GMCforum
For enthusiast of the Classic GMC Motorhome built from 1973 to 1978. A web-based mirror of the GMCnet mailing list.

Home » Public Forums » GMCnet » Oil filter bypass plug
Oil filter bypass plug [message #297142] Fri, 11 March 2016 12:58 Go to next message
dr.diesel is currently offline  dr.diesel   United States
Messages: 85
Registered: April 2015
Location: The Haute, Indiana
Karma: 0
Member
Not being a fan of the filter bypass, this is how I plugged mine with a 1/4" pipe plug.

There wasn't enough room to run the tap down far enough, so I cut some grooves in a brass extension to finish the job.

I was surprised to find the adapter to block gasket was embossed metal? Any reason not to carefully cut one from a sheet of make-a-gasket material?

http://streamlinemechatronics.com/picts/oiladaptor1.jpg

http://streamlinemechatronics.com/picts/bottomingtap.jpg


77 Kingsley
Re: Oil filter bypass plug [message #297147 is a reply to message #297142] Fri, 11 March 2016 15:53 Go to previous messageGo to next message
USAussie is currently offline  USAussie   Australia
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
Senior Member
To answer your question I reckon it would be OK to make a gasket.

Regarding removing the bypass I would suggest you check these photos:

http://www.gmcmhphotos.com/photos/g6398-455-2f-403-engine-oil-flow-path.html

http://www.gmcmhphotos.com/photos/g6677-oil-filter-adapter-to-oil-cooler-adapter-sealing.html

The filter bypass was installed to assure that the engine got oil pressure on cold morning at initial start up. Since you live in Terra Haute that's more of a probability than possibility. The bypass valve is set to open at 5.3 to 6.3 psi in a Toronado which DID NOT HAVE an oil cooler in the radiator.

It is my theory that freshly rebuilt engines suffer premature failures because the engine oil cooler gets loaded up with crap from the failed engine which causes the pressure drop through it to force the bypass valve to stay open and allow unfiltered oil back into the engine which over a relatively short period of time causes rod and main bearing failure.

Yesterday I finished building the test adapter to install on Tom Pryor's 455 so we can test my theory in June. I will post a separate email regarding that subject.


Regards, Rob M. (USAussie) The Pedantic Mechanic Sydney, Australia '75 Avion - AUS - The Blue Streak TZE365V100428 '75 Avion - USA - Double Trouble TZE365V100426
Re: Oil filter bypass plug [message #297150 is a reply to message #297142] Fri, 11 March 2016 16:15 Go to previous messageGo to next message
JohnL455 is currently offline  JohnL455   United States
Messages: 4447
Registered: October 2006
Location: Woodstock, IL
Karma: 12
Senior Member
Cool Rob, the rig is built. Thanks and keep us posted. I need to understand this system in full perspective for the GMC and other GM applications which also use the cooler addaptor.

John Lebetski
Woodstock, IL
77 Eleganza II
Re: Oil filter bypass plug [message #297152 is a reply to message #297142] Fri, 11 March 2016 17:07 Go to previous messageGo to next message
dr.diesel is currently offline  dr.diesel   United States
Messages: 85
Registered: April 2015
Location: The Haute, Indiana
Karma: 0
Member
It's my understanding that no oil drains out of the loop when stopped? So, using the Taco Bell analogy, something in means something immediately out, ha ha ha. In a positive displacement system, assuming it's not so thick you open the oil pump pressure relief, there is plenty of oil flow on startup.

Right or wrong I've been plugging the bypass on all engines I've built over the past 25 years, but I'm very anxious for your testing results! Always willing to learn something new.

I have the equipment to do high speed data acquisition, with some work I could log engine RPM vs Oil Pressure on start up.







