[GMCnet] External engine oil cooler

[Scott Nutter]

I am getting ready to replace my old external oil cooler (the nipple leaks on the old one). My existing radiator does not have the built in coolers.
The new oil cooler is a vertical unit.
My question is what flow direction should l plan for on a vertical cooler?
After researching old posts, I'm still somewhat unsure.
Should I route the flow to the top of the cooler and let gravity help out a bit? Or route the flow to the bottom and the return line out the top?
The 2nd option sounds best to me. The reason being is that the oil might be slowed a little pumping up hill, allowing it to be cooled further and
reduce the possibility of air bubbles. And I thought the rule of thumb with liquid cooling in a vertical cooler was to flow from bottom to top.
Any suggestions, ideas, recommendations?? Or am I overthinking this thing all together! Thanks
--
Scott Nutter
1978 455 Royale Center Kitchen.
Houston, Texas

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[Johnny Bridges]

I think you're overdoing it. If it were me, and I thought I needed an external cooler (I don't) I'd plumb it easiest way.

--johnny
--
'76 23' transmode Norris upfit
Braselton, Ga.

"Sometimes I wonder what tomorrow's gonna bring when I think about my dirty life and times" --Warren Zevon

[Thomas Phipps]

Having looked at the oil cooler assembly in GM Heavy Duty pick-up trucks, GM plumbed the oil lines to a flat plate cooler with the in and the out in
the same horizontal frame. In the top on one side and out the top on the other side. They did install a vertical oil cooler on the same mounting
frame, but it was sized for and used to cool the transmission oil. This is from memory and may vary. Local pull-a-part has several of these
additional GM factory oil coolers available. I have thought that the next time I go there, I'll grab one or two. I did grab one of the transmission
oil coolers - nice and compact. Would be easy to plumb into a GMC.
I realize that this does not answer your question, so this is just an observation.
Tom, MS II
--
1975 GMC Avion
KA4CSG

[Scott Nutter]

I would be a little reluctant to install a used cooler based on older posts. Unless it can be 100% cleaned. Seems the big concern is introducing
possible contamination into the oil system from a used cooler.
--
Scott Nutter
1978 455 Royale Center Kitchen, Quad bags.
Houston, Texas

[Adrien Genesoto]

Scott Nutter wrote on Wed, 02 December 2015 12:49

> I am getting ready to replace my old external oil cooler (the nipple leaks on the old one). My existing radiator does not have the built in
> coolers.
> The new oil cooler is a vertical unit.
> My question is what flow direction should l plan for on a vertical cooler?
> After researching old posts, I'm still somewhat unsure.
> Should I route the flow to the top of the cooler and let gravity help out a bit? Or route the flow to the bottom and the return line out the top?
> The 2nd option sounds best to me. The reason being is that the oil might be slowed a little pumping up hill, allowing it to be cooled further and
> reduce the possibility of air bubbles. And I thought the rule of thumb with liquid cooling in a vertical cooler was to flow from bottom to top.
> Any suggestions, ideas, recommendations?? Or am I overthinking this thing all together! Thanks

Scott,

I see it this way. If it's in at top then the cooler could or may be drained when changing oil filter, therefor replacing that amount more.
In at the bottom, the oil might not be drained at oil filter change time.
Either way, it may not make the much of a difference over all.

JM2C FWIW

--
”When we avoid the mistakes we might have made, we sometimes make the mistakes that we might have avoided.”

Adrien & Jenny 6993339035
75 Glenbrook
Yuba City,Ca.

[Robert Mueller]

Scott,

I would suggest you consider an oil cooler with a fan and a thermostat (if it doesn't come with one):

Tiny URL: http://tinyurl.com/jddz5q7

Full URL:

http://www.amazon.com/gp/product/B000CN6TPU/ref=pd_lpo_sbs_dp_ps_2/180-9370957-8622730?pf_rd_m=ATVPDKIKX0DER&pf_rd_s=lpo-top-stripe-
1&pf_rd_r=0MEZDX2PYPXJRG7C2WRD&pf_rd_t=201&pf_rd_p=1944687762&pf_rd_i=B000CIGEA0

Or

Tiny URL: http://tinyurl.com/jddz5q7

Full URL:

http://www.amazon.com/70297-Hi-Tek-Transmission-Cooling-System/dp/B000CIIE1W/ref=sr_1_8?s=automotive&ie=UTF8&qid=1449094169&sr=1-8&k
eywords=b%26m+oil+coolers

As far as mounting it goes it doesn't matter, the oil is under pressure and will flow up / down or left / right.

