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[GMCnet] Tid Bits: Why engines burn oil. [message #336538] Thu, 30 August 2018 15:38 Go to next message
BobDunahugh is currently offline  BobDunahugh   United States
Messages: 2465
Registered: October 2010
Location: Cedar Rapids, IA
Karma: 11
Senior Member
Short answer. Miles, and contamination in the oil. There are 3 ways oil gets into the combustion chamber. By the piston rings is the major way. Rings can last an extremely long time. Their life gets shortened in several ways. The choke on the carburetor isn't adjusted correctly. And stays on too long. choke pull off not working, carb float too high, enrichment valve open too long, metering rods not working correctly. This over rich fuel/oxygen fuel charge to the pistons. Gets way over the preferred 14 ppm ox to 1 ppm fuel. This slows down the flame front that travels across the combustion chamber from the spark plug. ( Indexing the spark plug to the chamber is preferred) All this allows some fuel to not get burned. Leaving raw unburned fuel to wash sway the tiny amount of oil on the cylinder walls. Plus producing excessive amounts of carbon in the chamber. Great if your making sandpaper. Luging the engine by not shifting down on hills. Puts excessive loads on rings. Engine overheating can take much of the tension out of the rings. Ignition timing way off. Valve stems/guide clearance is another expressway for oil to the chamber. Again here. An over rich fuel ratio is very damaging. The positive crankcase ventilation system is next. This system generally has few issue. Replace the PCV valve in the valve cover. And NEVER put on ANY pretty valve cover that doesn't have the stock baffle. Not having that stock type baffle. Makes a very nice express way for oil to the combustion chamber. The Howell EFI with spark control will solve all this except the PCV issues.

Now to the oil control piston ring. This lower ring on the piston. Is there to make sure that the cylinder walls, and the 2 upper rings get the proper amount of oil. That oil that this ring puts on the cylinder wall. Is a mind boggling tiny amount. And more bearing clearance with a HV pump doesn't help. There is absolutely no one on this earth that knows more about the 403, and 455. Then the hundreds of engineers at GM. And how these engines have held up for going on a half century proves that. There are 5 changes made on the 455 for the TZE units. 1-Water pump. 2- carburetor. 3- lowered intake manifold. 4- Distributor. 5 - higher Nickle content in the engine block. The 403 didn't have a lower intake manifold. Just the standard rear wheel drive car intake. A larger bearing clearance, and a HV oil pump aren't on that GM list. And for good reason.

So why do some engines fail at 75,000 miles. And some are running well at more the 200,000 miles. That's in the maintenance. And the carburetor issues above. It's the oil dilution by unburned fuel. The main/rod bearings should never come in contact with the crankshaft. There should always be an oil film between them. And cleaner oil will not have as much abrasive carbon floating in the oil. Frequent oil/filer changes have always been the salvation for you engine. By draining out the diluted oil by fuel, and the contamination contained in that used oil. I've known owners that changed the filter ever other oil change. That is pure dumb. In the microscopic world out there in our engines. Our oil filters. NO MATTER the brand. Are only filtering out the LARGE ROCKS that are traveling around the inside of our engines. And the ONLY way to remove the slightly smaller rocks, then the larger ones that got filtered out. Draining the contaminated oil out. The 403 that was in our 78 Royale. Had 152,000 miles on it. Was in pure excellent condition. The log book that came with it. Showed only a hand full of oil/filter changes that went over 3,000 miles. Synthetic oils are excellent for the modern clean engines of today. We need to change our oil to soon to take advantage of their longer mileage cycles. OK. I'll stop babbling, For now. GRIN Bob Dunahugh
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Re: [GMCnet] Tid Bits: Why engines burn oil. [message #336539 is a reply to message #336538] Thu, 30 August 2018 16:05 Go to previous messageGo to next message
Cesar Carrasco is currently offline  Cesar Carrasco   United States
Messages: 30
Registered: September 2017
Location: Riverside, California
Karma: 0
Member
Bob, I just want you to know, that your postings and emails are not for
nothing. I save them. I don't know about other folks, but I learn a lot
from them. Keep posting and emailing.