77 Kingsley
Re: [GMCnet] Oil filter bypass plug [message #297154 is a reply to message #297152] Fri, 11 March 2016 17:31 Go to previous messageGo to next message
USAussie is currently offline  USAussie   United States
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
Senior Member
Andy,

I'm sorry to disagree, the question for the Olds Powerplant engineers was "is the amount of oil flow through a 21 micron filter
great enough to lubricate the engine when cold?" Evidently they did not believe it was hence the bypass set at 5.3 to 6.3 psi. I'll
wager dollars to donuts that the bypass setting was determined by engine testing, and not at Taco Bell. :-)

I'll bet Matt Colie (the engine lab rat) could provide some insight into that question.

Unfortunately the testing Tom and I will be doing will be in Florida in June so we're not going to determine what happens in the
frozen north! HOWEVER, if the flow is reduced at start up at 70°F ambient it is reasonable to assume it will be further reduced at
30°F.

Regards,
Rob M.
The Pedantic Mechanic

-----Original Message-----
From: Andy

It's my understanding that no oil drains out of the loop when stopped? So, using the Taco Bell analogy, something in means
something immediately out, ha ha ha. In a positive displacement system, assuming it's not so thick you open the oil pump pressure
relief, there is plenty of oil flow on startup.

Right or wrong I've been plugging the bypass on all engines I've built over the past 25 years, but I'm very anxious for your testing
results! Always willing to learn something new.

I have the equipment to do high speed data acquisition, with some work I could log engine RPM vs Oil Pressure on start up.






--
77 Kingsley

_______________________________________________
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



Regards, Rob M. (USAussie) The Pedantic Mechanic Sydney, Australia '75 Avion - AUS - The Blue Streak TZE365V100428 '75 Avion - USA - Double Trouble TZE365V100426
Re: Oil filter bypass plug [message #297155 is a reply to message #297142] Fri, 11 March 2016 17:46 Go to previous messageGo to next message
dr.diesel is currently offline  dr.diesel   United States
Messages: 85
Registered: April 2015
Location: The Haute, Indiana
Karma: 0
Member
No worries Rob, you might just be correct!

Have you documented your testing, in a method I accurately reproduce here?


77 Kingsley
Re: [GMCnet] Oil filter bypass plug [message #297179 is a reply to message #297154] Sat, 12 March 2016 09:11 Go to previous messageGo to next message
Matt Colie is currently offline  Matt Colie   United States
Messages: 8547
Registered: March 2007
Location: S.E. Michigan
Karma: 7
Senior Member
OK Guys,

It is morning in the east and here I am.

Andy, you seem to have a common condition that exists among rational people (it get worse with increasing talent and education). You don't have an effective grasp of how little thinking actually goes on in the general population. That is what all this stuff has to be built to withstand.

If you are the junior engineer assigned to assemble the engine part of the owner's manual, there are some things that have to enter into your thinking.
1 - Not every owner is a brain trust.
2 - Not all equipment gets maintained to requirements listed in the manual.

Remember, when you read the owners manual, it still recommends a straight 30SAE weight lube oil down to a 40°F ambient.
Now, just suppose someone did a spring oil change and drained the 10W that was there and put that in just in time for a sub-freezing over night soak....
What will happens when he grabs his coffee the next morning, fires that poor thing up and revs it a bit to warm it up faster. That 30SAE is going somewhere. It won't go through an intact filter, but if it can't go around it, it will make a way to go through it.

That is why there is a by-pass.
It is not to prevent oil starvation if the filter media gets so loaded it is restrictive. If that ever happens, the engine was toast already.

In the labs, we cut open lots of lube oil filters. It was not uncommon (particularly in the warranty evaluation) to find breached filter media. When that media is examined for wear debris, there is never enough to have caused the delta-P on the filter to cause a breach. Cold start damage is harder to see in a modern engine because the fuel controls work better.

Andy, - Yes, all engines exhibit some hot drain-down. If they did not, they would indicate lube oil pressure while cranking and instantly at idle. Some engine do this worse than others.
Plug the filter by-pass if you choose, I doubt you are the case above. But, when you part with that engine, be certain that the SO knows that is the case.

Rob, - When you and Tom are at this and if you have some straight 30, put it in the freezer over night and watch how it pours in the morning.
(Oh, and kick Tom "Hello" for me.)