Regards,
Rob M.
The Pedantic Mechanic
Sydney, Australia
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426

-----Original Message-----
From: Scott Nutter

I am getting ready to replace my old external oil cooler (the nipple leaks on the old one). My existing radiator does not have the
built in coolers.
The new oil cooler is a vertical unit.
My question is what flow direction should l plan for on a vertical cooler?
After researching old posts, I'm still somewhat unsure.
Should I route the flow to the top of the cooler and let gravity help out a bit? Or route the flow to the bottom and the return line
out the top?
The 2nd option sounds best to me. The reason being is that the oil might be slowed a little pumping up hill, allowing it to be
cooled further and reduce the possibility of air bubbles. And I thought the rule of thumb with liquid cooling in a vertical cooler
was to flow from bottom to top. Any suggestions, ideas, recommendations?? Or am I overthinking this thing all together! Thanks
--
Scott

[George Beckman]

Scott Nutter wrote on Wed, 02 December 2015 10:49

> I am getting ready to replace my old external oil cooler (the nipple leaks on the old one). My existing radiator does not have the built in
> coolers.
> The new oil cooler is a vertical unit.
> My question is what flow direction should l plan for on a vertical cooler?

> The 2nd option sounds best to me. The reason being is that the oil might be slowed a little pumping up hill, allowing it to be cooled further and
> reduce the possibility of air bubbles. And I thought the rule of thumb with liquid cooling in a vertical cooler was to flow from bottom to top.
> Any suggestions, ideas, recommendations?? Or am I overthinking this thing all together! Thanks

I favor letting it fill from the bottom and return out the top. I agree this may prevent having bubbles of air with fluid trickling around them. I did
my external transmission cooler that way as well.

I do have a fan on it that I control. It runs most of the time unless it is very cool outside. I do have the original radiator coolers as well.
--
'74 Eleganza, SE, Howell + EBL
Best Wishes,
George

[Jim Kanomata]

What is important is that the cooler be about an inch from the radiator
face so that the fan will pull air through the cooler.
Going down the road the air will tend to go around the cooler and little
through the cooler if mountd far from the face of radiator.

--
Jim Kanomata
Applied/GMC, Fremont,CA
ji...@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502

[Matt Colie]

In recent years, a number of Detroit OEs have made cars that need extra oil cooling. What I have seen most of were Modine pancake units. They are
about the same price as any oil cooler and could easily replace the cooler adapter that is on our coaches. Instead of running new oil lines, it could
be put in series with the water heater. The only thing I have never decided about the coach application is if I would put it in the feed to or the
return from the HWH.
It sure was clean on the two cars that I had with them.

Matt
--
Matt & Mary Colie - Members GMCMI, GMCES
'73 Glacier 23 - Still Loving OE Rear Drum Brake with Applied Control Arms
SE Michigan - Twixt A2 and Detroit

[Jerry Sitzlar]

This past summer I installed the Derale external oil cooler that Rob referenced. I installed it horizontally and it works great. Derale suggested,
that it didn't matter which end was up or in and out.

Jerry

--
Jerry Sitzlar..... 77 Eleganza II, Twin bed, dry bath......
Lenoir City, TN

[Scott Nutter]

