oil pressure sender

[mgcjag]

Hi Paul..check out Merlin Motorsports......Steve

[malcolm]

I read with interest these posts and others on this forum regarding oil pressure senders and gauges. I am of the old fashioned mechanical bias and have been contemplating replacing my electrical setup with a capillary system. My S2 on a fairly low mileage engine shows about 45-50 when cold and then drops back a little.
I note that MC Wilkinson sell a kit but shows it only with a braided hose and some owners recommend nylon.Are there any other suppliers members may know of these days.
Paul.

I'm sure there must be a reason, but don't know why nylon hose is favoured? My mechanical guage came from SNG, with braided hose, and works perfectly. Figures were compared to those from a propfessional capillary system strapped to the door frame while being driven. Figures were identical.

[Fuel.inj]

Out of interest Malcolm, where exactly did you route the braided hose through the bulkhead as I would prefer it to nylon if I do buy a mechanical system.
Paul.

[MarekH]

The only thing the braid is bringing to the party here is some abrasion protection and possibly a little heat insulation. The hose underneath is probably nylon anyway. At the pressures generated, it isn't a case of stopping the hose from ballooning out and thus under reporting the pressure. Nylon is chosen because it is flexible (more so than a capillary made of similar sized copper tubing), it is inert chemically and engine bay temperatures are way too low to affect its mechanical properties.

kind regards
Marek

[PeterCrespin]

I have always slipped a plastic wrap or slit tube over any copper capillary tube to prevent electrical shorts behind the folded panel. I’d do the same for braided.

Unlike a closed brake system, where maximum sustainable pad pressure would be temporarily compromised before bursting, a ballooned nylon capillary wouldn’t reduce line pressure or gauge pressure in an open system with essentially infinite oil volume and pump stroke. That’s why a ballooned aortic aneurysm or cranial vessel holds pressure until it bursts.

Incidentally (and probably weirdly) I always think of the aorta when working on the oil pioes in the sump. Why? Because apart from doing similar jobs, the average aorta running down the back of your chest is very roughly the size and shape of an XK oil pump feed pipe.

[malcolm]

Out of interest Malcolm, where exactly did you route the braided hose through the bulkhead as I would prefer it to nylon if I do buy a mechanical system.
Paul.

Sorry I didn't answer earlier Paul, I missed the post somehow.

From the sender area, the hose goes round the front of the carbs then back along the frames







It then goes through the top of the bulkhead on the drivers side above throttle linkage





Then round the back of the drop down panel into the guage

Hope this helps

[Fuel.inj]

Thanks Malcolm. That’s very helpful.
Regards, Paul.