STUMPED: Mark 4 exhaust problem

[Tennessee Tim]

I know I'm a little late to the party, and this may be a stupid question, but are the elephant ears installed? I recently fit my body and when I test fit the pipes, I ran into the same issue. However, once I installed the elephant ears, it pulled the opening out enough to make for a decent fit. I ended up only having to make some minor tweaks to the cutouts.

Just a thought...

Tim

[Michael Everson]

In my case, yes. They were installed. Look at the pictures though. No way to make up that 2 inches.

[evvander11]

Originally Posted by Tennessee Tim

I know I'm a little late to the party, and this may be a stupid question, but are the elephant ears installed? I recently fit my body and when I test fit the pipes, I ran into the same issue. However, once I installed the elephant ears, it pulled the opening out enough to make for a decent fit. I ended up only having to make some minor tweaks to the cutouts.

Just a thought...

Tim

Not a stupid question Tim! In my photos they are not installed but we did flex the body out as if they were. As Mike said that alone wouldn't make up the ~2" that the pipe is off. Compounding the issue is that it's the drivers side which raises under engine torque.

[BULLITT428]

I just wondering? I'm not close to putting my body on yet but just the same wondering if this is an issue with both BBK and Hooker Headers? I have Hooker Headers with a Dart Iorn Eagle 351 block?

Ed

[Zaphod]

Sorry for jumping in here without a previous introduction.

I am not yet building a FFR roadster - I'm still at the stage of convincing my wife that I am not completely insane for wanting to do so. It's a work in progress.

Having said that...... For me, as a potential first-time builder and FFR customer, this issue of incorrect fitting of headers is something that frankly gives me pause. Particularly the sense I get that FFR isn't trying to get ahead of the issue and discover the root cause.

I hope that all you guys with fitment problems get them worked out. I don't think it should be necessary, in a well-engineered kit, for the builder to have to resort to grinding header flanges, installing wedge spacers, getting custom headers, or any other similar time-consuming and costly solution. I will be following this thread to see if you guys find a solution, and if FFR is part of the solution. Good luck to all of you and thanks for all the great info on the boards.

--Tom

[gyow]

I have the same problem. I have a big block with 4 into 1 headers. They are hooker headers. Chasis number: 7669. Does anyone have a solution for this? Does anyone have pictures of what the finished body looks like after making the cutouts larger?

Greg

[Rickster]

Ive been out of the game for awhile, but is it possible the headers need to swap sides? I seem to remember they had an ever so slight bend on the straight pipes..?

[gyow]

Rick

In my case, the big block headers are unique from left to right.


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[Michael Everson]

Based on those pictures, that's going to be a tough fix. You cannot move the engine and tranny because the passenger side is already very close to the fender flare. How does it look if you rotate the engine so that both sides are even height wise?
Mike

[Sn8keman]

Car is almost done and this is my first post - but yes I have this exact problem.

302 SBF engine with Edelbrock E-Street heads, Energy Suspension motor mounts that are nicely seated on the frame mounts with pins in holes, motor is level to within 0.1 degrees according to digital inclinometer, both machined faces of the heads exhaust ports angled down at 15.4 degrees (or 74.6 degrees from horizontal), body fits 'perfectly' on frame with all measurable points well within 1/8" all around - including the top of the two exhaust cut-outs which based on my ride height happen to be 11.5" each above the floor - BUT - the passenger side BBK header tip must drop 1" and the driver side must drop 2" to avoid cutting glass.

Measured the angle of the headers from the facing of the engine-end flange to the long straight part of the tubes and found the passenger header to point downwards 11.1 degrees and the drivers side 4.6 degrees. Even with the 20" versus 22" header length difference that angular difference seems too much. Asked FFR what the angles of the headers should be yesterday and am awaiting response.

In meanwhile talked to a few local 'hot rod' shops and the generally agreed and least intrusive way forward they suggest would be to mill a bevelled wedge to place between the heads and the headers, then install studs to allow a little flex in the fasteners in lieu of milling a relief where the fastener head hits the now angled header flange surface.

Am thinking to start with a pair of these Jegs header plates and go forth . . .

