BBQ tick - another attempt to understand

[dirty-max]

So my car does have a tick when I rev it to 1200 rpm in nuetral. Not as loud or obnoxious as your guy's cars. You can barely hear it but it's there. It kind of just pops off randomly.

I swear these ticks sound just like a loose exhaust

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[Condor1970]

I swear these ticks sound just like a loose exhaust

I would agree to it being possible, if it wasn't for adding Ceratec making it instantly go away.

 

[GT Pony]

I would agree to it being possible, if it wasn't for adding Ceratec making it instantly go away.

Yep, it's somthing inside the engine that's lubricated by oil, and is affected by changing the oil formulation with the additive.

 

[TheLion]

My BBQ tick went away with TriboTEX and thus far has NOT returned even after changing the oil at 24,500 miles. The top end tick it has is rythmic with the engine RPM and becomes inaudible past maybe 1500 rpm (most noticeable at idle next to a barrier) when just freely revving it in neutral, but is not audible when loaded (as in starting the car from a stop). My Gt has always had that mild top end tick off and on since the car was stock with only 5,600 miles when I first bought it. It still does it some times even with the Ravenol PAO based 5W-20 I'm currently running, did it with PUP, M1 and MC Semi-syn, especially after hard driving when the oil temps get up higher, it can be quite clanky. But it still runs like a champ, no CEL, no abnormal behavior, I still can manage 29~30 mpg at 75 mph on a known stretch of highway since adding TriboTEX 5,000 miles ago...still pulls very well all the way through the rev range...

I've listened to some other modern high performance V8 engines and come to the conclusion that skeletal cast aluminum blocks, heavy valve springs, lots of valves / cams / timing chains / stainless tube headers or thin cast headers and thinner viscosity oils (5W-20 or 5W-30) are a recipe for ticks, knocks and taps that you might not notice with more common engine designs or when running much thicker oils like 40 and 50 weights. You have to factor in the much higher thermal loads of these performance V8's, especially the revv tot he moon 5.0's. To accommodate that you need to allow for enough thermal expansion which means looser bottom end and top end clearances than say a 2.0L 4 cylinder would use in a Focus. My Ecoboost was very clanky, sounded like it was falling apart at times. Traded it in for the GT at 36k and the only issue it had was a bad belt tensioner that was dealer replaced.

I was at a traffic light just this past summer and a white 2014+ white Corvette (newest body style with 5th gen LT1) pulled up next to me in a left turn lane. Low and behold it had a very distinct rhythmic ticking to it. I was actually quite surprised and my wife heard it too as we had the windows down. There's all sorts of parts that can wear in and develop a mild tick to them. Some may have wide enough clearances from the get go to allow some slop that is taken up when oil pressure rises which is a valid explanation for why it occurs at lower RPMs but not past a certain point as oil pressure builds.

Mechanically, these engines are still pretty simple. The only big changes design wise would be the addition of camshaft torque actuated mid-lock cam phasors and for the 2018's DIPI + spray on cylinder liners (which only serves to slightly increase bore size, but not by much). The electronic controls have become more advanced and computer modeling has aided in much higher flowing heads than the cars of yester year. But they still have 32 valve, 32 hydraulic lifters, roller finger followers, 4 cam shafts, 8 pistons, 8 cylinders, 8 rods, 8 rod bearings, 5 main bearings, gerotor positive displacement oil pump, 4 cam phasors and 4 timing chains.

What is actually very complex is the software that runs all of the hardware. There are what, 400+ some tables of data for the 2nd gen 5.0 where the first gen 5.0 was quite simple with just a handful of tables? 3rd gen is even more complex. Anyway, just my two cents on this whole ticking issue. I have not owned a car yet that hasn't had a tick or even a light knock at times, yet so far all of them have run to at least 175k miles and were still running when I sold them / traded them in.

I still haven't tracked down that burning oil smell I still get. Comes and goes, again did it since I got the car. At this point I haven't found any signs of leaks around the heads on the outside, so I'm thinking I have a small drip where one of the plugs are or it's dripped down onto a header and burning up without leaving any signs right where the heat shield is around the edge of one the valve covers. The car isn't perfect, but it runs very well and has been pretty reliable so far despite any ticks or taps and oil burning smells.

