Gauges

[RF_Burns]

I agree with Emery.

Since I have the Ragusa pan with a gauge, I clamped my tranny sensor to the out line to the cooler. So now the DigiPanel shows the hot temp going to
the cooler. I haven't seen it go higher than the engine temp, but them I only do high hills, not mountains.

--
Bruce Hislop
ON Canada
77PB, 455 Dick P. rebuilt, DynamicEFI EBL EFI & ESC.
Hubler 1 ton front end
http://www.gmcmhphotos.com/photos/showphoto.php?photo=29001
My Staff says I never listen to them, or something like that

 

[RF_Burns]

Rob,
FYI, I found a single fitting that allowed 2 oil pressure gauges to be mounted in the same place on my 455.

http://www.gmcmhphotos.com/photos/misc/p63220-mounting-dual-oil-pressure-sendors.html

here is the fitting itself:
http://www.gmcmhphotos.com/photos/misc/p63221-mounting-dual-oil-pressure-sendors.html

--
Bruce Hislop
ON Canada
77PB, 455 Dick P. rebuilt, DynamicEFI EBL EFI & ESC.
Hubler 1 ton front end
http://www.gmcmhphotos.com/photos/showphoto.php?photo=29001
My Staff says I never listen to them, or something like that

 

[robert mueller]

Bruce,

Thanks!

Found it: https://www.mcmaster.com/#50785k222/=19lbwcd

Regards,
Rob M.
The Pedantic Mechanic
Sydney, Australia
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426
USA '77 Kingsley - TZE 267V100808


-----Original Message-----
From: Gmclist [mailto:gmclist-bounces] On Behalf Of Bruce Hislop
Sent: Thursday, September 28, 2017 8:55 PM
To: gmclist
Subject: Re: [GMCnet] Gauges

Rob,
FYI, I found a single fitting that allowed 2 oil pressure gauges to be mounted in the same place on my 455.

http://www.gmcmhphotos.com/photos/misc/p63220-mounting-dual-oil-pressure-sendors.html

here is the fitting itself:
http://www.gmcmhphotos.com/photos/misc/p63221-mounting-dual-oil-pressure-sendors.html

Bruce Hislop

 

[Rdenney]

I seems to recall issues of fatigue failures caused by heavy senders
threaded into brass tee fittings in a high-vibration environment.
Considering the consequences of such, I built my tee using high-pressure
steel fittings, which are forged and strong. They are also available at
McMaster-Carr.

I have one connection to a tube compression fitting that goes to my
mechanical gauge, and the other for a cutoff switch for the electric fuel
pump. I wouldn't be afraid to stack another tee for an idiot light sender,
but it would be just as easy to wire the warning light to the fuel pump
wire using a relay to reverse the voltage.

Rick "who has an Equus digital gauge but has never installed it" Denney

> Bruce,
>
> Thanks!
>
> Found it: https://www.mcmaster.com/#50785k222/=19lbwcd
>
> Regards,
> Rob M.
> The Pedantic Mechanic
> Sydney, Australia
> AUS '75 Avion - The Blue Streak TZE365V100428
> USA '75 Avion - Double Trouble TZE365V100426
> USA '77 Kingsley - TZE 267V100808
>
>
> -----Original Message-----
> From: Gmclist [mailto:gmclist-bounces] On Behalf Of Bruce
> Hislop
> Sent: Thursday, September 28, 2017 8:55 PM
> To: gmclist
> Subject: Re: [GMCnet] Gauges
>
> Rob,
> FYI, I found a single fitting that allowed 2 oil pressure gauges to be
> mounted in the same place on my 455.
>
>
> http://www.gmcmhphotos.com/photos/misc/p63220-mounting-dual-oil-pressure-sendors.html
>
> here is the fitting itself:
>
> http://www.gmcmhphotos.com/photos/misc/p63221-mounting-dual-oil-pressure-sendors.html
>
> Bruce Hislop
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
--
Rick Denney
73 x-Glacier 230 "Jaws"
Off-list email to rick at rickdenney dot com

 

[robert mueller]

Rick,

IIRC the failures were because a long nipple used below the "t" to connect to the engine block. Plus the nipple came from China and
the wall thickness was minimal.

