Electric Oil Pressure Gauge

[Lou R]

Hello All,

I was wondering if anyone on this forum has switched their oil pressure gauge from mechanical to electric.  It seems to be a fairly straightforward switch - the only problem might be a clearance issue of the sender on the side of the block.  Typically the electric senders are fairly large - seems probable it may butt up against the starter.  Has anyone performed this upgrade ?  If so, could you please advise which sender you used.  I know I could probably get it to work with various adapters to clear the starter but I'm afraid it may look somewhat odd if I have to go more than an inch or so.

Thanks,

Lou R   

[snowrx]

A search should come up with lots of sensor geometries. You are packed in with the dizzy, manifold and starter. An angle fitting or tee could give you the orientation you want. Even a large sender could be fitted with  short braided hose to wherever there's' room, similar to the turbos' oil feed line. The galley block is pretty simple and could be drilled from stock with any direction you chose for the fitting(s), and even tapped with a more common thread than the BSP, saving you adapter space.

[ekwan]

5 hours ago, Lou R said:

Hello All,

I was wondering if anyone on this forum has switched their oil pressure gauge from mechanical to electric.  It seems to be a fairly straightforward switch - the only problem might be a clearance issue of the sender on the side of the block.  Typically the electric senders are fairly large - seems probable it may butt up against the starter.  Has anyone performed this upgrade ?  If so, could you please advise which sender you used.  I know I could probably get it to work with various adapters to clear the starter but I'm afraid it may look somewhat odd if I have to go more than an inch or so.

Thanks,

Lou R   

Done that on my S3 NA. No issues. Just needed an adaptor machined to fit. I bought an electrical Smiths oil pressure gauge to retain the original look. 

Edited January 5, 2023 by ekwan

[drdoom]

Eric, which sender did you use?

[jonwat]

The 4 cylinder cars from 1995 on used electrical oil pressure gauges & sender part number A082N4038F 👍

[drdoom]

Thanks John, different gauges than those in the early cars so not quite what Eric has been coming up with as far as I know.

Cheers

[Lou R]

Steve,

If you're planning to go the Smiths route you can use the "Smiths Classic Oil Pressure Sender 1/8" NPT".  It's not cheap but it will surely guarantee the gauge and sender work together.

Lou R

[Lou R]

Thomas (snowrx),

Only after looking at the block did I realize how limited the space is for a 52mm x 40mm sender.  Just about everything is in the way to prevent mounting the sender at the BSPT adapter.  Might be able to mount it with a 45 degree adapter (going aft and up) but it starts to get awfully close to the dizzy/plug wires.   Maybe I could make a bracket and mount it on the aft most leg of the engine mount with a short hose as you suggested.  Looks like I'll have to make up a 52mm x 40mm dummy to see where it'll fit best.  Thanks for the comments - very helpful !

Lou R

[drdoom]

I would not hesitate to remote the sender to a nearby location off engine. It's how it was done on the S1.

Cheers

[Lou R]

Steve,

I was thinking about that just yesterday and went on a blitz to see if I could find some fittings that might work.  The existing BSPT/NPT fitting already in the block is close to a 45 degree angle coming out of the block.  If I add a female to female NPT 45 degree fitting to the BSPT/NPT block fitting the  result will be a close to vertical positioning.  I can then add a male to female NPT extended fitting (1 3/4") and install the sender. I'm hopeful it will be high enough to clear the starter and not interfere anything else.  I'll report back with some photos after I've received the parts noted above and have installed everything.

Lou R 

[drdoom]

Well, be wary of creating a tower attached to the block as 4 banger engines generate some considerable vibrations. The S1 solution uses a short flex hose off the block fitting feeding the sender which mounts off the engine. Safe management of any such forces.

Cheers 

[Lou R]

Steve,

Do you know where the S1's mounted the sender ?  I've looked around but didn't see any logical place relatively close to the engine.  I'm sure I can easily fabricate a bracket I'm just not certain where it would fit best.  Hence my question on the S1 location.

Lou R

[snowrx]

+1 on what drdoom said.

Mind the vibration failure risk. The senders aren't light, the engine's buzzy and any adapter in the stack is most likely going to have sharp cut threads ready to start a fatigue crack and just ruin your day, someday. My plan if  I eventually went electric was to do a custom galley block, but my engines very different anyway.

[ekwan]

On 05/01/2023 at 13:08, drdoom said:

Eric, which sender did you use?

Smiths own sender  

https://www.merlinmotorsport.co.uk/p/smiths-classic-oil-pressure-sender-1-8npt-cb-os-18

 

 

[drdoom]

Sorry, Lou, can't scrape up anything in my archived pics indicating where the transmitter was positioned. That said, It's sensible to consider finding a way to bracket off the nearest chassis stud and that wouldn't take great effort.

Cheers 

[Lou R]

I've since learned the sender was mounted on the S1 chassis just aft of the header tank (which, I believe, was mounted at the front of the engine on S1's).  I'll have a look and see if I can figure it out or maybe find some photos.  I've been thinking about installing it on the tall stud found on the S2 chassis just forward of the header tank.  I'd have to mount it above the Flowlock Valve (which also shares this tall stud) which implies I'd need to fab a spacer to separate them but it might be an ideal arrangement (?).    

[drdoom]

@Lotusfab has fully restored his S1, perhaps could offer a helpful photo or 2?

[drdoom]

I wonder whether we have sufficient reason to warrant shifting away from the mechanical gauge? Does the OEM unit read and respond accurately? Is there meaningful risk of leakage from the supply line?

[Lou R]

Steve,

I never really liked the idea of running a plastic tube through the console and up into the gauge.  There's some possibility of the tube breaking/leaking or the o-ring not doing its job, or a leaking ferrule resulting in a mess on new carpeting and the subsequent hassle of re-fitting everything to correct it.  Even using a braided line leaves some risk.  I just feel a whole lot better with an electric version.  My car will be virtually new once it's finished - I'd hate to see carpeting ruined with oil.  Might just as well change/upgrade it now before the car is back on the road.  My car has not been running since I got it so I don't know the accuracy of the existing  mechanical gauge - not much on the mechanical side that is more important than oil pressure so there's some concern with the OEM gauge.  I really want an accurate pressure reading and the added cost of fitting a new electric Smiths gauge and a new Smiths sender seems like $100 well spent (cheap parts or reproductions never pay off).  I believe the likelihood of failure of the existing mechanical set-up is not great but it's much less with the electrical set-up.  That's my logic.

Lou R