31812 - JEGS High Performance

[gyow]

I was able to improve my header alignment to the body by tilting the engine on the driver's side, but the pipes are still too far forward. See below for the best alignment I could even out between the passenger and driver side. I contacted F5 and they sent me another pair of headers. The alignment on the driver's side improved about 1/4". But the headers they sent me only had 4 mounting holes, not 8. My conclusion is that hooker has quality control issues on these headers. Maybe there is a design issue as well. F5 is supposed to send me another set of headers.

[Michael Everson]

snakeman. I wouldnt use the flanges. I would just mill the proper angle right on the header. thats how I fixed mine. If you use the spacer, you will have 2 gaskets to potentially blow out as well as longer studs to buy.
I tightened up my header and measured it with a digital angle finder. I then loosened the bolts until the header dropped to the right height and measured the angle again. The difference is what I milled off the face of the header. Worked perfect.



GYOW. There was only four bolt holes on the head side of the flange? I wonder if they were for a different engine?

Mike

[lmmargheritis]

Not surprised at all about the quality control issues given the fact that there are so many issues with fitment but this is pretty strange and says a lot about the "give a shit" of the manufacturer. How do you only get 4 of 8 holes in the header flange? I thought the header flanges were a given for fitment.

Originally Posted by gyow

I was able to improve my header alignment to the body by tilting the engine on the driver's side, but the pipes are still too far forward. See below for the best alignment I could even out between the passenger and driver side. I contacted F5 and they sent me another pair of headers. The alignment on the driver's side improved about 1/4". But the headers they sent me only had 4 mounting holes, not 8. My conclusion is that hooker has quality control issues on these headers. Maybe there is a design issue as well. F5 is supposed to send me another set of headers.

[Ringo222]

I just ordered a kit and questioned the driver side fit problems on the 302 headers. They told me most are fitting fine just some oddballs popping up. Has anyone who picked up a kit recently had the driver side headers fit on a 302?

[Tennessee Tim]

I may be an oddball, but my headers fit very nicely. The exhaust cutouts required only minor trimming, and header height was the same on both sides.

Tim

[Bob Pedley]

I had the exact same problem and used a large C clamp to pull the engine and motor mounts down into the frame. It took several tries but the final result was good. My frame number is 7475

[gyow]

Here are the headers without the mounting holes for those that are curious.

[Michael Everson]

Never seen a flange like that.

[Avalanche325]

Originally Posted by gyow

Here are the headers without the mounting holes for those that are curious.

It looks like the welds aren't finished.

[Bart Carter]

Originally Posted by Avalanche325

It looks like the welds aren't finished.

Headers tubes are typically welded to the flange on the inside. The outside welds (if any) are for extra support, usually top and bottom because the sides need all the bolt clearance they can get.

[Sn8keman]

Michael Everson - agreed that I wanted to just machine the actual header flange rather than machine a wedge for all the reasons you pointed out.

But - in the case of my drivers side I will have to machine 10.4 degree angle which will taper the flange thickness from 0.375" at the very top to 0.171" at the very bottom, so was concerned about eventual warping and loss of sealing on the lower edges of the gasket surface.

Figure that a tapered wedge 'sandwiched' between a full 0.375" header flange and the head will survive better and I will just have to live with the possibility of double the exhaust leak opportunities.

[Wayne Presley]

Sn8keman, do you really have to move the outlet 4.12"???
header length 22.5" x Tan 10.4° = distance moved of the end of the pipe.

[Olli]

Forget the FFR headers. Garbage Hooker QC. Junk.

Get your headers from Stainless Headers. If you want the fit perfect get their mock up header and now fit your sidepipes absloutely perfect. Send the mock up back to them and they build YOUR headers.

Olli

[Michael Everson]

Wayne. I was thinking the same thing. I moved mine 5.5 degrees. 10 is way too much.

[gyow]

F5 has been good to deal with on this issue. I talked to Hooker headers today. I told him about the issue with the headers being too high and too far forward. I asked if they could measure my original ones against ones they had in stock. The answer was that they didn't. It seems odd that they have no way of measuring what they make for quality control. At any rate he is going to try and figure something out.


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[Gopher]

What Olli says I help Stainless develope the system it works .Why fight the it .There prices are very reasonable and they garuanty the fit.

