Notices
1987 - 1996 F150 & Larger F-Series Trucks 1987 - 1996 Ford F-150, F-250, F-350 and larger pickups - including the 1997 heavy-duty F250/F350+ trucks
Sponsored by:
Sponsored by:

What to do with smog tubes??

Thread Tools
 
Search this Thread
 
  #1  
Old 01-20-2011, 10:06 PM
86--F250's Avatar
86--F250
86--F250 is offline
Freshman User
Thread Starter
Join Date: Jan 2011
Posts: 42
Likes: 0
Received 0 Likes on 0 Posts
What to do with smog tubes??

Hi im tryin to str8t pipe my truck completly and idk what to do with the smog tubes...im gonna put headers on it and the cats and all the stock exhaust is comin out

ps its a 302 motor
 
  #2  
Old 01-20-2011, 10:52 PM
Conanski's Avatar
Conanski
Conanski is offline
FTE Legend
Join Date: Jun 2006
Location: Ottawa, Ontario
Posts: 30,966
Likes: 0
Received 985 Likes on 777 Posts
Remove it all and plug any vacuum lines that are left.
 
  #3  
Old 01-21-2011, 04:33 AM
86--F250's Avatar
86--F250
86--F250 is offline
Freshman User
Thread Starter
Join Date: Jan 2011
Posts: 42
Likes: 0
Received 0 Likes on 0 Posts
can you give a little more detail?
 
  #4  
Old 01-21-2011, 05:37 AM
oldfordisbetter's Avatar
oldfordisbetter
oldfordisbetter is offline
Senior User
Join Date: Dec 2010
Posts: 261
Likes: 0
Received 0 Likes on 0 Posts
remove all the way back to where they start out? plug them? this wont cause any harm?
 
  #5  
Old 01-21-2011, 05:41 AM
86--F250's Avatar
86--F250
86--F250 is offline
Freshman User
Thread Starter
Join Date: Jan 2011
Posts: 42
Likes: 0
Received 0 Likes on 0 Posts
ok sounds good to me
 
  #6  
Old 01-21-2011, 06:06 AM
f100beatertruck's Avatar
f100beatertruck
f100beatertruck is offline
Cargo Master

Join Date: Apr 2003
Location: Parkesburg PA
Posts: 2,408
Likes: 0
Received 2 Likes on 2 Posts
Won't cause any problems. Probably won't pass emissions but doesn't sound like you're worried...

When I did heads on my 86 (EFI 302) I had them block the ports in the head. You'll probably need to leave the crossover and can remove the lines from the check valve to the pump.
 
  #7  
Old 01-21-2011, 09:57 AM
Conanski's Avatar
Conanski
Conanski is offline
FTE Legend
Join Date: Jun 2006
Location: Ottawa, Ontario
Posts: 30,966
Likes: 0
Received 985 Likes on 777 Posts
Originally Posted by 86--F250
can you give a little more detail?
Sure.. remove it all meaning the tubes, the control valves, and the air pump too if you're feeling ambitious. You'll need 5/8 x 1" coarse thread bolts with copper washers to seal the holes in the back of the heads, this is important because there can't be any exhaust leaks upstream of the O2 sensor. The valves in this system are controlled by two solenoids beside the coil, these need to remain electrically connected and the vacuum lines between these and the valves plugged. Last thing is the air pump, there is nothing wrong with leaving it connected but you may want to connect the output directly to the smaller of the two cylinders on the passenger fender which is a small muffler, the larger one is the intake filter for the air pump. The other option is to remove the air pump but you'll need a shorter belt or an eliminator pulley to do that.
None of this will affect engine operation as long as the heads are plugged correctly.
 
