Motor Oil "SCHOOL"

[eec564]

Yes, I know it's winter. From my book I read ( It's dutch ):

 

Bv een motorolie 15W40.

Bij temperaturen onder 0°C zal de viscositeit overeenkomen met de viscositeitklasse SAE 15W en voor temperaturen boven 0°C zal de viscositeit overeenkomen met die van de viscositeitklasse SAE 40.

 

Saying the low number is the thickness when the engine is cold, and high number at operating temperature.

 

That's why street driven/track cars need thicker oils like Castrol 10W60 or MPM 10W50.

 

I have never problems with engine oils so far. Maye I read it a bit different than you guys, but I understand.

 

I think a description that would appease more HybridZers would be thus:

 

The number before the W is the SAE weight the oil behaves like when cold.

The number after the W is the SAE weight the oil behaves like when hot.

10W40 acts like cold 10 wt oil when cold, and acts like hot 40 wt oil when hot.

 

 

Also, question:

 

...But to make it easy there are 4 categories:

 

- Minarel

- Semi Synthetic

- Synthetic

- Full Synthetic

...

 

I understand mineral and semi-synthetic, but what's the difference between synthetic and full synthetic?

 

-Eric

[260DET]

On the subjest of the location of oil coolers of the radiator type, the one on the 280ZX was located in the right front wheel well in front of the wheel but far enough forward so as to avoid the high pressure zone immediately in front of the wheel. The cooler is not particuularly big but it is working well at keeping oil temperatures under control, air is vented in from the front spoiler opening via a diffuser.

 

This location of course gets the heat away from the front where it can recycle back into the engine bay, the last place its wanted. The right front wheel and brake do not run noticeably hotter as a result either.

 

In the attached pic the power steering cooler is on the left.

[woldson]

I think a description that would appease more HybridZers would be thus:

 

The number before the W is the SAE weight the oil behaves like when cold.

The number after the W is the SAE weight the oil behaves like when hot.

10W40 acts like cold 10 wt oil when cold, and acts like hot 40 wt oil when hot.

 

Kinda, it would seem to be more accurate to say the first number represents a lower thickness at startup, witch is good but still high, and the second number represents a high thickness at operating temp of 212. (keeping in mind they all are very close at operating temp and even closer at 312.

[eec564]

Yes, but I always found that description a little confusing as cold 10 wt oil is still way thicker than hot 40 wt. It's a bit too easy to interchange an oil's SAE weight and it's thickness rating at a given temperature.

 

I like the description (albeit un-quantified) of multi-grade oils simply not thickening as much when the cool to room temperature, allowing for better engine start-up.

[PETEW]

 

I understand mineral and semi-synthetic, but what's the difference between synthetic and full synthetic?

 

-Eric

 

The difference between Synthetic and full synthetic is that a synthetic oil is mineral based with modifiers in it so it can be called synthetic. An example of this would be Mobil 1 or Castrol (remember a few years ago Mobil sued Castrol for this). A Full synthetic oil is one that came from a synthetic base, and is not mineral based at all. An example of this would be Mobil 1 extended life, or Amsoil.

[eec564]

Ahh, thank you.

[Drax240z]

Sticky!

[MREDDLE]

I don't know if anyone know this but many companys will analyses oil samples for anyone any oil. I use Schaeffer oil (supreme 7000 and 9000). You buy a sample kit, send it in and they send bake a full printout of everything that is in the oil and if there is anything wrong with it. You can also call them up and they will go over the print out with you. Very nice people to deal with and the best oil I have ever used.

 

 

BTW..YAY, My first sticky.. Sorry I dont know why this makes me happy.

[Art Nadel]

Modifying your oiling system to include a good heat exchanger which keeps the oil temps between 220 and 260 on the track will do far more towards protecting your engine. You will also reduce the heat input into the oil with a lower viscocity oil. I saw an average 15 degree drop in oil temps switching from (you guessed it) Mobil 1 15W-50 to 5W-30 on the race engine in the ROD, as measured at Willow Springs and Buttonwillow during the 2003 race season.

 

 

John,

 

Always appreciate your comments.

 

Am installing a "junkyard" L28ET in my 280ZXT to replace my engine which failed rod bearing.

 

What do you think about putting synthetic into a high milage engine with unkonwn history? Saw it run before it was removed. Oil press good, compression very good and even.

 

Now have done about 500 laps at Big WSIR and was down to mid 1:41 before the failure.

 

Art

[Bart Hoedemaker]

I have to say, with all older cars, even if it's a standard motor, here in this climate they all run best with thicker oils. And climate here in NL, is about the same as in New York region.

[Nismo280zEd]

There are a few non racing type oils that still have the zinc/phosphorous additives including some diesel oils, some Amsoil synthetics too. Its my understanding that such additives may not be present in the latest standard oils because of environmental concerns and cat converter damage.

 

So, contary to what the article says, the latest standard may not always be best. Will have to read the article again but basically all he seems to be saying is to match the oil viscosity to the cars use.

 

I was wondering if I was the only one that was aware of this aswell. The article seems to imply oils with additives can be bad.

 

Its bad times right now for good oil for older vehicles. Our Z's grew up with oil loaded with high ppm of ZDDP in it. Recently the government keeps changing standards based on efficiency (mpg) and pollution. As noted here... the ZDDP is toxic to catalytic converters, however let me ask this.

How many people have had to replace the cat on their 83Z because it was too clogged to operate anymore?

 

The current laws want the catalytic converters to last the life of the car, in order to do this they came up with new standards for oil. Reduction of ZDDP for tail pipe reasons. I've been doing research on this for the last month about and still learning things; however, from what I have read is that optimal engine wear of older vehicles you should be looking at a 1200ppm-1400ppm of ZDDP in your oil. Most oils on the market are around 800ppm or lower.

