Exhaust leak after shorty header install

[moooosestang]

So maybe it's not so obvious in the video. The engine noise and ehaust is drowning it out some, but it lasts for about 25 seconds and starts a couple of seconds after a cold start. it is even more obvious with the hood closed. So what are my options? i can't tighten the bolts anymore, shit is tight! i could remove the header, spray the gasket with some high temp rtv or possibly add another gasket and spray both. I feel like just removing them at this point. I'm not all that impressed with the throatier sound at low rpms. The deeper tone at idle is nice. Can't say i feel anymore power either, but the car is running a 3.25 inch pulley so probably not going to feel a few horses at any point in the power band.

 

[moooosestang]

my current plan is to pull the drivers side header, check the flange with a straight edge, spray copper seal on both sides of the oem gaskets and reinstall. i'd really like to give these time to grow on me. Anyone shopping for shorties i think i'd avoid the pricier tuned length if you are just looking for something that looks nicer than stock. these really changed the tone at idle and part throttle and not so much for the better at part throttle imo.

 

[Badd GT]

Getting aggravated yet?

 

[moooosestang]

So i narrowed it down to the rear of the header using a piece of flexible conduit up against my ear. it's either that collector, 02 sensor or the rear most port. I'll try soapy water again tomorrow before i remove anything. here's a rev to 3k. i like the sound from the back, not sure i love the sound inside the car though. Will driving the car damage anything? i can't hear any leak while driving.

 

[moooosestang]

Getting aggravated yet?

Not yet, haven't even started cursing. i'm 50, way past aggravated. if i get aggravated it will be on the 6 o'clock news.

 

[moooosestang]

It's not that hard to install these. suspension work is more aggravating. it's time consuming with no lift but i could pull one out now in an hour i bet. i need some new bolts for my aftermarket motor mounts because tightening those motor mount bolts with vice grips was the must frustrating part. no way to get an allen socket in there, not even a cut down allen key would work.

 

[xeninworx]

I used a belt sander https://www.homedepot.ca/product/ryobi-120v-4-inch-by-36-inch-belt-disc-sander/1000747387 like this to grind the flanges flat without taking off too much material and a Felpro gasket that came with my AFE power headers. I have a V6 so the headers fit perfectly on top the sander. Never had a leak.

 

[JEWC_Motorsports]

What gasket did you use?

 

[RED09GT]

Can you feel where it is pulsing from?
I had a similar noise, it ended up being between the connection of my exhaust manifold and the Y-pipe for my turbo. It only lasted 30 seconds or so as the Y-pipe heated up and closed the gap.

 

[moooosestang]

Has anyone had that flange leak with shorty headers and stock mid pipe? The collector on the bbk headers is a lot larger than the stock one

What gasket did you use?

oem steel gaskets made by Mahle.

 

[moooosestang]

Can you feel where it is pulsing from?
I had a similar noise, it ended up being between the connection of my exhaust manifold and the Y-pipe for my turbo. It only lasted 30 seconds or so as the Y-pipe heated up and closed the gap.

I couldn't feel anything the first time i checked it, but it heats up so fast. I should be able to pinpoint it now that i know it's in the rear.

 

[moooosestang]

I used a belt sander https://www.homedepot.ca/product/ryobi-120v-4-inch-by-36-inch-belt-disc-sander/1000747387 like this to grind the flanges flat without taking off too much material and a Felpro gasket that came with my AFE power headers. I have a V6 so the headers fit perfectly on top the sander. Never had a leak.

i've got a belt sander and lots of different grit belts. I hope it doesn't come to that. I'd probably fix one leak and create another.

 

[xeninworx]

Maybe try a different gasket like Felpro. MAHLE gaskets are good if your flanges are completely flat and no warping. Felpro is a little thicker so it would seal better with a slightly warped flange.

 

[JC SSP]

When you remove the header measure the collector diameter and then measure your factory H-pipe. I recall, when I had my custom aftermarket H-pipe made my muffler guy put a reducer insert inside it... Once I installed the BBK shorties I got rid of those.

I will look for the reducers at my warehouse and post pics if and when I find them...

 

[moooosestang]

Maybe try a different gasket like Felpro. MAHLE gaskets are good if your flanges are completely flat and no warping. Felpro is a little thicker so it would seal better with a slightly warped flange.

Yeah, kooks has one that is metal and looks thick, gets good reviews. i might try that. first i'm going to put some copper rtv around that flange and around the outside of the o2. that should rule them out.

 

[JC SSP]

Yeah I used Kooks aluminum header gaskets PY-8023A-AL

Also, did a little copper seal spray on both sides... no leaks after several years.

 

[Midlife Crises]

I have been using the cooks aluminum flange gasket sense 2011. Had them off a couple times. Scrape them clean and tap them flat then put Hi temp silicone on both sides and tighten the headers up evenly. No problems. With leaks.

 

[Jwood562]

I have been using the cooks aluminum flange gasket sense 2011. Had them off a couple times. Scrape them clean and tap them flat then put Hi temp silicone on both sides and tighten the headers up evenly. No problems. With leaks.

good to hear, this thread has been scaring me! I have a set of bbk shorties about to be installed. then i heard the BBK gaskets can fail, so i bought kooks. then some people said mahale would be best, so i bought those too! after looking at them, Im gonna run the kooks

 

[moooosestang]

good to hear, this thread has been scaring me! I have a set of bbk shorties about to be installed. then i heard the BBK gaskets can fail, so i bought kooks. then some people said mahale would be best, so i bought those too! after looking at them, Im gonna run the kooks

lol! i ordered the kooks gaskets just in case. i didn't have time Wed. to look at it, but i should have a good idea this afternoon if mine is leaking at the gasket or flange/o2. it's nothing to be afraid of, it will get sealed one way or another. in the future if the header flange warps and starts leaking i'll have the kooks on hand to swap out. i'm going to drop the mid pipe and put high temp rtv on the collector. seams to be a common leak area with shorties when using a stock mid pipe. Here's a tip. if you can get all the upper studs out, do it, leave just the two outside lower studs to hang the gaskets and headers on. using a dap of copper rtv to hold the gasket to the head wouldn't be a bad idea either. just enough to make it stick. Trying to get the bbk's over both top and bottom studs requires jacking the motor way, way up and even then it's tight! The passenger side lower rear most stud will hit the tube on the bbk tuned length shorties, but if you just file off a millimeter it will clear. no need to remove that stud.

 

[msvela448]

Kooks aluminum gaskets are great... I also love the Percy's dead soft aluminum header gaskets (basically the same).

But every pair of aftermarket headers I've owned (and some OEM sets) needed to have the flange sanded or machined flat. I had to take my Kooks long tubes to a machine shop to mill the flange flat. When I sent pictures to Kooks of the warpage, right out of the box, they refunded enough money for me to cover the machining.

I would also suggest buying grade 8 studs, stainless steel or zinc coated, from BelMetric... If I recall they are M8x1.25 and 50mm length... That way you'll use the entire depth of the threads in the head. I torque mine to about 20 ft. lbs. You can get also get the matching zinc coated or stainless washers and nuts from BelMetric.

https://pertronixbrands.com/products/patriot-exhaust-66081-seal-4-good-ford-5-4-4-6l-3v-oem

https://kooksheaders.com/accessorie...e-header-gaskets-46l54l-3v-cylinder-heads-mla

https://belmetric.com/m8-full-thread-stud-din-976-class-8-8-steel/?sku=S8X50FCLZ

https://belmetric.com/m8-full-thread-stud-din-976-stainless/?sku=S8X50FSS





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