Hi all

I am running a 10W40 semi-synthetic with 2000km change intervals. Lets not get into mineral vs synthetic etc.
Single turbo T70 oil only cooled (not water), extend ported. 360hp.

My question is that under normal driving my oil temp sees 70-80 degrees C and as soon as i get on high boost, even one 3rd gear WOT pull only the oil temp shoots up by 20-30 degrees C based on the oil filter temp reading.

I wonder if I should be running 20W50 to provide more support to the cheap T70 turbo journal bearing? Or is this temperature rise normal? The turbo must be getting bloody hot, and in fact the it gets hotter after you turn the car off, even if the turbo timer runs for few minutes, the oil temperature stays reasonably high at idle as there is no airflow over the twin oil coolers, and once you turn the car off it must all drain out.
This turbo is NOT water cooled so my concern is for the turbo bearing.

It is coming into summer here but highs would not usually be over 25 degrees C so not really a very hot climate.

Basically with an oil cooled only turbo should I be using a thicker oil?

Thanks in advance

 

Even 110C is not excessively hot for oil temps. A good full synthetic will likely be better for your turbos.

 

Does your car have dual oil coolers?

 

You are in NZ do they sell penrite oil there [is made in ozz ] if so try their HPR40 oil Is a 25-70 specialy made for turbo engines and great in rotaries .I use it in all my race engines and have for 25+ years with great results

 

Hi there, I DD my car and iv used cheap castrol gtx 15w-40 for years..I buy it when its like 2 for $45 or whatever @ super cheap / repco and change it often.
And yea you should have two oil coolers if you dont already

 

just noticed Castrol GTX is on special now for $19.98 per 4L at super cheap auto..im off to grab a few and stock up!

 

Running the turbo timer will make your oil temps go up as there is no air going through the oil coolers. I would stop doing that.

Aside from that, I always run 20w50 in my turbo rotaries.

 

I do have factory twin coolers. I run the turbo timer for at least a minute if I have been driving hard due to localised turbo temps probably being higher but yes often bulk oil temps rise 10 or so degrees due to lack of air flow.

I have gone to 20w50 semi synthetic. Nulon high km engine oil was 36$ on special. All good so far. Went for a 150km long hoon and I think oil temps were slower to react and didnt get as high which is what I was after.