Cesar Carrasco
Riverside California
74 Glacier
73 Sequoia


On Thu, Aug 30, 2018 at 1:39 PM Bob Dunahugh wrote:

> Short answer. Miles, and contamination in the oil. There are 3 ways oil
> gets into the combustion chamber. By the piston rings is the major way.
> Rings can last an extremely long time. Their life gets shortened in several
> ways. The choke on the carburetor isn't adjusted correctly. And stays on
> too long. choke pull off not working, carb float too high, enrichment
> valve open too long, metering rods not working correctly. This over rich
> fuel/oxygen fuel charge to the pistons. Gets way over the preferred 14
> ppm ox to 1 ppm fuel. This slows down the flame front that travels across
> the combustion chamber from the spark plug. ( Indexing the spark plug to
> the chamber is preferred) All this allows some fuel to not get burned.
> Leaving raw unburned fuel to wash sway the tiny amount of oil on the
> cylinder walls. Plus producing excessive amounts of carbon in the chamber.
> Great if your making sandpaper. Luging the engine by not shifting down on
> hills. Puts excessive loads on rings. Engine overheating can take much of
> the tension out of the rings. Ignition timing way off. Valve stems/guide
> clearance is another expressway for oil to the chamber. Again here. An over
> rich fuel ratio is very damaging. The positive crankcase ventilation system
> is next. This system generally has few issue. Replace the PCV valve in the
> valve cover. And NEVER put on ANY pretty valve cover that doesn't have the
> stock baffle. Not having that stock type baffle. Makes a very nice express
> way for oil to the combustion chamber. The Howell EFI with spark control
> will solve all this except the PCV issues.
>
> Now to the oil control piston ring. This lower ring on the piston. Is
> there to make sure that the cylinder walls, and the 2 upper rings get the
> proper amount of oil. That oil that this ring puts on the cylinder wall.
> Is a mind boggling tiny amount. And more bearing clearance with a HV pump
> doesn't help. There is absolutely no one on this earth that knows more
> about the 403, and 455. Then the hundreds of engineers at GM. And how these
> engines have held up for going on a half century proves that. There are 5
> changes made on the 455 for the TZE units. 1-Water pump. 2- carburetor. 3-
> lowered intake manifold. 4- Distributor. 5 - higher Nickle content in the
> engine block. The 403 didn't have a lower intake manifold. Just the
> standard rear wheel drive car intake. A larger bearing clearance, and a HV
> oil pump aren't on that GM list. And for good reason.
>
> So why do some engines fail at 75,000 miles. And some are running well
> at more the 200,000 miles. That's in the maintenance. And the carburetor
> issues above. It's the oil dilution by unburned fuel. The main/rod
> bearings should never come in contact with the crankshaft. There should
> always be an oil film between them. And cleaner oil will not have as much
> abrasive carbon floating in the oil. Frequent oil/filer changes have
> always been the salvation for you engine. By draining out the diluted oil
> by fuel, and the contamination contained in that used oil. I've known
> owners that changed the filter ever other oil change. That is pure dumb. In
> the microscopic world out there in our engines. Our oil filters. NO MATTER
> the brand. Are only filtering out the LARGE ROCKS that are traveling around
> the inside of our engines. And the ONLY way to remove the slightly smaller
> rocks, then the larger ones that got filtered out. Draining the
> contaminated oil out. The 403 that was in our 78 Royale. Had 152,000 miles
> on it. Was in pure excellent condition. The log book that came with it.
> Showed only a hand full of oil/filter changes that went over 3,000 miles.
> Synthetic oils are excellent for the modern clean engines of today. We
> need to change our oil to soon to take advantage of their longer mileage
> cycles. OK. I'll stop babbling, For now. GRIN Bob Dunahugh
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
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Re: [GMCnet] Tid Bits: Why engines burn oil. [message #336540 is a reply to message #336539] Thu, 30 August 2018 16:25 Go to previous messageGo to next message
James Hupy is currently offline  James Hupy   United States
Messages: 6806
Registered: May 2010
Karma: -62
Senior Member
You are spot on on GM ENGINEERS, up to about 1972. Then they literally flew
the coop, through early golden parachute retirement packages, etc.
Then came the big whammy. They took the lead out of gasoline. The
Arabs decided to hold us hostage for crude oil, and created a whole new
industry in the USA. Growing corn to make alcohol. Boy oh boy, what a
boondoggle that turned out to be. Combine that with bumper safety mandates
that turned a $300.00 dollar bumper into a $3000.00 piece of plastic
overnight, along with "bean counters instead of stylists" in charge of
making auto designs, and the big flusheroo began. If you think it is
better, you have some fuzzy thinking going on.
Bob is dead right on the quality of the 455 and 403 engines. For
purposes intended, they do the job very well. Only heavy duty diesel
engines will out last them.
Jim Hupy

