Question: Popping injectors at 2600psi - Page 3 - Diesel Place : Chevrolet and GMC Diesel Truck Forums
 
Home Forum Market Place Garage Tuning Library DTC Tool Register Vendors
Go Back   Diesel Place : Chevrolet and GMC Diesel Truck Forums > GM Diesel Engines > 6.5L Diesel Engine > 6.5/6.2 High Performance Engine Modifications
Register FAQ Forum Rules My Replies My Threads Mark Forums Read Advertise

6.5/6.2 High Performance Engine Modifications High Performance Turbocharger and Engine Related Modifications Discussion Forum - Specific To The GM 6.2 & 6.5 Diesel Engine.

DieselPlace.com is the premier Duramax Diesel Forum on the internet. Registered Users do not see the above ads.
Like Tree47Likes

Reply
 
LinkBack Thread Tools
Old 02-09-2015, 02:34 AM   #21 (permalink)
94C1500
Diesel Specialist
 
94C1500's Avatar
 
Join Date: Mar 2009
Posts: 3,231
iTrader Score: 1 reviews

peak pressure occurs after injection with combustion, but the pressures noted are just at TDC assuming ignition doesn't start much before TDC. And injection may be at 15 to 25 degrees before TDC, maybe, but the last about 10 degrees isn't much in the way of added vertical motion of the piston.

GM planned a healthy 600psi margin between potential cylinder air pressure and injection pop pressure, when using their designed boost values. You need decent pressure differential to get atomization, otherwise fuel could come out in globs and ignite right at the tips of the injectors.

__________________
1994 C1500 - 4L80E & 3.42 rear; Custom Multi-Program Chip; L65 intake; "FTB", Walbro FRC-10 lift pump, pre-LP fuel filter & OPS relay mod; D-Tech FSD on heatsink; Big Turbo, 4" to 5" exhaust exits before axle, Cone air filter; "marine" injectors. Propane fumigation and WMI.
ENGINE DESIGN CALCULATORS
LIST OF RECOMMENDED MNX & MODS
HX40 or HX35 V-Band Exhaust Elbows

Last edited by 94C1500; 02-09-2015 at 02:45 AM.
Offline   Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Old 02-09-2015, 02:44 AM   #22 (permalink)
94C1500
Diesel Specialist
 
94C1500's Avatar
 
Join Date: Mar 2009
Posts: 3,231
iTrader Score: 1 reviews

Quote:
Originally Posted by dieselmike1 View Post
Its hard to explain, it runs well enough, but when pulling hard at max boost it acts like its just not pulling as good as it could, sorta like when you float the valves out at higher rpm on a gasser. In other words im guessing.
Not saying it couldn't be the injection pump starting to show its age, as it has been in service for many a miles.
Might be that you could use less injection advance at high load, although I do not know what your timing curve is like. In testing, I found that somewhere around 17 degrees in the programming is enough to clear the smoke in the 2400-3000rpm area, and less at lower RPMs. Its a table of RPM against fuel rate. So defining the RPM range that you get the feeling may help if you want to get it tweaked.

High boost leads to high IATs, which leads to higher cylinder temps and shorter ignition delay. So less injection advance or an intercooler may be the fix for you.

__________________
1994 C1500 - 4L80E & 3.42 rear; Custom Multi-Program Chip; L65 intake; "FTB", Walbro FRC-10 lift pump, pre-LP fuel filter & OPS relay mod; D-Tech FSD on heatsink; Big Turbo, 4" to 5" exhaust exits before axle, Cone air filter; "marine" injectors. Propane fumigation and WMI.
ENGINE DESIGN CALCULATORS
LIST OF RECOMMENDED MNX & MODS
HX40 or HX35 V-Band Exhaust Elbows
Offline   Reply With Quote Quick reply to this message
Old 02-09-2015, 03:13 AM   #23 (permalink)
turbonator
respect the DB4 5722....
 
turbonator's Avatar
 
Join Date: Oct 2009
Location: lac superieur, quebec
Posts: 12,490
iTrader Score: 27 reviews

Quote:
Originally Posted by 94C1500 View Post
Might be that you could use less injection advance at high load, although I do not know what your timing curve is like. In testing, I found that somewhere around 17 degrees in the programming is enough to clear the smoke in the 2400-3000rpm area, and less at lower RPMs. Its a table of RPM against fuel rate. So defining the RPM range that you get the feeling may help if you want to get it tweaked.

