I just ripped the factory exhaust off my 1992 f 350 dually's 460 and replaced it with a set of Heddman headers, "x" pipe, dual high flow converters, dual Dynomax super turbos and 2 1/2" pipes. Just got the truck back yesterday from the exhaust shop. At first she was very quiet and saw very little if no difference in power. After about an hour of showing it off to my buddies I noticed a MAJOR difference in both sound and power. Am I going nuts or did it just have to "break in"?

Also, It did stall while idling. My buddy and I were just talking and all of a sudden it loaded up and choked out. The check engine light used come on when coming off the highway and I noticed it came on later that night in my driveway too. I live in Rhode Island and emissions are pretty strict here so I made sure all the emissions crap was kept and re-connected.

Has any of you guys ever did a similar modification?
Has anyone ever ran into troubles after doing them?
Should I be concerned or do I just need to tweak things out a bit?

One last thing, the headers are very noisy both in and out of the cab. It sounds like an exhaust leak, you know, that "tapping" sound. You can't hear it at idle, just when you give it the gas. The exhaust shop said that it wasn't leaking just the sound of the air going through the pipes. Is he blowing smoke up my a..?

Thanks!!

 

I am not sure just how much computer control you have, but some of the problems you have may be your computer getting used to the new components.
With my limited experience with headers, I have found that if you hear a tapping noise, they are leaking.
Out of curiousity, where do you find high flow converters? And a true dual exhaust setup. Most of the exhaust mods I have seen want to go into a y pipe and then through a standard type 55 gallon drum converter. Mine is a '93 F-250 so that might be the difference.

 

www.jcwhitney.com

 

dj,

Did you clear your codes after all this? Before you ran it again?

If you had old codes in the comp before the mods, and it didn't reset, they're still there.

I would recommend pulling the battery cable and resetting the computer.

Now that the puppy breathes better, I would recommend doing a straight up timing chain and gears.

Also, you might want to pull the codes before you clear the computer. Post those here and we might be able to help with those. They may be exhaust related, or something else that is killing the mods. IE EGR valve.

Just a few thoughts.

 

Thanks for the info guys. I just replaced the o2 sensor and re-set the computer(disconnecting the batt for 1 min). Haven't checked for codes yet and it's first highway run,since exhaust work, will be tonight when I go to work. So far though no check engine light. I do have a worse problem though. The headers are ticking like a time bomb. Both sides are leaking badly, like there isn't even a gasket there. I used the gasket that came with the headers. Was told it was of pretty good quality. Anyone ever run into this problem?

Thanks again!!

 

Ok, here is my idea. I had headers on my old Chevy truck with a 350. I went through those felt/carboard exhaust manifolds like water. I would throw any of those away and find the brass ones. They are mostly used for racing and I would think that where ever you found the headers and such should have them or have access to them. What helps with the brass ones, is that they will expand with heat like everything else and seal much better.

Have you checked the bolts? They tend to back out, especially when new as the motor goes through the temperature cycling. If you put a drop of locktite on the threads, it will help this. What I would do is carry a wrench with you once you replace the gaskets, for the next 5 runs or so, check the bolts. They will loosen, but if you get them set after the first few times you run the motor, you should be fine.

Those felt gaskets, even the thick ones just cant take the heat and pressure on headers. I don't really understand why, but that is my experience.

 

Thanks!!
I'm trying to find copper gaskets but everyone I talk to say they only go as far as 1990. Something about in 91-92 ect.. the fuel injection motor heads are diffrent and no one has copper gaskets for my 92 460. Any suggestions where I can find a set for my year truck??

 

I really don't have a clue. Let me do some looking and I'll let you know if I find anything in the next hour or so.

 

Here are a few links. None of them say anything about year. You probably already found these sites, if not, might check them out.

Hope this helps.

http://www.jegs.com/cgi-bin/ncommerc...46&prmenbr=361


http://www.goracin.com

http://www.xtremeheatcoatings.com/cg_advantage.htm

http://store.summitracing.com/partde...art=SCE%2D4035

Good luck and keep up posted if this solves the problems.

 

dj,

I just did a search on copper gaskets here. One of the threads was georgedavila, I think, said to use red RTV around the ports with no gaskets. Said it works great. Might want to look into that also.

 

Ok, took her out on the highway last night and it seems we got rid of the check engine light problem but guess what... yup got a new problem now. Before when I opened her up on the highway the trans seemed to shut down at 90 mph. Now it does it at 80 mph. So basically I got a big block that doesn't do over 80 mph so if I ever wanted to race a 4 cylinder I'd loose. I'm begining to regret ever doing this exhaust. Instead of making the truck better it's making it weaker than a ford focus......
Open to suggestions.......

 

hey, My truck almost 2 years ago but fixed than,started slackin power and its stock exhaust, so i see ya say ya kept all yur polution stuff on, i got my Catalatic Converter cleaned and new Distributor cap and such, as soon as i started it, noticed the difference, now my trucks a 91 but should be similulair, i got the Gas and Propane conversion as well, also maybe cause yur air fuel mixture is different knwo that the exhaust flow is, i just today finished doin all four shocks, and upppers and lowers Balljoints, went good and went a few blocks, now i notice the whole tire is loose so i figure the spindle Nut Backed off a little , any of yas experienced this situation, changed Ujoint/Axle Joints as well, things went good and tight when first checked, once i found out i needed a spindle nut wrench, things went good, let me know whats up .

 

SCE makes a copper gasket for your application Pn 4253. Summit Racing or your local speed shop can get them for you. They are a stock item at Summit for about at 31-31 bucks for a pair.

That said this may not fix your problem. You may have the sealing sufaces in the heads warped. If you check your old exhaust manifolds you will probably find they are warped also. While you are installing gaskets or sealer I would check the header flanges for flatness. Most are not straight unless either you or the factory grind them to be flat.

I would try the copper gaskets. Red or copper silicone is another option although if you do any serious towing up hills they may melt immediately as they are rated for 600-700 degrees intermittent and about 500 or so steady state. Your headers should run a lower temperature than the cast iron exhaust manifolds so silicone may be O.K. but given the pain it is to remove and install the headers I would go for the copper gaskets and fix it once and for all (providing the head mounting surfaces are not severely warped).

Good luck

 

I went though the same thing you are right now. Get you copper gaskets from summit or where ever, and you might need to get some different header screws to tighten them down in the hard to reach spots, I have 7/16 screws on my headers. They probably put the wrong gaskets on at the exhaust shop. There are a few different heads for the 460 in different years. Local "Autozone" parts stores will always give you the wrong gaskets when you tell them what you need. The guys at summit are really helpfull if you give the all the spacific engine info. I went through about 5 sets of gaskets B4 calling summit. Make sure to specify that you have square exhaust ports or thats what mine are anyway. Reguardless you might have to tighten them down ever now and again but mine have worked great for about 2 years now.

 

Thanks for the replies guys but I already called summit and the only carry copper gaskets for years up to 1988. This is my problem, nobody has them for a 1992.

Does anybody have any onfo on a chip or re-programmer for this same truck. My computer used to shut the engine down at 90 mph before the exhaust upgrade. Now it's shutting it down at 80 mph. I got 4 bangers blowing my doors off on the highway!!!!!!!