TheDieselPage.com Forums  
2018 - TDP's 22nd Anniversary
What's New: | Feature Articles: | Product Reviews: | Member's Area: | Subscribe:
Duramax 6600 Diesel Page | Advertiser's Section | Classified Ads | Photo Album | Diesel Books, GM Licensed T-shirts


Go Back   TheDieselPage.com Forums > The Diesel Page Member Forums > 6.2L Diesel
Register FAQ Members List Photo Album Mark Forums Read

6.2L Diesel 1982-93 6.2L Diesel - Member access forum for any questions or information exchange related to the 6.2L engine.

Reply
 
Thread Tools Display Modes
  #1  
Old 01-24-2018, 09:43 AM
High Toned SOB High Toned SOB is offline
Newbie
 
Join Date: Mar 2017
Location: Ohio
Posts: 9
Default .31 pump mods for performance but relaibility

Hi all,
82 6.2 block, full 5 point girdle
Arp headstuds, felpro gaskets
18:1 compression
2831 pump new with 3/8 inlet
He351vgt turbo, custom manifolds
Stock 6.2 intake with homemade hat/intercooled

What can i do to the pump/timing to give maximum performance but also good reliabilty? Gov weights/metering spring/etc?

Also, this is in a 97 truck, used to be a gasser. I just put a new fuel pump in it, and the pressure is 60psi. I know i need it lower, but do i put the regulator on the inlet or outlet of the IP?
Sounds like a dumb question at first, but almost all fue pressure regulators are on the return side of the system, i just dont see how that will work correctly with this pump. Most of the time you are trying to boost pressure, not bring it down, so it seems the only place it can go is on the feed side with a regulated return?

Or tear my brand new in tank module apart and put a TBI pump in it?

Thanks
Reply With Quote
  #2  
Old 01-24-2018, 10:38 AM
DmaxMaverick's Avatar
DmaxMaverick DmaxMaverick is offline
Administrator
 
Join Date: Apr 2001
Location: CA
Posts: 11,881
Arrow

Almost any OEM fuel injection pump can and will (if healthy) provide more fuel pressure and volume than the 6.2L engine can (sustainably) survive. Timing can be advanced, and advance cam adjusted/modified to optimize combustion. An electronic IP (DS4) would increase the flexibility across a greater power range, but the ultimate usable fuel supply limits are no greater. The caution is keeping EGT's within a reasonable limit for the duration. An intercooler and more efficient turbo go a long way to increase the output within the limits. Be aware, though, the situation you have created WILL force the powertrain to seek a point of failure it was previously designed to withstand. I suggest start building its replacement before it needs one (now is a good time).

Fuel pressure should be no more than about 12 PSI, with constant positive volume. The IP does the high pressure heavy-lifting, and ONLY needs a minimal positive fuel supply (above zero pressure, at all times). The fuel injection pump performance is affected by housing (return) pressure. The recommendation you reference regarding where to regulate the pressure (being after the pump), refers ONLY to the fuel lift pump (gassers don't generally have a fuel injection pump). Gassers with fuel injection rely on the lift pump to provide fuel injector pressure, very much unlike that of Diesels. 60 PSI at the IP inlet is excessively too high. Either regulate it to ~10 PSI before the IP inlet, or use a more appropriate fuel lift pump.
__________________
1985 Blazer 6.2
2001 GMC 2500HD D/A
2014 Chevy Cruze Diesel - Fabulous car, no problems at all, but sold Nov. 2016 @ 55K miles.
dmaxmaverick@thedieselpage.com
Reply With Quote
  #3  
Old 01-24-2018, 11:09 AM
High Toned SOB High Toned SOB is offline
Newbie
 
Join Date: Mar 2017
Location: Ohio
Posts: 9
Thumbs up

Quote:
Originally Posted by DmaxMaverick View Post
Almost any OEM fuel injection pump can and will (if healthy) provide more fuel pressure and volume than the 6.2L engine can (sustainably) survive. Timing can be advanced, and advance cam adjusted/modified to optimize combustion. An electronic IP (DS4) would increase the flexibility across a greater power range, but the ultimate usable fuel supply limits are no greater. The caution is keeping EGT's within a reasonable limit for the duration. i can add some water meth later if needed, but we are talking about a 60mm wheel with a almost unlimited hot side, and a intercooler. I dont know if a .310 pump could push enough fuel to get hot in a automatic 5000lb truckAn intercooler and more efficient turbo go a long way to increase the output within the limits. Be aware, though, the situation you have created WILL force the powertrain to seek a point of failure it was previously designed to withstand. I suggest start building its replacement before it needs one (now is a good time).

the rest of the driveline is pretty heavy, built th400, 205, 14bolt/d44, etc

Fuel pressure should be no more than about 12 PSI, with constant positive volume. The IP does the high pressure heavy-lifting, and ONLY needs a minimal positive fuel supply (above zero pressure, at all times). The fuel injection pump performance is affected by housing (return) pressure. The recommendation you reference regarding where to regulate the pressure (being after the pump), refers ONLY to the fuel lift pump (gassers don't generally have a fuel injection pump). Gassers with fuel injection rely on the lift pump to provide fuel injector pressure, very much unlike that of Diesels. 60 PSI at the IP inlet is excessively too high. Either regulate it to ~10 PSI before the IP inlet, or use a more appropriate fuel lift pump.
i know its a different animal, but all my 6b's (p7100) have the ofv (regulator) on the outlet/return of the ip. Thats why i was asking about this one. Makes total sense to put it on the inlet side, just double checking.

My "real world" knowledge on the db pumps is great on paper, but i do lack in practical mods for a "reliable play truck." I can bump the timing and crank the fuel up, but other than that, i have never messed with cutting a delivery valve, cam ring, arm advance adjustment, metering springs, high rpm adjust, etc. Those are the mods i am kinda specifically asking about.

Thank your sir!
Reply With Quote
  #4  
Old 01-24-2018, 11:35 AM
DmaxMaverick's Avatar
DmaxMaverick DmaxMaverick is offline
Administrator
 
Join Date: Apr 2001
Location: CA
Posts: 11,881
Arrow

Your P7100 pumps are regulated at the outlet/return to maintain minimal case pressure. The Stanadyne DB pumps do this internally. The HPCA (Housing Pressure Cold Advance) increases the case pressure to advance timing during cold starts.

Turbo housing, compressor and turbine can be more efficient, but the 6.2L engine will withstand finite cylinder pressure and temperature limits, despite anything else you do. Exceed that, and it fails, now or later, or progressively. This is written in stone. Increasing efficiency only extends the output, not the internal limits. Increased (single) turbo efficiency almost always decreases optimal operational range(s). If you find a way around that, please share.
__________________
1985 Blazer 6.2
2001 GMC 2500HD D/A
2014 Chevy Cruze Diesel - Fabulous car, no problems at all, but sold Nov. 2016 @ 55K miles.
dmaxmaverick@thedieselpage.com
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not 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

Forum Jump


All times are GMT -7. The time now is 09:54 PM.


Powered by vBulletin® Version 3.8.2
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
Copyright 1996-2018 by TheDieselPage.com - All Rights Reserved