**UPDATE**
New oil cooler install update

Installed today. I used a vertical USA made 1/2" nipple 5 loop oil cooler from Summit racing. I took out the old rubber lines and replaced with
hi pressure 1/2 Id hyd hose(temporary, until I save enough to go with JR Slatens hard lines). I routed the oil flow to the BOTTOM of the cooler to
pump up hill through the cooler,then exit from the top, then back to the filter assembly. I forgot to mention that I mounted the cooler on the lower
front of the radiator housing passenger side, 1 1/2" Space between radiator and oil cooler.
iNTERESTING FIND. After taking out the old vertical cooler, that was originally mounted right next to to the radiator with minimal space
between the two, there was a solid build up of dirt, gunk, bugs that only caked the inside dimensions of the oil cooler!! So thank you Jim K from
Applied for specifly mentioning to mount the new cooler AT LEAST 1" away from the fadiator. GOOD ADVICE!! The PO lost at lease 15% of air cooling
from not spacing correctly..
HANGER REPORT. Not enough time for a road report tonight. Only had time to fill with oil (Rotella T6 full syn) and start.
Why does a car always sound better with new oil, and goes faster with fresh wax!! Who knows, I'll file that with women's orgasims and ufo's.
Bottom line my old original oil gauge showed a increase of two needles of STEADY oil pressure.
BOTTOM LINE. The gunk that I swabbed out of the old oil cooler was insane...it was like cleaning out a grease trap. No wonder my oil gauge would
fluctuate in a previous life. If you run a cooler, maybe think about changing out every 5 years. Cheap insurance, and oil is our coaches blood line..

--
Scott Nutter
1978 455 Royale Center Kitchen, Quad bags.
Houston, Texas

[Robert Mueller]

Scott,

Would like some clarification of your email below, questions in CAPS for clarity I'm not shouting.

Regards,
Rob M.
The Pedantic Mechanic

-----Original Message-----
From: Scott Nutter

**UPDATE**
New oil cooler install update

Installed today. I used a vertical USA made 1/2" nipple

DOES THE COOLER HAVE 1/2" PIPE NIPPLES OR 1/2" INVERTED FLARE FITTINGS?

5 loop oil cooler from Summit racing.

WHICH ONE? LINK?

I took out the old rubber lines and replaced with hi pressure 1/2 Id hyd hose (temporary, until I save enough to go with JR Slatens
hard lines).

JR PRODUCES TWO TYPES OF OIL COOLER LINES THAT CONNECT THE OIL COOLER ADAPTER TO THE OIL COOLER IN THE OEM RADIATOR; THEY MIGHT NOT
WORK WITH YOUR COOLER.

FOR THE 455: http://www.appliedgmc.com/prod.itml/icOid/1301 + http://www.appliedgmc.com/prod.itml/icOid/587

FOR THE 403: http://www.appliedgmc.com/prod.itml/icOid/586

I routed the oil flow to the BOTTOM of the cooler to pump up hill through the cooler, then exit from the top, then back to the

filter assembly. I forgot to mention that I mounted the cooler on the lower front of the radiator housing passenger side, 1 1/2"
Space between radiator and oil cooler.

A PHOTO WOULD BE INTERESTING.

After taking out the old vertical cooler, that was originally mounted right next to to the radiator with minimal space
between the two, there was a solid build up of dirt, gunk, bugs that only caked the inside dimensions of the oil cooler!! So thank
you Jim K from Applied for specifly mentioning to mount the new cooler AT LEAST 1" away from the fadiator. GOOD ADVICE!! The PO lost
at lease 15% of air cooling from not spacing correctly.

YOU'RE SAYING THAT THE AIR FLOW PATH WAS CHOKED UP?

HANGER REPORT. Not enough time for a road report tonight. Only had time to fill with oil (Rotella T6 full syn) and start.
Why does a car always sound better with new oil, and goes faster with fresh wax!! Who knows, I'll file that with women's orgasims
and ufo's. Bottom line my old original oil gauge showed a increase of two needles of STEADY oil pressure.

WHERE WAS THE NEEDLE ON THE OEM GAGE.

BOTTOM LINE. The gunk that I swabbed out of the old oil cooler was insane...it was like cleaning out a grease trap. No wonder my oil
gauge would fluctuate in a previous life. If you run a cooler, maybe think about changing out every 5 years. Cheap insurance, and
oil is our coaches blood line.

DID YOU SWAB OUT BOTH THE INLET AND OUTLET OF THE OIL COOLER? WHAT DID THE GUNK LOOK LIKE?