Matt - the engine lab refugee



USAussie wrote on Fri, 11 March 2016 18:31
Andy,

I'm sorry to disagree, the question for the Olds Powerplant engineers was "is the amount of oil flow through a 21 micron filter
great enough to lubricate the engine when cold?" Evidently they did not believe it was hence the bypass set at 5.3 to 6.3 psi. I'll
wager dollars to donuts that the bypass setting was determined by engine testing, and not at Taco Bell. Smile

I'll bet Matt Colie (the engine lab rat) could provide some insight into that question.

Unfortunately the testing Tom and I will be doing will be in Florida in June so we're not going to determine what happens in the
frozen north! HOWEVER, if the flow is reduced at start up at 70°F ambient it is reasonable to assume it will be further reduced at
30°F.

Regards,
Rob M.
The Pedantic Mechanic

-----Original Message-----
From: Andy

It's my understanding that no oil drains out of the loop when stopped? So, using the Taco Bell analogy, something in means
something immediately out, ha ha ha. In a positive displacement system, assuming it's not so thick you open the oil pump pressure
relief, there is plenty of oil flow on startup.

Right or wrong I've been plugging the bypass on all engines I've built over the past 25 years, but I'm very anxious for your testing
results! Always willing to learn something new.

I have the equipment to do high speed data acquisition, with some work I could log engine RPM vs Oil Pressure on start up.

--
77 Kingsley



Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
Re: Oil filter bypass plug [message #297181 is a reply to message #297142] Sat, 12 March 2016 09:26 Go to previous messageGo to next message
JohnL455 is currently offline  JohnL455   United States
Messages: 4447
Registered: October 2006
Location: Woodstock, IL
Karma: 12
Senior Member
Are there not more than one (3???) bypass parhs in an Olds with the add on cooler. Even without the cooler, and the filter screwed right to the engine is not there a built in bypass AND a pressure relief(back to pan) system. That's 2. The screw on addaptor has it's own valve in the event the cooler loop is restricted. That's 3. This is why we need Rob's empirical documentation and testing. By pluging the cooler bypass you may not be accomplishing what you think you are if my theory is correct.

John Lebetski
Woodstock, IL
77 Eleganza II
Re: Oil filter bypass plug [message #297188 is a reply to message #297142] Sat, 12 March 2016 10:56 Go to previous messageGo to next message
dr.diesel is currently offline  dr.diesel   United States
Messages: 85
Registered: April 2015
Location: The Haute, Indiana
Karma: 0
Member
Testing will prove very interesting. I can join by logging (if this engine lasts long enough - for those that have read some of my previous threads, this engine is toast) RPM vs Oil Pressure at up to several hundred thousands samples per second, faster than the sender can respond I'm sure.

As an engineer myself I fully appreciate all of the "safe guards" auto manufactures must endure to protect from the back yard mechanic. ha ha.



77 Kingsley
Re: [GMCnet] Oil filter bypass plug [message #297199 is a reply to message #297188] Sat, 12 March 2016 12:47 Go to previous messageGo to next message
USAussie is currently offline  USAussie   United States
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
Senior Member
Andy,

Thanks, unfortunately the delta P gage we will be using only has a human interface; you look at it and write down the pressure drop.
;-)

Regards,
Rob M.
The Pedantic Mechanic


-----Original Message-----
From: Andy

Testing will prove very interesting. I can join by logging (if this engine lasts long enough - for those that have read some of my
previous threads, this engine is toast) RPM vs Oil Pressure at up to several hundred thousands samples per second, faster than the
sender can respond I'm sure.

As an engineer myself I fully appreciate all of the "safe guards" auto manufactures must endure to protect from the back yard
mechanic. ha ha.


