Page Loading... please wait!


This message not going away?
Ensure Javascript is on and click the box
Unregistered? Register for a user account. Home :: Downloads :: Submit News :: Reviews :: FAQ   

Online

There are 30 unlogged users and 0 registered users online.

You can log-in or register for a user account here.

Languages

Preferred language:



Post new topic   Reply to topic
View previous topic Printable version Log in to check your private messages View next topic
Author Message
daywilmOffline
Post subject: Running a V12 Without Cats?  PostPosted: May 03, 2013 - 07:58 PM
KitCentral Fellow


Joined: Nov 22, 2009
Posts: 279
Location: Tulsa, Oklahoma
Status: Offline
I'm working on installing the M70 v12 in my build and since I live in Oklahoma where we don't have emission testing I would like to run it without using catalytic converters. Main reason is because of the room they take up and they add additional heat which can be a problem with these builds anyway. I've looked through the past posts on this subject and it appears there is a difference of opinion whether the engine will run properly without signals from the O2 sensors or if the computers can be "fooled" to think they are receiving this signal. Anyone get a v12 to run properly without the O2 sensors or are the cats a requirement?
 
 View user's profile Send private message Send e-mail  
Reply with quote Back to top
AdrianBurtonOffline
Post subject: RE: Running a V12 Without Cats?  PostPosted: May 03, 2013 - 09:29 PM
KitCentral Fellow


Joined: Jul 22, 2003
Posts: 1752
Location: Mooresville, NC
Status: Offline
If I am not mistaken the O2 sensors are before the cats, so the cats are a non issue

_________________
Now building in Mooresville NC
http://www.flickr.com/photos/adrianburton
http://profile.imageshack.us/user/AdrianBurton
http://s997.photobucket.com/albums/af91/AdrianBurton/
 
 View user's profile Send private message Send e-mail Visit poster's website  
Reply with quote Back to top
Richard454Offline
Post subject:   PostPosted: May 04, 2013 - 03:47 AM
Member


Joined: Mar 06, 2010
Posts: 36
Location: Atlanta, GA
Status: Offline
Adrian is correct-

You do need to use the O2s w/ BMW ECU's

M70 is OBDI- only pre cat O2- Where as the M73 has O2s before and after cat since it's OBDII... regarding STOCK BMW ECUs...However the M73 is a moot point because I don't know anyone running the OEM electronics...

There is some talk about cat removal lessening the lower end torque a bit due to reduced backpressure...but again- a moot point on a V12!!!
 
 View user's profile Send private message  
Reply with quote Back to top
lambo1Offline
Post subject:   PostPosted: May 04, 2013 - 10:51 AM
KitCentral Fellow


Joined: May 14, 2005
Posts: 167

Status: Offline
Guys, I spent hours crawling over my 88 750 donor looking for the o2 sensors, mainly because the 02 relay socket was there but the relay was missing, the service manual shows the relay, in front of the driver on the inner guard, and the sensors on the top front of the cat, but after hours searching I talked to an old BMW mechanic, he stated the English cars did not have 02 or the relays fitted, so I now have no idea how it senses the o2, I bought my donor as a non runner and when I finally got it running it smoked so bad the cars behind disappeared, my heart sunk, thinking I had just bought a m70 that would now become a coffee table lol, but the old mechanic asked did the sump leak oil, and if I raise the front of the car about 6 " it leaks out the back of the pan, apparently if the sump leaks m70 smoke like you would not believe, it somehow sucks the oil from the sump up through the intake and also fowls the plugs real quick, strange things these bmmmrrs.
Does anyone have a spare abs computer for this car as mine just comes up error and the asc does nothing, it also seems to run very very rich even at idle but cant find out why, maybe its to do with the sump problem
regards
Lambo1
 
 View user's profile Send private message Visit poster's website  
Reply with quote Back to top
daywilmOffline
Post subject:   PostPosted: May 06, 2013 - 07:02 PM
KitCentral Fellow


Joined: Nov 22, 2009
Posts: 279
Location: Tulsa, Oklahoma
Status: Offline
Thanks to all for the information. I'm trying to gather as much information as I can before I actually pull this thing out of the 750. It runs great now and hope I don't mess it up during the transplant! I'm about ready to take a deep breath and dig in. I have a lot of information (thanks to Jim Dinner and others) so hopefully I can get it done without too much drama.
 
 View user's profile Send private message Send e-mail  
Reply with quote Back to top
jdinnerOffline
Post subject:   PostPosted: May 07, 2013 - 02:33 AM
KitCentral Fellow


Joined: Nov 10, 2003
Posts: 3076
Location: Toronto, Ontario, Canada
Status: Offline
I am running mine without cats.....no problem. I had to remove them purely because they got so hot.
The early M70's did not have O2 sensors. 1988 did not have O2 sensors.
As for the oil issue. Install a catch can to collect the oil that is being sucked past the PCV.
See drawing...
https://docs.google.com/drawings/d/1fmTkX8sHaq6mROi6jIR5zS7Y07PcwgJ9uOPvQNDGLRw/edit?usp=sharing

_________________
Visit http://jimdinner.wordpress.com/
 
 View user's profile Send private message Send e-mail Visit poster's website  
Reply with quote Back to top
lambo1Offline
Post subject:   PostPosted: May 07, 2013 - 06:30 AM
KitCentral Fellow


Joined: May 14, 2005
Posts: 167

Status: Offline
Thanks Jim, I will look into the catch can idea, but I think I will ultimately need to fix the leaky sump because if I raise the front of the car more than 6" the oil just pours out the rear of the sump, I talked to the BMW mechanic and he said it was a full exhaust system out, transmission out to get to the rear bolts for the sump, apparently they are hidden by the bell housing, one guy I spoke to had the same problem and he bored two holes in the bell housing to get at the hidden bolts, from underneath don't know how that got him around the torque converter through. Someone just posted this on another forum, perhaps I should brake out the skill saw and my welding plant and go for it.
http://www.foxnews.com/leisure/2013/05/06/diy-chevrolet-v12/ now that it a large engine.
 
 View user's profile Send private message Visit poster's website  
Reply with quote Back to top
Display posts from previous:     
Jump to:  
All times are GMT - 8 Hours
Post new topic   Reply to topic
View previous topic Printable version Log in to check your private messages View next topic
Powered by PNphpBB2 © 2003-2006 The PNphpBB Group
Credits
 
Page created in 0.25124096870422 seconds.