Engine oil

[SJ Lambert]

G’day Rohan

Is the Redline synthetic still your #1 choice for race engines?

[rgh0]

Redline for gearboxes and diffs absolutely. For the competition twincams I have started using the Penrite 10 Tenths 15W - 50 which is a similar blend of PAO Group 4 and Polyolester Group 5 base stocks like the Redline engine oils and is substantially cheaper which is nice given you change engine oil much more frequently than diff or GB oil.

The hot performance of the Penrite appears just as good from my unscientific measure of do I have adequate idle oil pressure when I drive back to the paddock at the end of a race.

If I was changing my oil after every race weekend and running a professional race team could afford it I would probably use the Redline Race engine oil but that would be overkill for what I do

cheers
Rohan

[2cams70]

Whilst on the topic of oils if you are based in Australia I must give a plug for the "Tru-Blu" oil company. They are a specialty company and one of the few that actually blends their own oil - as opposed to those that just market their own oil (as a lot do). A lot of it is just marketing spin when it comes to oils.

They will sell direct from the factory and have a great family run atmosphere. No doubt they are the name behind some of the other names in the industry. I buy specialty industrial products from them that aren't available elsewhere.

Check out their website:

https://www.trubluoil.com.au/products/automotive/

[fotsyr]

A other option in the USA is Brad penn, which is the old Kendal oil. Has lots of zinc.

[Bigbaldybloke]

A bit off subject maybe but here goes anyway. I have a can of Valvoline oil sat by the car ready to put in it. The car has been off the road for some years now but before putting it to rest I drained the oil and refilled it with a basic mineral oil and ran the engine briefly to circulate it round. I’m at the stage of changing this oil out now for the Valvoline
I have read the comments in the thread about oil temperature and pressure so thought I’d just comment on these in my latest Porsche with the 2.9l V6 engine, water temperature runs at around 100C and oil at around 105C. The interesting one is the oil pressure which appears to be under some sort of dynamic control which depends on engine load rather than purely revs. At idle or at a constant cruising speed, be it 40mph or rather more, the pressure is a constant 22psi, but as soon as you accelerate briskly the pressure rises to over double that, it almost seems like it’s linked to turbo pressure, which probably makes sense as it has to lubricate the turbos. Not sure exactly what the pressure goes up to as when accelerating hard I tend to be concentrating on the road rather than the gauge panel!

[h20hamelan]

Do you have a leak in your Porsche turbo
If the seals are bad, should be able to notice excess oil in the intake side of the inter cooler etc
Don’t think oil pressure should raise like that. Guessing the dip stick doesnt pop out and there’s a seal on the top?

[rgh0]

Many modern engines have variable displacement oil pumps controlled by the ECU to provide optimum oil flow and thus resulting pressure at all operating conditions. The days of a simple mechanical relief valve as gone

cheers
Rohan

[Bigbaldybloke]

Hi Rohan, I agree it’s ecu controlled but as an engineer I wondered what parameters were used in the algorithm that controls it and is it just done using a pcv or is it more complex using a variable flow rate pump. I posted a similar question on a Porsche forum and drew a complete blank on how it functions other than people confirming theirs works the same. I’ll have to do more research to find out about it, hopefully I’m due another invite to the Porsche centre at Silverstone so they might know more about it.
Anyway this is way off topic so I’ll leave it there.

[rgh0]

Nothing wrong with a bit of thread drift

I believe it will be aimed at minimising power used by the oil pump while ensuring adequate lubricant flow rates that the engine may require depending on its speed, load, boost, turbo speed. coolant and oil temperatures etc etc etc there are many many sensors on modern engines and you will use them all if you can to optimise the engine

The algorithm to do all that will be very and probably unnecessarily complex as befits a Porsche engineer with access to unlimited computer power and a huge development budget

cheers
Rohan

[JJDraper]

My last post on the oil thread was 9 years ago... perhaps time for an update.

A year or so back, the water pump on my +2 engine finally let go and I took the opportunity to do a full engine rebuild. I did the head, and a well know Lotus specialist (Father & son team) took on the short block. I was fully expecting worn bearings, pistons & bores but very little wear was seen. The comment from the builder was that the wear looked minimal; shells, bores even the rings looked good. This bottom end had done over 100k in my ownership, and a few more by the PO. He replaced shells & rings, 'because we are in there', but the pistons were fine. His other comment was that it was nice to work on an engine that was clean internally and didn't smell of burnt oil!

