620" bbc oil return problems - Yellow Bullet Forums

Go Back   Yellow Bullet Forums > Fire your bullets!!! > Trash Or Be Trashed

Trash Or Be Trashed Where the weak are killed and eaten!!!! Vulgar language and nudity may be enclosed!! NWS

Reply
 
Thread Tools Display Modes
Old 01-13-2012, 11:40 PM   #1
bigsix
Junior Member
Launchin
 
bigsix's Avatar
 
Join Date: Nov 2007
Location: Crookston, MN
Posts: 472
Default 620" bbc oil return problems

I have a wet sump pump gas 620" bbc with a donovan aluminum block, 8 quart Billit Fabrication pan and the Titan pump and on the dyno we see the oil pressure drop from 65 lbs-45 lbs after 2 seconds on a pull @ 6000 rpm. The builder wants to add external return lines and try that before a vacum pump. The motor has tightened clearances, .100 restrictors and it appears that it is a windage problem and the oil does not get back to the pan. He has not made a good pull with the pressure dropping back like it is. Has anyone else had a similar problem or any ideas?
bigsix is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 01-13-2012, 11:43 PM   #2
Coloradoracer
Senior Member
Smoked another BBC
 
Coloradoracer's Avatar
 
Join Date: Oct 2009
Location: Morrison, Colorado
Posts: 2,581
Default Re: 620" bbc oil return problems

Definately run some sort of vent from valve covers to the crankcase.........I'm sure it would help
__________________
Mark Goulette
Owner and driver, Livin' the Dream Racing Dragster
Speed kills but it's better than going slow!
www.livinthedreamracing.com
Authorized Amsoil Dealer
Coloradoracer is offline   Reply With Quote
Old 01-13-2012, 11:52 PM   #3
CutlassRacer
X275!
Smoked Another SBC
 
CutlassRacer's Avatar
 
Join Date: Nov 2006
Location: Gainesville, FL
Posts: 4,957
Default Re: 620" bbc oil return problems

I would guess that the oil is getting pushed to one side of the pan from all of the wind that big arm makes.
__________________
Kevin
78 Cutlass Turbo Olds Project
FlatOut Racing - 91 Nissan 300ZX & 240SX & Lexus SC300 CHUMPCAR Endurance Racers
Want to race for 2 hours at a time? Contact me about road racing car rentals!

KSR Performance & Fabrication
Dealer for: TRZ, AFCO, PST, and more!
CutlassRacer is offline   Reply With Quote
Old 01-13-2012, 11:54 PM   #4
overkill69
Senior Member
Smoked another BBC
 
overkill69's Avatar
 
Join Date: Sep 2008
Posts: 1,214
Default Re: 620" bbc oil return problems

Our blown chevy needs 15qts with return hoses from the heads. Titan wetsump system.
overkill69 is offline   Reply With Quote
Old 01-14-2012, 12:06 AM   #5
greg hindman
Senior Member
Smoked Another SBC
 
greg hindman's Avatar
 
Join Date: Oct 2008
Location: vancouver, washington
Posts: 6,856
Default Re: 620" bbc oil return problems

i have a wet sump 632 and it has a 11 quart pan..
no problems..

but i had this issue before with my 648.. the fine crew at steve schmidt honed my lifter bores when i sent the block in for routine sleeve renewal.
they knocked four thou out of the hole..
oil just poured out between lifters and bore when on a pull but would idle fine run.
so the engine could scavenge fast enough when the rpm was down or low and oil wasnt slinging like crazy.

but as soon as you cut the bitch loose oil pressure would go from 60psi to 30 psi in about 2 seconds into the pull...

what pissed me off is engine guy checked all our tolerances before engine left..
so my engine guy had no clue they honed/ruined the lifter bores.. especially because there was no need too..
he disassembled the engine 3 times looking for cracks etc. just trying to find what the issue was..
changed thousands of dollars in dry sump shit to find that wasn't the issue either..
we put restrictors in, ran relif hoses , blah blah... mind you i ran the engine for three years prior and never had this issue and never ran restrictors or return hoses before. was all a waist of time and money...
good luck man i hope you find the issue cause its gets frustrating chasing your ass on deals like this.. oh and expensive..
__________________
carbon fiber is like diamonds for men
greg hindman is offline   Reply With Quote
Old 01-14-2012, 12:20 AM   #6
Qrtrmilepimp
Junior Member
Pre-Staged
 
Qrtrmilepimp's Avatar
 
Join Date: Dec 2010
Location: north highlands ca
Posts: 82
Default Re: 620" bbc oil return problems

man i just had that same problem with my 588 big chief motor didnt realize it was hapening till i blew it up after 10 pass then went home and looked at the in car cam and sure enough the oil preesure would drop right after launch it would go to 75 on the brake then when i would pull second it would be at 60 then pull high gear it would be low 50s by the time i hit the stripe it was at 40 at 7600 not good !!!so i learned a good leason that day drain backs on big chief are a must they have shitty drain backs and i run a accusump now with tree extra quarts in it and plus two over in the pan..... thriteen quarts total hope this helps !!!!
__________________
Qrtrmilepimp is offline   Reply With Quote
Old 01-14-2012, 12:24 AM   #7
bigsix
Junior Member
Launchin
 
bigsix's Avatar
 
Join Date: Nov 2007
Location: Crookston, MN
Posts: 472
Default Re: 620" bbc oil return problems

