Blower gear housing pressure - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Engine
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 08-18-2008, 04:05 PM
Registered User
 
Last photo:
Join Date: Aug 2008
Location: Phoenix, Arizona
Posts: 9
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Blower gear housing pressure

I have a new Weiand 671 and am having a problem with pressure in the front gear housing at 3500 rpms and above. Weiand says it is ok but if I don't vent it, it leaks by the front nosecone seal. If I vent it, it comes out the vent under pressure at 3500 and above. What is the causing this and what is the fix.
Thanks,
Stevej66

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 08-18-2008, 05:10 PM
41willys's Avatar
Blowin' it
 
Last wiki edit: Choosing a trailer
Last journal entry: Running again...
Last photo:
Join Date: Aug 2002
Location: Katy, Texas
Age: 39
Posts: 417
Wiki Edits: 11

Thanks: 0
Thanked 0 Times in 0 Posts
I would call Weiand and ask to speak with a supervisor of tech support. You will get pressure in the front cover, but the pressure is not supposed to be relieved unless repairs are being made and the front cover is being removed.

You will obviously get pressure in the front cover, but the fact that it is puking fluid states that it is excessive. This could be caused by an issue from the blower case to the backside of the front cover. At 3500+ RPM's you are making boost, and the pressures are making it into the front gear housing. Could be a seal, a bad gear housing, or a bad case.

That is just my guess.

Jason
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 08-18-2008, 05:18 PM
techinspector1's Avatar
Senior Curmudgeon
 
Last wiki edit: DynoSim combinations Last photo:
Join Date: Oct 2005
Location: Hemet, California, USA
Age: 72
Posts: 13,284
Wiki Edits: 326

Thanks: 829
Thanked 1,146 Times in 945 Posts
Never having rebuilt a Weiand, I'll give this a shot anyway. It seems obvious that the gear housing is getting pressurized from boost. Pressure could get into the housing, the way I see it, by one of the following ways:
1. Porous front cover casting.
2. Casting not flat and parallel with the blower case, allowing boost to push past the rotor shaft seals.
3. Faulty rotor shaft seals or perhaps seals that were installed backwards (if that's possible??).

Like I said, no hands-on experience at it, just trying to help you think it out.

41 Willys, sorry, I was typing my reply and you had already posted.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 08-18-2008, 06:14 PM
41willys's Avatar
Blowin' it
 
Last wiki edit: Choosing a trailer
Last journal entry: Running again...
Last photo:
Join Date: Aug 2002
Location: Katy, Texas
Age: 39
Posts: 417
Wiki Edits: 11

Thanks: 0
Thanked 0 Times in 0 Posts
Techinspector, de nada.

I am still trying to figure out why he was told it is normal, or that Weiand tells him it is o.k. I was thinking the same thing you stated, just not as detailed as yours.

Jason
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 08-18-2008, 06:34 PM
techinspector1's Avatar
Senior Curmudgeon
 
Last wiki edit: DynoSim combinations Last photo:
Join Date: Oct 2005
Location: Hemet, California, USA
Age: 72
Posts: 13,284
Wiki Edits: 326

Thanks: 829
Thanked 1,146 Times in 945 Posts
1. They don't want to be bothered with after-sale support.
2. They don't have to clean up the mess.
Those would be my best guesses.

Like you said, I'd be gettin' hold of somebody who could make it right, all the way to the chairman of the board if necessary.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 08-18-2008, 08:31 PM
BOBCRMAN@aol.com's Avatar
Member
 
Last photo:
Join Date: May 2002
Location: Holly, michigan
Posts: 8,236
Wiki Edits: 0

Thanks: 30
Thanked 296 Times in 276 Posts
I am far from an expert on the subject. But, my B&M/Weiand blower also has had some vent issues since new. A simple/terrible venting system. Now has over six thousand miles in a street rod. I just clean up the drips when I wash the car/motor.

I asked one of my customers, an engineer on the supercharged GM 3800 engines project, about the venting problem.

His reply was that GM also had venting problems. Theirs is a much more sophisticated setup. But, they settled on venting thru the drive shaft of the blower. Somewhat solved their problems.

