Re: Crankcase ventilation - operation and description question - Saab 9000 Bulletin Board - Saabnet.com
The banner above is an advertisment - if it asks you to download software, please ignore.
Site News -
4/9 Saab Owners' Convention Day Pass Raffle |
3/26 M Car Covers (by State of Nine)
[General |
Members |
C900 |
9000 |
NG900 & OG93 |
93 |
95 |
NG95 |
99 |
Sonett |
Vintage Models |
Clubs |
Other Cars |
FAQs |
Gifts |
Member Photo Galleries |
Member Directory |
Classifieds |
Manuals |
*Buddy Registry |
*Mileage Registry |
Polls |
What's New |
Raffle |
Photo of the Month |
Sponsors]
[Main 9000 Bulletin Board | BBFAQ |
Prev by Date | Next by Date | Post Followup ]
Member Login / Signup - Members see fewer ads. - Latest Member Gallery Photos
Re: Crankcase ventilation - operation and description question
Posted by Smeter12 [Email] (more from Smeter12) on Mon, 2 Nov 2020 06:46:58
In Reply to: Re: Crankcase ventilation - operation and description question, Simon S, Sat, 31 Oct 2020 09:03:46
Members do not see ads below this line. - Help Keep This Site Online - Signup
Simon S,
FACT - Many manufacturers since the 1960's have had closed crankcase ventilation systems since the era of the down draft tube (i.e. venting combustion gases out of the crankcase with a tube hanging very low and getting vented while the vehicle is in motion). A typical closed PCV system would include the design of a "fresh air in" into the crankcase which id behind the air filter assembly and the "blow-by gases" would then be directed back to the intake manifold = your closed PCV system.
The problem I am having (specific to the Saab 9000 B234 engine) is - where is the fresh air intake? I would you think you need a fresh air intake (because not only does the crankcase's PCV valve design regulate flow of the blow-by gases, it also regulates the lubrication for the bearings in the crankcase... blow-by gases exit to fast = to much oil taken from the crankcase = take out your bearings) like a gas tank needs fresh air intake. As pressures and temperature change for your gas tank, the vent valve in the EVAP system prevents your gas tank from expanded or contracting in unwanted ways. In my mind, with similar logic, you want to be able to control the changes in temperature and pressures in the crankcase with the help of fresh air being introduced so you have proper control over flow as well as lubrication for the bearings. Hence my confusion with regards to no "fresh air intake".
If Saab engineer's decided not to use a fresh air intake for the B234 engine, then I don't understand how (from an engineering/science perspective) that system works when considering your typical "fresh air in" and "blow-by gases directed back to the intake" crankcase venting design.
As always - thoughts appreciated.
posted by 70.181.172...
Posts in this Thread:
Members do not see ads below this line. - Help Keep This Site Online - Signup
Post a Followup
No Site Registration is Required to Post - Site Membership is optional (Member Features List), but helps to keep the site online
for all Saabers. If the site helps you, please consider helping the site by becoming a member.
StateOfNine.com
|
SaabClub.com
|
Jak Stoll Performance
|
M Car Covers
|
Ad Available
|
Random Saabnet.com Member Gallery Photos (Click Image)
This is a moderated bulletin board - Posting is a privilege, not a right.
Unsolicited commercial postings are not allowed (no spam). Please, no For Sale or Wanted postings, SERIOUSLY.
Classifieds are to be listed in The Saab Network Classifieds pages.
This is a problem solving forum for over 250,000 Saab owners, so expect to see
problems discussed here even though our cars are generally very reliable. This is not an anything goes
type of forum. Saabnet.com has been a moderated forum since 1988. For usage guidelines, see the
Saabnet.com Mission and Purpose Page. Please remember that you are
not anonymous. Site Contact | Site Donations | Other Sites by SP -
Poverty2Prosperity.org | Run Club Menlo Park | ScreenBot
Site Members do not see red text instructions, bottom of the page anchor ads, or box ads.
Click here to see all
the Site Membership Benefits!