6.7 Twin Turbo Setup

[Dan]

For engineers also designed the connecting rods in this engine....

Works good at stock hp levels...

 

[CATDiezel]

Viscosity is at rated temperature. Oil manufacturers are held to the CJ-4 standard and they rate it at 100*C. For a given weight.

The 6.7L has two oil classifications.

#1 walmart trips or your favorite grocery store
#2 Work (ford calls it severe duty)


Where guys go wrong is when they want to hot rod with the grocery getting oil and then are shocked that their oil viscosity ((which they don't know)) is somewhere below zero because they are running 5 weight singer sowing machine lube oil. Lol. The biggest reason for running 5w or 10w oil in these trucks was for fuel mileage and oil consumption. Cold oil will not wipe properly off the cylinder walls as it actually pushes the oil wiper ring back into the piston grove allowing it to pass by.

This is why you see big bore engines (say 35liter and up) slobber so bad. Cold oil. Heavy weight.

There's a lot to explain other than just saying I want colder oil temps and throw a larger cooler on it.

However. Get into strait weight oils with no additives and are ashless you want to run cooler temps. And the piston rings and cylinders are designed for that. Say an 8000hp 16 cylinder engine. It's oil runs at 140* but it's a special oil and is in its designed limitations to maintain its specific gravity and viscosity.

Like said.... The road is narrow and their is a ditch on both sides.

 

[97stoker350]

Good explanation cat. And Dan, exactly stock hp levels. If they encouraged us to go throw 100mm turbos and double the amount of fuel injected on the trucks then why would that void the warranty? You saying what u said is like saying a person that designs a bridge to hold 10000 lbs is a dumbass because someone tried to take 15000 lbs over the bridge but fell through. Not the engineers fault. It's the dumbass that pushed the limits fault. And maybe you haven't been doing your homework on 6.7s lately but throwing rods is a thing of the past..

 

[CATDiezel]

Ahh..

I'm still wanting to see what your beast beholds when Wayne is finished with it.

It takes money to make these things happen and glad you're able to do it.

 

[Powerstroked162]

Lmao. If Ford wanted the engine to run at 197° I bet you a million bucks this engine would run at that temperature. Contrary to popular belief, people that build these trucks are smarter than 99% of us and 2 people don't build one over the course of a couple months. So there is probably a reason why they run at 250° bone stock and didn't "opt for lower oil temps". But hey someone's gotta be the Pioneer right?

They don't run at 250*.

 

[Dan]

Ok ya caught me 97 strokes 350 I'll be the dumbass over here pushing the limits...

I'm taking my 150000 lbs across but first I'm gonna install and an aux oil cooler on my bridge

 

[bricewise]

Ok ya caught me 97 strokes 350 I'll be the dumbass over here pushing the limits...

I'm taking my 150000 lbs across but first I'm gonna install and an aux oil cooler on my bridge

Not trying to be the asshole here but you and a few others keep saying your pushing the limits. I beg to differ, MPD truck and Caleb's truck are pushing the limits of the 6.7...hell even mikes truck in the making is more useful. You don't collect data and you break ****. Not sure which limits your pushing here. What did we learn from your CFD build or your CA build.

 

[Spatel23]

Ding ding ding

We have a winner

 

[Wayne]

Here's a pretty good explanation of viscosity as there was misleading info earlier.
http://www.upmpg.com/tech_articles/motoroil_viscosity/
We also need to keep in mind oil gets thinner as it gets hotter. The thinner it is, the easier it flows out of bearing surfaces, and the less ability it has to protect and maintain adequate pressure. This is especially important where the engine is being taken beyond it's original design limits. Last round the truck didn't get the bugs all worked out before it was stressed to the point of failure. A known problem at the time was excessive oil temps, so he is having changes made to keep it in check. There is no finger pointing going on here, just soving a known problem. If everybody had more time to dial in the truck before dpc, all that stuff would have been addressed previously, but they ran out of time.

Considering the oil is cooled by engine coolant, we can easily see the target oil temp is also the target coolant temp, controlled by the primary cooling system thermostats. When the engine goes back in the truck, the plan is to add an oil to air heat exchanger with a mechanical bypass until it meets a minimum temperature. It will also have a thermostatically controlled fan to make sure it stays in a target range.