[Steve1979]

For those of you in the process of building and want to know whether you may be heading towards this problem, watch for the following. With the body off, engine in, headers on, put your side pipes on and level them to the side of the passenger box. Now, install your hangers (or try to), with them on you should have about a 1/2inch gap under the 2x2 foot box frame. That is, the hanger should run parallel to the bottom of the 2x2 frame with about a 1/2inch gap between the frame and the hanger. If you cannot put both bolts through the hanger into the sidepipe without hitting the frame, then your header is most likely high and with the body on you will not be able to bolt them up.
Another quick measurement with the same idea in mind, is to see if the sidepipe muffler is above or below the 2x2 frame. The muffler portion should be about 1.25 inches below the 2x2 frame.
This will only tell you how the headers fit vertically (up/down). To find out how they fit in the horizontal direction (front to back) you will need to put the body on.

I talked to FFR before even having the body on, about this problem I was having, back around 4/2010. My original kit came with Hookers, which were really bad on both sides. I went through 3 different sets of BBK’s where the driver’s side was too high. I was even told at one point it might even be the way the side pipe flange was welded, so they sent another one, did not change anything.
What I was able to figure out in the end is that the driver’s side header has the wrong angle at the head flange. The driver’s side header even being longer by 2” inches should be almost at the same angle as the passenger side (about 1 degree less). My passenger side angle at the flange was about 79* (if you use the top two tubes as a reference). My driver’s side was about 85*. Over a length 22 inches, that 5*'s moves the tubes up over 1.750 inches at the end. After explaining what I thought was wrong with the driver’s side header angle to someone at FFR, I asked if they could check the master template headers or print to see what the angle was suppose to be. They told me that the originals were mistakenly sold and he could only go by what they had in house, which was the same as what I had.
So the next thing I did was call BBK and talk to a sales/tech guy. He said that they have a jig that is used for the header builds and it was made by whatever header that was supplied by FFR. I asked him them if I could buy an uncoated set from BBK because I wanted to possibly cut or torch the tubes to bend them because they are just made wrong and he said they were made in batches and I needed to contact FFR for something like that. I was able to buy a sidepipe end flange from them for what I did next.
Long story short, I had a muffler shop torch the tubes so they could be bent a little down. What this did was put it in the ball park, so next I cut the original flange out with a dremel and cutoff wheel. Setup my side pipe where I wanted it, and with the flange not welded yet I was able to move it around for a pretty close fit. I tacked it in place and had a muffler shop finish the welding inside the flange.
This work out fine with the body on, did not need any wedges or shims, but after I brought it in for paint and hidden body mounts, I guess the hidden body mounts caused a shift in the sidepipe cutout (of course). In the end I figured out another way of bending the tubes in the directing I needed to go, used two very thin wedge to move in the direction I needed to go.

I do wish a vendor would sell an uncoated set of headers without the lower end flanges welded in place. It would be a lot easier to bend the longer straight tubes without the flange welded and you could also then move the flange around for better fitment and have them welded later. Once complete you could then have them coated.
My thoughts,
Steve

[Gopher]

This is what the adjustable setup looks like. With all the adjustability built into this you can see how you can over come your problems. Stainless headers has the solution to all the side pipe nightmares.

[Sn8keman]

Wayne, Michael - shortly after my last post I realized I had made a math error in calculating my angle (radius vs diameter - almost too embarrassing to admit) - but once I got it right I basically have to mill it half as many degrees as I stated. But thanks for you guys being on your toes and so helpful!

Will steal another KISS idea from Michael and simply torque the headers on fully, measure angle with digital inclinometer, then loosen bolts until side pipe fits as desired and re-read angle. Probably more accurate in that I can actually see the exact fitment of the side-pipe in the body cut-out this way (and even I will be able to do that subtraction math)

[Sn8keman]

So after some back and forth with FFR, they are unable to help me with the header issue because my headers are to spec - so trading headers will get me no where. I am off to the milling machine. . .

As an FYI - here's how they determined my headers were to spec. They sent me the attached pictures of how they check their headers and asked me to repeat the test on mine and mail them back the pictures. My headers were within 1/16" and 3/16" respectively so not going to do anything about my missing the cut-outs by close to 1" on one side and 2" on the other.