Exhaust leak after shorty header install

[moooosestang]

Both sides seam to be high in the middle.

 

[JC SSP]

Good catch. Take a bench grinder to it and you will be fine.

 

[moooosestang]

Heads look very flat. This piece of marble is what I'm using to true these up. If I'm not happy with the results I'll take them to a machine shop on monday. We shouldn't have to do this. Ignore all that red clay stuck to my block. i lived on a dirt road many years ago and it's still there.

 

[msvela448]

Heads look very flat. This piece of marble is what I'm using to true these up. If I'm not happy with the results I'll take them to a machine shop on monday. We shouldn't have to do this. Ignore all that red clay stuck to my block. i lived on a dirt road many years ago and it's still there.

View attachment 87867 View attachment 87868

Love your idea to use the marble for a flat surface. If you don't have any machinist marking dye, you can also just use a big permanent marker to color the face of the flange so you can see the high and low spots as you sand.

Looking forward to hearing that all your hard work paid off.

Sent from my SM-N986U using Tapatalk

 

[Dino Dino Bambino]

Ignore all that red clay stuck to my block.

That's ceramic coating and you got it for free.

View attachment 87865 Both sides seam to be high in the middle.

That speaks highly of BBK quality!
For comparison, the flanges on my $120 Chinese eBay JBA knock-offs were perfectly flat.

 

[Jwood562]

@moooosestang, a couple things. im sorry you had to go through all of this because of what a pain in the ass it is to install and remove these, but i cant thank you enough for posting your findings as it for sure has helped me, who is about to head down the exact same install path.

i would have never thought to check the square of the flanges, i still havent but will soon. and if they are in spec im lucky, but if they are all wonky i can address it before the install and save some money, time and headaches.

so once again, thank you

 

[moooosestang]

That's ceramic coating and you got it for free.



That speaks highly of BBK quality!
For comparison, the flanges on my $120 Chinese eBay JBA knock-offs were perfectly flat.

Damn! Those ebay headers look so nice, but i so reviews saying they had fitment issues too. I still think there's a pinhole in one of these welds. doesn't seem warped enough to cause a leak with those aluminum gaskets. i will check it with compressed air tomorrow.

 

[Dino Dino Bambino]

Damn! Those ebay headers look so nice, but i so reviews saying they had fitment issues too.

Only in so far as the clearance of the driver's side header from the steering shaft is very tight, but then the real JBA Cat4ward shorty headers also have the same issue. You can shim the driver's side motor mount bracket to gain a few mm more clearance if needed.

 

[xeninworx]

Heads look very flat. This piece of marble is what I'm using to true these up. If I'm not happy with the results I'll take them to a machine shop on monday. We shouldn't have to do this. Ignore all that red clay stuck to my block. i lived on a dirt road many years ago and it's still there.

View attachment 87867 View attachment 87868

I was using the same setup to grind down the flanges. Sanding belt on a flat surface. Takes so much time. Glad I found a belt sander big enough for my headers. Saved so much time. Maybe check some local machine shops to grind them down. They’d have a much larger belt sander.

 

[moooosestang]

I was using the same setup to grind down the flanges. Sanding belt on a flat surface. Takes so much time. Glad I found a belt sander big enough for my headers. Saved so much time. Maybe check some local machine shops to grind them down. They’d have a much larger belt sander.

Yeah, it ain't quick. no machine shops open on the weekend and i'd really like to get this shit done.

 

[xeninworx]

What’s the length of the flanges? I measured the distance on belt sander at the middle of each roller and I’ve got 14.5” of flat surface. You might be able to fit it on a belt sander and since you’re only taking material off the middle, you’re not actually using the whole surface area of the belt sander. Also, wear gloves and a mask. There’s a lot of metal dust that you don’t want to breathe in or get all over your hands. Keep a vacuum handy too.