On Thu, Aug 30, 2018, 2:06 PM Cesar Carrasco
wrote:

> Bob, I just want you to know, that your postings and emails are not for
> nothing. I save them. I don't know about other folks, but I learn a lot
> from them. Keep posting and emailing.
>
> Cesar Carrasco
> Riverside California
> 74 Glacier
> 73 Sequoia
>
>
> On Thu, Aug 30, 2018 at 1:39 PM Bob Dunahugh wrote:
>
>> Short answer. Miles, and contamination in the oil. There are 3 ways oil
>> gets into the combustion chamber. By the piston rings is the major way.
>> Rings can last an extremely long time. Their life gets shortened in
> several
>> ways. The choke on the carburetor isn't adjusted correctly. And stays on
>> too long. choke pull off not working, carb float too high, enrichment
>> valve open too long, metering rods not working correctly. This over rich
>> fuel/oxygen fuel charge to the pistons. Gets way over the preferred 14
>> ppm ox to 1 ppm fuel. This slows down the flame front that travels across
>> the combustion chamber from the spark plug. ( Indexing the spark plug to
>> the chamber is preferred) All this allows some fuel to not get burned.
>> Leaving raw unburned fuel to wash sway the tiny amount of oil on the
>> cylinder walls. Plus producing excessive amounts of carbon in the
> chamber.
>> Great if your making sandpaper. Luging the engine by not shifting down on
>> hills. Puts excessive loads on rings. Engine overheating can take much
> of
>> the tension out of the rings. Ignition timing way off. Valve stems/guide
>> clearance is another expressway for oil to the chamber. Again here. An
> over
>> rich fuel ratio is very damaging. The positive crankcase ventilation
> system
>> is next. This system generally has few issue. Replace the PCV valve in
> the
>> valve cover. And NEVER put on ANY pretty valve cover that doesn't have
> the
>> stock baffle. Not having that stock type baffle. Makes a very nice
> express
>> way for oil to the combustion chamber. The Howell EFI with spark control
>> will solve all this except the PCV issues.
>>
>> Now to the oil control piston ring. This lower ring on the piston. Is
>> there to make sure that the cylinder walls, and the 2 upper rings get
> the
>> proper amount of oil. That oil that this ring puts on the cylinder wall.
>> Is a mind boggling tiny amount. And more bearing clearance with a HV
> pump
>> doesn't help. There is absolutely no one on this earth that knows more
>> about the 403, and 455. Then the hundreds of engineers at GM. And how
> these
>> engines have held up for going on a half century proves that. There are 5
>> changes made on the 455 for the TZE units. 1-Water pump. 2- carburetor.
> 3-
>> lowered intake manifold. 4- Distributor. 5 - higher Nickle content in
> the
>> engine block. The 403 didn't have a lower intake manifold. Just the
>> standard rear wheel drive car intake. A larger bearing clearance, and a
> HV
>> oil pump aren't on that GM list. And for good reason.
>>
>> So why do some engines fail at 75,000 miles. And some are running well
>> at more the 200,000 miles. That's in the maintenance. And the carburetor
>> issues above. It's the oil dilution by unburned fuel. The main/rod
>> bearings should never come in contact with the crankshaft. There should
>> always be an oil film between them. And cleaner oil will not have as much
>> abrasive carbon floating in the oil. Frequent oil/filer changes have
>> always been the salvation for you engine. By draining out the diluted oil
>> by fuel, and the contamination contained in that used oil. I've known
>> owners that changed the filter ever other oil change. That is pure dumb.
> In
>> the microscopic world out there in our engines. Our oil filters. NO
> MATTER
>> the brand. Are only filtering out the LARGE ROCKS that are traveling
> around
>> the inside of our engines. And the ONLY way to remove the slightly
> smaller
>> rocks, then the larger ones that got filtered out. Draining the
>> contaminated oil out. The 403 that was in our 78 Royale. Had 152,000
> miles
>> on it. Was in pure excellent condition. The log book that came with it.
>> Showed only a hand full of oil/filter changes that went over 3,000 miles.
>> Synthetic oils are excellent for the modern clean engines of today. We
>> need to change our oil to soon to take advantage of their longer mileage
>> cycles. OK. I'll stop babbling, For now. GRIN Bob Dunahugh
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
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Re: [GMCnet] Tid Bits: Why engines burn oil. [message #336542 is a reply to message #336538] Thu, 30 August 2018 18:51 Go to previous messageGo to next message
jhbridges is currently offline  jhbridges   United States
Messages: 8412
Registered: May 2011
Location: Braselton ga
Karma: -74
Senior Member
Those engines were designed with a lot of leeway. Came the ability to computer simulate operation, the builders found they could save money by getting within a rat's ass of unreliability with designs and materials. Unfortunately, they occasuionally ran up on a rat with a narrow ass and built a dud. (First Mopar Ultras).
As one rebuilder says, keep clean oil, keep it cool, and drive it like you stole it.