 

[TheLion]

Just for reference guys, Ravenol's SFE 5W-20 has a HTHS viscosity that meets SAE specs for ALL of the following SAE viscosities:

20 weight, 30 weight and the following 40 weights: 0W-40, 5W-40 and 10W-40.

https://wiki.anton-paar.com/en/sae-viscosity-grades/

HTHS spec is 2.9. So does RedLine's 5W-20 with a HTHS spec of 3.0. Either is a very good choice for high RPM protection with RedLine being a little more track focused while Ravenol is a little more street car focused.

At what point do we stop increasing viscosity and at what point does increasing viscosity limit volume of flow to the point where we are going backwards and actually reducing protection by incurring too much dwell time? The longer the dwell time of the oil (directly related to volume of flow), the hotter the oil will become as it remains in contact with the bearing surfaces, hence the thinner it will become.

There IS a point where a higher viscosity will actually see flow rates reduced such that the film on the bearings is actually thinner because of excessive localized heating due to very long dwell times...just sayin...maybe the Ford engineers actually did something for a reason other than CAFE standards. I'm not suggesting 5W-30 is at that point given how close it actually is to 5W-20, but to simply say 5W-20's can't offer enough protection and their only driving motivation is CAFE is D.U.B. (purposely miss-spelled).

I have no doubt that fuel economy was a factor in 5W-20's, but there are 900+ HP NASCARS running oils as thin as 0W5 at 9,500 RPM for 500 miles straight without rod bearing failures...there are many other cars also running very thin viscosities like Pro Stock for example etc...0W5...9,500 RPM...500 miles constant WOT at speeds ranging from 140 to 175 MPH+. They might be onto something

 

[TheLion]

https://blog.amsoil.com/what-happens-if-i-use-the-wrong-weight-viscosity-of-oil/

Here's an intriguing article from AMSOIL on oil viscosity. Remember lower pumping losses = higher power output AND better fuel economy. Both go hand in hand in many cases and losses occur throughout the RPM range. Some losses are non-linear, so they occur in larger magnitudes at certain RPM's, but pumping losses as well as friction losses are somewhat linear (at least until a saturation point occurs then they tend to go exponential).

Again, I'm NOT suggesting one SAE grade higher will result in a failed engine, but will it actually provide better protection? Or could the longer dwell time (increased localized heating) of the slightly higher viscosity off-set the added protection?

I read an article on Engine Builder Mag a while back that higher actual film area can be achieved with lower viscosity and tighter clearances than with larger clearances and higher viscosity in rod bearings and that is another reason (other than reduced pumping losses) for NASCARS using thinner weights of oils. Yes, they are more sensitive to contamination, the tighter the clearances the better quality the filters must be to avoid particulate wear issues, but the film actually fills more of the bearing surface area and tends to do it more uniformly.

Running thicker oil is generally an old school rule of thumb because using tight clearances is more expensive and harder to do on custom built hot rod engines. But there's plenty of people who have done it successfully. It's also a band aid for inadequate cooling. I think using a thermostat controlled Air to Oil cooler is more advantageous than running a higher viscosity oil. The whole point of running thicker weights for track is to counteract heating.

But the more ideal solution is control temperature and use a more temperature stable oil. Consistency is the key. Too thin and you have metal on metal, too thick and you also have metal on metal. The more the viscosity varies, weather due to oil selection or due to heating, the more likely you are to run into problems. That being said, using AMSOIL's water wetter may provide a slight improvement in cooling capacity. Combing that with reducing friction losses with TriboTEX or something similar AND using a high stable base stock oil like AMSOIL, RedLine, Ravenol or Driven etc. will probably yield some of the best results.

For track I think the better solution is to follow the user manual's suggestion, added cooling.

Straight from AMSOIL:

Since thicker oils don’t transfer heat as well as thinner oils, operating temperatures will increase, too, possibly leading to accelerated chemical break down and harmful sludge and deposits.

Remember, don't twist what I"m suggesting here out of proportion. There's an optimal range. Some times a little thicker is ok to compensate, just don't go crazy. At most I'd not go above a 5W-30, but I think a good quality PAO or Ester 5W-20 + increased cooling capacity / efficiency is the better solution. The more stable the temp, the more ideal the operating environment.

I really like the Ravenol 5W-20 PAO base oil blend. It has a HTHS of a SAE 30 weight but at 100 C it's only 8.4. Right in the middle of what most 5W-20's are. Very temp stable base stock. Their USVO should be even better once it hits US markets. RedLine's 5W-20 is also extremely good with a HTHS of 3.0, but at 100C it's on the high side of SAE 20 weight limit at 9.0, but still not bad. Not sure on Driven's specs for their FR20, but it's PAO and from a high end company, so I'd wager it's very similar to Ravenol's PAO formulas.

