Talk Morgan Forums Morgan Sports Cars Morgan Three Wheeler & Super 3 M3W OIL PRESSURE GAUGE

I have checked out the May 2020 article in MTWC following which I contacted Merlin Motor Sport.

They do not do a kit for the M3W so am at a loss as to which individual parts I would need to install the oil pressure gauge as KBMOG

I do like the lightspeed method-for clarity I take it the gauge is electrical with analogue readout? which saves on adapter plates etc. Has anyone gone down this route and again what parts are needed.


Thanks

The parts you require from Merlin to fit the SPA-DG201B gauge kit are:
Extension Bolt 3/4" UNF M-EB-3/4UNF
Billet Sandwich plate M-TGASP200X.
Merlin have supplied several owners with these items in the past and the person who was there did know what was involved in fitting this gauge in a M3W, maybe they are no longer working there?

Lightspeeds installation is good but it is only for a pressure gauge not a pressure and temperature indicator as the SPA is. I don't think the temp sender would work at the end of a long dead end pipe, it needs to be located on the engine.

I've done something similar to LightSpeed but using a sandwich plate with a temperature sender screwed directly in to it and a hose run from it to a pressure sender mounted up under the bonnet. There wasn't really room to safely fit the pressure sender directly to the sandwich plate and you don't want to subject the sensor to all of the engine vibration.

Thanks planenut and Calum

I did have to modify the rectifier mounting plate to give some clearance for the pressure transmitter as it does get close. I have a diagram of what is required. The remote mounting for the pressure transmitter, as suggested by Calum, may well be the better option as it does get it away from the vibrating engine as well as better clearance. The sandwich plate does have two 1/8 NPT and one 3/8 BSP take off points, so plenty of options. I think if you want to do more than just a pressure indicator, the sandwich plate is the way to go.

I find that oil temperature is important with this engine and useful to know, particularly when in traffic on a hot day. It is also surprising how cool the engine oil runs on "normal" UK weather days.

Thanks Planenut have sorted out the parts with Merlin. Advised by Gary that as the pressure sender is 1/8" BSP you may want to tap out one of the 1/8" NPT outlets on the sandwich plate. (He did mention that most just let the sender recut its own thread s differences are minimal?

Before I order up the parts I do quite like the idea of remotely locating the pressure sensor say under the bonnet - any idea what additional parts I need to order up? Also regarding picking up the 12v power supply how is this best achieved?

When it comes to setting up the SPA Gauge can the bulk of this be done on the bench before installation

Maybe Calum or Lightspeed will advise about the extension hose? A grease gun hose was mentioned earlier as being suitable and that sounds good to me.

You probably can set the SPA gauge up on a bench prior to installation but it will still be equally fiddly to do as installed. It has a multifunctional button that requires lots of presses in different menues in the set up. At least you only have to do it the once really. One thing I would say is to use the pressure "damper" option so that the display changes slowly, say a 2 or 3 second setting or the display is just a blur of constantly changing numbers.

If you don't have heated seats then there is a spare supply for that you can use for power, or just splice into an ignition load 12v supply. Make sure you don't get the grey/black lead near the fuse box as that will be 5v and is for the speedometer calibration mode switching.

I didn't actually record what parts I used...I had some braided hose left over from re-plumbing the fuel system so used that with AN fittings each end. I think I used a straight 1/8NPT nipple to AN fitting into the sandwich plate in a hole I drilled and tapped to get it where I wanted it and just have the hose tie wrapped to the fuel hoses up by the pressure regulator I fitted beside the oil tank. I think it was AN-6 hose with stainless inner and nylon outer braid and matching fittings that I used. The fittings are easy enough to assemble though the stainless braid tends to be a bit sharp and painful!
I fitted gauges that have NPT threads on the senders so didn't have to worry over much about compatibility. I have heard various things over the years about cross-compatibility of certain NPT/NPTF/BSP etc. threads and remain somewhat unconvinced.

Thanks again planenut and Callum.
I do not have heated seats but am unable to find a spare connector- I have found one for the intercom which is fused at 5amp.(would that work as there is no load to speak of on the SPA Gauge). Even checking out the wiring diagram I cant seem to find a spare for the heated seats.
Callum did you fit the SPA unit and senders?

After further digging around I have found a couple more spare connector plugs - one which is fed by two black cables which I assume go to earth and another with a black cable with orange tripe and black cable could this be the one for the heated seats- how ever like I said I could not reference it on the wiring diagram or fuse box.