Unfortunately the McMaster Carr drawing of the run tee does not show the wall thickness.

https://www.mcmaster.com/#50785k222/=19lbwcd

I too purchased high pressure SS fittings from McMaster Carr for The Blue Streak to connect a separate oil pressure sender.

Regards,
Rob M.
The Pedantic Mechanic
Sydney, Australia
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426
USA '77 Kingsley - TZE 267V100808


-----Original Message-----
From: Gmclist [mailto:gmclist-bounces] On Behalf Of Richard Denney
Sent: Friday, September 29, 2017 9:36 AM
To: gmclist
Subject: Re: [GMCnet] Gauges

I seems to recall issues of fatigue failures caused by heavy senders
threaded into brass tee fittings in a high-vibration environment.
Considering the consequences of such, I built my tee using high-pressure
steel fittings, which are forged and strong. They are also available at
McMaster-Carr.

I have one connection to a tube compression fitting that goes to my
mechanical gauge, and the other for a cutoff switch for the electric fuel
pump. I wouldn't be afraid to stack another tee for an idiot light sender,
but it would be just as easy to wire the warning light to the fuel pump
wire using a relay to reverse the voltage.

Rick "who has an Equus digital gauge but has never installed it" Denney

 

[les burt]

Rob,
You indicated a preference for mechanical "wet" gauges due to their superior accuracy. I have to agree on accuracy, but they are not necessarily the best choice for continuous automotive use.

The tubing required to connect a mechanical pressure gauge introduces several failure points. I've seen my fair share of broken/leaking tubes/hoses/gauges over the years. Failures due to chafing, flex fatigue, loose ferrule nuts, présure pulsations, yetc. Some of the leaks went un-noticed long enough to cause damage. For this reason, I prefer quality electronic gauges where feasible.

Les Burt
Montreal
'75 Eleganza 26'

>
> Rick,
>
> IIRC the failures were because a long nipple used below the "t" to connect to the engine block. Plus the nipple came from China and
> the wall thickness was minimal.
>
> Unfortunately the McMaster Carr drawing of the run tee does not show the wall thickness.
>
> https://www.mcmaster.com/#50785k222/=19lbwcd
>
> I too purchased high pressure SS fittings from McMaster Carr for The Blue Streak to connect a separate oil pressure sender.
>
> Regards,
> Rob M.
> The Pedantic Mechanic
> Sydney, Australia
> AUS '75 Avion - The Blue Streak TZE365V100428
> USA '75 Avion - Double Trouble TZE365V100426
> USA '77 Kingsley - TZE 267V100808
>
>
> -----Original Message-----
> From: Gmclist [mailto:gmclist-bounces] On Behalf Of Richard Denney
> Sent: Friday, September 29, 2017 9:36 AM
> To: gmclist
> Subject: Re: [GMCnet] Gauges
>
> I seems to recall issues of fatigue failures caused by heavy senders
> threaded into brass tee fittings in a high-vibration environment.
> Considering the consequences of such, I built my tee using high-pressure
> steel fittings, which are forged and strong. They are also available at
> McMaster-Carr.
>
> I have one connection to a tube compression fitting that goes to my
> mechanical gauge, and the other for a cutoff switch for the electric fuel
> pump. I wouldn't be afraid to stack another tee for an idiot light sender,
> but it would be just as easy to wire the warning light to the fuel pump
> wire using a relay to reverse the voltage.
>
> Rick "who has an Equus digital gauge but has never installed it" Denney
>
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org

 

[steve southworth]

> Rick "who has an Equus digital gauge but has never installed it" Denned

I have an Equius installed. I like it's features. However it has two shortcomings that kill it's good features. It has an alarm function that
lights a LED. The LED is not bright enough for use in a GMC and there is no audible warning. The display is too dim and very difficult to see, day
or night.

As for mounting senders on the engine block I had the fuel system pressure switch, OEM sender, Equis sender, and an idiot light pressure switch. A
high pressure flex line connects the engine to a manifold with all these items.