_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org



Regards, Rob M. (USAussie) The Pedantic Mechanic Sydney, Australia '75 Avion - AUS - The Blue Streak TZE365V100428 '75 Avion - USA - Double Trouble TZE365V100426
Re: [GMCnet] Oil filter bypass plug [message #297200 is a reply to message #297181] Sat, 12 March 2016 12:45 Go to previous messageGo to next message
USAussie is currently offline  USAussie   United States
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
Senior Member
John,

There is one and only one bypass in the oil system. There is a relief valve in the oil pump that sets the oil pressure it puts out.
You can get different springs for that relief valve to set it where you like. Ken Frey puts a spacer under the spring to raise it.
He built the 455 in Double Trouble 80,000+ miles ago and it runs 50 psi at highway speeds hot.

Check this album for the photos of the bypass valve in the oil filter adapter:

http://www.gmcmhphotos.com/photos/g6398-455-2f-403-engine-oil-flow-path.html

and this one for the relief valve in the oil pump:

http://www.gmcmhphotos.com/photos/mechanical/p50100-pv-closed.html

Regards,
Rob M.
The Pedantic Mechanic

-----Original Message-----
From: John R. Lebetski

Are there not more than one (3???) bypass parhs in an Olds with the add on cooler. Even without the cooler, and the filter screwed
right to the engine is not there a built in bypass AND a pressure relief(back to pan) system. That's 2. The screw on addaptor has
it's own valve in the event the cooler loop is restricted. That's 3. This is why we need Rob's empirical documentation and testing.
By pluging the cooler bypass you may not be accomplishing what you think you are if my theory is correct.
--
John


_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org



Regards, Rob M. (USAussie) The Pedantic Mechanic Sydney, Australia '75 Avion - AUS - The Blue Streak TZE365V100428 '75 Avion - USA - Double Trouble TZE365V100426
Re: [GMCnet] Oil filter bypass plug [message #297203 is a reply to message #297199] Sat, 12 March 2016 12:55 Go to previous messageGo to next message
dr.diesel is currently offline  dr.diesel   United States
Messages: 85
Registered: April 2015
Location: The Haute, Indiana
Karma: 0
Member
USAussie wrote on Sat, 12 March 2016 13:47


Thanks, unfortunately the delta P gage we will be using only has a human interface; you look at it and write down the pressure drop.
Wink



So you'll be testing the delta across the bypass with different oils/filters/temps/etc? No startup flow/pressure testing?


77 Kingsley
Re: [GMCnet] Oil filter bypass plug [message #297207 is a reply to message #297203] Sat, 12 March 2016 13:24 Go to previous messageGo to next message
USAussie is currently offline  USAussie   United States
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
Senior Member
Andy,

Yesterday I finished making an adapter that will allow me to force the bypass valve in the oil filter adapter closed I'll be posting
photos of it and the test setup.

The problem I have is I contacted Melling and George Richardson gave me the flowmeter (vane) that they use and it will cost me $500.
I am trying to find a cheaper alternative. You can buy glass tube flowmeters from China but since the testing will be performed on
an engine I DO NOT OWN I damn sure don't want to blow it up because a piece of test equipment fails.

This testing will not happen until mid June and I will put together a comprehensive test plan for all and sundry to peruse and
comment on before I start. HOWEVER, my MAIN objective is to determine if the setting of the bypass valve in the oil filter adapter
(5.3 to 6.3 psi) is correct for the GMC with an oil cooler in the radiator. The Toronado NEVER had an engine oil cooler. I don't
know if other Olds vehicles of the period did.

Regards,
Rob M.
The Pedantic Mechanic

-----Original Message-----
From: Gmclist [mailto:gmclist-bounces@list.gmcnet.org] On Behalf Of Andy
Sent: Sunday, March 13, 2016 5:55 AM
To: gmclist@list.gmcnet.org
Subject: Re: [GMCnet] Oil filter bypass plug

USAussie wrote on Sat, 12 March 2016 13:47
> Thanks, unfortunately the delta P gage we will be using only has a human interface; you look at it and write down the pressure
drop.
> ;)

So you'll be testing the delta across the bypass with different oils/filters/temps/etc? No startup flow/pressure testing?
--


_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org



Regards, Rob M. (USAussie) The Pedantic Mechanic Sydney, Australia '75 Avion - AUS - The Blue Streak TZE365V100428 '75 Avion - USA - Double Trouble TZE365V100426
Re: Oil filter bypass plug [message #297222 is a reply to message #297142] Sat, 12 March 2016 18:49 Go to previous messageGo to next message
dr.diesel is currently offline  dr.diesel   United States
Messages: 85
Registered: April 2015
Location: The Haute, Indiana
Karma: 0
Member
dr.diesel wrote on Fri, 11 March 2016 13:58
Any reason not to carefully cut one from a sheet of make-a-gasket material?