  #8  
Old 08-03-2011, 12:30 PM
hivoltj's Avatar
hivoltj
hivoltj is offline
Cargo Master
Join Date: Apr 2010
Location: Billings, MT
Posts: 2,538
Received 35 Likes on 32 Posts
Originally Posted by Conanski
Sure.. remove it all meaning the tubes, the control valves, and the air pump too if you're feeling ambitious. You'll need 5/8 x 1" coarse thread bolts with copper washers to seal the holes in the back of the heads, this is important because there can't be any exhaust leaks upstream of the O2 sensor. The valves in this system are controlled by two solenoids beside the coil, these need to remain electrically connected and the vacuum lines between these and the valves plugged. Last thing is the air pump, there is nothing wrong with leaving it connected but you may want to connect the output directly to the smaller of the two cylinders on the passenger fender which is a small muffler, the larger one is the intake filter for the air pump. The other option is to remove the air pump but you'll need a shorter belt or an eliminator pulley to do that.
None of this will affect engine operation as long as the heads are plugged correctly.

What about the stock cats Paul? Will they be fine without the smog pump? I have the motor out of my '92, and was going to do shorties and a nice exhaust, but now I'm being bent over the counter, and won't have the $. Will I be OK running stock exhaust w/o the smog pump? I really don't want to put all that crap back on only to pull it off later. I don't care if they are less effective, only if they will become plugged.
 
  #9  
Old 08-03-2011, 01:56 PM
Kemicalburns's Avatar
Kemicalburns
Kemicalburns is offline
Hotshot
Join Date: Jul 2002
Location: Bend,OR
Posts: 14,271
Received 8 Likes on 7 Posts
the stock cats need the air injection to burn properly. if you are to replace with the latest hi flow cats they dont require the air injection anymore.
 
  #10  
Old 08-03-2011, 02:13 PM
hivoltj's Avatar
hivoltj
hivoltj is offline
Cargo Master
Join Date: Apr 2010
Location: Billings, MT
Posts: 2,538
Received 35 Likes on 32 Posts
Originally Posted by Kemicalburns
the stock cats need the air injection to burn properly. if you are to replace with the latest hi flow cats they dont require the air injection anymore.

Right, but they will just pollute more, or they will plug up? I would really like to know from someone who has done it. I will only be running it this way until funds recover and I can do an exhaust on it.
 
  #11  
Old 08-03-2011, 03:58 PM
Kemicalburns's Avatar
Kemicalburns
Kemicalburns is offline
Hotshot
Join Date: Jul 2002
Location: Bend,OR
Posts: 14,271
Received 8 Likes on 7 Posts
i am running that way right now. I have my egr stull plumbed and running from header to intake, smog is disconnected and heads are plugged. running hiflow magniflow cat for 3yrs and no issues.
 
  #12  
Old 08-04-2011, 09:57 AM
hivoltj's Avatar
hivoltj
hivoltj is offline
Cargo Master
Join Date: Apr 2010
Location: Billings, MT
Posts: 2,538
Received 35 Likes on 32 Posts
Originally Posted by Kemicalburns
i am running that way right now. I have my egr stull plumbed and running from header to intake, smog is disconnected and heads are plugged. running hiflow magniflow cat for 3yrs and no issues.

I was wondering about running no smog pump with the STOCK CATS though. I'm thinking the smog pump was just a band-aid fix to help them pass emissions, but it could also be a band-aid fix to help them live, I don't know?
 
  #13  
Old 08-04-2011, 08:33 PM
V10man's Avatar
V10man
V10man is offline
Postmaster
Join Date: Feb 2000
Location: Mesa
Posts: 3,897
Likes: 0
Received 4 Likes on 4 Posts
All the pump does is blow a little air into the hot exhaust to help burn off more of the exhaust. Like blowing on a fire.
 
  #14  
Old 08-05-2011, 10:56 AM
Kemicalburns's Avatar
Kemicalburns
Kemicalburns is offline
Hotshot
Join Date: Jul 2002
Location: Bend,OR
Posts: 14,271
Received 8 Likes on 7 Posts
the smog pump does help the originals work properly. if you remove the pump with out upgrading your cats then the originals will not function properly. upgrade the cat then remove the pump
 
  #15  
Old 08-05-2011, 11:20 AM
ChristopherN's Avatar
ChristopherN
ChristopherN is offline
Elder User
Join Date: Jun 2010
Location: Northern IL
Posts: 568
Likes: 0
Received 0 Likes on 0 Posts
Can I keep the pump in place if I get get a new cat or does it have to be removed?
 


Quick Reply: What to do with smog tubes??



All times are GMT -5. The time now is 03:01 PM.