Oil pressures/volume. Myth/fact. And what GM required back in the 70's.

[Bob Dunahugh]

Prior to the early 50's. Splash systems were common. Then in the late 50's=
. Valve spring pressures went up along with compression ratio's, and highe=
r RPM engines. These were the main engine changes. That brought on the wide=
spread use of the direct pressure systems of today. GM found many decades =
ago. That at load. Not at idle. 25 PSI was more then adequate for the engin=
es with compression ratios below 9.5. ( Our 403's, and455's are at 8.) At i=
dle. 15 PSI was normal. As there was no real load on the engine. GM had th=
e low oil pressure light come on at 7, to 10 PSI back in the 60's and 70's.=
These where pressures that GM felt comfortable with to protect their warra=
nty with. When the public started to want the gauge back. And not get compl=
aints. Oil pressure gauges displayed LOW, and HIGH. Thus avoiding numbers. =
Nowadays. Some engine builders address this issue by putting in high volume=
oil pumps in all their engine to avoid these same issues with their custom=
ers. And the customer is impressed with the fact that they have a high vol=
ume oil pump. The HV pump then covers up that the builder did. Built the en=
gine at the outer limits of the GM specs. GM knew their engines more then A=
NYONE. Thus GM put in the MOST CORRECT sized oil pumps. I believe about 5.2=
gallons per minute? That would serve that engine for it's entire life spa=
n. HV pumps don't lube the engine any better then the GM stock pump. They j=
ust produce more oil pressure at idle. And that's not needed. That 50% more=
oil they pump. Just goes directly back into the oil pan ONLY. And NOT to a=
ny of the engine moving components. The HV pump does produce 50% more heat=
then stock. And take 50% more horse power to run. I build engines. And wou=
ld never install one on a properly built engine. The HV pump well help to e=
xtend the life of a bad engine. The 403/455 are very robust engine. Nothin=
g hard, or special to remanufacture. They, as any engine. Require much att=
ention to cleanliness. Not bells, and trinkets to make the build sound, or =
look like more then they are. Bob Dunahugh

 

[Jim Hupy]

Yup!
Jim Hupy
Salem, Or
78 GMC 403 (127,120 Miles on the clock, still on the original timing gears
and chain, though I am probably pushing my luck on that)

> Prior to the early 50's. Splash systems were common. Then in the late
> 50's. Valve spring pressures went up along with compression ratio's, and
> higher RPM engines. These were the main engine changes. That brought on the
> wide spread use of the direct pressure systems of today. GM found many
> decades ago. That at load. Not at idle. 25 PSI was more then adequate for
> the engines with compression ratios below 9.5. ( Our 403's, and455's are at
> 8.) At idle. 15 PSI was normal. As there was no real load on the engine.
> GM had the low oil pressure light come on at 7, to 10 PSI back in the 60's
> and 70's. These where pressures that GM felt comfortable with to protect
> their warranty with. When the public started to want the gauge back. And
> not get complaints. Oil pressure gauges displayed LOW, and HIGH. Thus
> avoiding numbers. Nowadays. Some engine builders address this issue by
> putting in high volume oil pumps in all their engine to avoid these same
> issues with their customers. And the customer is impressed with the fact
> that they have a high volume oil pump. The HV pump then covers up that the
> builder did. Built the engine at the outer limits of the GM specs. GM knew
> their engines more then ANYONE. Thus GM put in the MOST CORRECT sized oil
> pumps. I believe about 5.2 gallons per minute? That would serve that engine
> for it's entire life span. HV pumps don't lube the engine any better then
> the GM stock pump. They just produce more oil pressure at idle. And that's
> not needed. That 50% more oil they pump. Just goes directly back into the
> oil pan ONLY. And NOT to any of the engine moving components. The HV pump
> does produce 50% more heat then stock. And take 50% more horse power to
> run. I build engines. And would never install one on a properly built
> engine. The HV pump well help to extend the life of a bad engine. The
> 403/455 are very robust engine. Nothing hard, or special to remanufacture.
> They, as any engine. Require much attention to cleanliness. Not bells, and
> trinkets to make the build sound, or look like more then they are. Bob
> Dunahugh
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

 

[richard michelhaugh]

My 1931 Graham has full pressure lube system. Even the tappets had pressure oil lube.