--johnny


Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons. Braselton, Ga. I forgive them all, save those who hurt the dogs. They must answer to me in hell
Re: [GMCnet] Tid Bits: Why engines burn oil. [message #336546 is a reply to message #336538] Thu, 30 August 2018 22:21 Go to previous messageGo to next message
BobDunahugh is currently offline  BobDunahugh   United States
Messages: 2465
Registered: October 2010
Location: Cedar Rapids, IA
Karma: 11
Senior Member
I just hate to see owners being told that they must, or should rebuild their engine because of the oil pressure gauge readings. Then being afraid to drive it. Basically. Give that engine a fiscal. Post the results. Talk it out. Then take it to a camp sites, or parks in your area. Get out there for a day to just enjoy life. That GMC doesn't have to be pretty. Our GMC's are absolutely just like most of us. Up in years. Don't look as good as we did a few decades ago. Don't perform simple task as fast as we use too. And have some parts that we just will have to put up with what we have. As is. So. Give that GMC a finical. As you do for yourself. Asses both reports. And keep the both of you on the road the best you can.

Yes. I'm a maintenance NUT. It's an ailment that I've had most of my life. We travel a lot in our GMC. It's our magic carpet ride. And with Linda confined to a power wheelchair. If we end up to the side of the road. With a ditch to our right. We can't put out the 8 ft ramp to just get her out. She's stuck in there. Our GMC is like Apollo 13. Failure is NOT an option. That's why there's $41,000 in parts there. About no one has this situation. So. Get it out. After making it safe. And enjoy the area around you. Bob Dunahugh 78 Royale Mouse House



________________________________
From: Bob Dunahugh
Sent: Thursday, August 30, 2018 3:38 PM
To: gmclist@list.gmcnet.org
Subject: Tid Bits: Why engines burn oil.


Short answer. Miles, and contamination in the oil. There are 3 ways oil gets into the combustion chamber. By the piston rings is the major way. Rings can last an extremely long time. Their life gets shortened in several ways. The choke on the carburetor isn't adjusted correctly. And stays on too long. choke pull off not working, carb float too high, enrichment valve open too long, metering rods not working correctly. This over rich fuel/oxygen fuel charge to the pistons. Gets way over the preferred 14 ppm ox to 1 ppm fuel. This slows down the flame front that travels across the combustion chamber from the spark plug. ( Indexing the spark plug to the chamber is preferred) All this allows some fuel to not get burned. Leaving raw unburned fuel to wash sway the tiny amount of oil on the cylinder walls. Plus producing excessive amounts of carbon in the chamber. Great if your making sandpaper. Luging the engine by not shifting down on hills. Puts excessive loads on rings. Engine overheating can take much of the tension out of the rings. Ignition timing way off. Valve stems/guide clearance is another expressway for oil to the chamber. Again here. An over rich fuel ratio is very damaging. The positive crankcase ventilation system is next. This system generally has few issue. Replace the PCV valve in the valve cover. And NEVER put on ANY pretty valve cover that doesn't have the stock baffle. Not having that stock type baffle. Makes a very nice express way for oil to the combustion chamber. The Howell EFI with spark control will solve all this except the PCV issues.

