Electric Fans, double nothing

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Pinger

I'm Awesome
Joined
Mar 10, 2020
Messages
3,013
Reaction score
5,934
Location
Scotland.
Just a question not trying to start anything just pure curiosity. How do you determine the cleanliness of it? By a test or just looking at it?

Both. Clean oil retains its colour visually. Have a look at the thread re oil analysis for an example of a typical report.
Oil analysis is useful not just for the state of the oil but for pending problems - eg, dirt due to a leak downstream from the air filter, overfuelling, coolant (pending gasket failure, etc. Also gives the wear metals and you can see the compositions of each change eg, during break-in on a rebuilt motor versus a fully run-in one.
 

Pinger

I'm Awesome
Joined
Mar 10, 2020
Messages
3,013
Reaction score
5,934
Location
Scotland.
Soot is the primary cause of rapid oil blackening in EGR equipped diesel engines, not the EGR system itself. In the industrial and heavy equipment world, the Tier 4 Interim engines were /are the worst. These were pre-SCR (pre DEF injection) engines that used overfueling and EGR to lower combustion temperatures to reduce NOx and meet emissions. They produced more soot from the overfueling, and then recycled that soot laden exhaust into the intake system, leading to high soot concentrations in the oil. They have a tendency to plug EGR coolers, coke valves, and plug DPF's. SCR engines (Tier 4 Final) use DEF injection for their primary NOx reduction strategy, and consequently don't have the overfueling and high soot production issues of the T4I engines. There's still EGR, the oil still gets black as soon as the engine starts, but it's LESS of a problem.

Agreed.
But with a gasoline engine and EGR there's exhaust products present during all of the four strokes. Without it, only for two. Not major but there nonetheless.

In contrast, gasoline engines running at or slightly leaner than stoich don't make soot, at least none worth noting. You'll see as much or more contamination of the intake tract from the PCV system as the EGR on most gasoline engines. Blowby is still the primary cause of oil contamination and breakdown, but is present in all piston engines and is just a given.

Not with LPG as it's a gas when introduced to the cylinder not a liquid as per gasoline which will wash down - this being worse from cold start-up due to the necessary enrichment. LPG already being gaseous needs no enrichment from cold. A significant benefit in IMO.

Here's what you need to do: build a draw through turbo system for your LPG rig, and get an Altronics NOx feedback system to kick in and control fueling during steady state cruising. That will accomplish the same thing as EGR as far as combustion temp reduction, increase your fuel economy on LPG, and make for a cleaner, more environmentally friendly truck overall. Not to mention a healthy horsepower gain over an NA LPG engine. You'll only need to fabricate your own draw-through LPG and turbocharger setup, and cobble together the control system from the factory ECM and the Altronics system. Small potatoes, right?

BIG potatoes - and a massive explosion if there's an inlet backfire!
 

Pinger

I'm Awesome
Joined
Mar 10, 2020
Messages
3,013
Reaction score
5,934
Location
Scotland.
There's more to consider re EGR and LPG. Eg, LPG has no cooling properties thus is more heat sensitive re detonation. LPG is fast burning - once lit. It is slow to ignite initially though and exhaust products in the mix don't help (think carbed 2-stroke at part throttle). The presence of exhaust products also limits AFR possibilities (think carbed 2-stroke at part throttle).

I'll be picking up on this stuff later but meantimes, if anyone can provide info as to when EGR is deployed in a Vortec - eg high load for NOx reduction, part load to reduce throttling losses, etc - it would be very useful to me.
 

smdk2500

I'm Awesome
Joined
Dec 26, 2017
Messages
971
Reaction score
945
Location
Nebraska
Both. Clean oil retains its colour visually. Have a look at the thread re oil analysis for an example of a typical report.
Oil analysis is useful not just for the state of the oil but for pending problems - eg, dirt due to a leak downstream from the air filter, overfuelling, coolant (pending gasket failure, etc. Also gives the wear metals and you can see the compositions of each change eg, during break-in on a rebuilt motor versus a fully run-in one.
Ok. I dont have a way of testing my oil but just on the visual "test" my 6.5's oil looks just as dark as my 6.7 cummins did My 6.5 does not have a egr and never did. The 6.7 did. Also on the reefer units I work on some have egr and some don't and the oil looks the the same in both. So with no egr on them how the oil get dirty so to say with your opinion of the egr letting it in. So in my opinion the look test proves nothing unless it looks glittery or has big chunks when it comes out of the pan. Again I am not trying to start a pissing match Im just trying to educate myself to other peoples thoughts and opinions.
 

SAATR

/\___/\___/\___/\___/\
Supporting Member
Joined
Dec 16, 2010
Messages
2,649
Reaction score
946
Location
Loo E Z an uh
Not with LPG as it's a gas when introduced to the cylinder not a liquid as per gasoline which will wash down - this being worse from cold start-up due to the necessary enrichment. LPG already being gaseous needs no enrichment from cold. A significant benefit in IMO.