I agree that GM knew what they were doing with the sizing of the oil pump.

Pressure is a function of clearances and oil flow rate at a given temperature.
If your operating pressure is going down, clearances are opening up due to wear.

Rick M.
--
1974 26' Canyonlands
aka "The General"
Clinton, TN

 

[Matt Colie]

Bob,

You are correct on a lot, but my 1928 Ford Model A had a oil pump. The somewhat older Model T engine that I once owned, did not.

I have owned many other vehicles that might now be classed as classic if not antique and only the one two-stoke (Gogo Mobile 5 moving parts, 9 if you
count the wheels) did not have a lube oil pump. I never owned a Saab.

With the refresh that I just did, I did go with a high volume pump, but I also know that the crank, rods and cam bearings are all slightly (and I mean
0.0005) looser than new. As one can no longer buy "tight" bearings for old engines, I thought that the higher volume with the standard pressure
spring was a good choice. If I could have put it back to stock clearances, I would have stayed with the standard pump. After 70k, it was still good.

Matt
--
Matt & Mary Colie - '73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan
OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Twixt A2 and Detroit

 

[Bob Dunahugh]

Many of the splash system had oil pumps. All of the manufactures back befo=
re the 50's had their own twist. Some were very ingenious, and fascinating =
to see. And showed just how little oil was needed. Bob Dunahugh ___=
_____________________________ From: Bob Dunahugh =
Sent: Monday, August 27, 2018 2:23 PM To: gmclist Su=
bject: Oil pressures/volume. Myth/fact. And what GM required back in the 70=
's. Prior to the early 50's. Splash systems were common. Then in t=
he late 50's. Valve spring pressures went up along with compression ratio's=
, and higher RPM engines. These were the main engine changes. That brought=
on the wide spread use of the direct pressure systems of today. GM found m=
any decades ago. That at load. Not at idle. 25 PSI was more then adequate f=
or the engines with compression ratios below 9.5. ( Our 403's, and455's are=
at 8.) At idle. 15 PSI was normal. As there was no real load on the engin=
e. GM had the low oil pressure light come on at 7, to 10 PSI back in the 60=
's and 70's. These where pressures that GM felt comfortable with to protect=
their warranty with. When the public started to want the gauge back. And n=
ot get complaints. Oil pressure gauges displayed LOW, and HIGH. Thus avoidi=
ng numbers. Nowadays. Some engine builders address this issue by putting in=
high volume oil pumps in all their engine to avoid these same issues with =
their customers. And the customer is impressed with the fact that they hav=
e a high volume oil pump. The HV pump then covers up that the builder did. =
Built the engine at the outer limits of the GM specs. GM knew their engines=
more then ANYONE. Thus GM put in the MOST CORRECT sized oil pumps. I belie=
ve about 5.2 gallons per minute? That would serve that engine for it's ent=
ire life span. HV pumps don't lube the engine any better then the GM stock =
pump. They just produce more oil pressure at idle. And that's not needed. T=
hat 50% more oil they pump. Just goes directly back into the oil pan ONLY. =
And NOT to any of the engine moving components. The HV pump does produce 5=
0% more heat then stock. And take 50% more horse power to run. I build engi=
nes. And would never install one on a properly built engine. The HV pump we=
ll help to extend the life of a bad engine. The 403/455 are very robust en=
gine. Nothing hard, or special to remanufacture. They, as any engine. Requ=
ire much attention to cleanliness. Not bells, and trinkets to make the buil=
d sound, or look like more then they are. Bob Dunahugh

 

[johnny]

A thing I read said Henry wanted the flathead V-8 to run on a splash system to save money.The author was a test driver who said the Ford design
engineers, who wanted pressure oiling told the test drivers to keep the cars in a turn until the engine blew from lack of oil. Henry relented, the
60HP flathead got an oil pump.

--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

 

[les burt]

Didn’t someone ask Patterson his opinion about HV oil pumps?

I recall some comments written here that mentioned running a HV pump combined with a lightly looser clearances to help with removing heat from the friction surfaces. Was that not one of Patterson’s tricks that he employed in his TZE specific engine builds?

It is my belief that HV oil pumps do have their place when used with the appropriate and necessary additional engine mods. It is also my belief that in most street driven applications , they are not a necessity, as previously stated here.