Now to the oil control piston ring. This lower ring on the piston. Is there to make sure that the cylinder walls, and the 2 upper rings get the proper amount of oil. That oil that this ring puts on the cylinder wall. Is a mind boggling tiny amount. And more bearing clearance with a HV pump doesn't help. There is absolutely no one on this earth that knows more about the 403, and 455. Then the hundreds of engineers at GM. And how these engines have held up for going on a half century proves that. There are 5 changes made on the 455 for the TZE units. 1-Water pump. 2- carburetor. 3- lowered intake manifold. 4- Distributor. 5 - higher Nickle content in the engine block. The 403 didn't have a lower intake manifold. Just the standard rear wheel drive car intake. A larger bearing clearance, and a HV oil pump aren't on that GM list. And for good reason.

So why do some engines fail at 75,000 miles. And some are running well at more the 200,000 miles. That's in the maintenance. And the carburetor issues above. It's the oil dilution by unburned fuel. The main/rod bearings should never come in contact with the crankshaft. There should always be an oil film between them. And cleaner oil will not have as much abrasive carbon floating in the oil. Frequent oil/filer changes have always been the salvation for you engine. By draining out the diluted oil by fuel, and the contamination contained in that used oil. I've known owners that changed the filter ever other oil change. That is pure dumb. In the microscopic world out there in our engines. Our oil filters. NO MATTER the brand. Are only filtering out the LARGE ROCKS that are traveling around the inside of our engines. And the ONLY way to remove the slightly smaller rocks, then the larger ones that got filtered out. Draining the contaminated oil out. The 403 that was in our 78 Royale. Had 152,000 miles on it. Was in pure excellent condition. The log book that came with it. Showed only a hand full of oil/filter changes that went over 3,000 miles. Synthetic oils are excellent for the modern clean engines of today. We need to change our oil to soon to take advantage of their longer mileage cycles. OK. I'll stop babbling, For now. GRIN Bob Dunahugh
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Re: [GMCnet] Tid Bits: Why engines burn oil. [message #336548 is a reply to message #336546] Fri, 31 August 2018 06:18 Go to previous messageGo to next message
Handyman is currently offline  Handyman   Netherlands
Messages: 229
Registered: April 2016
Location: The Netherlands
Karma: 2
Senior Member
Thanks, Bob

Really appreciate your daily's ... or how are they named ?
You give us top notch inside info.
I knew they did a hell of a job in those days, testing and constructing from scratch, but after your explanations I understand more of the insides of the 455/403 Gas engines ...

Please keep it on ...

Bye, Daniel


Daniel Jacobs, NL-USA 1977 GMC Eleganza II, Rebuild 455 (2019) 3.55 FD. FiTech and (Modified) FCC, Electric Pump, insulated GasTanks, 100A Alternator, APC, McDash, Schräder Valves + extern Fills, Ceramic Film, TPMS, FlexSteel Seats
Re: [GMCnet] Tid Bits: Why engines burn oil. [message #336557 is a reply to message #336546] Fri, 31 August 2018 11:18 Go to previous message
Mike Kelley is currently offline  Mike Kelley   United States
Messages: 467
Registered: February 2017
Karma: -2
Senior Member
Bob D.:
I agree w/ C. C. - keep that knowledge flowing! I save/flag most of your e mails for future reference as I can easily understand your straight talk and know you have been there, done that!
Even a non mechanic like me knows that it’s all about good maintenance - and you remind us to do it and how and why!!!
Thanks for sharing!!!
Mike/The Corvair a holic

