 PM
#22
Racer
Absolutely true; I know, I spent 2 days under the car replacing the oil pump. You may be correct; the guide seals may have been bad from the initial rebuild. I'll let you know in a couple of months after I get back to Minnesota an pull it apart for (I hope) the last time. Check the NCRS board; there are several instances of "Race Engine Builders" doing us a "favor" by installing HV/HP oil pumps.
02-11-2015, 05:02 PM
#23
Le Mans Master
High Pressure and High Volume pumps normally cause no issue other than wasting horse power and a little efficiency. They are very popular with engine rebuilders because all buyers of new engines want good oil pressure. Buyers see this as a sign of a good rebuild.
If you have excess clearances on the rods and mains or cam bearings a high volume pump will normally hide that fact and keep oil pressure high and make a happy customer.
If the Rod clearance is excessive, anything more than .00275 clearance between the rod bearing and the crankshaft it creates quite a leak internally, this oil is also thrown off onto the cylinder walls as the crank rotates and can overwhelm the ability of the oil ring to scrape it away. This can cause oil burning in a otherwise good engine.
This is especially true if running reduced or light tension oil rings.
Tighter rod bearings can fix this. .0015 to .0025
You can buy rod bearings in .001, .011 and .021 oversizes to fix a Std, 10 under or 20 under crank.
Large shops used to use a Sim Test machine, after assembly and before an oil pan went on the rebuilt engine was ran on the Sim Test. A device was hooked to the crankshaft and oil was hooked to the oil pump. They ran it at 400 RPM and tested flow and leaks. They picked up many issues before the engine went to final assembly and shipment.
Often switching in oversize bearings fixed oil pressure issues.
Comebacks were expensive in that business so this extra step was taken by many large shops.
On your issue of burning oil I think you are probably looking at an issue with the overhead. Manifold seal or Valve Stem Seals as was discussed by several people earlier.
What was your oil pressure at idle and at 3,000 RPM? It should have been at least a solid 60 psi with the pump you had. Hope this helps.
If you have excess clearances on the rods and mains or cam bearings a high volume pump will normally hide that fact and keep oil pressure high and make a happy customer.
If the Rod clearance is excessive, anything more than .00275 clearance between the rod bearing and the crankshaft it creates quite a leak internally, this oil is also thrown off onto the cylinder walls as the crank rotates and can overwhelm the ability of the oil ring to scrape it away. This can cause oil burning in a otherwise good engine.
This is especially true if running reduced or light tension oil rings.
Tighter rod bearings can fix this. .0015 to .0025
You can buy rod bearings in .001, .011 and .021 oversizes to fix a Std, 10 under or 20 under crank.
Large shops used to use a Sim Test machine, after assembly and before an oil pan went on the rebuilt engine was ran on the Sim Test. A device was hooked to the crankshaft and oil was hooked to the oil pump. They ran it at 400 RPM and tested flow and leaks. They picked up many issues before the engine went to final assembly and shipment.
Often switching in oversize bearings fixed oil pressure issues.
Comebacks were expensive in that business so this extra step was taken by many large shops.
On your issue of burning oil I think you are probably looking at an issue with the overhead. Manifold seal or Valve Stem Seals as was discussed by several people earlier.
What was your oil pressure at idle and at 3,000 RPM? It should have been at least a solid 60 psi with the pump you had. Hope this helps.
02-12-2015, 09:56 AM
#24
Burning Brakes
Member Since: Jun 2005
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Why do people continue to call main and rod bearings oversize when in fact they are undersize to fit a crankshaft whose journals have been ground to a smaller diameter.
02-12-2015, 10:07 AM
#25
Moderator
Thread Starter
High Pressure and High Volume pumps normally cause no issue other than wasting horse power and a little efficiency. They are very popular with engine rebuilders because all buyers of new engines want good oil pressure. Buyers see this as a sign of a good rebuild.
If you have excess clearances on the rods and mains or cam bearings a high volume pump will normally hide that fact and keep oil pressure high and make a happy customer.
If the Rod clearance is excessive, anything more than .00275 clearance between the rod bearing and the crankshaft it creates quite a leak internally, this oil is also thrown off onto the cylinder walls as the crank rotates and can overwhelm the ability of the oil ring to scrape it away. This can cause oil burning in a otherwise good engine.