High boost leads to high IATs, which leads to higher cylinder temps and shorter ignition delay. So less injection advance or an intercooler may be the fix for you.
have you started to play with OBDII yet buddy? is it feasible for you to take a heath tune and tweak it?
__________________
Building power "Sanford and Son Style"

1998 gmc 3500 RCLB/4X4, 4L80E, DB2 converted, 6.2l #599 casting, bored .040", water-cooled garrett gt3271G turbo, CTS manifold, j-code intake, .290" IP, delphi injectors popped to 2300PSI with modded tips, 3" D.P., aero stainless muffler, triangle tip side pipe, Holley Red lift pump @ 5PSI, canton racing oil filter delete, remote filters, custom 5000psi gates oil cooler lines, over-sized long oil cooler, over-sized hayden tranny cooler, other than that its a "stock" engine....


acolytes of the "aggressive buddist's" principles since march 13th 2014
jim&jeff....
Offline   Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Old 02-09-2015, 03:26 AM   #24 (permalink)
turbonator
respect the DB4 5722....
 
turbonator's Avatar
 
Join Date: Oct 2009
Location: lac superieur, quebec
Posts: 12,490
iTrader Score: 27 reviews

Quote:
Originally Posted by 94C1500 View Post
peak pressure occurs after injection with combustion, but the pressures noted are just at TDC assuming ignition doesn't start much before TDC. And injection may be at 15 to 25 degrees before TDC, maybe, but the last about 10 degrees isn't much in the way of added vertical motion of the piston.

GM planned a healthy 600psi margin between potential cylinder air pressure and injection pop pressure, when using their designed boost values. You need decent pressure differential to get atomization, otherwise fuel could come out in globs and ignite right at the tips of the injectors.
We are getting set up here, to read the passenger side lobes on an OEM cam(curious as to what Joe Heath said about grinding different passenger and drivers side of cams). At same time, will do my math for the BTDC vertical change rate and measurements, then actually measure it off a couple of pistons. Might as well get as much info as we can, all the better to build with, then it will be open for all to view on the web.....
__________________
Building power "Sanford and Son Style"

1998 gmc 3500 RCLB/4X4, 4L80E, DB2 converted, 6.2l #599 casting, bored .040", water-cooled garrett gt3271G turbo, CTS manifold, j-code intake, .290" IP, delphi injectors popped to 2300PSI with modded tips, 3" D.P., aero stainless muffler, triangle tip side pipe, Holley Red lift pump @ 5PSI, canton racing oil filter delete, remote filters, custom 5000psi gates oil cooler lines, over-sized long oil cooler, over-sized hayden tranny cooler, other than that its a "stock" engine....


acolytes of the "aggressive buddist's" principles since march 13th 2014
jim&jeff....
Offline   Reply With Quote Quick reply to this message
Old 02-09-2015, 07:01 AM   #25 (permalink)
Mike K3500
Diesel Head
 
Join Date: Mar 2011
Location: Central Michigan
Posts: 557
iTrader Score: 1 reviews

Quote:
Originally Posted by 94C1500 View Post
The pressure is not bogus, so if you cant do the math, or understand the physics please do not comment on it.

If you are basing it on compression tests, let me explain that. When you run compression tests while cranking, most of the pressure is lost around the rings because it is so slow. As RPM increases, less and less pressure is loss because there is less time for it to leak. This is why the more RPMs when cranking the more pressure you see when testing it, and easier they are to start. Ever check the pressure using a military 24V starter setup? You'll get like 100psi higher numbers than with our standard 12V starters.

It is wise to increase injector pop pressure if you are going to pushing more than 20psi of boost with near stock CR. Did GM do it just for fun with turbo trucks, and higher for marine applications that would run higher RPM more consistently?

With the pressure lost around the rings, then 2300psi pop should be fine for up to 20psi boost, but it takes away the margin that GM had assuming only 10psi of boost and 2100psi pop pressure.


Very interesting on the 24v compression test..
I remember when I got my Optimizer and the Compression test slip that came with it was in the 500 lb range if memory serves me correctly. I kinda thought it to be a bit higher then a standard auto 12v test.
__________________
So far...