Scott

[Ken Henderson]

Scott,

I'm afraid you misinterpreted JimK's recommendation: "...about an inch
from the radiator..." was followed by "...air will tend to go around the
cooler and little through the cooler if mounted too far from the
radiator...".

A little space is good for removal of debris like you found; but, as Jim
and every authoritative reference I know says, no MORE than 1". It's the
turbulence between the two that creates the problem.

Ken H.
​​

[John R. Lebetski]

Regarding the Modine cooler/adaptors. These were used on a variety of stern drives and as I found out looking at a 89 Turbo Trans Am last week on
those too. I'm sure they make one to fit Olds as lots of those were used in boats. Says Modine on the cooler adaptor. If you search Wixfilters it
shows VIN 7 89 TTA and a list of boat apps.
--
John Lebetski
Woodstock, IL
77 Eleganza II
Source America First

[Scott Nutter]

Rob
The new cooler is the Perma-cool #691 from Summit racing. The hose nipples are the 1/2" hose barb type.
And yes, the air path was completely blocked between the oil cooler and the radiator. I tried to wire brush and air blow the rad fins, but I won't be
happy till I can get some hi pressure water in there. I should of taken a photo, but I was up against the clock.
On the oem oil press gauge, it would run on the half mark. Now it runs two needle widths above half. But now I'm running Rotella fully synthetic oil

Ken,
Your right, and thanks for the correction.

--
Scott Nutter
1978 455 Royale Center Kitchen, Quad bags.
Houston, Texas

[Robert Mueller]

Scott,

The fins of a radiator are thin, if you use a high pressure water washer to clean the crap that is in between them be careful not to
hit the fins at an angle as they bend easily.

http://www.dieselplace.com/forum/63-gm-diesel-engines/21-6-5l-diesel-engine/48141-will-hurt-pressure-wash-radiator.html

Regards,
Rob M.
The Pedantic Mechanic

-----Original Message-----
From: Scott Nutter

Rob
The new cooler is the Perma-cool #691 from Summit racing. The hose nipples are the 1/2" hose barb type.
And yes, the air path was completely blocked between the oil cooler and the radiator. I tried to wire brush and air blow the rad
fins, but I won't be happy till I can get some hi pressure water in there. I should of taken a photo, but I was up against the
clock.
On the oem oil press gauge, it would run on the half mark. Now it runs two needle widths above half. But now I'm running Rotella
fully synthetic oil

[Johnny Bridges]

If it was me, I'd take my hose to the rear of the radiator and run it forward (against the normal air flow)with no more pressure than the hose
supplies through a spray nozzle. That will usually push even the toughest grot forward out of the fins, I just gave half a GMC Unit to recore it, no
way I'm gonna bend up the flues in the new core with a pressure washer. The crud will wash out frontwards, perhaps with a bit of help with a bristle
round parts brush, again applied from the rear.

--johnny
--
'76 23' transmode Norris upfit
Braselton, Ga.

"Sometimes I wonder what tomorrow's gonna bring when I think about my dirty life and times" --Warren Zevon

[Joe Weir]

[...half a GMC unit...]

LOL!

--
76 Birchaven - "Wicked Mistress" - New engine, trans, alum radiator, brakes, Sully airbags, fuel lines, seats, adult beverage center... those Coachmen
guys were really thinking about us second hand owners by including that beverage center...
Columbia, SC.

[Hal StClair]

The most efficient,effective way to mount the cooler would be with the flow horizontal and the 'hot' fluid entering from the top and returning from
the bottom. Of course it's not always possible or convenient to mount the cooler in that position and the advantages are probably marginal.
Just my thoughts,
Hal
--
1977 Royale 101348,

1977 Royale 101586,

1974 Eagle Bus 45',w/slideout

[John Heslinga]

Scott
Oil coolers need to flow from bottom to top. (Check out the instructions that come with your cooler. Or in such a way that air will not accumulate.
Air that gets trapped in tbe cooler will force oil to flow only where there is no air, Decreasing the efficiency of the cooler. (Especially where
there are headers such as many have) Here is my installation of a B&M large Hi Tech engine cooler with fan.

http://www.gmcmhphotos.com/photos/discussion-photos/p58168-oil-coolers-in-place.html