So I ended up reusing the factory (I think factory) embossed steel gasket. Took quite a bit of effort to remove the hard plastic like sealing goop, which was at a min partially blocking the oil passages, then a nice skim of high tack. Did the trick and no leaks.



77 Kingsley
Re: [GMCnet] Oil filter bypass plug [message #297230 is a reply to message #297207] Sat, 12 March 2016 22:04 Go to previous messageGo to next message
Ken Henderson is currently offline  Ken Henderson   United States
Messages: 8726
Registered: March 2004
Location: Americus, GA
Karma: 9
Senior Member
Rob,

Without knowing how you're going to plumb the test rig, nor why you're
using a flow meter vs a differential pressure gauge (as I'd understood your
previously stated plan) I'm probably talking through my hat: Instead of
the $500 gauge, why not use two inexpensive pressure sensors and an
electrical gauge. It would be trivially simple to set up a pneumatic test
rig to calibrate the two sensors. Perhaps a pair of these:

http://www.ebay.com/itm/Pressure-transducer-or-sender-100-psi-stainless-steel-for-oil-fuel-air-water-/261260635816?hash=item3cd458eea8:g:wEgAAOSw2XFUg I6K&vxp=mtr

or

http://goo.gl/PsPDCq

And you can always find another use for them later. :-)

Ken H.


On Sat, Mar 12, 2016 at 2:24 PM, Robert Mueller
wrote:

> Andy,
>
> Yesterday I finished making an adapter that will allow me to force the
> bypass valve in the oil filter adapter closed I'll be posting
> photos of it and the test setup.
>
> The problem I have is I contacted Melling and George Richardson gave me
> the flowmeter (vane) that they use and it will cost me $500.
> I am trying to find a cheaper alternative. You can buy glass tube
> flowmeters from China but since the testing will be performed on
> an engine I DO NOT OWN I damn sure don't want to blow it up because a
> piece of test equipment fails.
>
> This testing will not happen until mid June and I will put together a
> comprehensive test plan for all and sundry to peruse and
> comment on before I start. HOWEVER, my MAIN objective is to determine if
> the setting of the bypass valve in the oil filter adapter
> (5.3 to 6.3 psi) is correct for the GMC with an oil cooler in the
> radiator. The Toronado NEVER had an engine oil cooler. I don't
> know if other Olds vehicles of the period did.
>
> Regards,
> Rob M.
> The Pedantic Mechanic
>
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org



Ken Henderson
Americus, GA
www.gmcwipersetc.com
Large Wiring Diagrams
76 X-Birchaven
76 X-Palm Beach
Re: [GMCnet] Oil filter bypass plug [message #297241 is a reply to message #297230] Sun, 13 March 2016 00:28 Go to previous messageGo to next message
USAussie is currently offline  USAussie   United States
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
Senior Member
Ken,

As they say a picture is worth a thousand words:

http://www.gmcmhphotos.com/photos/oil-system-flow-testing/p58296-oil-flow-test-schematic.html

As you can see I will be using a delta P gage to measure the pressure across the output TO the oil cooler in the radiator and the
return FROM the oil cooler in the radiator AND a flowmeter as well.

The flowmeter will be plumbed into the line that leaves the oil cooler adapter which goes to the oil cooler in the radiator.

Therefore I will be able to measure the pressure drop across the oil cooler as well as the flow.

When we first start a cold engine I believe that the pressure drop across the "loop" will force the bypass in the oil filter adapter
to open as I believe it will be more than 5.3 to 6.3 psi. As the oil heats up the flow will increase as the pressure drop across the
"loop" will decrease.

