Correct oil for flat tappets

Gokhan

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Originally Posted by RDY4WAR
I know what asperities are. I've done a lot of cylinder honing, crankshaft polishing, and lifter bore honing. Even fine tuning a targeted asperity height, shape, and gap for specific applications. I was asking if you were saying the oil film in the gaps was more important than the polar molecules on the asperities. I can see where your argument is going, but it doesn't align with what I've seen with my own engines and others in the real world. Additive types and concentrations have made huge differences, but practically none observed with base oil changes. I feel like the activation of anti-wear additives in mixed and boundary lubrication is far more important than the base oil.
I wouldn't call them polar molecules. These additives form chemical bonds and tribofilms, not just loosely attach to surfaces. The additives are usually not a variable unless you want to pour in some aftermarket ZDDP etc. However, the base-oil viscosity is. You're also talking about anecdotal experiences, which are subject to many sources of bias, on highly specific engines in highly specific operating conditions. Moreover, you blend your own oils, which brings many question marks such as additive compatibility and lack of thorough testing other than some racing events, which run the coolant only at around 60 °C and the oil only at around 70 °C thanks to specialized cooling. In addition to the Chevron brochure I posted above, there is a paper by Nissan that emphasizes base-oil viscosity for reducing the wear in timing chains: Nissan study on wear in timing chains Regarding ZDDP there is no evidence that now-obsolete oils with high ZDDP content resulted in less wear than modern oils. On the contrary it turns out that the opposite is the case. For this reason there is no direct relation between the ZDDP content and wear. However, there is a direct relation between the base-oil viscosity and wear. I have a thread on this, too: Wear and fuel economy results for selected SF through SN oils: PCMO3 engine test
 

SR5

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Originally Posted by Gokhan
The additives are usually not a variable unless you want to pour in some aftermarket ZDDP etc. However, the base-oil viscosity is. Regarding ZDDP there is no evidence that now-obsolete oils with high ZDDP content resulted in less wear than modern oils.
Yes the additives are a variable by selecting an oil with the add level and type you require. It's called a free market and we are discussing suitable oils right now. Sometimes you select a smaller manufacturer for just that reason. There is ample evidence that ZDDP works in high stress applications to reduce wear, hence their continued presence in modern racing oil like Penrite 10-Tenths, Valvoline VR-1, M1 Racing etc. The only question is what level is required for your particular application. In this respect I believe Rdy4war has ample real world experience.
 
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Originally Posted by SR5
. Sometimes you select a smaller manufacturer for just that reason.
Zigactly - just use Penrite and forget about all this stuff.
 
One of the reasons behind me running 20W-50 in my 1988 Escort is to try and prevent valvetrain wear. It has the venerable Ford CVH ( Compound Valve Hemispherical ) 8v SOHC engine, they have very stiff springs from the factory, as the discovered early on that the valves could bounce at high revs. It's an odd design for a SOHC engine, the hydraulic flat tappets ride on top of the cam like they would in a pushrod engine, and push directly on the rocker arms. They have a well known tendency to wear out camshafts sometimes in 100k miles or less. The oil i am running is a modern Synthetic Blend 20W-50 that is API SM, and ACEA A3/B4, and Repsol have confirmed to me that it has over 1100ppm of Zddp ( They would not tell me exactly how much )
 