GEP N/A long block that's been converted to "turbo" spec, by me.
Custom machined pre-cups.
Custom built / popped Bosch injectors with marine nozzles.
DSG gear drive timing set.
Fluiddamper harmonic balancer.
ARP head studs, + .010 Fel-pro head gaskets, heads torqued to 125lbs.
Typical Diamond Eye 4" exhaust as of now...
2000+ cooling system upgrades, aluminum radiator, kodiak fan clutch, Duramax fan blade.
DB4 pump with a Ford 7.3 inlet cone 3/8" inlet, FFM modded with a 3/8" supply side.
"random, inferior chinese" HX 40 turbo.. for now.
Offline   Reply With Quote Quick reply to this message
Old 02-09-2015, 07:41 AM   #26 (permalink)
dieselmike1
Diesel Champ
 
dieselmike1's Avatar
 
Join Date: Oct 2011
Location: Missouri
Posts: 1,939
iTrader Score: 0 reviews

I don't think its the tune, I just noticed what I described, as just coming on recently, well after my re-tune of which Bill and I spent considerable amount of time on getting it the way I wanted.
Their is no missing, or unusual smoke going on, fuel mileage is not abnormal. Its kinda funny as I sit here typing this, I was thinking about fuel pressure, as I have not checked it lately because I been planning on my FTB mod. in fact I just finished receiving all of my parts for it. I was waiting for it to warm up a little, as I don't have heat in my shop, but maybe I better get started on it, as this could be a symptom.
__________________
2016 Chevy Colorado Z71, 2.8 Duramax, 4x4, C.C., shortbed.
Gone, but not forgotten. 2000 K3500 6.5 C.C. Dually
Proud Member#1076 of the 3500 Dually Club
Offline   Reply With Quote Quick reply to this message
Old 02-09-2015, 12:35 PM   #27 (permalink)
94C1500
Diesel Specialist
 
94C1500's Avatar
 
Join Date: Mar 2009
Posts: 3,231
iTrader Score: 1 reviews

Quote:
Originally Posted by turbonator View Post
have you started to play with OBDII yet buddy?
Nah, the day job has been crazy for a long while, and I probably won't get an OBDII truck to be able to test any of it.
__________________
1994 C1500 - 4L80E & 3.42 rear; Custom Multi-Program Chip; L65 intake; "FTB", Walbro FRC-10 lift pump, pre-LP fuel filter & OPS relay mod; D-Tech FSD on heatsink; Big Turbo, 4" to 5" exhaust exits before axle, Cone air filter; "marine" injectors. Propane fumigation and WMI.
ENGINE DESIGN CALCULATORS
LIST OF RECOMMENDED MNX & MODS
HX40 or HX35 V-Band Exhaust Elbows
Offline   Reply With Quote Quick reply to this message
Old 02-10-2015, 04:10 AM   #28 (permalink)
turbovanman
Diesel Guru
 
turbovanman's Avatar
 
Join Date: Mar 2006
Location: Abbotsford, BC
Posts: 9,975
iTrader Score: 2 reviews

When I ran my n/a injectors, it ran great at 22 psi, and the only thing that caused it to hit brickwalls was my compressor wheel choice and of course, some pumps. I know, its not much to add but find it interesting about the higher pop pressure being needed at higher boost when mind ran fine?
__________________
1984 G20 Diesel Get a Way Van, 6.2L turbo. Rebuilt 1989 700R4, 3.08 gears. Fluidamper, modified hummer headers, 2.5" mandrel Y-pipe to 3 inch single system, Hooker Max Flo muffler, 3 inch F350 mandrel bent tailpipe-passenger side exit, 6.5L turbo lower intake, 6.5 military IP-5149, Turbonator open faced injectors set to 2500 psi, HX35W with a 60x86mm cast wheel at 15psi, ARP studs, .010" head gaskets, bypass oil system, Dmax van fuel pump/filter combo, Aeromotive fuel pump. REMOTE MOUNT TURBO INSTALLED!!!! Burning hydraulic fluid, jet fuel, WMO.
2003 VW Wagon 2.0L TDI auto, silver, heavily modified-Wife's.
2004 VW Wagon TDI 5 speed-blue-also modified-Mine!