When we get to operating temperature I will slowly turn the wing nut on the test adapter which will push the micarta poppet closed.
The flow reading will go up.

I am up to my eyeballs getting ready to fly out of Sydney on Wednesday, once I get to the USA I will write a step by step test plan
and share it with the GMCnet.

Regards,
Rob M.
The Pedantic Mechanic


-----Original Message-----
From: Ken Henderson

Rob,

Without knowing how you're going to plumb the test rig, nor why you're
using a flow meter vs a differential pressure gauge (as I'd understood your
previously stated plan) I'm probably talking through my hat: Instead of
the $500 gauge, why not use two inexpensive pressure sensors and an
electrical gauge. It would be trivially simple to set up a pneumatic test
rig to calibrate the two sensors. Perhaps a pair of these:

http://www.ebay.com/itm/Pressure-transducer-or-sender-100-psi-stainless-steel-for-oil-fuel-air-water-/261260635816?hash=item3cd458ee
a8:g:wEgAAOSw2XFUgI6K&vxp=mtr

or

http://goo.gl/PsPDCq

And you can always find another use for them later. :-)

Ken H.


_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org



Regards, Rob M. (USAussie) The Pedantic Mechanic Sydney, Australia '75 Avion - AUS - The Blue Streak TZE365V100428 '75 Avion - USA - Double Trouble TZE365V100426
Re: [GMCnet] Oil filter bypass plug [message #297242 is a reply to message #297230] Sun, 13 March 2016 06:55 Go to previous messageGo to next message
dr.diesel is currently offline  dr.diesel   United States
Messages: 85
Registered: April 2015
Location: The Haute, Indiana
Karma: 0
Member
Ken Henderson wrote on Sat, 12 March 2016 23:04
Rob,
Perhaps a pair of these:

http://www.ebay.com/itm/Pressure-transducer-or-sender-100-psi-stainless-steel-for-oil-fuel-air-water-/261260635816?hash=item3cd458eea8:g:wEgAAOSw2XFUg I6K&vxp=mtr



Being in the instrumentation industry, and personal experience with the above type of pressure sensor, be sure and characterize its reading first.

In a delta configuration your data could be off by 3PSI and still be within their spec, but I have found some off by up to 10%.


77 Kingsley
Re: [GMCnet] Oil filter bypass plug [message #297243 is a reply to message #297242] Sun, 13 March 2016 07:58 Go to previous messageGo to next message
USAussie is currently offline  USAussie   United States
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
Senior Member
Andy,

I appreciate your suggestions, however, please be advised that I worked for a company called Hamilton Standard as a field rep based
at the Johnson Spacecraft Center.

I serviced and tested the Portable Life Support System that the Astronauts wore on the Moon.

I also built ground support equipment and am quite familiar with test instruments manufactured by Wallace & Tiernan, Ashcroft,
Mid-West Instruments, Brooks, etc.

I found a used delta P gage made by Mid-West Instruments; model 109ME-10-YO which is 0-15 PSID and according to the specs the gage
is +/- 1/2 or 1%. I would have preferred 0-10 PSID, however, I got this one for $120.

George Richmond of Melling provided me with the flowmeter they use to test their pumps but I have yet to purchase it as it costs
$500.00 and I'm looking for a cheaper alternative. Tom Pryor's engine has a Melling high volume pump on it which will produce 12.4
GPM if you know of a cheaper flowmeter I'm all ears!

Regards,
Rob M.
The Pedantic Mechanic

-----Original Message-----
From: Gmclist [mailto:gmclist-bounces@list.gmcnet.org] On Behalf Of Andy
Sent: Sunday, March 13, 2016 10:55 PM
To: gmclist@list.gmcnet.org
Subject: Re: [GMCnet] Oil filter bypass plug

Ken Henderson wrote on Sat, 12 March 2016 23:04
> Rob,
> Perhaps a pair of these:
>
>
>
http://www.ebay.com/itm/Pressure-transducer-or-sender-100-psi-stainless-steel-for-oil-fuel-air-water-/261260635816?hash=item3cd458ee
a8:g:wEgAAOSw2XFUg
> I6K&vxp=mtr

Being in the instrumentation industry, and personal experience with the above type of pressure sensor, be sure and characterize its
reading first.

