Oil jet piston cooling and its effects on oil?

[Shannow]

Originally Posted By: Jetronic
I'd rather reduce oil leakage in the bearings by going up a few grades than do without the oil squirters.


Misaligned squirters are reputed to be an issue with the engine in my Nissan (ZD30 turbodiesel), and the number three pot failure...I'm not convinced, as there appear to be other issues afoot as well, but at least on the diesels, the squirters are a dead necessity these days.

Had a big post on the MC forum regarding squirters.

Looking at the typical squirter, the flow through them is going to be more dependent on pressure than viscosity. Nearly all have a length of reasonably large diameter tube (to reduce the effects of viscosity), and a short section of "nozzle", which flows according to pressure, diameter, and density with little viscosity effect.

In short, if you choose a viscosity that drops your oil pressure (e.g. BLS running AFE0w30 in his bike), squirter flow and piston cooling suffers

 

[artificialist]

I read some very lengthy articles in the May 1998 issue of Sport compact Car which covered the Nissan 300ZX Twin Turbo.

The writer claimed that oil squirting jets added to overall durability, and that they lowered the temperature of the piston. It was claimed that this prevented detonation at high boost levels.

 

[06VtecV6]

Originally Posted By: DoubleWasp
The thing is, most engine builders are doing everything they can to control how oil moves in the crankcase. Piston squirters are the bull in the china shop.

I'd rather have good piston coatings than oil squirters. Keeping heat out of the piston beats trying to remove it.


They use oil squitters anywhere there is a need for additional lubrication or when "insufficient lubrication" rears it's you know what. [censored] there was in the transmission of a brand new car I once bought, the venerable Vtec V6 (See sig) Yeah, I made sure to chec that box that said EXTENDED WARRANTY but it was the price I had to pay for buying what subsequently became known as the "AutoTragic" Accord. how do you like these green apples?!

 

[OVERKILL]

Originally Posted By: 06VtecV6


They use oil squitters anywhere there is a need for additional lubrication or when "insufficient lubrication" rears it's you know what.


The primary purpose of piston oil squirters is to cool the underside of the piston.

 

[MolaKule]

Originally Posted By: krismoriah72
Break the engine in.

Motorcraft 5w20 semi syn at 1000, 3000, then 5000..then change at 5000 with same oil til you get tired of it.

Piston-cooling jets squirt oil on the underside of the pistons to keep the piston crowns cool under extreme operating conditions. The cooling jets also allow for a higher compression ratio for better engine efficiency and faster engine oil warm-up on cold starts, also improving fuel economy.

 

[PeterPolyol]

Originally Posted by afree
The high horsepower Supra guys have been removing these things for years. They seem to cause damage in high output applications:

http://www.supraforums.com/forum/showthread.php?633865-Oil-Squirters-Yay-or-Nay

Even sell block off plates for them:

https://www.acceleratedperformance.com/product/2jz-Oil-Squirter-block-off-Kit

Not saying this is for everyone, just a fun fact

Wow, that SF thread is some serious cancer. Think I lost a few IQ points after reading it... got all these casuals ganging up on a guy making irrefutable points about the benefits of piston quirters, and supporting their ideology with nothing but insult and consensual horse hockey. "Shock cooling the cast iron pistons too fast" "Only cools at stock power levels so delete them if you run more power" my goodness.. makes this board look like a SAE conference

 

[ZeeOSix]

Originally Posted by bdcardinal
Originally Posted by hatt
Originally Posted by bdcardinal
When the Coyote 5.0L came out in 2011 they had them installed. Then around 2013ish or so Ford eliminated them while adding a different coating to the piston skirts. I still would rather my engine have them than not as there is no downside aside from some increased windage that can be taken care of with shielding.
I still have no idea if my truck has them or not. So much conflicting info.

Ya it is confusing even for me. When I look my car up in the catalog, it shows them. But when I check the block, it shows the block is one without.


The Ford shop manual shows the Gen2 Coyote (2015 - 2017) in the Mustangs to have piston oil squinter nozzles.

 

[4WD]

Originally Posted by OVERKILL
Originally Posted by 06VtecV6


They use oil squitters anywhere there is a need for additional lubrication or when "insufficient lubrication" rears it's you know what.


The primary purpose of piston oil squirters is to cool the underside of the piston.


Both my L83's have them and oil coolers … my 2017/2018 engines are quieter on 0w20 than my 2010 was on 0w40

 

[oghl]

I thought oil cooling jets puts less overall stress on oil and engine components, therefore it's a reliability feature. Not an expert at all here, but I thought that oil jets cool the very hot part of the piston so that pistons don't get TOO hot. Therefore while the jets get hot, because of the higher volume of oil touching the piston bottom, the oil doesn't get as hot as without the jets (splash only).

