Engine Oil, The High Cam, And The Tree Huggers...

[Stan]

Over time engine oil specs have been revised to suit various needs and concerns. The Elise oil specs include an API SL and 5W40 rating among others.

Over the last few API (American Petroleum Institute) spec updates various antiwear additives have been capped and reduced in allowed amounts. This is being done because some of the additives can eventually reduce catalytic converter effectiveness. Such as when a car eventually burns oil and has maybe 100-150K miles on it. The catalytic converter can get coated and so is less able to do it's thing in such cases.

One of the indirectly capped additives is ZDDP which includes both zinc and phosphurus. It's wonderfully effective in reducing wear on those items which slide against one another under pressure, such as piston rings and nonroller cams.

Guess what? Our low cam is a roller (which ZDDP won't help, nor does it need any help there). But the high cam is a slipper arrangement which has that rubbing / sliding action ZDDP can benefit. And it's an aggressive profile. Note that overall, the ZDDP thing is mostly an older domestic car thing as flat tappets were the rule.

One thing that freaked me about in my research is that the API's new SM rating (the next one past the now out of date SL) has way less allowance for zinc/phosphorus additives like ZDDP than API SL oil. And SL was already cut back. The API says no problem...we tested older cars (such as non roller pushrod domestics) and kept wear down to "acceptable" levels. Only...they *tripled* the allowed amount of allowed camshaft area wear. Which would allow an oil to "pass" their test more easily!

For sure good oils to use for the moment include diesel oils such as Rotella T group III semisynth, Mobil 1 Delvac 1 and a variety of other excellent gas and/or diesel oils. Diesel oils will get their additive packs revised in the next oil spec for 2007 vehicles, so they get affected next.

If you do lots of track days where the time spent on cam is high I'd give this stuff some thought. I'm not saying that your cams will be destroyed if you load in an API SM rated oil, but simply to think about this stuff and pay attention to how things develop over time as their are some unknowns. If you are particularly concerned, ANY oil can be enhanced with (believe it or not) STP 4 cylinder formula or GM's EOS. In some areas like California such additives are no longer allowed or available.

There is a thread at http://www.exiges.com that discusses a case or two where a 2zzge engine experienced high-cam lobe problems while the low cam was fine. I am not sure what happened there, it certainly could have been other issues besides oil sublteties, I will watch that one. Suffice it to say that a variety of motors with nonroller cams have had cam troubles related to the new oils over the last few years.

[edaddy]

Great info Stan, thanks! Do you think it's still safe to use Mobil 1 0W-40 in the Elise/Exige?

[Stan]

Great info Stan, thanks! Do you think it's still safe to use Mobil 1 0W-40 in the Elise/Exige?

Don't get me wrong, just about any oil is safe if it's close to the correct viscosity range figures. Mobil 1 0W-40 is now SM rated, meaning that by necessity the old school style cam protecting additives were reduced. It's more of a long term wear thing. For now I'm using 5W40 Mobil Delvac 1 which is 100 % true synthetic in the European sense. And it has plenty of the ZDDP high cam protection stuff. Just keep an eye open and use an additive for track days if your oil is blended for roller cams (our low cam = roller and is unaffected by this potential concern).

Many folks will never put many miles on their Lotus. So the main thing is just to HAVE oil and to change it before storage periods! Race car motors mostly die through downshift overrevs or crashes. Not oil subtleties requiring research to figure out. I'm at about 40,000 miles so wear issues are relevant to me.

A few years back Mobil sued Castrol. They said Castrol was cheating and calling their processed dino oil synthetic. Well they lost and in America you can call that 100% synthetic for years now. Mobil 1 stayed 100% synthetic. They had pride and decades of history as a premium product. Now Exxon Mobil reformulated some of the Mobil 1 varieties so they are doing what the sued Castrol for doing! At least a few now use processed mineral oil, but are actually higher priced than before. Ironically one of the very best true, real, actual synthetics that is widely available = 0W30 (only) Castrol made in Germany. Amazing.

[ChrisH]

Stan, do you know the difference between the following?

a) Mobile Delvac 1 5W-40
http://www.mobil.com/USA-English/Lubes/ ... _5W-40.asp

and

b) Mobil 1 Turbo Diesel Truck 5W-40
http://www.mobiloil.com/USA-English/Mot ... 5W-40.aspx

Does the second one include ZDDP at the same level as the first? Or is there something else in the difference we should be concerned about?

