Oil Sending Units?

RL Chilton

I'd like to run a seperate oil pressure gauge.  Does anyone have a part # for an Oil Sending Unit on a 308 that's been converted to 12V?  

Park_W

Russ, I went "dual mode" with mine, i.e., kept the original sender for the oil light, and added a "hydraulic/mechanical" type pressure gauge.  See photo of connection point for the gauge tube.

RL Chilton

That's perfect, Park.  That's exactly what I would like to do.  Do you have a reproduction Part # for the original styled oil sending unit for the light?  

Park_W

The original oil light switch works fine with 12 volt system.  NAPA has them, but I don't have a current number.

RichardD

Park, on my '53-308, the Fram oil filter line connects to the outlet where your capillary connects. The aftermarket oil pressure gage AND the original 'oil' light connect at the block outlet above the oil pump. There is a 'T' in the short pipe that goes to the block. The oil pressure capillary connects on one side of the 'T' and the generic elec. oil pressure {cut off/cut on} sender is on the other side of the 'T'. Seems to work OK~~

RL Chilton

Richard-

Post a pic of that set-up, please.  

Park-

Went at lunch and got the sending unit.  NAPA part # is OP6613.  

RichardD

can't post photo--obscured by headers and oil pump; rather straight forwarded, but I have no idea if it is original.

RL Chilton

Doesn't sound original.  

RichardD

Decided I would raise on lift and look to see if I could reach camera there and I could. I know the headers aren't original nor is the oil pressure gage. The sender is basically same as what you have. Gage capillary connects to a fitting hidden at bottom of photo; and you can see sender.

RL Chilton

Thanks, Richard for going to the trouble and getting the photo.  Interesting set-up!  I like it.  

RichardD

Should have wiped it off, tho; hate for Park to see the oil film I put on for protection--lol.

If you have a filter you will have to have a Tee somewhere.

 It would have provided a shorter capillary to have the oil filter supply with the Tee since the oil gage, etc are on that side.

My gages on left side>>

Frankvintagefullflowcom

Using the bypass filter supply port (as shown in the first photo) will not show pressures below about 20 psi since that port is occluded until the pressure rises to that point, by design. It will be fine above that, but you will notice that, at start-up, the gauge will not move at first, then jump quickly to 20+ psi and go up from there (assuming a mechanical gauge). That's the effect of the regulator plunger disallowing flow to that port until the pressure rises enough to open it.
A gauge plumbed in at the original pressure switch location will read correctly at all times.
F

Park_W

Well geez, Frank . . .  so tell me where in should be connected.  On a Tee with the warning light switch?  :-)

Frankvintagefullflowcom

I did!    "A gauge plumbed in at the original pressure switch location will read correctly at all times."

The one connected at the bypass filter supply port will tell the truth unless the pressure drops below ~20psi. At that point it will drop to zero (or near it) since the plunger will occlude the filter supply orifice below that pressure. You may still have oil pressure but won't know if it's 19 or 3. Of course, if you have both the gauge and light, the light will come on when it drops to whatever pressure it is set at.
Now you know what you are doing tomorrow.
F

Frankvintagefullflowcom

I should add: My implication that you should rush right out and change your set-up was "tongue-in-cheek". It's likely that you run over 20 psi at hot idle unless your engine is getting tired (I'll bet you don't have one of those) so you'll never see pressures below 20 anyway. If it dropped to the point where the gauge went to zero, you'd stop to find out why. If it really was a "No oil Pressure" situation, the light would have come on as well.
I'm a believer in the combo of gauge and light......I'm considering a buzzer, too. I need all the notification I can get.
Frank

Park_W

I did!    "A gauge plumbed in at the original pressure switch location will read correctly at all times."

Sorry about that, Frank . . .  guess I read it too quickly!  I'm fine with it working as is, but will change it over if I have the engine out some time.

Frankvintagefullflowcom

And......don't forget to upgrade the system to a full-flow filtration set-up while you're at it. Let's see if I get ousted for plugging my product.
Frank

RL Chilton

And......don't forget to upgrade the system to a full-flow filtration set-up while you're at it. Let's see if I get ousted for plugging my product.
Frank

Never.  It's Hudson-related.