I really don't get why you guys are mocking him for upgrading an insufficient oil cooler. It's not like he's shooting for a temp range out of the ordinary here. Back when I did a lot of heavy towing with my built motor 6.4, my primary concern was excessive oil temp, followed closely by coolant. This was with a new, clean factory oil cooler. Pyro was a distant 3rd for temp concerns, and I towed in the race tune. Granted, I'm not complaining because I was flying past people who were maxed out, and I had way more weight. It was nearly perfect for what I wanted. That's what this is all about; a guy setting up his truck the way he wants, for how he intends to use it. Personally I think the oil cooler deal is a great upgrade. I look forward to seeing everything come together the way Dan wants it under less rushed circumstances.

 

[4EverBoosted1]

Not trying to be the asshole here but you and a few others keep saying your pushing the limits. I beg to differ, MPD truck and Caleb's truck are pushing the limits of the 6.7...hell even mikes truck in the making is more useful. You don't collect data and you break ****. Not sure which limits your pushing here. What did we learn from your CFD build or your CA build.

I just wash my truck and stare at it...... LOL but really, I wouldn't say I push it to it's limits. I do give it hell from time to time for some fun ass weekend nights. However, for the most part I let it cruise and just enjoy having it. My oil temps normally hang around 215 on the highway at 75-80. Haven't really noticed them go much higher than that.

 

[Dan]

Right on... I dunno if you caught the sarcasm...

Let's not get carried away... The only limits I'm pushing is the old bank account... A truck that's been parked for the past over a year... And hasn't even managed to get a tank a fuel through it... It's now just a big joke. Hahaha but as allways my level of "give a f*ck" I pretty damn low!

Like I say, I'm here for the LOLs

 

[CATDiezel]

Here's a pretty good explanation of viscosity as there was misleading info earlier.
http://www.upmpg.com/tech_articles/motoroil_viscosity/
We also need to keep in mind oil gets thinner as it gets hotter. The thinner it is, the easier it flows out of bearing surfaces, and the less ability it has to protect and maintain adequate pressure. This is especially important where the engine is being taken beyond it's original design limits. Last round the truck didn't get the bugs all worked out before it was stressed to the point of failure. A known problem at the time was excessive oil temps, so he is having changes made to keep it in check. There is no finger pointing going on here, just soving a known problem. If everybody had more time to dial in the truck before dpc, all that stuff would have been addressed previously, but they ran out of time.

Considering the oil is cooled by engine coolant, we can easily see the target oil temp is also the target coolant temp, controlled by the primary cooling system thermostats. When the engine goes back in the truck, the plan is to add an oil to air heat exchanger with a mechanical bypass until it meets a minimum temperature. It will also have a thermostatically controlled fan to make sure it stays in a target range.

I really don't get why you guys are mocking him for upgrading an insufficient oil cooler. It's not like he's shooting for a temp range out of the ordinary here. Back when I did a lot of heavy towing with my built motor 6.4, my primary concern was excessive oil temp, followed closely by coolant. This was with a new, clean factory oil cooler. Pyro was a distant 3rd for temp concerns, and I towed in the race tune. Granted, I'm not complaining because I was flying past people who were maxed out, and I had way more weight. It was nearly perfect for what I wanted. That's what this is all about; a guy setting up his truck the way he wants, for how he intends to use it. Personally I think the oil cooler deal is a great upgrade. I look forward to seeing everything come together the way Dan wants it under less rushed circumstances.

While I agree with all you said wayne....

One thing.

The truck will spend a VAST LARGE amount of time cruising and not WOT if it's a daily driver truck.

Maybe if the system was set up as a bypass, as in something a quick flip of a valve you could isolate the extra cooler.

I've delt with ExxonMobil directly with this in regard to caterpillar.. learned alot from lab testing on this subject. More damage is done with cold oil verse hot oil. The thin oil plays less affect and still floats the crank or cam much better than cold oil does. Especially full true synthetic, not blended.

I'm with you tho Wayne. Really am. But to me this is just like turbos. Guys say "oh man this thing spools" sure at WOT but it's horrible cruising.

Anyways. I was just throwing this out there for conversation other than a bunch of slams against the guy. Not mocking his setup either. It's more than I've done or would be willing to do!!