And they conclude:

Bottom line…
If you use a viscosity that’s one grade higher or lower than what’s recommended for your engine, it’s unlikely you’ll do any lasting harm. But, to alleviate any concerns about engine protection and your vehicle warranty, it’s best to use the viscosity recommended in your owner’s manual.

If you have questions or concerns, contact AMSOIL Technical Services ([email protected]) to determine the appropriate viscosity for use.

 

[Condor1970]

The Coyote oil pump is designed for thin oil to keep the cost down. Putting thick oil in the engine might result in starvation.

By thick, what do you mean? It is designed to run 5w20 and 5w30 specifically. It's also a positive displacement pump. Unless the oil gets very thick from super cold temps, and the pump cavitates badly from loss of suction, the same volume of oil will be pumped through the engine. Most synthetic oils which have good pour characteristics in cold temps, like Pennzoil or Mobil 1, will have virtually no difference in performance between 5w30 and 5w20 during normal driving. When the engine is pushed hard, then 5w30 is actually a better oil to use...As stated in the owners manual. In fact, the primary reason they want to use 5w20 is for fuel efficiency reasons.

 

[GT Pony]

The Coyote oil pump is designed for thin oil to keep the cost down. Putting thick oil in the engine might result in starvation.

What's the technical reasoning behind that theory?

Positive displacement oil pumps work more efficiently with thicker oil because there is less rotor tip leakage.

 

[GT Pony]

I still haven't tracked down that burning oil smell I still get. Comes and goes, again did it since I got the car. At this point I haven't found any signs of leaks around the heads on the outside, so I'm thinking I have a small drip where one of the plugs are or it's dripped down onto a header and burning up without leaving any signs right where the heat shield is around the edge of one the valve covers. The car isn't perfect, but it runs very well and has been pretty reliable so far despite any ticks or taps and oil burning smells.

Check the valve cover bolts, and look around the bottom edges of the valve cover for leakage. Some guys have reported slight leakage due to not very tight valve cover bolts.

 

[GT Pony]

There IS a point where a higher viscosity will actually see flow rates reduced such that the film on the bearings is actually thinner because of excessive localized heating due to very long dwell times...just sayin...maybe the Ford engineers actually did something for a reason other than CAFE standards. I'm not suggesting 5W-30 is at that point given how close it actually is to 5W-20, but to simply say 5W-20's can't offer enough protection and their only driving motivation is CAFE is D.U.B. (purposely miss-spelled)

I've posted links in the past on this board that show statements from Ford engineers saying they saw more engine wear on their test engines when running 5W-20. Also, on bobistheoilguy there were threads that showed links to Ford letters talking about the use of 5W-20 and the CAFE connection to it all.

I have no doubt that fuel economy was a factor in 5W-20's, but there are 900+ HP NASCARS running oils as thin as 0W5 at 9,500 RPM for 500 miles straight without rod bearing failures...there are many other cars also running very thin viscosities like Pro Stock for example etc...0W5...9,500 RPM...500 miles constant WOT at speeds ranging from 140 to 175 MPH+. They might be onto something

Only reason those NASCARs can run that thin of oil and have the engine survive is because they use super insane oil coolers that keep the oil as close to 200~210 F as possible. Plus, they really don't care if there is some engine wear as long as it doesn't cause major issues during the race. They could care less if the engine totally grenades 100 ft after crossing the finish line.

 

[GT Pony]

https://blog.amsoil.com/what-happens-if-i-use-the-wrong-weight-viscosity-of-oil/

Here's an intriguing article from AMSOIL on oil viscosity. Remember lower pumping losses = higher power output AND better fuel economy. Both go hand in hand in many cases and losses occur throughout the RPM range. Some losses are non-linear, so they occur in larger magnitudes at certain RPM's, but pumping losses as well as friction losses are somewhat linear (at least until a saturation point occurs then they tend to go exponential).

Again, I'm NOT suggesting one SAE grade higher will result in a failed engine, but will it actually provide better protection? Or could the longer dwell time (increased localized heating) of the slightly higher viscosity off-set the added protection?

I read an article on Engine Builder Mag a while back that higher actual film area can be achieved with lower viscosity and tighter clearances than with larger clearances and higher viscosity in rod bearings and that is another reason (other than reduced pumping losses) for NASCARS using thinner weights of oils. Yes, they are more sensitive to contamination, the tighter the clearances the better quality the filters must be to avoid particulate wear issues, but the film actually fills more of the bearing surface area and tends to do it more uniformly.