On the head, cams, lobes perfect & the valve guides had a little wear, but not beyond tolerances, again after 100k miles. Even the valve stems were good & passed muster by specialists. Admittedly I don't have hairy cams, just Q360s, but what's the obsession with extra zinc additives? Just keep the oil clean'

This points to good lubrication, and I have mostly used synth - 20-60 for touring abroad (remember that) and 10-40 for colder weather. Nothing special, just full synth, usually ford spec (Triple QX brand in the UK, often discounted). I may not be a tribologist, but based on my experience, I can think of no cogent reason to use mineral oil, even cost.

Anyway, ++2 for Synth.

Jeremy

[h20hamelan]

on the hunt VR1, as my stock of VR1 is low.
What are people using in N America

VR1 gone it seems, Lucas, who I am not a huge fan of

https://lucasoil.com/pdf/TDS_HotRodClas ... _20W50.pdf

and I can't tell

https://sharena21.springcm.com/Public/D ... 162d889bd3

[mbell]

Royal Purple HPS 20/50:
https://www.summitracing.com/parts/rpo-31250

Or Reline 20/50W
https://www.summitracing.com/parts/red-12505

I think the Redline is the better oil and costs a bit more. Any decent 20/50 Synthetic with high Zinc/ZDDP should be ok.

[Quart Meg Miles]

St Wilkins, who wrote the book, recommends Morris 20-50 and averaging 3000 miles annually I change oil and the filter every year. It's always black despite clean rebuilds and I have yet to regrind the crank though it has 0.001 inch wear in places.

I fitted a capillary oil temperature gauge through the sump plug 50 years ago and the readings were often 70 degrees (C) and up to 90 degrees down motorways. Primarily I use it as a warm-up indicator and 15 years ago fitted it through its own bush welded into the sump on the exhaust side. It now reads 10 degrees higher even after heavy insulation against exhaust heat. I assume the deeper insertion reduces the cooling from the fixing assembly.

[berni29]

My last post on the oil thread was 9 years ago... perhaps time for an update.

A year or so back, the water pump on my +2 engine finally let go and I took the opportunity to do a full engine rebuild. I did the head, and a well know Lotus specialist (Father & son team) took on the short block. I was fully expecting worn bearings, pistons & bores but very little wear was seen. The comment from the builder was that the wear looked minimal; shells, bores even the rings looked good. This bottom end had done over 100k in my ownership, and a few more by the PO. He replaced shells & rings, 'because we are in there', but the pistons were fine. His other comment was that it was nice to work on an engine that was clean internally and didn't smell of burnt oil!

On the head, cams, lobes perfect & the valve guides had a little wear, but not beyond tolerances, again after 100k miles. Even the valve stems were good & passed muster by specialists. Admittedly I don't have hairy cams, just Q360s, but what's the obsession with extra zinc additives? Just keep the oil clean'

This points to good lubrication, and I have mostly used synth - 20-60 for touring abroad (remember that) and 10-40 for colder weather. Nothing special, just full synth, usually ford spec (Triple QX brand in the UK, often discounted). I may not be a tribologist, but based on my experience, I can think of no cogent reason to use mineral oil, even cost.

Anyway, ++2 for Synth.

Jeremy

Hi

I like these sorts of posts based on real user experiences. Thank you. When I rebuilt the engine on my Porsche 993 at 186k miles (admittedly just the top end, which includes cylinders and pistons on these engines), it was so clean inside you could have eaten off it. You could still see the cross hatching on the cylinder bores. The valve guides were toast though, so not all good news. That engine was run on Magnatec 10/40 for nearly all of its life and I would never use anything different in it. I use Triple QX in my other cars, and will likely use it in Ford spec for my Twinc when it goes back together based on your post.

All the best

Berni

[h20hamelan]

From what I can tell, a N American data shows the Lucas with better additives only in their Classic and HotRod stuff.
Both RedLine and Royal are much lower, which is why the Valvoline was nice as it was higher than the Lucas.