1989 Dodge Caravan ex daily driver, 2.5L TIII DOHC Turbo, GT35R, [email protected] mph.

2002 Gold Dmax 4 door, 2500HD 4x4-new camper/trailer hauler-minor mods and a small tow tune!
Offline   Reply With Quote Quick reply to this message
Old 02-10-2015, 10:10 AM   #29 (permalink)
94C1500
Diesel Specialist
 
94C1500's Avatar
 
Join Date: Mar 2009
Posts: 3,231
iTrader Score: 1 reviews

Quote:
Originally Posted by turbovanman View Post
When I ran my n/a injectors, it ran great at 22 psi, and the only thing that caused it to hit brickwalls was my compressor wheel choice and of course, some pumps. I know, its not much to add but find it interesting about the higher pop pressure being needed at higher boost when mind ran fine?
Don't misunderstand, the IP can push over 9,000 psi if it has to, so the fuel will get injected. So it all works, but just because it works doesn't mean its working optimally and you might burn a hole in a piston 10,000 miles down the road if you commonly run sustained high boost at high load, like towing in the mountains.
__________________
1994 C1500 - 4L80E & 3.42 rear; Custom Multi-Program Chip; L65 intake; "FTB", Walbro FRC-10 lift pump, pre-LP fuel filter & OPS relay mod; D-Tech FSD on heatsink; Big Turbo, 4" to 5" exhaust exits before axle, Cone air filter; "marine" injectors. Propane fumigation and WMI.
ENGINE DESIGN CALCULATORS
LIST OF RECOMMENDED MNX & MODS
HX40 or HX35 V-Band Exhaust Elbows
Offline   Reply With Quote Quick reply to this message
Old 02-10-2015, 01:40 PM   #30 (permalink)
turbovanman
Diesel Guru
 
turbovanman's Avatar
 
Join Date: Mar 2006
Location: Abbotsford, BC
Posts: 9,975
iTrader Score: 2 reviews

Quote:
Originally Posted by 94C1500 View Post
Don't misunderstand, the IP can push over 9,000 psi if it has to, so the fuel will get injected. So it all works, but just because it works doesn't mean its working optimally and you might burn a hole in a piston 10,000 miles down the road if you commonly run sustained high boost at high load, like towing in the mountains.
Ok, maybe you answer this, has anyone ever put a hole in a piston from too low pop pressure or a bad injector? To me, theory wise, its impossible as the precup will pretty well cover up any bad injection event.

__________________
1984 G20 Diesel Get a Way Van, 6.2L turbo. Rebuilt 1989 700R4, 3.08 gears. Fluidamper, modified hummer headers, 2.5" mandrel Y-pipe to 3 inch single system, Hooker Max Flo muffler, 3 inch F350 mandrel bent tailpipe-passenger side exit, 6.5L turbo lower intake, 6.5 military IP-5149, Turbonator open faced injectors set to 2500 psi, HX35W with a 60x86mm cast wheel at 15psi, ARP studs, .010" head gaskets, bypass oil system, Dmax van fuel pump/filter combo, Aeromotive fuel pump. REMOTE MOUNT TURBO INSTALLED!!!! Burning hydraulic fluid, jet fuel, WMO.
2003 VW Wagon 2.0L TDI auto, silver, heavily modified-Wife's.
2004 VW Wagon TDI 5 speed-blue-also modified-Mine!

1989 Dodge Caravan ex daily driver, 2.5L TIII DOHC Turbo, GT35R, [email protected] mph.

2002 Gold Dmax 4 door, 2500HD 4x4-new camper/trailer hauler-minor mods and a small tow tune!
Offline   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 Diesel Place : Chevrolet and GMC Diesel Truck Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

PLEASE READ! You must check your email inbox for the confirmation link to complete registration. Please check your spam box if you do not see the email in your inbox.

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


Thread Tools

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 Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
popping dave-lly Suspension & Steering - 2001 - 2010 7 07-10-2014 08:28 PM
Question: New injectors smoking and a popping allsierra123 6.5L Diesel Engine 14 09-22-2013 05:00 PM
Popping when Turning craigknox Suspension & Steering - 2001 - 2010 7 05-04-2009 10:03 PM
still popping!!!!! someone help my2500hd Duramax Second Generation: 2004.5-2005 (LLY) 1 07-17-2006 11:35 PM
popping sound markssylver Duramax Second Generation: 2004.5-2005 (LLY) 13 07-01-2005 12:00 AM


All times are GMT -4. The time now is 07:36 PM.


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.1
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.
Shoutbox provided by vBShout v6.2.1 (Lite) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd. Runs best on HiVelocity Hosting.
© AutoGuide