This is especially true if running reduced or light tension oil rings.
Tighter rod bearings can fix this. .0015 to .0025
You can buy rod bearings in .001, .011 and .021 oversizes to fix a Std, 10 under or 20 under crank.
Large shops used to use a Sim Test machine, after assembly and before an oil pan went on the rebuilt engine was ran on the Sim Test. A device was hooked to the crankshaft and oil was hooked to the oil pump. They ran it at 400 RPM and tested flow and leaks. They picked up many issues before the engine went to final assembly and shipment.
Often switching in oversize bearings fixed oil pressure issues.
Comebacks were expensive in that business so this extra step was taken by many large shops.
On your issue of burning oil I think you are probably looking at an issue with the overhead. Manifold seal or Valve Stem Seals as was discussed by several people earlier.
What was your oil pressure at idle and at 3,000 RPM? It should have been at least a solid 60 psi with the pump you had. Hope this helps.
If you have excess clearances on the rods and mains or cam bearings a high volume pump will normally hide that fact and keep oil pressure high and make a happy customer.
If the Rod clearance is excessive, anything more than .00275 clearance between the rod bearing and the crankshaft it creates quite a leak internally, this oil is also thrown off onto the cylinder walls as the crank rotates and can overwhelm the ability of the oil ring to scrape it away. This can cause oil burning in a otherwise good engine.
This is especially true if running reduced or light tension oil rings.
Tighter rod bearings can fix this. .0015 to .0025
You can buy rod bearings in .001, .011 and .021 oversizes to fix a Std, 10 under or 20 under crank.
Large shops used to use a Sim Test machine, after assembly and before an oil pan went on the rebuilt engine was ran on the Sim Test. A device was hooked to the crankshaft and oil was hooked to the oil pump. They ran it at 400 RPM and tested flow and leaks. They picked up many issues before the engine went to final assembly and shipment.
Often switching in oversize bearings fixed oil pressure issues.
Comebacks were expensive in that business so this extra step was taken by many large shops.
On your issue of burning oil I think you are probably looking at an issue with the overhead. Manifold seal or Valve Stem Seals as was discussed by several people earlier.
What was your oil pressure at idle and at 3,000 RPM? It should have been at least a solid 60 psi with the pump you had. Hope this helps.
02-12-2015, 12:17 PM
#26
Melting Slicks
02-12-2015, 01:29 PM
#27
Team Owner
Member Since: Mar 2003
Location: Greenville, Indiana
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02-12-2015, 02:13 PM
#28
Safety Car
A oversized bearing has the same material thickness on the inside of the bearing facing the crankshaft journal, and more material on the outside facing the bore. Oversized bearings are used after a block has been line bored. A undersized bearing there is more material on the inside facing the journal, and the same amount facing the bore it fits into. Undersized bearings are for a smaller diameter journal or for a machined crankshaft journal.
-Bruce
02-12-2015, 05:27 PM
#29
Le Mans Master
Oversized bearings are for repairing used engines or tightening the clearances.
Bearings are available for the small block in Std, .001,.002, .010, .020 all the way to .050. Oversized bearings allow the builder to grind the crank smaller and give you a new crankshaft finish to run with. This allows multiple rebuilds before the crank needs to be scrapped.
Undersized bearings do just the opposite. Some new race cranks sold are a little fat for the builders needs so bearings are available to help correct that. For the small block GM they have race bearings in .001 or 1x, .009, .010, .011, .019, .020, .021.
All these sizes allow the engine builder to hit his preferred oil clearance.
Normally this will be .001 to .0035 depending on the builder and purpose.
Now one more twist, sometimes the Connecting rods were damaged and need to be repaired so they now have Oversize Housing bore bearing to fit connecting rods that have been honed oversize. Today the standard oversize is .002.
These bearings are listed as: 10x2 meaning the crankshaft is .010 under and the rods are .002 oversize. Many new rods can only be repaired by honing them oversize so this type bearing is becoming more popular.
Bearings are available for the small block in Std, .001,.002, .010, .020 all the way to .050. Oversized bearings allow the builder to grind the crank smaller and give you a new crankshaft finish to run with. This allows multiple rebuilds before the crank needs to be scrapped.
