Oil pressure sigma 150

[pilotprice]

Hi guys

Just finished the car, full rebuild from head to toe with a 125-150 sigma conversion along the way

Very very happy with the engine performance and characteristics

I do have a niggle though, which has caused some concern!
On start up I get a solid 4 bar until the water temp hits 50-80'c then the oil pressure will drop to just above the red mark at idle?
Once revs or load is added then pressure will rise to 3.5-4bar, pressure increases the higher the rpm and is progressive. Not jumpy!

Good patter coming from the block with the filler cap off, I can see plenty of oil spitting out when cap removed also?

My taco can very rarly jump about a bit, I know the sender gets a feed from here? Could be linked? Bad earth?
I know the senders can be a bit unreliable but it does read 4 bar when cold and will increase from the red zone steady with revs

[pilotprice]

How it started, well, kinda

[downsman]

My Sigma 125 shows 4 bar at idle when cold, increasing to about 6 bar when driving.
Once the oil is warm (water at 80 for a few miles) idle pressure is 2 bar and increasing to 4 bar when driving.
Pressure drops to just above the red at idle (still 4 bar at speed) after a 15 minute track session.

I hope this helps
Your car looks great.

[pilotprice]

Thanks for the reply and comment
Mine seems to be the same when cold but reads like yours does after track, for just normal warm up

I'm going to buy a stack mechanical guage tomorrow and go from there !

[Bone Rat]

Hi,

I have a factory built 150 and it does exactly the same as yours, always has. Did phone Caterham, guess what, they all do that!