need some help from you electical types

RodneyWright · **Posted:** Tue Nov 04, 2014 2:48 pm

so after reading some more on this issue and the fact that adding some in-line restricters will change the linear function of the gauge, I've decided to order the proper sending unit and unfortunately an adapter so it fits the 14x1.5 opening. My concern is to make the adapter some what permanent w/ a glue of some sort. I looked and JB Weld does not conduct electricity, so it would kill the ground. I found that Radio Shack sells a graphite based high temp glue, so I hope this stuff will work.

Is there any other type of glue I should consider to attach the adapter to the sending unit? If I ever take this back out, I don't want to be stuck w/ the adapter ring lodged in the sender opening.

Richard Casto · **Posted:** Tue Nov 04, 2014 3:29 pm

Rodney,

I am somewhat confused around the glue thing. Why do you need to glue it?

Does the adapter not have any external fitting (i.e. hex shape) so that you can both tighten and remove it? If it doesn't have any, how can you tighten it? I don't know where this installs, so I can't speak to what problems you might be having (such as access issues that prevents using proper tools), but I would think that you would not need to glue anything. That just sounds like you are asking for trouble. Especially with respect to the ground issue.

Richard

Edit: I am assuming your adapter is something like this...

http://www.summitracing.com/parts/atm-2267

RodneyWright · **Posted:** Tue Nov 04, 2014 4:27 pm

Richard Casto wrote:

Edit: I am assuming your adapter is something like this...

http://www.summitracing.com/parts/atm-2267

Almost, what VDO offered last time did not have the hex head, it's simply a collar. I guess the better view of it would like a helicoil, hence I don't won't it to separate from the sending unit. I had a heck of a time getting the water temp sending unit to seat, and that's the same style VDO gauge and sender. Now if what I ordered does indeed have the hex head, them problem solved. Should receive this by Friday, so I'll know better....

George Bright · **Posted:** Wed Nov 05, 2014 9:59 pm

To answer Charlie's question about which way the sending unit goes. It is 180 ohm=0 and 10 ohm= fullscale. since the meter is going off scale it is going below 10 ohms so a low value resistor between the sending unit and the wire to the gauge should rescale it so that the 100 psi gauge is not full scale at 80 psi into the 80 psi sending unit. This will probably make the 100 psi scale a little inaccurate but I assume you are not worried if the actual pressure is 91 psi instead of say 95. The 80 psi sending unit might also stop changing its output when the pressure goes above some point.

I used to run a VDO 150 psi gauge in my 510 which put the readings below the rather compressed top end of the scale. It did peg the gauge when the pressure relieve valve in the oil pump got stuck and about 5 seconds later the case blew off the oil filter.

RodneyWright · **Posted:** Thu Nov 06, 2014 1:43 pm

so no glue needed. the VDO supplied adapter does indeed have a hex head, so this will be easy to install. Will be nice to have the oil gauge working properly now.

RodneyWright · **Posted:** Thu Nov 06, 2014 5:06 pm

dang it!!!! Another brick wall. The fitting is square and not tapered and will not "fit" into the receiver hole. I did a good job and managed to cross thread the adapter. Fortunately I was able to back out before I inflicted too much damage. Another issue is the combined assembly is too long to fit into the space, it hits part of the engine support. I guess what I need now is some tapered fittings and one 45 or 90 degree fitting so I can aim it down, plenty of room in that direction.

Is there anywhere locally that sells tapered fittings? I need a combo of 14x1.5 and 1/8" npt. Going to hit Lowes and some of the local hardware stores this weekend...

Vincent Keene · **Posted:** Thu Nov 06, 2014 5:15 pm

RodneyWright wrote:

dang it!!!! Another brick wall. The fitting is square and not tapered and will not "fit" into the receiver hole. I did a good job and managed to cross thread the adapter. Fortunately I was able to back out before I inflicted too much damage. Another issue is the combined assembly is too long to fit into the space, it hits part of the engine support. I guess what I need now is some tapered fittings and one 45 or 90 degree fitting so I can aim it down, plenty of room in that direction.

Is there anywhere locally that sells tapered fittings? I need a combo of 14x1.5 and 1/8" npt. Going to hit Lowes and some of the local hardware stores this weekend...

It's not the best plan to mount that sender directly to the block due to vibration on the fittings (probably brass right?). A better idea is to route a braided hose from the block to a location on the firewall where you have more room for the sender.

BTW, a mechanical gauge solves all these problems.

Richard Casto · **Posted:** Thu Nov 06, 2014 5:51 pm

RodneyWright wrote:

Is there anywhere locally that sells tapered fittings? I need a combo of 14x1.5 and 1/8" npt. Going to hit Lowes and some of the local hardware stores this weekend...