In a delta configuration your data could be off by 3PSI and still be within their spec, but I have found some off by up to 10%.



_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org



Regards, Rob M. (USAussie) The Pedantic Mechanic Sydney, Australia '75 Avion - AUS - The Blue Streak TZE365V100428 '75 Avion - USA - Double Trouble TZE365V100426
Re: Oil filter bypass plug [message #297244 is a reply to message #297142] Sun, 13 March 2016 08:19 Go to previous messageGo to next message
dr.diesel is currently offline  dr.diesel   United States
Messages: 85
Registered: April 2015
Location: The Haute, Indiana
Karma: 0
Member
Super, and sorry, I just now getting to know people here. An extensive test without verified and accurate instrumentation could lead all of us down the wrong path. A lot of times even good stuff is out of spec out of the box, due to a variety of reasons.

Although I now do custom work, my last job I was a Sr EE responsible for the I@C department at a power plant, which had over 35,000 individual hard IO points. Massive amounts of process instrumentation, many of which were accurate to 0.04% at 4000PSIG.

Anyhow, super duper. Razz


77 Kingsley
Re: [GMCnet] Oil filter bypass plug [message #297250 is a reply to message #297241] Sun, 13 March 2016 09:03 Go to previous messageGo to previous message
Ken Henderson is currently offline  Ken Henderson   United States
Messages: 8726
Registered: March 2004
Location: Americus, GA
Karma: 9
Senior Member
OK. I understand better now -- you're planning what I suspected. My
suggestion was for the delta-P gauge. Those sensors are available down to
no more than 15 psi, and even a DVM could be used for the gauge, so you
shouldn't spend much on a specialized gauge. We can easily do any
necessary fabrication here next month.

Looking at some of the eBay listings for flowmeters, it appears that you
may have the need for some power supplies. I've got a BUNCH of them of
almost any fixed or variable voltage you might need. We can select and
wire what you need. Plus, of course, any other wiring you may need from my
50 year collection. :-)

Feel free to have anything you need to order sent here.

Ken H.


On Sun, Mar 13, 2016 at 1:28 AM, Robert Mueller
wrote:

> Ken,
>
> As they say a picture is worth a thousand words:
>
>
> http://www.gmcmhphotos.com/photos/oil-system-flow-testing/p58296-oil-flow-test-schematic.html
>
> As you can see I will be using a delta P gage to measure the pressure
> across the output TO the oil cooler in the radiator and the
> return FROM the oil cooler in the radiator AND a flowmeter as well.
>
> The flowmeter will be plumbed into the line that leaves the oil cooler
> adapter which goes to the oil cooler in the radiator.
>
> Therefore I will be able to measure the pressure drop across the oil
> cooler as well as the flow.
>
> When we first start a cold engine I believe that the pressure drop across
> the "loop" will force the bypass in the oil filter adapter
> to open as I believe it will be more than 5.3 to 6.3 psi. As the oil heats
> up the flow will increase as the pressure drop across the
> "loop" will decrease.
>
> When we get to operating temperature I will slowly turn the wing nut on
> the test adapter which will push the micarta poppet closed.
> The flow reading will go up.
>
> I am up to my eyeballs getting ready to fly out of Sydney on Wednesday,
> once I get to the USA I will write a step by step test plan
> and share it with the GMCnet.
>
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org



Ken Henderson
Americus, GA
www.gmcwipersetc.com
Large Wiring Diagrams
76 X-Birchaven
76 X-Palm Beach
Previous Topic: [GMCnet] Rear main seal
Next Topic: Converter Charger
Goto Forum:
  


Current Time: Fri Oct 18 19:45:36 CDT 2024

Total time taken to generate the page: 0.01086 seconds