 

[Six_Sloww]

So let's say you run "grocery getter" 5w-40 and you have an external oil cooler that keeps temps around 190-210.. Is that causing damage? I don't see how those temps could be doing damage but I'm not educated in the subject.

 

[CATDiezel]

Another reason for higher temps is flashing off moisture molecules and suspended diesel molecules off in the oil. That is the relative theory for a diesel engine. Natural gas engines obviously do not have that problem. And the big bores especially because they have no coolant flowing around the cylinder liners.

But.... even with all that said. Your right. The oil and coolant will track pretty close regardless in a unregulated system.

This is all just food for thought.

Better than the blasting crap about who's ding ding is bigger than who's on first.

 

[CATDiezel]

So let's say you run "grocery getter" 5w-40 and you have an external oil cooler that keeps temps around 190-210.. Is that causing damage? I don't see how those temps could be doing damage but I'm not educated in the subject.

The grocery oil (lol) is intended for short burst runs when the truck never reaches operating temp. Or cruising.

It's still 40 weight oil at 212*F. BUT the additives that make the oil viscosity (the 5w) runs out and is much less affective at higher temps. That's why they raise the additive to 15w-- remember it's still 40. It sustains lubricity in a higher temp value. However. It has an opposite side affect and that is cold weather.

For a dedicated drag truck your best off with a 0w-30. With a optimum oil cooler. Full synthetic.

I wish I was sitting at my desk so I could make this not such a scatter brained reply!!

 

[CATDiezel]

Now this is not official... but one thing to remember is that the colder the oil the higher the viscosity is. A 40 weight oil is actually around 110weight at 75*F. And this is not a linear scale either. It's a graphical slope and that even changes depending on what additives are in the oil.

Thick oil provides much less protection in high speed moving parts than thin oil. Thin oil is leaving the designed space between the bearing and journal with enough room to allow the nicely heated oil molecules to roll properly. Cold oil molecules bond together and bunch up. "Pushing" things around.

If a man could keep his oil temp a constant 212* he would have zero issues concerning oil. The is the ASI test bed platform temperature rating for CJ-4 oil.

 

[Joe@Ideal]

For a dedicated drag truck your best off with a 0w-30. With a optimum oil cooler. Full synthetic.

Thick oil provides much less protection in high speed moving parts than thin oil. Thin oil is leaving the designed space between the bearing and journal with enough room to allow the nicely heated oil molecules to roll properly.

Not calling you out here, I am not equipped to do so. These statements go against what my understanding was for high HP engines. I've built some race engines, (gas), in the past and an engine builder explained to me the function of the oil between the crank and rod bearings was not only to lubricate but to resist being squished out under high load causing a metal on metal situation. It was stated thicker oils provide better protection through greater resistance to compression.

I'm pretty sure I saw a top fuel team using straight 70W. Probably apples and oranges though. Maybe you could provide comment on this?

 

[Six_Sloww]

Haha I would venture to say the rules are different when you make 6000 hp and rebuild your engine every other run

 

[Joe@Ideal]

Haha I would venture to say the rules are different when you make 6000 hp and rebuild your engine every other run

I'm not so sure about that. I had a drag motor with a filled block not making the horsepower Dan's setup likely is and I couldn't keep my oil temps under 260 in a quarter pass. And that is only where the temp sensor is picking it up. What is it at the bearings? What's your viscosity there??

 

[CATDiezel]

Not calling you out here, I am not equipped to do so. These statements go against what my understanding was for high HP engines. I've built some race engines, (gas), in the past and an engine builder explained to me the function of the oil between the crank and rod bearings was not only to lubricate but to resist being squished out under high load causing a metal on metal situation. It was stated thicker oils provide better protection through greater resistance to compression.

I'm pretty sure I saw a top fuel team using straight 70W. Probably apples and oranges though. Maybe you could provide comment on this?

As one commented. They rebuild every pass. The high load of a 800 hp diesel compared to a 8000hp small block is a bit different. They are not worried about piston jets cooling the cylinder walls either. AND there clearance tolerances are alittle bigger to accommodate for such high weight oil and the extreme heat they run. Where we are worried about 250*F. They are seeing in excess of 350*F fast and In a hurry. So there oil is getting close to a flash point if they don't knock it off soon. 70w oil at 350-400*F Flows like water.

The engine design from a drag car to this 6.7L isn't a fair comparison at all.