Undersized bearings do just the opposite. Some new race cranks sold are a little fat for the builders needs so bearings are available to help correct that. For the small block GM they have race bearings in .001 or 1x, .009, .010, .011, .019, .020, .021.
All these sizes allow the engine builder to hit his preferred oil clearance.
Normally this will be .001 to .0035 depending on the builder and purpose.
Now one more twist, sometimes the Connecting rods were damaged and need to be repaired so they now have Oversize Housing bore bearing to fit connecting rods that have been honed oversize. Today the standard oversize is .002.
These bearings are listed as: 10x2 meaning the crankshaft is .010 under and the rods are .002 oversize. Many new rods can only be repaired by honing them oversize so this type bearing is becoming more popular.
02-12-2015, 05:40 PM
#30
Le Mans Master
"Good info. I've always used 10/30 dino oil. At cold engine idle the gauge is pinned at 80. Hot idle is 40+. Hot engine at speed will be 60ish. Just got home from a business trip so I will get an engine leak down tester today." from MasterDave
Dave, A simple compression test with the engine warm and no oil added down the spark plug hole will give you a good read on general condition of your rings and cylinder walls.
If you find a low cylinder the leak Down will help identify where the leak is.
Sealed Power Piston Ring Engineers told me Compression Tests win races and Leak Down tests do not. They used this line because Total Seal rings had better leak down numbers but Sealed Power rings won more races. I trusted those guys then and now so I lean more on Compression Tests to determine engine health.
Rings rotate in normal engine operation, sometimes the ring gaps align in normal operation. If you do a leak down and they happen to be aligned at that point in time you will have a big leak in that cylinder. Run the engine for one minute and test again and the same cylinder may have a great leak down number. They may only line up like this once in 50 tests but it can happen. So if you do a leak down and find one bad hole run it a little and test that hole again.
The leak down does help identify the exact location of a leak, Exhaust Valve, Intake Valve or piston rings but if you have good compression you do not have those leaks to start with.
Dave, A simple compression test with the engine warm and no oil added down the spark plug hole will give you a good read on general condition of your rings and cylinder walls.
If you find a low cylinder the leak Down will help identify where the leak is.
Sealed Power Piston Ring Engineers told me Compression Tests win races and Leak Down tests do not. They used this line because Total Seal rings had better leak down numbers but Sealed Power rings won more races. I trusted those guys then and now so I lean more on Compression Tests to determine engine health.
Rings rotate in normal engine operation, sometimes the ring gaps align in normal operation. If you do a leak down and they happen to be aligned at that point in time you will have a big leak in that cylinder. Run the engine for one minute and test again and the same cylinder may have a great leak down number. They may only line up like this once in 50 tests but it can happen. So if you do a leak down and find one bad hole run it a little and test that hole again.
The leak down does help identify the exact location of a leak, Exhaust Valve, Intake Valve or piston rings but if you have good compression you do not have those leaks to start with.
02-12-2015, 05:43 PM
#31
Le Mans Master
Member Since: Nov 2003
Location: Maryland
Posts: 5,656
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St. Jude Donor '05, '09, '15
Hope this helps... A oversized bearing has the same material thickness on the inside of the bearing facing the crankshaft journal, and more material on the outside facing the bore. Oversized bearings are used after a block has been line bored. A undersized bearing there is more material on the inside facing the journal, and the same amount facing the bore it fits into. Undersized bearings are for a smaller diameter journal or for a machined crankshaft journal. -Bruce
-BruceTom
02-12-2015, 07:56 PM
#32
Moderator
Thread Starter
"Good info. I've always used 10/30 dino oil. At cold engine idle the gauge is pinned at 80. Hot idle is 40+. Hot engine at speed will be 60ish. Just got home from a business trip so I will get an engine leak down tester today." from MasterDave
Dave, A simple compression test with the engine warm and no oil added down the spark plug hole will give you a good read on general condition of your rings and cylinder walls.
If you find a low cylinder the leak Down will help identify where the leak is.
Sealed Power Piston Ring Engineers told me Compression Tests win races and Leak Down tests do not. They used this line because Total Seal rings had better leak down numbers but Sealed Power rings won more races. I trusted those guys then and now so I lean more on Compression Tests to determine engine health.