Gokhan

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Originally Posted by SR5
Originally Posted by Gokhan
The additives are usually not a variable unless you want to pour in some aftermarket ZDDP etc. However, the base-oil viscosity is. Regarding ZDDP there is no evidence that now-obsolete oils with high ZDDP content resulted in less wear than modern oils.
Yes the additives are a variable by selecting an oil with the add level and type you require. It's called a free market and we are discussing suitable oils right now. Sometimes you select a smaller manufacturer for just that reason. There is ample evidence that ZDDP works in high stress applications to reduce wear, hence their continued presence in modern racing oil like Penrite 10-Tenths, Valvoline VR-1, M1 Racing etc. The only question is what level is required for your particular application. In this respect I believe Rdy4war has ample real world experience.
This is the take of a retired oil blender from Europe on this issue, whom I didn't always agree or get along with. He says the most important thing for an oil's antiwear performance is its base-oil viscosity (its viscosity before the VII is added, which is also lower than its HTHS viscosity):
Originally Posted by SonofJoe
Okay. You lost me at 'reverse cooling'! As Shannow & other BITOGers know well, I don't do nuts & bolts stuff. The last time I wielded a spanner in anger was forty years ago! That said, it sounds from what you say, because of the reverse cooling system you employ, that your oil doesn't actually get that hot (180F or 82C). Notwithstanding that the oil will temporarily get somewhat hotter as it traverses the bearings, this is very moderate indeed. Even the lowliest of Group I oils could easily contend with this level of heat for a few minutes at a time. I guess an appropriate question to ask would be how fast do you want to go and how far are you prepared to compromise engine life? If your priority is wear (especially cam & tappet wear) then your priority should be to use a heavy oil containing not a lot of shearable VII; something like a 'tight' 20W50 for example. I used to get paid to sell additives and yes there's a lot you can do to counter wear with Zinc & Moly. However, any formulator worth his salt will tell you that, in terms of anti-wear, there's no substitute for non-shearable high viscosity & the presence of some genuinely heavy base oil in the blend. By all means slap in a goodly amount of Zn & Mo on top but go heavy! BTW, it won't matter what type of ZDDP you use at these kind of temps as both will be well above their respective activation temperatures. Of course heavy oils are 'power sappers' and directionally will slow you down. I suspect you will go a bit quicker if you put a 0W16 in the sump...but it's not going to be as kind to your engine!
I read a lot of hype on the Penrite site. Motorcycles run just as well on plain Rotella. (Don't try Nutella. wink ) Flat tappets have been around forever, but the antiwear additives have only excelled in the last decades. Regarding mega doses of ZDDP providing more protection for flat tappets, it's going to remain an old wives' tale until someone comes with a scientific study showing it's the case. Here is a good ZDDP thread, where the quote above came from: https://www.bobistheoilguy.com/forums/ubbthreads.php/topics/4853520/primary-vs-secondary-zddp
 

SR5

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So you admit that ZDDP is a variable and that "there's a lot you can do to counter wear with Zinc & Moly. " Thank you for agreeing with me and acknowledging that part of your previous post was incorrect. I certainly agree with you and Joe about using thick base oils and low VII load. I was into tight viscosity oils back when you were preaching M1 0W40 as the golden elixir to everything. I wasn't arguing with the bits I believed to be right, but rather when you went a step too far and start saying things like "The additives are usually not a variable unless you want to pour in some aftermarket ZDDP ". When quite simply it clearly is a variable even without aftermarket adds, and as a completely separate point to viscosity which is also a variable and also important. Your style is to have some very good points (which I acknowledge) but then often go too far in your excitement to show your point, and when others pull you up on a subset of your post, you get defensive and argue something slightly different where you have a better case, but ignoring the actual issue raised. I should point out that the main reason people pause to point out areas they believe to be incorrect and misleading is for the benefit of the casual reader who deserves the right to hear a counterpoint to a debatable point. I know you have enough skill and knowledge to buy suitable oils for your car.
 
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Originally Posted by PontiacHO
Are bikes being built with flat tappet currently?
High performance bikes still use cam lobe directky on bucket shim style valve train. It's the best set-up for high RPM. My 2005 Tacoma 4.0L V6 has cam lobe on bucket shim valve train also. Seems like a lot of Japanese engines use direct cam lobe valve actuation.
 
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Originally Posted by RDY4WAR
Even stock hydraulic flat tappet cams with 90 lb springs and <.450" lift and turning <5500 rpm still operate in boundary lubrication. I don't see how a more viscous starting base oil is going to improve upon that when there is no appreciable oil film present. Say if we did have an impact of oil film, how can you substantiate any claims of better protection between different base oils of kinematic viscosity. This would claim that a 5w-30 using base oils with a higher pressure-viscosity coefficient wouldn't perform as well as a 10w-30 with a lower P-V coefficient. Are we just going to ignore the more relevant properties of these base oils and look at KV alone?
Correct. [email protected] has no effect on wear in boundary lubrication.
 

Gokhan

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Originally Posted by SR5
saying things like "The additives are usually not a variable unless you want to pour in some aftermarket ZDDP ". When quite simply it clearly is a variable even without aftermarket adds, and as a completely separate point to viscosity which is also a variable and also important.
What I meant was that the ZDDP level is fixed by the oil recommendation in the owner's manual, which specs an ILSAC, ACEA, or OEM category. Owners wouldn't be willing to deviate from that and void the warranty, and they shouldn't deviate for good reasons with the aftertreatment devices installed in their vehicles. It's true that the same also applies to the viscosity but to a lesser extent. For old cars with flat tappets, you can pretty much select any oil out there, from various oil types, ZDDP contents, etc. One of my points was that any modern oil of any ZDDP content has a better antiwear package than any obsolete oil of any ZDDP content at the time when these engines were introduced. There is ample evidence calling for a thicker base oil, such as no thinner than that of a good 10W-30 and preferably as thick as that of a 15W-40 or even a 20W-50. I know old Fiats in Europe run on 20W-50, regardless of the climate, and they go a million miles without an engine rebuild.
 