Lack of fuel dilution and cylinder washdown is certainly a benefit of gaseous fuels, but my point is that they still have the same gapped ring design as any other ICE and will therefore have combustion byproducts that get beyond the rings and into the crankcase. That, in turn, oxidizes the oil and depletes the additive package. Gaseous fuel engines, with a few exceptions, will have cleaner oil and longer service intervals, but aren't immune from the intrinsic properties of the fuel burning piston engine.

BIG potatoes - and a massive explosion if there's an inlet backfire!

No more likely or worse than your NA engine. I've worked on Caterpillar's and Kohler's version of the 5.7L Vortec in genset application, both running off of CNG or LPG, and haven't had one "sneeze" yet. I've seen several natural gas engines pop back, and while loud it usually isn't particularly destructive. The worst damage was a blown up compressor wheel on the turbo, damaged carburetor diaphragm, and blown regulator diaphragm. I'm not saying it can't be worse, but it's an inherent risk with a gaseous fuel and a flooded intake. A turbo would certainly help take advantage of the inherent knock resistance of the fuel. A NOx or O2 feedback system set up for lean burn would be very effective.
 

SAATR

/\___/\___/\___/\___/\
Supporting Member
Joined
Dec 16, 2010
Messages
2,649
Reaction score
946
Location
Loo E Z an uh
Ok. I dont have a way of testing my oil but just on the visual "test" my 6.5's oil looks just as dark as my 6.7 cummins did My 6.5 does not have a egr and never did. The 6.7 did. Also on the reefer units I work on some have egr and some don't and the oil looks the the same in both. So with no egr on them how the oil get dirty so to say with your opinion of the egr letting it in. So in my opinion the look test proves nothing unless it looks glittery or has big chunks when it comes out of the pan. Again I am not trying to start a pissing match Im just trying to educate myself to other peoples thoughts and opinions.

The 6.5 is a Prechamber style diesel engine, vs the Direct Injection of all modern diesels and the 6.5's Ford and Cummins contemporaries. They are inherently a bit dirtier than DI engines, and but don't soot the oil more, if any at all, than other designs. EGR systems on diesels do tend to put more soot in the lube systems, primarily because the soot is recycled back to the combustion chamber instead of being sent out the exhaust. That said, heavily soot loaded oils tend to feel slightly gritty on the fingers and the blackness doesn't wipe off as easily as newer or cleaner oil. Strictly speaking, there is no accurate way of judging an oil's condition by sight alone, save if the oil is heavily contaminated by water, coolant, fuel, etc. "Looks" good doesn't mean it IS good, or vice versa. If the oil has contaminants suspended in it, then it is doing its job, and your filtration simply isn't good enough to remove them.
 

TheAutumnWind

I'm Awesome
Joined
Feb 11, 2019
Messages
698
Reaction score
740
Location
California
Bobby


2 12” fan won’t get you to the 4100 cfm numbers your looking for. A single 16” if mounted in the center of the radiator will hit the water pump pulley and at the most a single 16” will give you 3500 cfm. With your trans cooler and a/c fan you won’t have enough room for a pusher fan in front of the radiator either. Another thing you have to consider is with a shroud you only you only have 4“ between the fan shroud and pulley surfaces (depending on how thick your radiator is). So you have to get slim fans. To optimize you electric fans you need a shroud. without a shroud you will have to run those plastic ties that go through your radiator.I recommend dual 16” fans mounted to the shroud.these fans are $99 each and would give you 3000 cfm per fan and are 3 1/4 thick. The next lowest cfm 16” fan is 2800 cfm but is 3.5” thick. I don’t think you will need a higher amp alternator because they only draw between 8 and 10 amps per fan. If they do cause your electrics to flicker you can always upgrade that later. But make sure you get a thermostatic adjustable on temperature off temperature fan controller with relays. I ran a Dakota digital fan controller with a bypass switch. It’s Bluetooth programmable, can hook up to most temperature senders, but it needs a second 70amp relay and has to be programmed to change some of the settings.


I would get:
2 16” 3000 cfm electric fans
1 dual champion 16” fan (34” shroud)
1 thermostatic dual fan controller with relays
1 bypass toggle for emergencies

You must be registered for see images attach


You must be registered for see images attach


You must be registered for see images attach


You must be registered for see images attach


You must be registered for see images attach
Why do people go this route when NBS fan/shroud setups can be found for less than $200 new that outperforms that setup
 

Pinger

I'm Awesome
Joined
Mar 10, 2020
Messages
3,013
Reaction score
5,934
Location
Scotland.
Ok. I dont have a way of testing my oil but just on the visual "test" my 6.5's oil looks just as dark as my 6.7 cummins did My 6.5 does not have a egr and never did. The 6.7 did. Also on the reefer units I work on some have egr and some don't and the oil looks the the same in both. So with no egr on them how the oil get dirty so to say with your opinion of the egr letting it in. So in my opinion the look test proves nothing unless it looks glittery or has big chunks when it comes out of the pan. Again I am not trying to start a pissing match Im just trying to educate myself to other peoples thoughts and opinions.