Running thicker oil is generally an old school rule of thumb because using tight clearances is more expensive and harder to do on custom built hot rod engines. But there's plenty of people who have done it successfully. It's also a band aid for inadequate cooling. I think using a thermostat controlled Air to Oil cooler is more advantageous than running a higher viscosity oil. The whole point of running thicker weights for track is to counteract heating.

But the more ideal solution is control temperature and use a more temperature stable oil. Consistency is the key. Too thin and you have metal on metal, too thick and you also have metal on metal. The more the viscosity varies, weather due to oil selection or due to heating, the more likely you are to run into problems. That being said, using AMSOIL's water wetter may provide a slight improvement in cooling capacity. Combing that with reducing friction losses with TriboTEX or something similar AND using a high stable base stock oil like AMSOIL, RedLine, Ravenol or Driven etc. will probably yield some of the best results.

For track I think the better solution is to follow the user manual's suggestion, added cooling.

Straight from AMSOIL:

Remember, don't twist what I"m suggesting here out of proportion. There's an optimal range. Some times a little thicker is ok to compensate, just don't go crazy. At most I'd not go above a 5W-30, but I think a good quality PAO or Ester 5W-20 + increased cooling capacity / efficiency is the better solution. The more stable the temp, the more ideal the operating environment.

I really like the Ravenol 5W-20 PAO base oil blend. It has a HTHS of a SAE 30 weight but at 100 C it's only 8.4. Right in the middle of what most 5W-20's are. Very temp stable base stock. Their USVO should be even better once it hits US markets. RedLine's 5W-20 is also extremely good with a HTHS of 3.0, but at 100C it's on the high side of SAE 20 weight limit at 9.0, but still not bad. Not sure on Driven's specs for their FR20, but it's PAO and from a high end company, so I'd wager it's very similar to Ravenol's PAO formulas.

And they conclude:

Here's some good journal bearing info. It basically says higher viscosity gives a thicker MOFT (even though it causes more shearing and heat as seen in the first table), which is the recurring message in all the technical info you can find about journal bearings. The local bearing oil temperature rise effect is most likely taken into account - it would have to be in order to determine the true MOFT in the bearing.

http://www.substech.com/dokuwiki/doku.php?id=oil_clearance_and_engine_bearings

I also attached a few graphs showing bearing info on what effects the MOFT, which is what you should always try to achieve the most of. Also, tighter bearing clearances gives a higher temperature rise in the bearing as the oil shears because tighter clearances flow less oil volume, which is what helps cool the heat from shearing.

 

[GT Pony]

http://www.mustangandfords.com/parts/m5lp-1003-2011-ford-mustang-gt-50-coyote-engine/

Coyote Oiling
Considerable work went into prepping the Coyote's oiling system for its 7,000-rpm redline and high-g Mustang home. It begins with thin 5W-20 mineral oil for reduced oil-pump-drive requirements, less internal drag, and quicker cold-start lubrication. Oil capacity was increased to 8 quarts, both to ensure adequate supply at high engine speeds and to increase oil change intervals to 10,000 miles.

That doesn't mean there will be "oil starvation" (as you mentioned in the other post) if a thicker oil is used. Ford used 5W-20 to gain 0.001 MPG (again CAFE driven) due to less oil pump work with the lower viscosity oil. Positive displacement oil pumps don't put out less oil flow with a higher viscosity oil. They call them "positive displacement" pumps for a reason.

 

[Condor1970]

Do these oil pumps still destroy their gears like the earlier Coyote versions? Add oil that's too thick and bust your pump, then it's new engine time.

So it's nice thin 5W-20 for me, just as the engine was designed for.

Considering the Owner's Manual says you can run 5w30 when running at high RPM at the track, I would say the pump probably won't catastrophically explode like a North Korean missile the moment you press the start button.

 

[88lx50]

Oil pump gears break when you add a supercharger, bang off the rev limiter, etc. 5w30 won't break oil pump gears lol.

 

[GT Pony]

Do these oil pumps still destroy their gears like the earlier Coyote versions? Add oil that's too thick and bust your pump, then it's new engine time.

So it's nice thin 5W-20 for me, just as the engine was designed for.

If that was the case, you better not go over 2,000 RPM until the 5W-20 warms up to 200 F. That 5W-20 is about 10 times thicker at 50 F than it is at 200 F.

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