SR5

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Originally Posted by Gokhan
a good 10W-30 and preferably as thick as that of a 15W-40 .
While I'm not convinced all obsolete oils were rubbish at doing their job, my friends and I were using high ZDDP and high TBN synthetic oils like M1 15W50 / 5W50 and Castrol Edge 10W60 / 0W40 back in the 90's, I do agree the average oil used today is much better than the standard issue oils of a few decades ago. This is due to the good work of API, ILSAC, ACEA and the OEMs. I also agree that a good 10W30 or 15W40 is an excellent choice for a flat tappet engine, something with a good dose of ZDDP. Here is a nice example recently posted in the VOA section https://www.bobistheoilguy.com/forums/ubbthreads.php/topics/5357491/ Shell Rotella T5 in 10W30 and 15W40 both are CK-4 10W30 Boron ~180 ppm Zinc ~1100 ppm 15W40 Moly ~60 ppm Boron ~120 ppm Zinc ~1200 ppm I think HDEOs and MotorCycle oils are perfect for old school flat tappet engines. Plus you have the smaller brewers like Driven, Penrite, RedLine, Schaeffers and the special products like Valvoline VR-1 or M1 15W50 (1300 ppm Zinc) M1 10W40 4T (1300ppm Zinc). Mobil says the 15W50 is for "Racing and Flat tappet applications" and the 4T is their motorcycle oil.
Originally Posted by SR5
Here is a link to a Castrol 10W40 semi-synthetic motorcycle oil, it has Moly 50ppm, Boron 60ppm and Zinc 1000 ppm with a TBN of 9.3 https://www.bobistheoilguy.com/forums/ubbthreads.php/topics/5343919/ The high zinc (ZDDP) is due to the engine oil also being the gear box oil in a shared sump motorcycle, so extra wear protection is required for the gears. Also this is a high shear environment so high shear resistant viscosity index improvers (VII) are used.
Lots of good oils out there.
 
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...while I appreciate the OP 're-opening'(?) my topic, I think I got the answers I was looking for - mostly what to make of the blog-that-shall-not-be-named. One of the reasons I was asking is related to a fresh 440 I will be running in my rock crawler (02 Dakota QC on 40's and a lot of other big hardware). Where we go we go slow, so heat can creep up and stay up, and the angles can get real steep. Heat wasn't a problem when I crawled my last truck with a 5.9 non-IC Cummins - it never got hot (go diesel), but the 440 may want to creep up on the temp scale, plus the truck will see deep sand to the go pedal will get a healthy workout now and then, not to mention the truck will be fully highway rated, so I was just wanting to make sure the 'flat-tappet' oils I'd thought were good were indeed good. My plans are to run Rotella T4 15W40 HD diesel oil in the summer and maybe switch to Rotella 10W30 T4 HD diesel oil for the winter wheelin'...tho I could probably run either all year and the engine likely wouldn't care. Again I appreciate the replies from the other forbidden thread, and this one as well. Cheers all, - Sam
 
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Originally Posted by Mad_Max_Sam
...while I appreciate the OP 're-opening'(?) my topic, I think I got the answers I was looking for - mostly what to make of the blog-that-shall-not-be-named. One of the reasons I was asking is related to a fresh 440 I will be running in my rock crawler (02 Dakota QC on 40's and a lot of other big hardware). Where we go we go slow, so heat can creep up and stay up, and the angles can get real steep. Heat wasn't a problem when I crawled my last truck with a 5.9 non-IC Cummins - it never got hot (go diesel), but the 440 may want to creep up on the temp scale, plus the truck will see deep sand to the go pedal will get a healthy workout now and then, not to mention the truck will be fully highway rated, so I was just wanting to make sure the 'flat-tappet' oils I'd thought were good were indeed good. My plans are to run Rotella T4 15W40 HD diesel oil in the summer and maybe switch to Rotella 10W30 T4 HD diesel oil for the winter wheelin'...tho I could probably run either all year and the engine likely wouldn't care. Again I appreciate the replies from the other forbidden thread, and this one as well. Cheers all, - Sam
Driven GP-1 15w-40 would be an excellent choice for the 440. Change it once a year, 3k miles, or 100 hours. It'll take whatever you can throw at it. Ca = 2200 Zn = 1300 P = 1200 B = 200 Mo = 350 High Performance Lubricants, a BITOG sponsor, also has a full line of synthetic HDEOs from 0w-8 to 20w-50 in multi-grades and SAE 20 to SAE 50 in monogrades. It has an older CI-4 add pack with a twist.
 