SAATR answers your question well with the paragraph below and post #56.

LPG does a good job of keeping the oil clean (I'll say a bit more of that In a moment) and although dirty looking oil isn't necessarily a bad thing (it shows its doing its job keeping the dirt in suspension, preventing it forming deposits in the engine) if you were running on a fuel that doesn't dirty the oil - wouldn't you want to retain that?

Lack of fuel dilution and cylinder washdown is certainly a benefit of gaseous fuels, but my point is that they still have the same gapped ring design as any other ICE and will therefore have combustion byproducts that get beyond the rings and into the crankcase. That, in turn, oxidizes the oil and depletes the additive package. Gaseous fuel engines, with a few exceptions, will have cleaner oil and longer service intervals, but aren't immune from the intrinsic properties of the fuel burning piston engine.

True. But consider for a moment those small engines for model aeroplanes. The earliest (so called diesels) ran fuel mixed equal parts ether, kerosene and castor oil. The castor oil was there purely to seal the ringless piston.
A gasoline engine will always be compromising the oil film around the rings through dilution whereas a gaseous fueled engine will maintain a more consistent oil film there - to the benefit of sealing.
Rings (along with the periphery of valves) are referred to as 'crevice volumes' as they trap gasoline and if/when they ever release the trapped fuel it burns so late and lazily it creates CO and UBHC - which the cat has to deal with. The rings just love to trap raw gasoline. I've heard of turbo Subarus here running on LPG and passing our annual emissions test (for CO and UBHC) without a cat. That's a significant difference - and achievement.

An additional point (a disadvantage of) gaseous fueled engines - the inlet valves can suffer due to lack of liquid fuel. Passing hot EGR past them isn't going to help that.



No more likely or worse than your NA engine. I've worked on Caterpillar's and Kohler's version of the 5.7L Vortec in genset application, both running off of CNG or LPG, and haven't had one "sneeze" yet. I've seen several natural gas engines pop back, and while loud it usually isn't particularly destructive. The worst damage was a blown up compressor wheel on the turbo, damaged carburetor diaphragm, and blown regulator diaphragm. I'm not saying it can't be worse, but it's an inherent risk with a gaseous fuel and a flooded intake. A turbo would certainly help take advantage of the inherent knock resistance of the fuel. A NOx or O2 feedback system set up for lean burn would be very effective.

I don't disagree with any of the above. It's just much more than I'm prepared to do. All the above is a pretty major project that I just don't have the time or resources for. (I also have a separate 2-stroke project I want to pursue which will soak up my time).
What I'm aiming for is just optimising the existing system as best as I can to suit the LPG. As far as I would go to gain further advantage from LPG's higher octane is slightly increase the CR. If I have the heads off for any reason I'll consider having them skimmed - or consider the higher CR Roadmaster pistons. But not so far as I lose the ability to run gasoline (with care) as back-up.

Re the explosion risk. Personally an intercooler primed with fuel is a risk further than I am prepared to accept (a personal decision). Due to a badly configured LPG system (common on mixer systems though) I had a crankcase explosion when an inlet backfire occurred. Blew the timing cover apart. Once bitten, twice shy....
 

L31MaxExpress

I'm Awesome
Joined
Apr 21, 2018
Messages
5,890
Reaction score
7,539
Location
DFW, TX
There's more to consider re EGR and LPG. Eg, LPG has no cooling properties thus is more heat sensitive re detonation. LPG is fast burning - once lit. It is slow to ignite initially though and exhaust products in the mix don't help (think carbed 2-stroke at part throttle). The presence of exhaust products also limits AFR possibilities (think carbed 2-stroke at part throttle).

I'll be picking up on this stuff later but meantimes, if anyone can provide info as to when EGR is deployed in a Vortec - eg high load for NOx reduction, part load to reduce throttling losses, etc - it would be very useful to me.

I have datalogged it. Its mostly under mid-heavy throttle to control NOX. It comes on just off-idle to mid throttle at about 2 mph and causes a noticeable hesitation on quick throttle opening. At cruising speeds it is either shut or almost shut depending on the engine load and rpm. Its also open at or very near WOT.
 

Pinger

I'm Awesome
Joined
Mar 10, 2020
Messages
3,013
Reaction score
5,934
Location
Scotland.
I have datalogged it. Its mostly under mid-heavy throttle to control NOX. It comes on just off-idle to mid throttle at about 2 mph and causes a noticeable hesitation on quick throttle opening. At cruising speeds it is either shut or almost shut depending on the engine load and rpm. Its also open at or very near WOT.

Brilliant! Thanks - much appreciated.
 
Top