Thread: What Oil do you use for the P38!!

Haven't I said enough a few years ago on this thread?

I can't remember, which side of the engine does the oil filter project on the V8?
Remember the P38 has the diff on the opposite side to a D1/2/RRC

The V8 oil filter is on the drivers side.

Cheers
Keithy

Originally Posted by Pedro_The_Swift

I am beginning to think this "may hit things" is an urban myth,, I have 20 years of disco's running Z9's and not a scratch,,

Happy to be set straight by someone thats actually hit it...

oh and another vote for HPR10..


The guy that said no Zinc for flat tappets is the lone voice in the wilderness..

You have an opinion Young Rick?

Rotella T5 on the P38, Falcon and the STI (soon he GTiI) as I always take care on warming up the car properly. Use the Z9 as well as the Falcon takes it as well, it's cheap and buy in bulk.

The problem is normally not the Zinc but the lack of Phosphorus which in combination with the Zinc gives the cams protection, I used to use the Mobil1 Racing which is illegal for the street as it's got a huge amount of Zinc and Phosphorus but it gets expensive quick, can't see the Rotella any worse than the Mobil1 Racing, it's a really kick ass oil specially if you can buy it in a big drum!

in order to hit the big Z9 in a P38 you would have to get through the radiator and the drag link ...

Originally Posted by DavidP38

Rotella T5 on the P38, Falcon and the STI (soon he GTiI) as I always take care on warming up the car properly. Use the Z9 as well as the Falcon takes it as well, it's cheap and buy in bulk.

The problem is normally not the Zinc but the lack of Phosphorus which in combination with the Zinc gives the cams protection, I used to use the Mobil1 Racing which is illegal for the street as it's got a huge amount of Zinc and Phosphorus but it gets expensive quick, can't see the Rotella any worse than the Mobil1 Racing, it's a really kick ass oil specially if you can buy it in a big drum!

in order to hit the big Z9 in a P38 you would have to get through the radiator and the drag link ...

ZDDP (Zinc dithiophosphate) is a homogenous compound, as the limits for phosphorous (along with sulphur and other sulphated ash compounds) has been reduced in motor oils to reduce catalyst poisoning ZDDP levels have been reducing.

I think I mentioned several years ago in this thread that ZDDP is good, but it is just one component in having a good oil and there are better and more expensive additives, it's just that ZDDP works and it's relatively inexpensive.
Interestingly most dedicated diesel oils work well in a flat tappet engine and they don't rely on ZDDP.
Boron compounds and tin napthenate are two additives that replace ZDDP and possibly give better results but are exxy in comparison. High performance, low SAPS oils use these compunds.
In the past lead napthenate was used in high performance oils as it's a very good anti-wear compound.
The pure race oils I used in the early-mid nineties were heavily laced with lead napthenate and modest amounts of ZDDP. Obviously lead is a no-no these days.
FWIW I never had lifter wear issues, but we were vigilant in checking lifter radius and lobe taper and running the cam and lifters in well before hard use.


Curious where you're buying Rotella in Australia?
Why not just buy Rimula R6?

I am currently running a test (the samples have been sent of to the lab) to see if I can determine detrimental results from not using the "right" oil, at the expense of my beautifully rebuilt engine...

A while back, last year I think, I posted a link to a very long article to which the tl;dr was: zinc in a running engine is no longer needed, modern oils can leave a film on the metal which can withstand enormous pressures that will protect our flat tappet engines just fine, even under heavy load and high revving. The only thing that ZDDP is really good for and modern oils, afaik, still have no alternative for is cold start protection. A modern thin engine oil seeps out of the bearings etc. and when starting the engine again the metal surfaces are under protected for a short period of time. This is also the moment where every engine wears the most. (not just our ancient lumps)

The engine oils with high ZDDP content (not too high) actually protect the engine better in those conditions is what I gather. Not that the oil is still sticking to the parts, but the zinc that has been deposited when running is what wears of first, protecting our precious metal parts. The down side is increased wear on the catalytic converters and the phosphor can cause carbon buildup in the valvetrain and engine bores.

If one were to look at purely at the best possible solution I think a good oil (regardless of ZDDP content) and a pre-oiler system would be best. The proper oil to keep our engines healthy when running, the pre-oiler for starting (turn on before starting ofcourse)

Cheers!

-P

PS I am considering a pre-oiler but let's just see what the lab finds the coming months.

Originally Posted by rick130

ZDDP (Zinc dithiophosphate) is a homogenous compound, as the limits for phosphorous (along with sulphur and other sulphated ash compounds) has been reduced in motor oils to reduce catalyst poisoning ZDDP levels have been reducing.

I think I mentioned several years ago in this thread that ZDDP is good, but it is just one component in having a good oil and there are better and more expensive additives, it's just that ZDDP works and it's relatively inexpensive.
Interestingly most dedicated diesel oils work well in a flat tappet engine and they don't rely on ZDDP.
Boron compounds and tin napthenate are two additives that replace ZDDP and possibly give better results but are exxy in comparison. High performance, low SAPS oils use these compunds.
In the past lead napthenate was used in high performance oils as it's a very good anti-wear compound.
The pure race oils I used in the early-mid nineties were heavily laced with lead napthenate and modest amounts of ZDDP. Obviously lead is a no-no these days.
FWIW I never had lifter wear issues, but we were vigilant in checking lifter radius and lobe taper and running the cam and lifters in well before hard use.


Curious where you're buying Rotella in Australia?
Why not just buy Rimula R6?

Friend has a farm outside of Toowoomba and I get a drum a year from him, change it every 6 months in the STI regardless of KM's (very low km's per year), the GTI drinks oil like a champion, about half litre every 2nd fill up and the P38 its pretty stable, only had the P38 for a short time but it's not drinking oil. The old falcon loves Rotella but that's probably because it's an old tractor engine (250 crossflow) but has solid cam, well rebuilding the engine now as chasing the 400hp out of it

Total make some ok Oil too, I guess as long as you replace oil in time who makes the oil don't really matter as long as not the cheapest thing at Supercheap on a sale. In my old BMW i exclusively used Castrol as per spec for 6 years and replaced it every 7.000km and when I had to replace the rocker cover gasket the sluge was insane, I moved to Shell Helix Ultra and when the vanos was fixed 5 years later the engine was super clean so I always used Shell Helix Ultra until I started racing and moved to Mobil1 Racing, that got expensive fast and moved to Rotella and never looked back. The GTI (Mk6) eats way less Rotella than the recommended Castrol R.

The P38 done just over 300k, original engine, good compression and perfect plug wear/color, previous owner did every service until 285k at LandRover so whatever they used it worked but I noticed with Rotella I get a tiny better fuel economy, when I drove from Melb to Bris I average 11.3L/100Km on 91RON, around town mixed Hwy I get about 15.8L/100km but I'm not trashing it so not sure how some hit over 20L/100km....my STI does double that but that's a different beast

Baldwin B2 filters are generally better than the ryco Z9 in my experience

Both are hydraulic oil filters and the B2 has better flow and better particulate retention (?) properties when i was on the tools

I jut put a ryco Z89AST filter on mine, i figure good filters and oil are cheaper than a rebuild !

Steve