|
Author
|
Topic: Smog Bumps in exhaust ports
|
Firechief1400
unregistered
|
posted 01-14-2004 05:42 PM
 
How inportant is removing the bumps in the exhaust ports. I am having a valve job done now and the machne shop really does not want to grind on the head. If I push them they will do it but they said they would not warranty the work if something goes wrong. So whats everyones opinion. Grind or don't grind and what performance do I really pick up? 
IP: Logged |
Moneymaker
Administrator Posts: 25052
From: Lyons, IL, USA
Registered: May 99
|
posted 01-14-2004 06:23 PM
 
I'd get rid of them in a heart beat.------------------
Alex Denysenko
Co-Administrator and Moderator NHRA/IHRA/SRA member and licensed Superstock driver
MCA member# 53321
NHRA and IHRA SS/LA & SS/MA National Record Holder '00,'01,'02,&'03
First SS/MA in the TENS!
IHRA division 5 Superstock Champion
Fleet of FoMoCo products including 88 ASC McLaren Mustang #28 The Barry of BarrysGrrl Quote #1: "I never met a magazine mechanic I liked."
Quote #2: "Make sure brain is in gear before engaging mouth!"
Quote #3: "If you can't run with the big dogs, stay on the porch!"
www.moneymakerracing.com
IP: Logged |
Daniel Jones
Gearhead Posts: 790
From: St. Louis, MO
Registered: Aug 99
|
posted 01-14-2004 08:50 PM
I just did this on a set of SBF heads. With a die grinder and a good carbide cutter, it takes minutes. You can have both heads done in no time. If your shop doesn't want to do this, it sounds like they have little experience with SBF heads. I'd look elsewhere for a shop that does.Dan Jones
IP: Logged |
Firechief1400
unregistered
|
posted 01-15-2004 01:13 AM
Thanks for the good information.
IP: Logged |
460-67Stang
Gearhead Posts: 288
From: Southern Ohio, USA
Registered: Feb 2001
|
posted 01-15-2004 10:05 AM
Yup, grind away. Absolutely. The bumps in my 1968 429 heads were more like small mountains. I don't know the specific flow improvement, but I'm certain it's made a big difference.
IP: Logged |
indyphil
Gearhead Posts: 2255
From: Senoia, G.A. USA
Registered: Jul 2002
|
posted 01-15-2004 11:16 AM
Anyone got any idea what kind of Hp increase its worth on a mild engine?maybe 5 horses?
IP: Logged |
trashline
Gearhead Posts: 1217
From: Levittown, Pa
Registered: Dec 2003
|
posted 01-15-2004 12:29 PM
and heres another question, what are they for what purpose do they serve?
IP: Logged |
Firechief1400
unregistered
|
posted 01-15-2004 01:12 PM
Beats me. Everyone says to remove the little buggers.1969 Sportroof 351W 4V Auto(Chrome Yellow)
IP: Logged |
JCQuinn@work
Gearhead Posts: 814
From: Lakewood, CO, USA
Registered: Jun 2001
|
posted 01-15-2004 01:21 PM
Back in the 60's Ford introduced an air pump system to inject air into the exhaust stream for cleaner exhaust. The bumps had holes in them that connected to a passage that ran the length of the head and connected to the air pump line. They used the bump so that the air is injected more into the center of the exhaust stream. The bumps started appearing sometime during the 67 production run. I seem to remember a couple of different designs for the bumps but they all hurt airflow. I don't think they ever redesigned the exhaust port after 68.John
IP: Logged |
trashline
Gearhead Posts: 1217
From: Levittown, Pa
Registered: Dec 2003
|
posted 01-15-2004 02:52 PM
really? so the exhuast ports in the head on 66s shouldnt have them? i have a 200 ci from i belive 66 but i know the motors were used before 66 like in falcons
IP: Logged |
Firechief1400
unregistered
|
posted 01-15-2004 02:56 PM
They did not redesign the heads as the 69 still has the bumps no air holes for the use of an air pump though. Good information
IP: Logged |
Moneymaker
Administrator Posts: 25052
From: Lyons, IL, USA
Registered: May 99
|
posted 01-15-2004 03:37 PM
quote:
Originally posted by trashline:
really? so the exhuast ports in the head on 66s shouldnt have them? i have a 200 ci from i belive 66 but i know the motors were used before 66 like in falcons
Only California stuff got smog stuff in 66.
The rest of the 49 state FoMoCo got Federal emmission mandates in 1968. ------------------
Alex Denysenko
Co-Administrator and Moderator NHRA/IHRA/SRA member and licensed Superstock driver
MCA member# 53321
NHRA and IHRA SS/LA & SS/MA National Record Holder '00,'01,'02,&'03
First SS/MA in the TENS!
IHRA division 5 Superstock Champion
Fleet of FoMoCo products including 88 ASC McLaren Mustang #28 The Barry of BarrysGrrl Quote #1: "I never met a magazine mechanic I liked."
Quote #2: "Make sure brain is in gear before engaging mouth!"
Quote #3: "If you can't run with the big dogs, stay on the porch!"
www.moneymakerracing.com
IP: Logged |
indyphil
Gearhead Posts: 2255
From: Senoia, G.A. USA
Registered: Jul 2002
|
posted 01-15-2004 03:50 PM
It was my understanding that in 66 all the heads had the bumps, only the california heads were drilled for the air injectors?So all 66 up heads have the bumps - that was my understanding. (I have a 66 289 engine but have not had a look yet) ------------------
'68 coupe 289 C code
66 heads, edel 600cfm carb, performer intake, dual exhaust http://www.geocities.com/ottouk_77/68mustang.htm
IP: Logged |
Mustangsandmore Forums
UBBFriend: Email This Page to Someone! 