Les Burt
Montreal
'75 Eleganza 26'

>
> A thing I read said Henry wanted the flathead V-8 to run on a splash system to save money.The author was a test driver who said the Ford design
> engineers, who wanted pressure oiling told the test drivers to keep the cars in a turn until the engine blew from lack of oil. Henry relented, the
> 60HP flathead got an oil pump.
>
>
> --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
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org

 

[Jim Hupy]

There is absolutely NO SUBSTITUTE for having an engine with the correct
clearances, align bored, with a straight crankshaft that is balanced to run
at the rpm's required, with smooth, straight, round cylinder bores, matched
valve springs, tight timing chain, that is carefully broken in.
Stock oil pumps provide way more than adequate flow and pressure
needed under these conditions.
There is one area in the OLDS 455 that needs special attention when it
comes to lubrication, and that is the main bearing that carries the end
play or thrust of the crankshaft. Many of the OLDS crankshafts that I have
encountered over the years, and that involves automobiles, motorhomes, and
jet boats. Both types of jet boats, heavily laden gill netters as well as
high speed pleasure/water ski types. All of those examples are as different
as night and day when lubrication requirements are examined.
The only appropriate time I have encountered the need for a high
volume/high pressure oil pump is on a 6000 rpm supercharged engine set up
at the high end of bearing clearances and piston fit to accommodate the
high rpm's. Even then, the bearings don't last well.

> Didn’t someone ask Patterson his opinion about HV oil pumps?
>
> I recall some comments written here that mentioned running a HV pump
> combined with a lightly looser clearances to help with removing heat from
> the friction surfaces. Was that not one of Patterson’s tricks that he
> employed in his TZE specific engine builds?
>
> It is my belief that HV oil pumps do have their place when used with the
> appropriate and necessary additional engine mods. It is also my belief that
> in most street driven applications , they are not a necessity, as
> previously stated here.
>
> Les Burt
> Montreal
> '75 Eleganza 26'
>
>
> > On Aug 28, 2018, at 9:00 AM, Johnny Bridges via Gmclist <

> >
> > A thing I read said Henry wanted the flathead V-8 to run on a splash
> system to save money.The author was a test driver who said the Ford design
> > engineers, who wanted pressure oiling told the test drivers to keep the
> cars in a turn until the engine blew from lack of oil. Henry relented, the
> > 60HP flathead got an oil pump.
> >
> >
> > --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
> >
> >
> > _______________________________________________
> > 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
>

 

[LarryW]

FWIW, I have seen high volume pumps put in older engines that had rod clearances on the high side of spec, begin to burn more oil as soon as the new
HV pump was put on. With a HV pump, more oil going to the rods and mains, means that more oil is also thrown onto the cylinder walls, and then the
scraper ring cannot handle the excess oil. More oil then gets by the rings into the combustion chamber, and oil consumption goes up. If you are going
to take it that far apart to replace the oil pump, you need to pull the rod caps and inspect the bearings. Then, plasti-gauge the rods and if at, or
over .002, either put a original volume pump back in, or pull the engine and get control of the clearances. With todays precision grinding equipment,
clearances should not be more than .0015 at the most and preferably closer to .001. Then run todays modern oils with a 5w30 or lighter oil. This with
everything that Jim Hupy mentioned with give you and engine that will pull hard, and with normal preventive maintenance last a long time. Other
considerations to consider keeping oil consumption down are, valve guide clearances within specs, and PC type seals on the intake with umbrellas on
the exhaust. That allows a minimum of oil sucked down the intake where there is vacuum and umbrellas allows a little more oil to lube the hot
pressurized exhaust valve guides. You also need to get control of the PCV system. Chrome valve covers may look nice but I have yet to see those covers
with baffles. No baffles on a PCV that is directly connected below the throttle plates where there is max vacuum, is a recipe for excess oil
consumption. In addition, placement of rings on pistons during assembly is critical in controlling oil and keeping compression consistent across all
cylinders. See this for proper ring placement.

http://www.gmcmhphotos.com/photos/g4104-putting-rings-on-pistons.html

All of the above...JMHO
--
Larry
78 Royale w/500 Caddy
Menomonie, WI.