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one of the criteria I'm also trying to satisfy is using an oil that is 'off-the-shelf' at most parts stores, Wally World, etc., and while that is of course not a show-stopper it is one piece of the equation I am trying to balance, as are most folks I'd imagine. I've used the J.G. oils before and loved them - and while they aren't available locally I could just order in a case and be fine. One thing I thought was also interesting is while I was talking with the tech folks at Shell (when they told me that all of the T-series oils (T4, 5 and 6) have the anti-wear package(s) for flat-tappet cams) they also told me that their 5W30 Gas-Truck oil does not have the same package - it is made for the 'newer' engines and would not recommend it for flat-tappet engines.
 
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Originally Posted by Mad_Max_Sam
one of the criteria I'm also trying to satisfy is using an oil that is 'off-the-shelf' at most parts stores, Wally World, etc., and while that is of course not a show-stopper it is one piece of the equation I am trying to balance, as are most folks I'd imagine. I've used the J.G. oils before and loved them - and while they aren't available locally I could just order in a case and be fine. One thing I thought was also interesting is while I was talking with the tech folks at Shell (when they told me that all of the T-series oils (T4, 5 and 6) have the anti-wear package(s) for flat-tappet cams) they also told me that their 5W30 Gas-Truck oil does not have the same package - it is made for the 'newer' engines and would not recommend it for flat-tappet engines.
So that's words straight from Shell basically saying they think zddp is important for flat tappet. Unless they are just saying it because they're aware that the majority of old car enthusiasts are under the impression that it is important? It may be easier for them to state which oil has higher zddp than to argue whether or not it is important. My feelings are that it's still important for vehicles with more aggressive camshaft profiles and stiff valve springs. Probably not on either of my engines. That said, there are a lot of factors you can consider when choosing oil. Straight 30w may be good in my cars in the summer, but would it be worth using when most of my trips are 6-7 minutes to work so the engine oil never gets completely warmed up. It gets longer trips every week including some very long trips however. The engine in my summer only car is 44 years old and it was 32 years old when I put it in the car 100k miles ago. It's had nothing but synthetic, from 0w30, 0w40, to 15w50. The engine looked very clean at the beginning but i assume some buildup from 32 years was likely cleaned out by using synthetic for that long. Maybe now is the time to stop using synthetic if there's no more benefit to it in my car, on the other hand it's runs almost like new still, exactly the same as when we put it in. It's had 10 psi oil pressure at hot idle for the past 12 years. I used higher zddp for a number of years and then decided it didn't need it maybe 4 years ago. Now I always use what's on sale at Canadian tire or Walmart. Usually Mobil 1, Castrol, Pennzoil, or Quaker state. The first few years I used expensive stuff like amsoil or German Castrol. I don't know if it would have held up this well with any oil changed on time. My other engine is an 83 305 Chevy with 240k miles. I put about 80k on it the past 10 years. They were known for camshaft failure back in the day but it was probably fixed a long time ago. It's a little bit worn (cold start piston slap and some slight valve train noise) but it runs smooth and has as good power as they ever did. I will continue to use 0w30 or 0w40 in it for winter cold starts but in the summer I'm considering 30w or 15w40 conventional. It needs valve seals but you can't notice anymore since I replaced the catalyst. But I know they're leaking and it used a qt per 2k miles at least now. I can buy a bulk barrel of straight 30 or 15w40 hdeo for very cheap. Then I could run it in both vehicles and maybe even the 05 Silverado (4.8 LS engine) I bought from my employer (I'll still be driving it for work every day). It also needs valve seals (200k on it). I'd prefer the straight 30w because the Olds 350 seems to be noisier on anything thicker than a xw30. Any thoughts on running the straight 30 in all three of these engines summer time? Like I said the majority of trips with the flat tappet car engines will be 6 minutes to work. The Silverado will spend most of the day somewhat warmed up, driving from job to job, and around the job sites. The fact that we've had to do zero exhaust work on any of these trucks after 15+ years shows that they get warmed up enough every day. The truck has had nothing but conventional 5w30 for 200k miles with a couple times I changed it myself with full synthetic 5w30. I assume the LS isn't picky about oil and would also be fine with 30w. It would be nice to buy oil in bulk since I'm now maintaining 3 vehicles and trying to make a profit with the Silverado.
 
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Originally Posted by caprice_2nv
So that's words straight from Shell basically saying they think zddp is important for flat tappet. Unless they are just saying it because they're aware that the majority of old car enthusiasts are under the impression that it is important? It may be easier for them to state which oil has higher zddp than to argue whether or not it is important.
my only point was that Shell did not recommend their 5W30 gas-truck oil for flat-tappet cams...when they could have just said 'yup they're all good' - I thought that was fairly forthright of them. I do have a fair amount of faith in the Rotella T4, 5, 6 oils now, plus it isn't spendy and it's easy to find just about anywhere. ...or I suppose I could also just get a case of Joe Gibbs HR-5 10W40 and call it good...
 
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