Thanks Greg, he has had the motor on the dyno three times. He has checked the lifter bores, made sure the lifters are not getting uncovered, checked all the oil passages and galleys, distributor bosses, upgraded from a Moroso cast pump and pickup to the Titan and changed the clearances again on the lower end per Donovan's instructions. We have talked to Jeff Johnson @ Billet Fabrication and we still have the issue. I have been purchasing the parts for the motor for 10 years and I am just sick about this as I am not made of money and sure cannot have major engine problems.
bigsix is offline   Reply With Quote
Old 01-14-2012, 12:27 AM   #8
greg hindman
Senior Member
Smoked Another SBC
 
greg hindman's Avatar
 
Join Date: Oct 2008
Location: vancouver, washington
Posts: 6,856
Default Re: 620" bbc oil return problems

my big chiefs did not have drain backs..... ran no restrictors.... springs lasted longer and bearings in rocker shafts... never broke a rocker either..
just my experience.

i would look more into windage issues...
__________________
carbon fiber is like diamonds for men
greg hindman is offline   Reply With Quote
Old 01-14-2012, 12:48 AM   #9
bigsix
Junior Member
Launchin
 
bigsix's Avatar
 
Join Date: Nov 2007
Location: Crookston, MN
Posts: 472
Default Re: 620" bbc oil return problems

The builder did a 598" bbc, Brodix aluminum block, dry sump motor for a super gas car and there was no oiling issues at all. The motor made 1050 hp and has been raced for 3-4 years with a yearly freshening and each time it looks good inside. The big difference is the dry sump oiling and that motor spins about 1000 rpm more tham mine. I agree, we feel that it is windage. A similar combo to mine, except it had a Dart iron 598" wet sump, pushed oil out the rear main seal under acceleration due to windage and a vacuum pump cured his issue. They did not catch that problem on the dyno, had to experience it in the car. His car has no external return lines from the covers to the pan.
bigsix is offline   Reply With Quote
Old 01-14-2012, 01:03 AM   #10
AlkyWagon
"Big Al" Sargent
Smoked Another SBC
 
AlkyWagon's Avatar
 
Join Date: Jan 2009
Location: North Georgia
Posts: 5,628
Default Re: 620" bbc oil return problems

Just asking, but did you put a windage tray in it? If so, is it built into the pan or does it bolt up to the main studs? Crank Scraper?
AlkyWagon is offline   Reply With Quote
Old 01-14-2012, 01:06 AM   #11
bigsix
Junior Member
Launchin
 
bigsix's Avatar
 
Join Date: Nov 2007
Location: Crookston, MN
Posts: 472
Default Re: 620" bbc oil return problems

Quote:
Originally Posted by AlkyWagon View Post
Just asking, but did you put a windage tray in it? If so, is it built into the pan or does it bolt up to the main studs? Crank Scraper?
Windage tray built into the pan, no scraper.
bigsix is offline   Reply With Quote
Old 01-14-2012, 01:23 AM   #12
Monte Smith
The nitrous guy
Smoked Another SBC
 
Join Date: Nov 2007
Location: North Alabama
Posts: 6,328
Default Re: 620" bbc oil return problems

Donovan blocks are drilled and tapped in the lifter valley for those aluminum stand pipes. If you have those installed, remove them, that will likely cure your problem.

Trapping oil in the heads, is not the problem. It is usually the lifter valley. As high as the lifter bosses are and the support ribs, they trap a LOT of oil in the lifter valley. If you have those stand pipes in there, it gets really full before it returns any

Monte
__________________

Monte Smith
Motorsports Technical Representative
Nitrous Oxide Systems
www.montesmithperformance.com
gtxmonte@msn.com
ph. 256-783-3418

Last edited by Monte Smith; 01-14-2012 at 01:25 AM.
Monte Smith is online now   Reply With Quote
Old 01-14-2012, 01:23 AM   #13
in the stands
Member
Pullin gears
 
Join Date: Jun 2007
Posts: 504
Default Re: 620" bbc oil return problems

Is it a Jeff Johnson pan with the balls in it?
in the stands is offline   Reply With Quote
Old 01-14-2012, 01:28 AM   #14
bigsix
Junior Member
Launchin
 
bigsix's Avatar
 
Join Date: Nov 2007
Location: Crookston, MN
Posts: 472
Default Re: 620" bbc oil return problems

Quote:
Originally Posted by Monte Smith View Post
Donovan blocks are drilled and tapped in the lifter valley for those aluminum stand pipes. If you have those installed, remove them, that will likely cure your problem.

Monte
I believe the motor does have them in the valley. I will mention this to the builder. I appreciate your help and everyone elses' posts on the issue.
bigsix is offline   Reply With Quote
Old 01-14-2012, 01:30 AM   #15
bigsix
Junior Member
Launchin
 
bigsix's Avatar
 
Join Date: Nov 2007
Location: Crookston, MN
Posts: 472
Default Re: 620" bbc oil return problems

Quote:
Originally Posted by in the stands View Post
Is it a Jeff Johnson pan with the balls in it?
No, it does not have the balls built into it.
bigsix is offline   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



All times are GMT -4. The time now is 12:43 AM.


Powered by vBulletin® Version 3.8.6
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Garage Plus vBulletin Plugins by Drive Thru Online, Inc.
Resources saved on this page: MySQL 2.82%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Yellow Bullet LLC