The nylon Stainless braided lines I had made by my local Hydraulic shop. And they go from the 455 steel lines to the cooler.
If I were to do it again. I would use "O ring" types of connectors because one small mistake in the tightening stratigy caused me to damage the first
cooler and they are not repairable. :(

Example.
http://m.alibaba.com/product/1885299803/Straight-Male-Tube-Fitting-Stainless-Steel.html

Here is the cooler unit out of the frame.
The cooler is on the side of the radiator that has no fan shroud (74s only covered about 4/5 of the rear of the rad) it had a thermostatic controlled
fan so when things get hot the fan blows through the Rad too. It is partially behind the frame so does not cool too much when it is not needed.

Here is a copy of the instruction sheet as to how a cooler should be installed.

http://www.bmracing.com/instructions/70298.pdf


--
John and Cathie Heslinga
1974 Canyonlands 260
455, Manny tranny and 1 ton, 3:70 LS,
Red Seal Journeyman, DTE, BEd. MEd.
Edmonton, Alberta

[Jim Kanomata]

Like everything, it is best to do it the best you can as there will be
times those simple procedures can end up to be critical ad costly.

--
Jim Kanomata
Applied/GMC, Fremont,CA
ji...@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502

[Robert Mueller]

John,

I'm sorry but I'm going to disagree with you re; "Oil coolers need to flow from bottom to top."

In an earlier email I noted that the orientation of the in and out ports on an oil cooler didn't matter; I arrived at that opinion
because the pressure (Min 25 psi) would compress them and/or the flow would flush them out. IIRC at idle (700 RPM) the oil pump flow
rate is about 3 GPM and at 2400 RPM it's about 8 GPM.

The Maintenance Manuals provide these two figures:

http://www.gmcmhphotos.com/photos/455-2f-403-engine-oil-flow-path/p53466-olds-455-oil-cooler-lines.html

http://www.gmcmhphotos.com/photos/455-2f-403-engine-oil-flow-path/p49555-olds-403-oil-cooler-lines.html

However, I would say that "best practice" would be to mount it as pictured in the B&M instructions.

Regards,
Rob M.
The Pedantic Mechanic


-----Original Message-----

From: John Heslinga

Scott
Oil coolers need to flow from bottom to top. (Check out the instructions that come with your cooler. Or in such a way that air will

not accumulate. Air that gets trapped in the cooler will force oil to flow only where there is no air, Decreasing the efficiency of

the cooler. (Especially where there are headers such as many have) Here is my installation of a B&M large Hi Tech engine cooler with
fan.

http://www.gmcmhphotos.com/photos/discussion-photos/p58168-oil-coolers-in-place.html

The nylon Stainless braided lines I had made by my local Hydraulic shop. And they go from the 455 steel lines to the cooler.

If I were to do it again. I would use "O ring" types of connectors because one small mistake in the tightening strategy caused me to

damage the first cooler and they are not repairable. :(

Example.
http://m.alibaba.com/product/1885299803/Straight-Male-Tube-Fitting-Stainless-Steel.html

Here is the cooler unit out of the frame.
The cooler is on the side of the radiator that has no fan shroud (74s only covered about 4/5 of the rear of the rad) it had a
thermostatic controlled fan so when things get hot the fan blows through the Rad too. It is partially behind the frame so does not
cool too much when it is not needed.

Here is a copy of the instruction sheet as to how a cooler should be installed.

http://www.bmracing.com/instructions/70298.pdf

John

[John Heslinga]

Yes Rob


a single path cooler like the oil coolers in the rad would not make much difference. Oil coolers that are a single path or pipe traversing back and
forth would also not make a difference either. However if you look at the B&M cooler which is multiple paths through each laminate. Oil can easily
flow through less than all the paths due to air locks. Many of the better coolers have headers and multiple paths. Many of the cooler installation
instructions ive followed have identified a bottom up installation.

This is one of the reasons for the "best practice" identified in the B&M instructions and others. I would say that one should probably make a good
effort use " Best Practice" and make it a "rule of thumb" and make sure you know why you wouldn't do it that way.

Wouldn't You?