 

[Bob Dunahugh]

Les. Mr Paterson has talked about reducing piston skirt temps with more oi=
l spray. For along time. By way of extra bearing clearances, and the HV oi=
l pump. I have great respect for Dick. And there is truth in that idea. But=
it's solving an issue that the Olds 403, and 455 never had. If there was=
a skirt heating issue. How have all these Olds engine lasted for all thes=
e years. Plus the GM engineering department would have found the problem=
then. And solved it. The stock GM oil pump can put out about 5.2 gallons o=
f oil per minute as I recall. The HV pump is at 7.8 GPM. 50% more. And tha=
t extra 50% just gets dumped directly back into the bottom of the oil pan. =
That's a lot. The 455 piston skirt will build slightly more heat then the =
403 skirt. And that is because of a longer stroke. And rod angle to the pis=
ton. The major heat source is the piston crown. This extreme heat load is d=
ispersed by the oil spray that's from the main/rod bearings. That oil spr=
ay comes in contact with the bottom of the piston, and skirt. Thus keeping =
the piston within the proper temperature paramotors that are set by GM engi=
neering. The bottom side of a used piston will display this well. K=
eep in mined that anytime that you move, or compress a liquid. It takes en=
ergy. And produces heat. The HV oil pump takes 50% more horse power to run.=
And produces 50% more heat then the stock oil pump. This issue also com=
es into play by the fact this oil spray from the main/rod bearings. Offers=
resistance to the rotation of the crankshaft, and connecting rods. This la=
st one is small. But it's there. I've spent a huge number of dino hours loo=
king for any tiny resistance to torque, and pony power. You don't get 250 p=
lus HP at 7,to 8,000 RPM's out of 164 cubic inch engine that's over 50 year=
s old. NO nitrous, turbo, or super chargers. It's the same with some GMC ow=
ners. Always looking for that extra ft lbs of torque. The HV pump h=
as it's place. If you add an extra non stock oil cooler. One of my track CO=
PO Yenko's has a very large Harrison aircraft engine oil cooler added. Add =
a non stock turbo, or super charger. There is ONE thing that I po=
sitively know. I'm not smarter then the engineers at GM that designed our 4=
03,or 455. Bob Dunahugh ________________________________ Fr=
om: Bob Dunahugh Sent: Monday, August 27, 2018 2:2=
3 PM To: gmclist Subject: Oil pressures/volume. Myth/fa=
ct. And what GM required back in the 70's. Prior to the early 50's.=
Splash systems were common. Then in the late 50's. Valve spring pressures=
went up along with compression ratio's, and higher RPM engines. These wer=
e the main engine changes. That brought on the wide spread use of the direc=
t pressure systems of today. GM found many decades ago. That at load. Not a=
t idle. 25 PSI was more then adequate for the engines with compression rati=
os below 9.5. ( Our 403's, and455's are at 8.) At idle. 15 PSI was normal. =
As there was no real load on the engine. GM had the low oil pressure light=
come on at 7, to 10 PSI back in the 60's and 70's. These where pressures t=
hat GM felt comfortable with to protect their warranty with. When the publi=
c started to want the gauge back. And not get complaints. Oil pressure gaug=
es displayed LOW, and HIGH. Thus avoiding numbers. Nowadays. Some engine bu=
ilders address this issue by putting in high volume oil pumps in all their =
engine to avoid these same issues with their customers. And the customer i=
s impressed with the fact that they have a high volume oil pump. The HV pum=
p then covers up that the builder did. Built the engine at the outer limits=
of the GM specs. GM knew their engines more then ANYONE. Thus GM put in th=
e MOST CORRECT sized oil pumps. I believe about 5.2 gallons per minute? Tha=
t would serve that engine for it's entire life span. HV pumps don't lube t=
he engine any better then the GM stock pump. They just produce more oil pre=
ssure at idle. And that's not needed. That 50% more oil they pump. Just goe=
s directly back into the oil pan ONLY. And NOT to any of the engine moving =
components. The HV pump does produce 50% more heat then stock. And take 50=
% more horse power to run. I build engines. And would never install one on =
a properly built engine. The HV pump well help to extend the life of a bad =
engine. The 403/455 are very robust engine. Nothing hard, or special to r=
emanufacture. They, as any engine. Require much attention to cleanliness. N=
ot bells, and trinkets to make the build sound, or look like more then they=
are. Bob Dunahugh

 

[les burt]