Sent from my iPhone

> On Aug 30, 2018, at 10:21 PM, Bob Dunahugh wrote:
>
> I just hate to see owners being told that they must, or should rebuild their engine because of the oil pressure gauge readings. Then being afraid to drive it. Basically. Give that engine a fiscal. Post the results. Talk it out. Then take it to a camp sites, or parks in your area. Get out there for a day to just enjoy life. That GMC doesn't have to be pretty. Our GMC's are absolutely just like most of us. Up in years. Don't look as good as we did a few decades ago. Don't perform simple task as fast as we use too. And have some parts that we just will have to put up with what we have. As is. So. Give that GMC a finical. As you do for yourself. Asses both reports. And keep the both of you on the road the best you can.
>
> Yes. I'm a maintenance NUT. It's an ailment that I've had most of my life. We travel a lot in our GMC. It's our magic carpet ride. And with Linda confined to a power wheelchair. If we end up to the side of the road. With a ditch to our right. We can't put out the 8 ft ramp to just get her out. She's stuck in there. Our GMC is like Apollo 13. Failure is NOT an option. That's why there's $41,000 in parts there. About no one has this situation. So. Get it out. After making it safe. And enjoy the area around you. Bob Dunahugh 78 Royale Mouse House
>
>
>
> ________________________________
> From: Bob Dunahugh
> Sent: Thursday, August 30, 2018 3:38 PM
> To: gmclist@list.gmcnet.org
> Subject: Tid Bits: Why engines burn oil.
>
>
> Short answer. Miles, and contamination in the oil. There are 3 ways oil gets into the combustion chamber. By the piston rings is the major way. Rings can last an extremely long time. Their life gets shortened in several ways. The choke on the carburetor isn't adjusted correctly. And stays on too long. choke pull off not working, carb float too high, enrichment valve open too long, metering rods not working correctly. This over rich fuel/oxygen fuel charge to the pistons. Gets way over the preferred 14 ppm ox to 1 ppm fuel. This slows down the flame front that travels across the combustion chamber from the spark plug. ( Indexing the spark plug to the chamber is preferred) All this allows some fuel to not get burned. Leaving raw unburned fuel to wash sway the tiny amount of oil on the cylinder walls. Plus producing excessive amounts of carbon in the chamber. Great if your making sandpaper. Luging the engine by not shifting down on hills. Puts excessive loads on rings. Engine overheating can take much of the tension out of the rings. Ignition timing way off. Valve stems/guide clearance is another expressway for oil to the chamber. Again here. An over rich fuel ratio is very damaging. The positive crankcase ventilation system is next. This system generally has few issue. Replace the PCV valve in the valve cover. And NEVER put on ANY pretty valve cover that doesn't have the stock baffle. Not having that stock type baffle. Makes a very nice express way for oil to the combustion chamber. The Howell EFI with spark control will solve all this except the PCV issues.
>
> Now to the oil control piston ring. This lower ring on the piston. Is there to make sure that the cylinder walls, and the 2 upper rings get the proper amount of oil. That oil that this ring puts on the cylinder wall. Is a mind boggling tiny amount. And more bearing clearance with a HV pump doesn't help. There is absolutely no one on this earth that knows more about the 403, and 455. Then the hundreds of engineers at GM. And how these engines have held up for going on a half century proves that. There are 5 changes made on the 455 for the TZE units. 1-Water pump. 2- carburetor. 3- lowered intake manifold. 4- Distributor. 5 - higher Nickle content in the engine block. The 403 didn't have a lower intake manifold. Just the standard rear wheel drive car intake. A larger bearing clearance, and a HV oil pump aren't on that GM list. And for good reason.
>
> So why do some engines fail at 75,000 miles. And some are running well at more the 200,000 miles. That's in the maintenance. And the carburetor issues above. It's the oil dilution by unburned fuel. The main/rod bearings should never come in contact with the crankshaft. There should always be an oil film between them. And cleaner oil will not have as much abrasive carbon floating in the oil. Frequent oil/filer changes have always been the salvation for you engine. By draining out the diluted oil by fuel, and the contamination contained in that used oil. I've known owners that changed the filter ever other oil change. That is pure dumb. In the microscopic world out there in our engines. Our oil filters. NO MATTER the brand. Are only filtering out the LARGE ROCKS that are traveling around the inside of our engines. And the ONLY way to remove the slightly smaller rocks, then the larger ones that got filtered out. Draining the contaminated oil out. The 403 that was in our 78 Royale. Had 152,000 miles on it. Was in pure excellent condition. The log book that came with it. Showed only a hand full of oil/filter changes that went over 3,000 miles. Synthetic oils are excellent for the modern clean engines of today. We need to change our oil to soon to take advantage of their longer mileage cycles. OK. I'll stop babbling, For now. GRIN Bob Dunahugh
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org

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