 

Diesels are still in the loop-hole and can have higher ppm of ZDDP in their oil, but now they are a target too. The latest CJ-4 rating effectively reduced the allowable concentration of ZDDP.

 

So this means like stated in the quote, newer ratings don't necessarily mean better. Modern engines are built much "tighter" now days, the specs are much closer, this is why they can get away with "thinner" oils. Also engine design has improved. The rockers in valvetrains have come a long way on modern motors from our Z motor. Thus our older motors require more protection from metal on metal wear.

 

To compare this to medical terms for the OP... It's like having the right viscosity of blood but less oxygen in it. Yeah you will still operate but your going to encounter more problems and a shorter life span.

 

Great article but don't push to the side the importance of additives, detergents, and friction modifiers.

[eec564]

Everything I've ever read is additive packages in standard oils, extended life oils (anti-sludging agents, thermal/viscosity/surface adhesion modifiers), racing oils (ZDDP) are good things and you should use one that's appropriate for your vehicle. It is the off-the-shelf cure-all additives such as Slick 50 with Teflon! that are to be generally avoided. Additives designed to alleviate a specific problem (such as lack of ZDDP) and don't make outrageous claims should be fine.

 

The toxicity of ZDDP to the catalytic converter is different. I think the term "Life of the car" is key here. New vehicles come with a warranty specific to the emissions system, and the catalytic converter has to last for that. Classic cars are not considered current life vehicles, so are not expected to have functioning original cats.

 

The elimination of ZDDP from new oils IS a problem not only for us, but for any vehicle with flat tappets. This is a greater problem with new or re-ground camshafts. Old, run-in engines have a very compatible contact pattern between the cam lobes and the lifers or rockers. Any high spots have been worn down gradually over dozens of heat cycles and thousands of miles. During that break-in, ZDDP and other phosphates helped protect the cam. Now, the use of ZDDP-free oils in a rebuilt engine during the break-in results in any slight manufacturing defects rearing the head in horrid ways. One problem that has been observed is there is a miss-match of hardness (read up on the Rockwell scale) between the lift/rocker and the cam. This is seen especially on Z cars using camshafts with blanks cast by CWC using high-pressure valve springs. A re-ground Nissan cam and re-surfaced (or new) Nissan rockers is the best way to go.

 

As for weights of oils, thinner is ideally better, to a point. Thinner oils have less friction, and less friction means parts move easier, and parts moving easier creates less wear and more power. The caveat for this is the oil must be thick enough to fill the gaps between moving parts and protect them. Our classic cars with larger bearing tolerances looser-fitting parts from older metalurgy compounded with sometimes hundreds of thousands of miles need thicker oil to fill those gaps. You could very well bulid and L-series engine with clearances, thermal expansion properties, oil galley sizes, oil pump capacity, etc that would be perfectly happy with 0W-20. Hypereutectic pistons and as small as possible bearing clearances would be big steps forward making an L-engine happy with thinner oil. A high capacity oil pump would also most likely be needed. Keep in mind that when new, an L-engine was rated to run 5-30 in cold climates. With new synthetics that protect better, a rebuilt engine could most likely be happy in all moderate climates (above freezing to mid 90s) with it.

[Nismo280zEd]

Well said...

I had forgotten those horrible bottle additives still exist. (slick 50, prolong,etc.)

 

I think this would be a good place for this link.

 

http://www.mobiloil.com/USA-English/MotorOil/Files/Mobil_1_Product_Guide.pdf

 

I found it very interesting. I also have some links to oil filter analysis if you'd like.

-Ed

[bryand2]

does anyone think 10w-30 is too heavy to run in an L28 along with lucas oil stabilizer?

[johnc]

Am installing a "junkyard" L28ET in my 280ZXT to replace my engine which failed rod bearing.

 

What do you think about putting synthetic into a high milage engine with unkonwn history? Saw it run before it was removed. Oil press good, compression very good and even.

 

Now have done about 500 laps at Big WSIR and was down to mid 1:41 before the failure.

 

IMHO, for track use a synthetic oil is the best choice regardless of engine mileage or condition. What's even more important is oil control through a racing pan with trap doors, baffles, windage trays, etc. or a dry sump system or an Accusump. Add in a heat exchanger too.

 

Its bad times right now for good oil for older vehicles. Our Z's grew up with oil loaded with high ppm of ZDDP in it.

 

So what? I've run a $18,000 L6 racing engine on low ZDDP oil without any problems and the engine builder said its not a concern for the OHC L6 engine.

 

does anyone think 10w-30 is too heavy to run in an L28 along with lucas oil stabilizer?

 

That oil weight is fine and don't use the Lucas stuff.

[misterZ]

 

That oil weight is fine and don't use the Lucas stuff.

 

 

Hey John,

Since you piqued my interest, I'll bite, why? I've never used the product but have considered trying it... also, what about Marvel's Mystery Oil? I hear a lot of folks swear by it adding it to oil and gas(?).

 

Thanks,

[johnc]

Motor oil formulations have gotten so much better over the last 20 years that these additives are completely unnecessary. Its just a waste of money and at best they do nothing.

[bryand2]

ok guys got a problem, changed the oil today with 10w-30 and added one quart of lucas oil stabilizer, now i added the oil yesterday and changed the filter but did not run the engine until today, now the head seems extremely loud and something doesnt seem right, idk if its cause i added the oil and let it sit overnight or cause of the lucas, anyone have an idea, im scared something is damaged

[AlexPie]

anyone use BG MOA additive?

[johnc]

anyone use BG MOA additive?

 

I'll repeat myself...

 

Motor oil formulations have gotten so much better over the last 20 years that these additives are completely unnecessary. Its just a waste of money and at best they do nothing.