[Stan]

Stan, do you know the difference between the following?

a) Mobile Delvac 1 5W-40
http://www.mobil.com/USA-English/Lubes/ ... _5W-40.asp

and

b) Mobil 1 Turbo Diesel Truck 5W-40
http://www.mobiloil.com/USA-English/Mot ... 5W-40.aspx

Does the second one include ZDDP at the same level as the first? Or is there something else in the difference we should be concerned about?

They are supposed to be the same oil. Except that the latter is cheaper. Around here a gallon of Delvac 1 is about 35 buck or nearly 9 dollars a quart. The truck 5W40 is now truck / SUV 5W30 it appears. No idea about the latest ZDDP content but the viscosity drop is the deal killer. The diesel oils are presently exempt from some of the additive caps.

[Stan]

I'm going to yank my valve cover to see how things are doing, I'm at 40k miles. This will provide some clues about oil too.

While I'm in there, I will change out the "lift bolts" as the Celica guys call them. They participate in the high/low cam changeover. They are wear items and can break. Early 2ZZs had many failures, there was a redesign and a TSB. If they break, it can lead to a $800 repair...at a Toyota dealer. Cams get removed, etc.

If your valve cover is off for some reason, it may make sense to simply change them out. Because if they are intact..you just unscrew the bolt ad screw in a new one, done. I mean they are 49 cents each and two are used (one for the intake cam, one for the exhaust). I got a few at the Toyota dealer, they are: Part Number 90105-06293 "Flange Bolt".

Here are lift bolts, old style (RHS - see the wear near the tip?)and new style (LHS) style. All Toyota / Lotus use the new style bolt:



Here is where they live...see how easy they are to change out if intact? If the break they tend to do so along the threads, leaving the lower half in the head, requiring disassembly (Not my car, these are Celica shots, but I added some labels)



Since Lotus cars get tracked more than Celicas...it could be a good idea to change these out periodically. Time will tell.

[macfly]

Bringing this back to life, please tell me what the very best oil is to put in my always/only tracked Exige S. This poor little thing has it's neck rung every time it gets driven, so I want to give it the very best oil I can.

[Griffin]

frequency of change and quality filters are most important. Change every 2500 or less for best results and longevity. Do some oil analysis through blackstone labs or a similar company to monitor the results of whatever regimen you decide on

I recently have become a fan of the synthetic blends, particularly Mobil 1. There are also a couple high dollar full synthetic Japanese oils that are quite good.

I also run a product called Polydyn TX7 but I don't have analysis data to back up its performance under track conditions in the 2ZZ.

[lotusmark]

I've been running Fuchs in my Rover motor for the last 6 or 7 years with no issues.

Primo stuff.

http://www.silkoleneoil.com/raceprod.htm

[surfdog]

What's the consensus on the Motul 8100 5w-40 that sector is selling? (I put that in my Elise last time around...........)

[Griffin]

What's the consensus on the Motul 8100 5w-40 that sector is selling? (I put that in my Elise last time around...........)

I tried Motul in my alltrac for a couple changes. It got real dirty real fast so I stopped using it.

[insane]

What's the consensus on the Motul 8100 5w-40 that sector is selling? (I put that in my Elise last time around...........)

I tried Motul in my alltrac for a couple changes. It got real dirty real fast so I stopped using it.

You might ask 'why' it got real dirty, real fast. A cheap oil with lacking proper detergent properties will seem cleaner, longer.

[ken wright]

Sorry off topic:

What is the function of the lift bolt? What is the part number? How many do I need? What torque when installing?

Thanks,

ken

[Griffin]

What's the consensus on the Motul 8100 5w-40 that sector is selling? (I put that in my Elise last time around...........)

I tried Motul in my alltrac for a couple changes. It got real dirty real fast so I stopped using it.

You might ask 'why' it got real dirty, real fast. A cheap oil with lacking proper detergent properties will seem cleaner, longer.

I ran Mobil1 full synthetic and castrol full synthetic both of which didn't have the issue. Both of them have adequate detergent pckages. I change my oil about every 500 miles on average and my motor is squeaky clean. Oil getting dirty in 300 miles is not acceptable.