You are going to get some pressure in the front cover.
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 08-18-2008, 09:15 PM
techinspector1's Avatar
Senior Curmudgeon
 
Last wiki edit: DynoSim combinations Last photo:
Join Date: Oct 2005
Location: Hemet, California, USA
Age: 72
Posts: 13,284
Wiki Edits: 326

Thanks: 829
Thanked 1,146 Times in 945 Posts
Thanks Bob. It's beginning to sound like everybody has the problem to one extent or another. The Rube Goldberg side of me can envision a catch can mounted higher than the housing, stuffed with steel wool and vented to atmosphere on the top of the can. Whatever oil blows up into it will, by gravity, flow back into the housing when the motor is shut off.
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 08-19-2008, 02:11 PM
Registered User
 
Last photo:
Join Date: Aug 2008
Location: Phoenix, Arizona
Posts: 9
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Thanks,
I've already done that and it has so much pressure it will empty the oil reservoir.
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 08-20-2008, 02:25 PM
Registered User
 
Last photo:
Join Date: Aug 2008
Location: Phoenix, Arizona
Posts: 9
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by 41willys
I would call Weiand and ask to speak with a supervisor of tech support. You will get pressure in the front cover, but the pressure is not supposed to be relieved unless repairs are being made and the front cover is being removed.

You will obviously get pressure in the front cover, but the fact that it is puking fluid states that it is excessive. This could be caused by an issue from the blower case to the backside of the front cover. At 3500+ RPM's you are making boost, and the pressures are making it into the front gear housing. Could be a seal, a bad gear housing, or a bad case.

That is just my guess.

Jason
Jason,
Thanks for the input. I was just informed by BDS that there has to be pressure in the gear case for the seals to work properly. Also I should not vent the case but use a manual pressure relief valve to periodically relieve pressure to prolong seal life.
Thanks again,
Steve
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 08-20-2008, 02:27 PM
Registered User
 
Last photo:
Join Date: Aug 2008
Location: Phoenix, Arizona
Posts: 9
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by techinspector1
Never having rebuilt a Weiand, I'll give this a shot anyway. It seems obvious that the gear housing is getting pressurized from boost. Pressure could get into the housing, the way I see it, by one of the following ways:
1. Porous front cover casting.
2. Casting not flat and parallel with the blower case, allowing boost to push past the rotor shaft seals.
3. Faulty rotor shaft seals or perhaps seals that were installed backwards (if that's possible??).

Like I said, no hands-on experience at it, just trying to help you think it out.

41 Willys, sorry, I was typing my reply and you had already posted.
Thanks for the input. I was just informed by BDS that there has to be pressure in the gear case for the seals to work properly. Also I should not vent the case but use a manual pressure relief valve to periodically relieve pressure to prolong seal life.
Thanks again,
Steve
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 08-20-2008, 02:32 PM
Registered User
 
Last photo:
Join Date: Aug 2008
Location: Phoenix, Arizona
Posts: 9
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by BOBCRMAN@aol.com
I am far from an expert on the subject. But, my B&M/Weiand blower also has had some vent issues since new. A simple/terrible venting system. Now has over six thousand miles in a street rod. I just clean up the drips when I wash the car/motor.

I asked one of my customers, an engineer on the supercharged GM 3800 engines project, about the venting problem.

His reply was that GM also had venting problems. Theirs is a much more sophisticated setup. But, they settled on venting thru the drive shaft of the blower. Somewhat solved their problems.

You are going to get some pressure in the front cover.

Thanks for the input. I was just informed by BDS that there has to be pressure in the gear case for the seals to work properly. Also I should not vent the case but use a manual pressure relief valve to periodically relieve pressure to prolong seal life.
Thanks again,
Steve
Reply With Quote Quick reply to this message
  #12 (permalink)  
Old 08-20-2008, 02:48 PM
41willys's Avatar
Blowin' it
 
Last wiki edit: Choosing a trailer
Last journal entry: Running again...
Last photo:
Join Date: Aug 2002
Location: Katy, Texas
Age: 39
Posts: 417
Wiki Edits: 11

Thanks: 0
Thanked 0 Times in 0 Posts
That is correct, you will have pressure in the front cover, but not to the point it is blowing out the oil.

Keep in mind that the manual release should not be used often.

Jason
Reply With Quote Quick reply to this message

Recent Engine posts with photos

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last 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.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
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



All times are GMT -6. The time now is 02:41 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.