Lean?? - Ford Powerstroke Diesel Forum
General Diesel Discussion Discuss everything else pertaining to Diesel Pickups.

Powerstroke.org is the premier Diesel Truck Forum on the internet. Registered Users do not see the above ads.
Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 02-15-2008, 09:34 AM
Premium Member
 

Join Date: Jan 2007
Location: Florida Panhandle
Posts: 1,710
Thanks: 0
Thanked 1 Time in 1 Post
Feedback Score: 0 reviews
Lean??

So I saw the post about "can you get too much air", and the guy building the 2 filter intake and the not so certain responses, that is what sparked this as I have been wondering for awhile. Coming from gas engines I have always wondered, can a diesel run too lean? If it does, will it damage anything? I know on gas engines that is a good way to put a hole in the piston, especially with a turbo or nitrous. After reading and learning I have NEVER heard anyone ever mention that you could damage anything running too lean. Since there is no throttle plate, it would seem to me that they are running lean at idle. In fact, I distinctly remember an article in a Diesel Power awhile back that said the only danger to running nitrous was that the power was easy to come by and addictive and you could easily overcome the HP threshold for the engine. (Not exact wording) SO, true or false....You cannot damage a diesel by running too lean.
-Aaron
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2  
Old 02-15-2008, 09:43 AM
Desert Shield/Storm Vet

 

Join Date: Dec 2006
Location: Munising, MI.
Posts: 9,092
Thanks: 0
Thanked 1 Time in 1 Post
Feedback Score: 0 reviews
Well the way the turbo diesel works if you don't get the fuel to turn the turbine you won't get any boost, so yeah you would seriously lack some go juice if you ran lean seems to me. Im sure one of the techs will chime in with a definate answer.
Reply With Quote Quick reply to this message
  #3  
Old 02-15-2008, 09:49 AM
Desert Shield/Storm Vet

 

Join Date: Dec 2006
Location: Munising, MI.
Posts: 9,092
Thanks: 0
Thanked 1 Time in 1 Post
Feedback Score: 0 reviews
Here is a good article Diesel-Central.com the technical source for Diesel Truck information, Truck Pulling, and Drag Racing
Reply With Quote Quick reply to this message
  #4  
Old 02-15-2008, 10:22 AM
Is it even worth it???



 
Join Date: Aug 2006
Location: Lex KY
Posts: 9,093
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
Send a message via AIM to ABOBB Send a message via Yahoo to ABOBB
While gasoline (and other spark) engines are throttled on air, diesels are throttled on fuel. What this means is that the amount of fuel that is metered into the engine controls rpms, power, etc... not the amount of air.

On a stock, or even a fairly wild street, diesel engine it is highly unlikely that you will do damage due to a lean condition.

Highly modified diesel engines however can do damage. That is the reason why you almost always see them spewing a lot of black smoke. They are using the excess fuel to keep things cool.
Reply With Quote Quick reply to this message
  #5  
Old 02-15-2008, 04:43 PM
Premium Member
 

Join Date: Jan 2007
Location: Florida Panhandle
Posts: 1,710
Thanks: 0
Thanked 1 Time in 1 Post
Feedback Score: 0 reviews
Allright, thanks everyone. I guess that answers the "$64,000 question".
-Aaron
Reply With Quote Quick reply to this message
  #6  
Old 02-15-2008, 04:57 PM
Premium Member
 

Join Date: Feb 2008
Posts: 340
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
vitalidle is joking, right?



"Highly modified diesel engines however can do damage. That is the reason why you almost always see them spewing a lot of black smoke. They are using the excess fuel to keep things cool."

I was under the impression that most modified diesels blow black smoke because of the delay in providing air to the fuel supply. In other words, the turbo doesn't spool fast enough to offset the quick increase in fuel.
Reply With Quote Quick reply to this message
  #7  
Old 02-16-2008, 04:05 AM
Desert Shield/Storm Vet

 

Join Date: Dec 2006
Location: Munising, MI.
Posts: 9,092
Thanks: 0
Thanked 1 Time in 1 Post
Feedback Score: 0 reviews
Quote:
Originally Posted by cotton View Post
vitalidle is joking, right?



"Highly modified diesel engines however can do damage. That is the reason why you almost always see them spewing a lot of black smoke. They are using the excess fuel to keep things cool."

I was under the impression that most modified diesels blow black smoke because of the delay in providing air to the fuel supply. In other words, the turbo doesn't spool fast enough to offset the quick increase in fuel.
Hey cotton I didn't write that article so like Ronald Reagan said you can trust but you must verify. So thats up to you to decide if its valid or not
Reply With Quote Quick reply to this message
  #8  
Old 02-16-2008, 04:34 AM
Premium Member
 

Join Date: Jan 2007
Location: Florida Panhandle
Posts: 1,710
Thanks: 0
Thanked 1 Time in 1 Post
Feedback Score: 0 reviews
Ok...So on a side note and for the sake of argument. Why are my EGT's so much cooler with my wastegate disconnected? Somewhere in the range of 300-400* at full throttle? I know the theory about more of the fuel being burned inside the cylinder instead of the burn being in process as the exhaust valve opens. But if being lean can (not necessarily will) damage the internals. Wouldn't that mean that EGT's would be higher with the same amount of fuel but more air? For instance, if 1500* EGT's can weaken pistons to the point of breaking ring lands, etc. Shouldn't a leaner engine with it's hotter combustion temps show a hotter EGT? The temps can't cool that much after the burn, right?

Sorry to be asking so many ""stupid questions, but I have been listening, reading and learning stuff for about a year (Since i bought my truck) and I am finally asking some of the questions that have been rattling around in my head for awhile. I am a "I need to know WHY something is the way it is, not just that that's the way it is" person.
Reply With Quote Quick reply to this message
  #9  
Old 02-16-2008, 04:43 AM
Desert Shield/Storm Vet

 

Join Date: Dec 2006
Location: Munising, MI.
Posts: 9,092
Thanks: 0
Thanked 1 Time in 1 Post
Feedback Score: 0 reviews
Quote:
Originally Posted by GreenF350 View Post
Ok...So on a side note and for the sake of argument. Why are my EGT's so much cooler with my wastegate disconnected? Somewhere in the range of 300-400* at full throttle? I know the theory about more of the fuel being burned inside the cylinder instead of the burn being in process as the exhaust valve opens. But if being lean can (not necessarily will) damage the internals. Wouldn't that mean that EGT's would be higher with the same amount of fuel but more air? For instance, if 1500* EGT's can weaken pistons to the point of breaking ring lands, etc. Shouldn't a leaner engine with it's hotter combustion temps show a hotter EGT? The temps can't cool that much after the burn, right?

Sorry to be asking so many ""stupid questions, but I have been listening, reading and learning stuff for about a year (Since i bought my truck) and I am finally asking some of the questions that have been rattling around in my head for awhile. I am a "I need to know WHY something is the way it is, not just that that's the way it is" person.
Well this is pure speculation on my part but if your wastegate is disconnected your talking about the red pressure line right? That means your going to build more boost or the turbine wheel is going to spin faster which in turn makes the compressor wheel go faster which will pull more cool air from the intake which will cool the egts. If the wastegate is connected and it opens the opposite will happen you will have the same amount of fuel going to the cylinders but not as much air to cool them
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Ford Powerstroke Diesel Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools
Display Modes

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -8. The time now is 01:44 AM.


Powered by vBulletin® Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Search Engine Optimization by vBSEO 3.6.1
Garage Plus, Vendor Tools vBulletin Plugins by Drive Thru Online, Inc.

vB.Sponsors