I=E2=80=99m not trying to argue anything here as I=E2=80=99m in agreement w=
ith what has been said on the subject. For discussion purposes though=
, I=E2=80=99m going to toss out a few more thoughts. It isn=E2=80=
=99t a secret that the Olds engines work much harder pushing a TZE than the=
y do pushing a car. Proof of that is in the number of TZE engines that surv=
ive over 200k miles before requiring major repair. . . Very few. I=E2=80=
=99ve seen several cars with 403s and 455s that exceeded 200k miles. =
Disregarding the short-lived rebuilds that have died from oil debris rel=
ated failures, what are the main causes that require a TZE engine to be pul=
led and overhauled? From my limited recollections, it appears to be mainly=
oil consumption or compression related issues that drive the need for such=
major repairs. This would indicate that the higher stresses encountered in=
a TZE affect the pistons and cylinders sooner than the rest of the rotatin=
g assembly. The above leads me to think Patterson was looking for way=
s to get a bit more life out of his TZE specific engine builds. Tossing mor=
e oil up on the cylinder walls and piston underside is one way to help redu=
ce thermal issues and improve lubrication. With modern ring technology and =
high quality machining/assembly techniques, oil control past the rings are =
less of an issue than it was in the 70s. Another issue that has an e=
ffect on all the above is oil viscosity. Running a thinner oil helps with o=
il flow, takes less HP to pump, and is less likely to overload the oil scra=
per rings. Thinner oil combined with a HV pump will build oil pressure quic=
ker on start-up, reducing rotating assembly wear. With Patterson havi=
ng likely spent many hours of Dyno time running olds engines, I=E2=80=99m s=
ure he had some test data to support his thinking. His engines have a reput=
ation for durability and longevity, so his thinking appears to have worked =
in his engine builds. I haven=E2=80=99t had the benefit of meeting D=
ick Paterson, nor have I viewed any of his presentations. All that I know a=
bout his engines has been acquired through comments made by others. That ma=
kes me less than an expert on the subject. Les Burt Montreal '=
75 Eleganza 26' > On Aug 28, 2018, at 5:24 PM, Bob Dunahugh wrote: > > Les. Mr Paterson has talked about reducing=
piston skirt temps with more oil spray. For along time. By way of extra b=
earing clearances, and the HV oil pump. I have great respect for Dick. And =
there is truth in that idea. But it's solving an issue that the Olds 403, a=
nd 455 never had. If there was a skirt heating issue. How have all these=
Olds engine lasted for all these years. Plus the GM engineering departm=
ent would have found the problem then. And solved it. The stock GM oil pump=
can put out about 5.2 gallons of oil per minute as I recall. The HV pump i=
s at 7.8 GPM. 50% more. And that extra 50% just gets dumped directly back =
into the bottom of the oil pan. That's a lot. The 455 piston skirt will bui=
ld slightly more heat then the 403 skirt. And that is because of a longer =
stroke. And rod angle to the piston. The major heat source is the piston cr=
own. This extreme heat load is dispersed by the oil spray that's from the =
main/rod bearings. That oil spray comes in contact with the bottom of the =
piston, and skirt. Thus keeping the piston within the proper temperature pa=
ramotors that are set by GM engineering. The bottom side of a used piston w=
ill display this well. > > Keep in mined that anytime that you move,=
or compress a liquid. It takes energy. And produces heat. The HV oil pump=
takes 50% more horse power to run. And produces 50% more heat then the sto=
ck oil pump. This issue also comes into play by the fact this oil spray =
from the main/rod bearings. Offers resistance to the rotation of the crank=
shaft, and connecting rods. This last one is small. But it's there. I've sp=
ent a huge number of dino hours looking for any tiny resistance to torque, =
and pony power. You don't get 250 plus HP at 7,to 8,000 RPM's out of 164 cu=
bic inch engine that's over 50 years old. NO nitrous, turbo, or super charg=
ers. It's the same with some GMC owners. Always looking for that extra ft l=
bs of torque. > > The HV pump has it's place. If you add an extra no=
n stock oil cooler. One of my track COPO Yenko's has a very large Harrison =
aircraft engine oil cooler added. Add a non stock turbo, or super charger.=
> > There is ONE thing that I positively know. I'm not smarter th=
en the engineers at GM that designed our 403,or 455. > > Bob Dunahugh=