Tid Bits: Why engines burn oil.

[Bob Dunahugh]

Short answer. Miles, and contamination in the oil. There are 3 ways oil get=
s 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 lo=
ng. 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 p=
pm 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 p=
referred) 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 prod=
ucing excessive amounts of carbon in the chamber. Great if your making sand=
paper. Luging the engine by not shifting down on hills. Puts excessive loa=
ds on rings. Engine overheating can take much of the tension out of the rin=
gs. Ignition timing way off. Valve stems/guide clearance is another expres=
sway for oil to the chamber. Again here. An over rich fuel ratio is very da=
maging. The positive crankcase ventilation system is next. This system gene=
rally 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 havin=
g that stock type baffle. Makes a very nice express way for oil to the com=
bustion chamber. The Howell EFI with spark control will solve all this exc=
ept the PCV issues. Now to the oil control piston ring. This lower rin=
g on the piston. Is there to make sure that the cylinder walls, and the 2 u=
pper 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 clear=
ance 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 t=
hat. 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 Nick=
le content in the engine block. The 403 didn't have a lower intake manifol=
d. Just the standard rear wheel drive car intake. A larger bearing clearan=
ce, 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 m=
ore 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 sho=
uld never come in contact with the crankshaft. There should always be an oi=
l 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 salv=
ation for you engine. By draining out the diluted oil by fuel, and the cont=
amination contained in that used oil. I've known owners that changed the fi=
lter 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 filte=
ring out the LARGE ROCKS that are traveling around the inside of our engine=
s. 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 condi=
tion. 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 m=
odern clean engines of today. We need to change our oil to soon to take ad=
vantage of their longer mileage cycles. OK. I'll stop babbling, For now. =
GRIN Bob Dunahugh

 

[cesar carrasco]

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

> 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
>

 

[Jim Hupy]

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
>
>

>
> > 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
>

 

[johnny]

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
--
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" - ol Andy, paraphrased

 

[Bob Dunahugh]

I just hate to see owners being told that they must, or should rebuild thei=
r 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 o=
ut. 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 ar=
e absolutely just like most of us. Up in years. Don't look as good as we di=
d 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 mai=
ntenance NUT. It's an ailment that I've had most of my life. We travel a lo=
t in our GMC. It's our magic carpet ride. And with Linda confined to a pow=
er wheelchair. If we end up to the side of the road. With a ditch to our ri=
ght. We can't put out the 8 ft ramp to just get her out. She's stuck in th=
ere. 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 R=
oyale Mouse House ________________________________ From: Bob D=
unahugh Sent: Thursday, August 30, 2018 3:38 PM =
To: gmclist Subject: Tid Bits: Why engines burn oil. =
Short answer. Miles, and contamination in the oil. There are 3 ways o=
il 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 severa=
l 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 valv=
e open too long, metering rods not working correctly. This over rich fuel/o=
xygen 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 comb=
ustion chamber from the spark plug. ( Indexing the spark plug to the chambe=
r is preferred) All this allows some fuel to not get burned. Leaving raw un=
burned fuel to wash sway the tiny amount of oil on the cylinder walls. Plu=
s producing excessive amounts of carbon in the chamber. Great if your makin=
g sandpaper. Luging the engine by not shifting down on hills. Puts excessiv=
e loads on rings. Engine overheating can take much of the tension out of t=
he 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 v=
ery damaging. The positive crankcase ventilation system is next. This syste=
m 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 t=
he combustion chamber. The Howell EFI with spark control will solve all th=
is except the PCV issues. Now to the oil control piston ring. This low=
er ring on the piston. Is there to make sure that the cylinder walls, and t=
he 2 upper rings get the proper amount of oil. That oil that this ring pu=
ts 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 enginee=
rs at GM. And how these engines have held up for going on a half century pr=
oves that. There are 5 changes made on the 455 for the TZE units. 1-Water p=
ump. 2- carburetor. 3- lowered intake manifold. 4- Distributor. 5 - highe=
r Nickle content in the engine block. The 403 didn't have a lower intake m=
anifold. Just the standard rear wheel drive car intake. A larger bearing c=
learance, 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 wel=
l 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 bearin=
gs 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 th=
e salvation for you engine. By draining out the diluted oil by fuel, and th=
e 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 wor=
ld 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 l=
arger ones that got filtered out. Draining the contaminated oil out. The 40=
3 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 t=
ake advantage of their longer mileage cycles. OK. I'll stop babbling, For=
now. GRIN Bob Dunahugh

 

[Daniel]

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 (almost a) 1977 GMC Eleganza II, 455 newer Tranny+3.55 FD. FiTech and FCC, new Hoses, Selector Valve and Electric Pump,
insulated Tanks, APC, McDash, Dash AC to Enviro Safe. Schräder V+extern Fills, Ceramic Film TPMS FlexSteel Seats

 

[Irish Rogue]

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 strai=
ght talk and know you have been there, done that! Even a non mechanic lik=
e me knows that it=E2=80=99s all about good maintenance - and you remind us=
to do it and how and why!!! Thanks for sharing!!! Mike/The Corvair a h=
olic Sent from my iPhone > On Aug 30, 2018, at 10:21 PM, Bob Duna=
hugh wrote: > > I just hate to see owners being=
told that they must, or should rebuild their engine because of the oil pr=
essure 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 site=
s, 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 perf=
orm simple task as fast as we use too. And have some parts that we just wi=
ll 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 ailmen=
t that I've had most of my life. We travel a lot in our GMC. It's our magi=
c 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. A=
bout 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=
ist.gmcnet.org > Subject: Tid Bits: Why engines burn oil. > > > S=
hort 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 lon=
g. 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 pp=
m 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 pr=
eferred) 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 produ=
cing excessive amounts of carbon in the chamber. Great if your making sandp=
aper. Luging the engine by not shifting down on hills. Puts excessive load=
s on rings. Engine overheating can take much of the tension out of the ring=
s. Ignition timing way off. Valve stems/guide clearance is another express=
way for oil to the chamber. Again here. An over rich fuel ratio is very dam=
aging. The positive crankcase ventilation system is next. This system gener=
ally has few issue. Replace the PCV valve in the valve cover. And NEVER p=
ut 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 comb=
ustion chamber. The Howell EFI with spark control will solve all this exce=
pt 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 cl=
earance with a HV pump doesn't help. There is absolutely no one on this ea=
rth 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 prove=
s 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 N=
ickle content in the engine block. The 403 didn't have a lower intake mani=
fold. Just the standard rear wheel drive car intake. A larger bearing clea=
rance, 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 we=
ll 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 beari=
ngs should never come in contact with the crankshaft. There should always b=
e 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 t=
he salvation for you engine. By draining out the diluted oil by fuel, and t=
he 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 wo=
rld out there in our engines. Our oil filters. NO MATTER the brand. Are onl=
y 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 4=
03 that was in our 78 Royale. Had 152,000 miles on it. Was in pure excellen=
t 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 fo=
r 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, Fo=
r now. GRIN Bob Dunahugh > ____________________________________________=
___ > GMCnet mailing list > Unsubscribe or Change List Options: > htt=
p://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org