 

[whitmanink]

ive got the same headers as dino,, mine were perfect as well,,, but.......
when i screwed up the drivers side collector to header,, i messed up and didnt have it lined up and it smashed the collector and theres a gap,, soooo since i wanted to drive the car asap,, i got me some jb weld high heat epoxy stick and put it around the gap until i feel like dropping the exhaust to fix it, i also used the flat side of my bbk header gaskets to the head , mine dont leak at all there,, the only way to tell where it was comming from was to have my hand around the collector as my wife started the car,, took about 1 sec to find it

 

[moooosestang]

What’s the length of the flanges? I measured the distance on belt sander at the middle of each roller and I’ve got 14.5” of flat surface. You might be able to fit it on a belt sander and since you’re only taking material off the middle, you’re not actually using the whole surface area of the belt sander. Also, wear gloves and a mask. There’s a lot of metal dust that you don’t want to breathe in or get all over your hands. Keep a vacuum handy too.

View attachment 87877

Duh! i think i can take the guards off and get it on my belt sander.

 

[moooosestang]

ive got the same headers as dino,, mine were perfect as well,,, but.......
when i screwed up the drivers side collector to header,, i messed up and didnt have it lined up and it smashed the collector and theres a gap,, soooo since i wanted to drive the car asap,, i got me some jb weld high heat epoxy stick and put it around the gap until i feel like dropping the exhaust to fix it, i also used the flat side of my bbk header gaskets to the head , mine dont leak at all there,, the only way to tell where it was comming from was to have my hand around the collector as my wife started the car,, took about 1 sec to find it

If i had of used the bbk gaskets i'd probably not have had a leak, but they are prone to blowing out. The oem gaskets will not burn out, but it needs to be very flat to seal correctly. Someone to start the car would have been nice. I'm not going to ask my wife to do it when she gets off work, i'll never here the end of it. "what the hell are you doing to that car now!".

 

[Robert Larimer]

Now I see why my Mac shorties for the 3.7 had separate flanges for each cylinder. It makes flatness only important on each flange, not across the entire header. Why don't more companies do that? Mine have been leakfree for over 7 years and were not even retightened after the install. I used OEM Ford gaskets.

 

[moooosestang]

Now I see why my Mac shorties for the 3.7 had separate flanges for each cylinder. It makes flatness only important on each flange, not across the entire header. Why don't more companies do that? Mine have been leakfree for over 7 years and were not even retightened after the install. I used OEM Ford gaskets.

This is a good question and i don't have a good answer. Some suggest cutting a notch in between each flange called a kerf i think. this allows the flange to twist a bit. If you check each port with a small straight edge they are all flat. I noticed the hooker shortys have big holes cut in between each port which probably allows them to flex a bit as well.

 

[Jwood562]

If i had of used the bbk gaskets i'd probably not have had a leak, but they are prone to blowing out. The oem gaskets will not burn out, but it needs to be very flat to seal correctly. Someone to start the car would have been nice. I'm not going to ask my wife to do it when she gets off work, i'll never here the end of it. "what the hell are you doing to that car now!".

damn you bring up a good point. are the BBK gasket prone to blow out because of the loose tolerances in their flange flatness? like beacuse of a high spot in the center of the header flagne, their own gasket may seal it but are subjected to higher pressures because of the flange clearance? food for thought

 

[JC SSP]

I have had no issues with my BBK shorty headers on my 05’ GT. I initially used the BBK gaskets but within a couple of years driverside blew out. So I replaced both with steel ones and have never had a problem.

BBK gaskets are just like most every other commercial gasket included in a header kit… bonded layers of fibers, paper, pulp, fabrics, etc. they are not the best quality and do not last very long.

30 years ago I used to soak these “paper” gaskets in water overnight. They would immediately dry with the heat and seal better but sooner than later they would deteriorate and blow out.

Avoid the headaches and use quality gaskets.

 

[moooosestang]

damn you bring up a good point. are the BBK gasket prone to blow out because of the loose tolerances in their flange flatness? like beacuse of a high spot in the center of the header flagne, their own gasket may seal it but are subjected to higher pressures because of the flange clearance? food for thought

right, it will seal up a big gap, but that gives the hot exhaust gases more room to push it out.