--
Steve Southworth
1974 Glacier TZE064V100150 (for workin on)
1975 Transmode TZE365V100394 (parts & spares)
Palmyra WI

 

[Rdenney]

Les, installation quality counts. I only use copper tubing (not plastic)
with plenty of room to move to relieve stress and absorb vibration. I have
had leaks twice in over 40 years of owning at least one vehicle with a
mechanical oil pressure gauge. The first was in a '74 GMC pickup with a
"Rocket" 250, and the previous owner had stretched the tubing tight so that
engine motion pulled a force vector right along the tubing. That was a
fatigue failure. The other was this year, when I installed the compression
ring in the copper tubing backwards when I put in the new engine--just a
bonehead mistake. It dripped but not much quantity escaped, and it was easy
to fix.

I also only use quality gauges. I have Autometer gauges in the coach--and
not their budget models. I've never had any of the better Autometer gauges
leak.

But I sure have read about lots of faulty electronic oil-pressure senders,
and those can hide fatal problems, too. I would use a mechanical oil
pressure gauge even if I had to replace the tubing every 10k miles to
prevent fatigue, but I have never had to do that. The kits to do it are on
the shelf at Autozone. I certainly don't mind a supplemental warning light
that runs on an electronic sender.

The one wet gauge I would never consider is for fuel pressure (not that I
feel much need to have a permanent fuel pressure gauge). But I have
mechanical oil pressure, coolant temperature, vacuum, and air system
pressure gauges.

Rick "who uses quality mechanical gauges so he can trust what they say"
Denney

> Rob,
> You indicated a preference for mechanical "wet" gauges due to their
> superior accuracy. I have to agree on accuracy, but they are not
> necessarily the best choice for continuous automotive use.
>
> The tubing required to connect a mechanical pressure gauge introduces
> several failure points. I've seen my fair share of broken/leaking
> tubes/hoses/gauges over the years. Failures due to chafing, flex fatigue,
> loose ferrule nuts, présure pulsations, yetc. Some of the leaks went
> un-noticed long enough to cause damage. For this reason, I prefer quality
> electronic gauges where feasible.
>
>
> Les Burt
> Montreal
> '75 Eleganza 26'
>
>
>
> --
Rick Denney
73 x-Glacier 230 "Jaws"
Off-list email to rick at rickdenney dot com

 

[les burt]

Agreed regarding installation quality. That applies to both mechanical as well as electrical gauges.

My view is this:

If it is important enough to monitor, then a gauge isn't enough. a warning light should also be employed. A gauge is only good if you look at it.

Most electronic pressure sender failures I've seen have been open or shorted circuit, giving either a zero or full scale gauge reading. I've seen quite a few bourdon tube gauges that failed and would not return to zero.

Les Burt
Montreal
'75 Eleganza 26'

 

[Matt Colie]

While I agree with a lot of what has been written here, there is an important feature that has not been included. While bleeding the line to the
instrument is important, the first fitting of the liquid line should also have a orifice installed. This orifice should be as small as can be
tolerated and still allow the instrument to respond. In my labs, we regularly used a two sizes. The fuel pressure taps were typically #60 (0.040)
and lube oil was typically #53 (0.0595). These gave effective response for the data acquisition system to secure the test.

Maybe I should also add that the pressure sensors we used were not like anything you ever saw in a vehicle. They were not a resistive sensor at all,
but a diaphragm and strain gage set. In the more recent versions that strain bridge is coupled to an onboard op-amp that delivers a 0-5V output for
the calibrated range. Shielding the 0-5 signal was never a problem. We tried the RS-232 version, but they were too slow.

The data-ack/cell control system we build used and sold to others did an entire data scan of temperatures, pressures and anything else at least once
per second some inputs more often. Instruments or not, we could not count on the reaction time of a "dyno-jock" to recognize and deal with a
situation.

I have a Digi-panel and I like it a lot because Mary likes to drive and I know that she does not run an instrument sweep. With a Digi-Panel, she does
not have to do one.

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