The lowered piston temp is good for piston/rings reliability, and the hot (oil but not as hot as without jets)would epcerience lesser stress as well.

Again just imagining things in my head. No data to back up any of it.

 

[Bryanccfshr]

This.
It is better overall heat equalization. More uniform heat distribution means less stress and wear. It also helps warm the engine and fluids faster, which reduces wear by activating aw additives sooner.
The piston Is not getting hot, because it is being cooled by a continuos flow of engine oil, so it isn't really extremely hot for the oil flowing accross the bottom of the piston.
Originally Posted by oghl
I thought oil cooling jets puts less overall stress on oil and engine components, therefore it's a reliability feature. Not an expert at all here, but I thought that oil jets cool the very hot part of the piston so that pistons don't get TOO hot. Therefore while the jets get hot, because of the higher volume of oil touching the piston bottom, the oil doesn't get as hot as without the jets (splash only).

The lowered piston temp is good for piston/rings reliability, and the hot (oil but not as hot as without jets)would epcerience lesser stress as well.

Again just imagining things in my head. No data to back up any of it.

 

[oghl]

Thank you. Much more succinctly and elegantly written than my incoherent babbling. I am surprise that you can follow my gibberish

 

[ZeeOSix]

Originally Posted by Bryanccfshr
It is better overall heat equalization. More uniform heat distribution means less stress and wear. It also helps warm the engine and fluids faster, which reduces wear by activating aw additives sooner. The piston Is not getting hot, because it is being cooled by a continuos flow of engine oil, so it isn't really extremely hot for the oil flowing accross the bottom of the piston.


It may also help reduce deposits and coking of the rings if the whole top of the piston runs cooler due to oil squirters keeping it cooler.

 

[4WD]

My newer 5.3L's do warm quicker … but they also have grill shutters that previous trucks did not …

 

[4WD]

Yes … vis the least, ID having the greatest impact on residual pressure loss, length more linear, and nozzle mostly kinetic?
So need to preserve a certain amount of pressure drop at the nozzle to do "work" (impact/distance/pattern etc) …
… do they clean a wee bit too …?
I really wonder about this … coated pistons have been in GM 5.3L's a long time … but that classic piston slap noise is gone … Did the focused injection of oil help ?

 

[Realtech214]

Like someone above said. My 5.3 L83 is also silent running on 0W20/5W20. Got 130000 miles now. I believe the squirters only work when the oil pump goes into the high pressure mode above 3500 RPM.

 

[240_Ed]

FWIW late model Volvo redblock (B2xxF/FT) engines were fitted with piston oil squirters and these engines are much less susceptible to developing cold piston slap as they age. The piston slap is a characteristic of these engines (my 240 sounds like castanets when you start it cold, and fades to nothing as it warms up) but the oil jets alleviated it considerably.

 

[StevieC]

I read somewhere that it also aids in emissions by keeping the pistons cooler so not so much EGR is required eliminating the need for and EGR valve in some cases where then it can be achieved by valve overlap timing alone aside from the benefits listed above, I'll see if I can find a link to that information.

 

[StevieC]

Quote
A Ford 2.4-liter 115PS light-duty diesel engine was modified to allow solenoid control of the oil feed to the piston cooling jets, enabling these to be switched on or off on demand. The influence of the jets on piston temperatures, engine thermal state, gaseous emissions and fuel economy has been investigated. With the jets switched off, piston temperatures were measured to be between 23 and 88°C higher. Across a range of speed-load points, switching off the jets increased engine-out emissions of NOx typically by 3%, and reduced emissions of CO by 5-10%. Changes in HC were of the same order and were reductions at most conditions. Fuel consumption increased at low-speed, high-load conditions and decreased at high-speed, low-load conditions. Applying the results to the NEDC drive cycle suggests active on/off control of the jets could reduce engine-out emissions of CO by 6%, at the expense of a 1% increase in NOx, compared to the case when the jets are on continuously. The corresponding change in fuel consumption would be insignificant.

https://www.sae.org/publications/technical-papers/content/2012-01-1212/

 

[supton]

Originally Posted by StevieC
I read somewhere that it also aids in emissions by keeping the pistons cooler so not so much EGR is required eliminating the need for and EGR valve in some cases where then it can be achieved by valve overlap timing alone aside from the benefits listed above, I'll see if I can find a link to that information.

Interesting. I kinda see how this could work, but then maybe kinda not. I would have guessed at controlling piston temps so as to avoid going overly rich to prevent knock.

 

[Malo83]

GM's 2.0T LTG turbo 4 has oil jets for better lubrication of the pistons.
https://www.gmpowertrain.com/engines/docs/GMQD16CL460_LTG_Product PDF.pdf