Locally? Probably hard to do. You could try "Wilders Bolts and Nuts" at 2406 Alwin Ct, Raleigh, NC 27604, but I don't know if they also do fittings like that. I actually have had bad luck trying to find anything out of the ordinary locally. Amazon with overnight shipping?

Vincent Keene wrote:

It's not the best plan to mount that sender directly to the block due to vibration on the fittings (probably brass right?).

So I am curious about this. I know that long runs of copper/brass pipe that can flex are not good due to work hardening and ultimately cracking. But is this a problem with short brass adapters? I can't imagine it would be? :whoknows:

Richard

George Bright · **Posted:** Thu Nov 06, 2014 6:05 pm

I had a T on my Datsun 210 with the factory switch in the side and the gauge sending unit straight away from the port on the oil pump. It broke off after a couple of months leaving me on the side of the road with a total loss oiling system. I then ran a piece of thick walled teflon tubing and mounted the sending units to the fender. So far it has lasted about 20 years.

I had a braided line on the 510 with the sending unit mounted to the inner fender. The VDO sending unit I used had a gauge output and an idiot light output. I bought it back in the late 70s.

RodneyWright · **Posted:** Thu Nov 06, 2014 6:13 pm

Richard Casto wrote:

RodneyWright wrote:

Is there anywhere locally that sells tapered fittings? I need a combo of 14x1.5 and 1/8" npt. Going to hit Lowes and some of the local hardware stores this weekend...

Locally? Probably hard to do. You could try "Wilders Bolts and Nuts" at 2406 Alwin Ct, Raleigh, NC 27604, but I don't know if they also do fittings like that. I actually have had bad luck trying to find anything out of the ordinary locally. Amazon with overnight shipping?

Richard

So after thinking about this, all I really need is a 45 degree adapter, male/female that is 14x1.5 on both ends. I can fit the adapter I have into the 45 and I "should" be good.... Thanks for the links to Wilders, appreciate that!

Charlie Guthrie · **Joined:** Thu Aug 28, 2003 8:14 pm **Posts:** 832

Parker hydraulics has a Raleigh location. It used to be on Yonkers Road near Capitol & I440. Parker's specializes in fittings and tubing; metric and Imperial.
VK has a point with the remote mounting, but I would choose poly (Teflon or nylon) tubing for the short run to the sending unit.
Charlie G

RodneyWright · **Posted:** Thu Nov 06, 2014 8:27 pm

Charlie Guthrie wrote:

Parker hydraulics has a Raleigh location. It used to be on Yonkers Road near Capitol & I440. Parker's specializes in fittings and tubing; metric and Imperial.
VK has a point with the remote mounting, but I would choose poly (Teflon or nylon) tubing for the short run to the sending unit.
Charlie G

This has to be grounded. I guess I could fab something up, but it's such a short run and this basically 1/2" tubing, so it's pretty stout. I made add some sort of support to it.

Charlie Guthrie · **Joined:** Thu Aug 28, 2003 8:14 pm **Posts:** 832

If you run the sender to a fender or firewall that can be the ground. As for using 1/2" tube, consider how fast that size will spill oil if it breaks. I'm partial to 1/8" OD tubing (size that comes with most mechanical gages) because it is far more flexible and unlikely to break due to fatigue or pressure. Not only that, but if it does break the small bore tube takes longer to bleed the engine dry and you would probably notice the smell (or fire) before you are out of oil. Military gear used this when I was a sailor ages ago.
Charlie G

DickRasmussen · **Posted:** Fri Nov 07, 2014 1:20 pm

Charlie Guthrie wrote:

If you run the sender to a fender or firewall that can be the ground. As for using 1/2" tube, consider how fast that size will spill oil if it breaks. I'm partial to 1/8" OD tubing (size that comes with most mechanical gages) because it is far more flexible and unlikely to break due to fatigue or pressure. Not only that, but if it does break the small bore tube takes longer to bleed the engine dry and you would probably notice the smell (or fire) before you are out of oil. Military gear used this when I was a sailor ages ago.
Charlie G

If you had the fittings and braided hose you could do the "tube" with aeroquip and AN fittings like I did in my FF when the GCR rules changed to no longer permit nylon tubes in or through the cockpit.

Quote:

All oil lines that pass into or through the driver/passenger compartment
shall be of metal braided hose (e.g., Aeroquip).

DickRasmussen · **Posted:** Fri Nov 07, 2014 1:23 pm

FYI if you end up mounting the sending unit "off" the engine . . . remember the engine moves relative to the body assuming you still have oem engine/trans mounts. :lol:

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