Rings rotate in normal engine operation, sometimes the ring gaps align in normal operation. If you do a leak down and they happen to be aligned at that point in time you will have a big leak in that cylinder. Run the engine for one minute and test again and the same cylinder may have a great leak down number. They may only line up like this once in 50 tests but it can happen. So if you do a leak down and find one bad hole run it a little and test that hole again.
The leak down does help identify the exact location of a leak, Exhaust Valve, Intake Valve or piston rings but if you have good compression you do not have those leaks to start with.
Dave, A simple compression test with the engine warm and no oil added down the spark plug hole will give you a good read on general condition of your rings and cylinder walls.
If you find a low cylinder the leak Down will help identify where the leak is.
Sealed Power Piston Ring Engineers told me Compression Tests win races and Leak Down tests do not. They used this line because Total Seal rings had better leak down numbers but Sealed Power rings won more races. I trusted those guys then and now so I lean more on Compression Tests to determine engine health.
Rings rotate in normal engine operation, sometimes the ring gaps align in normal operation. If you do a leak down and they happen to be aligned at that point in time you will have a big leak in that cylinder. Run the engine for one minute and test again and the same cylinder may have a great leak down number. They may only line up like this once in 50 tests but it can happen. So if you do a leak down and find one bad hole run it a little and test that hole again.
The leak down does help identify the exact location of a leak, Exhaust Valve, Intake Valve or piston rings but if you have good compression you do not have those leaks to start with.
02-12-2015, 08:13 PM
#33
Le Mans Master
Try Mechanics gloves, for $20 bucks your hands will appreciate the help.
In my experience the good ones work and the cheap copies only work half as well.
Like most things, you get what you pay for.
In my experience the good ones work and the cheap copies only work half as well.
Like most things, you get what you pay for.
02-14-2015, 12:44 PM
#35
if you have a PCV system do you have the proper rocker cover with the baffles around the PCV valve ??? I have also seen after market PCV valve cause oil burning
Last edited by MasterDave; 02-19-2015 at 07:25 PM.
02-19-2015, 07:24 PM
#36
Moderator
Thread Starter
OK, just got back in the house after doing a compression check on a warm engine. I got hot hands but no burns. 150 pounds across the board. It is probably a bit more actually due to the rubber nipple on my antique gauge being split and cracked which made it impossible to get a complete seal. A friend helped and he had the same oil use issue with his BB with a hi volume/pressure oil pump. He put a standard pump on and his problem was solved. I will get a standard pump and oil pan (I have the Moroso 8 qt now) and give that a try. I have not done a leak down test yet. Should I still do it?
150 pounds across the board. It is probably a bit more actually due to the rubber nipple on my antique gauge being split and cracked which made it impossible to get a complete seal. A friend helped and he had the same oil use issue with his BB with a hi volume/pressure oil pump. He put a standard pump on and his problem was solved. I will get a standard pump and oil pan (I have the Moroso 8 qt now) and give that a try. I have not done a leak down test yet. Should I still do it?
02-19-2015, 07:29 PM
#37
Moderator
Thread Starter
02-19-2015, 07:42 PM
#38
02-19-2015, 09:08 PM
#39
Moderator
Thread Starter
I have a push in breather in one valve cover and the PCV in the other. Do they make a push in breather that will fit in the PCV hole?
02-20-2015, 02:39 AM
#40
Le Mans Master
Dave, your cam is big which will bleed some compression, I am assuming you run flat top pistons? Flat Tops with 64cc should be close to 10:1 in a 350, I would expect 160 to 175 compression but even at 150 all cylinders is good and the sign of a good engine.
A leakdown may show you are leaking past the rings in all 8 but that would surprise me.
You bought the tool, might as well play with it.
We have given ideas for checking the manifold seal and finally valve stem seals, after leak down I would go that way. Since compression is the same a leak down test will probably back you up and say all 8 are healthy.
A leakdown may show you are leaking past the rings in all 8 but that would surprise me.
You bought the tool, might as well play with it.
We have given ideas for checking the manifold seal and finally valve stem seals, after leak down I would go that way. Since compression is the same a leak down test will probably back you up and say all 8 are healthy.