--
John and Cathie Heslinga
1974 Canyonlands 260
455, Manny tranny and 1 ton, 3:70 LS,
Red Seal Journeyman, DTE, BEd. MEd.
Edmonton, Alberta

[Robert Mueller]

John,

I'm confused!

Here's a group of photos I took of the engine and transmission oil coolers, are you saying these are single pass coolers?

http://www.gmcmhphotos.com/photos/g6805-oem-engine-26amp-3b-trans-oil-coolers.html

Regards,
Rob M.
The Pedantic Mechanic

-----Original Message-----
From: John Heslinga

Yes Rob

a single path cooler like the oil coolers in the rad would not make much difference. Oil coolers that are a single path or pipe
traversing back and forth would also not make a difference either. However if you look at the B&M cooler which is multiple paths
through each laminate. Oil can easily flow through less than all the paths due to air locks. Many of the better coolers have
headers and multiple paths. Many of the cooler installation instructions ive followed have identified a bottom up installation.

This is one of the reasons for the "best practice" identified in the B&M instructions and others. I would say that one should
probably make a good effort use "Best Practice" and make it a "rule of thumb" and make sure you know why you wouldn't do it that
way.

Wouldn't You?

John

[John Heslinga]

Rob.

Check out this link. (Note Bullet 3)
http://www.carid.com/images//bm/cooling-systems/pdf/coolers-user-guide.pdf


Check out this link (Note instruction 10)
http://www.mossmotors.com/graphics/products/instructions/056-290.pdf


Check this Link (Note the Orientation Paragraph)
http://www.hot4cold.co.za/Downloads/Products/282012122941Installation%20instructions%20for%20STD%20oil%20coolers.pdf


Check This Link (Note Imageand discription on Page 12)
http://www.bulletproofdiesel.tv/Files/Documents/BulletProofDiesel%20Engine%20Oil%20Cooler%20Install%20Manual,%20BPD%20Oil%20Filter.pdf


Best Regards

John

--
John and Cathie Heslinga
1974 Canyonlands 260
455, Manny tranny and 1 ton, 3:70 LS,
Red Seal Journeyman, DTE, BEd. MEd.
Edmonton, Alberta

[John Heslinga]

Rob.
I can't begin to explain (and I won't try) why GM plumbed this cooler the way it did and why they would not follow a common practice. (Many still
put coolers in that are plumbed with both fittings down!!) (would you call that good practice??) I would say no. I can however cite many
instances where Auto designers and engineers have made design mistakes that seem pretty stupid when you look back at them. Dealerships are full of
service bullitins , upgrade instructions and upgraded parts to prove that. Not trying to say I'm smarter. This is just something I've found to be a
problem in other applications.

--
John and Cathie Heslinga
1974 Canyonlands 260
455, Manny tranny and 1 ton, 3:70 LS,
Red Seal Journeyman, DTE, BEd. MEd.
Edmonton, Alberta

[Robert Mueller]

John,

I am NOT disagreeing with any of the instructions in the attached links.

As far as I know:

1) The Toronado radiator did not have an engine oil cooler in it

2) It did have a transmission fluid cooler

3) The oil cooler in the GMC Motorhome radiator is a stacked plate oil cooler

4) The engineer(s) at GMC that added the stacked plate oil cooler in the radiator of the motorhome plumbed it so the oil went in the
top and out the bottom.

Regards,
Rob M.
The Pedantic Mechanic

-----Original Message-----
From: John Heslinga

Rob.

Check out this link. (Note Bullet 3)
http://www.carid.com/images//bm/cooling-systems/pdf/coolers-user-guide.pdf

Check out this link (Note instruction 10)
http://www.mossmotors.com/graphics/products/instructions/056-290.pdf

Check this Link (Note the Orientation Paragraph)
http://www.hot4cold.co.za/Downloads/Products/282012122941Installation%20instructions%20for%20STD%20oil%20coolers.pdf

Check This Link (Note Imageand discription on Page 12)
http://www.bulletproofdiesel.tv/Files/Documents/BulletProofDiesel%20Engine%20Oil%20Cooler%20Install%20Manual,%20BPD%20Oil%20Filter.p
df

Best Regards
John