Aaaaaaaaaaaaaagh...yet another issue with 408

S

Sweeet Ride

New Member

Jun 20, 2006

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0

Calgary, Alberta

Jul 9, 2007

#1

• Jul 9, 2007

• #1

I am getting a lot of nasty exhaust gasses from this engine....went with Crane cam #449601 (lumpy idle but not a really wild cam). I am assuming this cam will leave us with some unburned gas smells but this seems worse than I have ever experienced or any of the other guys around me are getting. Is there something else I am missing....anyone else have same problem.

 

dodgestang

Active Member

Dec 15, 2003

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37

Cecil County, MD

Jul 9, 2007

#2

• Jul 9, 2007

• #2

HAve you tried replacing your truck weatherstripping?

 

65ShelbyClone

Founding Member

Sep 9, 2000

4,675

38

119

Antelope Valley, SoCal

Jul 9, 2007

#3

• Jul 9, 2007

• #3

Did you just put this engine in and now you have funky exhaust, or did you only change the cam and now it's fuming? Did you try adjusting the carb at all?

 

rbohm

Founding Member

Apr 12, 2002

6,698

550

204

tucson,az

Jul 9, 2007

#4

• Jul 9, 2007

• #4

sounds like some fuel and ignition system tuning is in order here. also check for vacuum leaks.

 

H

htwheelz67

Member

May 18, 2007

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16

mission viejo ca.

Jul 9, 2007

#5

• Jul 9, 2007

• #5

what carb are you running? I would think that cam would be pretty mild in a 408, I'll guess your getting it alot at idle?

 

jcode68

Active Member

Jul 15, 2003

892

1

29

Massachussetts

Jul 10, 2007

#6

• Jul 10, 2007

• #6

What fuel pump are you using and do you know what the PSI is currently set to?

 

S

Sweeet Ride

New Member

Jun 20, 2006

24

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Calgary, Alberta

Jul 10, 2007

#7

• Jul 10, 2007

• #7

htwheelz67 said:

what carb are you running? I would think that cam would be pretty mild in a 408, I'll guess your getting it alot at idle?

Click to expand...

Its a Holley 670 (new) and we've already taken it apart and cleaned it looking for another small problem.

 

S

Sweeet Ride

New Member

Jun 20, 2006

24

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0

Calgary, Alberta

Jul 10, 2007

#8

• Jul 10, 2007

• #8

65ShelbyClone said:

Did you just put this engine in and now you have funky exhaust, or did you only change the cam and now it's fuming? Did you try adjusting the carb at all?

Click to expand...

This is a new engine and all parts including 670 Holley and mechanical fuel pump are new. We have adjusted and taken the carb apart looking for another small issue.....we've checked for vacuum leaks etc etc......we have hooked to a scope and tested for exhaust gas and the scope says its within normal range but the whole shop reeks when this car is running. We are about to dyno this engine and tune on the dyno now that we have about 1000 miles on it.

 

S

Sweeet Ride

New Member

Jun 20, 2006

24

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0

Calgary, Alberta

Jul 10, 2007

#9

• Jul 10, 2007

• #9

htwheelz67 said:

what carb are you running? I would think that cam would be pretty mild in a 408, I'll guess your getting it alot at idle?

Click to expand...

You're correct.....its a problem at idle!!!!
I have talked with other guys who say they have had the same problem but then there are many who don't seem to have it at all. Ideas????

 

blown65

Founding Member

Jul 7, 1999

1,938

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39

Queen Creek Arizona

Jul 10, 2007

#10

• Jul 10, 2007

• #10

Just tune it on the dyno with a wideband. That should cure the issues and get things sorted out.