JBA Shorty Headers on 4.6 DOHC from 2004 Mach 1

[Alan_C]

Anyone out there successfully fit JBA shorty headers to 2003/2004 Mach 1 DOHC engine for the roadster? I was unable to locate a set of the Ford Racing shorty headers for this engine, so I went with the shorty headers from JBA. I was test fitting the headers and I see two issues. On the passenger side of the engine, the lower tube from cylinder 4 hits the engine mount. The amount of interference looks pretty substantial, I would estimate 1/4 to 3/8 of an inch. On the drivers side, I would need to cut the header flange in the center between cylinders 6 and 7 to make room for the dip stick tube. The mod for the dip stick tube looks easily doable, but the engine mount issue is more significant. I might be able to have a header shop bend the tube enough, but I am concerned about restricting the flow. If anyone has made these headers fit, what was your solution? Pictures if you have them would help.

Thanks, Alan

[Alan_C]

With no response to my original post after 100 plus views, I figured I was pretty much out of luck. Before taking the OEM exhaust manifolds to have them ceramic coated, I figured I would look at the clearance issue one more time. Attached are two pictures that show the interference issue between the header and the engine mount on the passenger side. My theory for a solution is to replace the rivet in the motor mount with a weld and cut off a section of the mount just above the rivet all the way across at the crease. A weld the full width of the bracket should have enough strength and cutting off the section below the crease will provide sufficient clearance. I will have to reshape the heat shield though. On the driver's side, I will have to cut the header flange between the 6th and 7th cylinder exhaust ports to make room for the oil dip stick tube. I really want to keep the JBA shorty headers, so I hope I can make the modifications work.

[rick8928]

Alan,
Sucks to get no responses to a post, so here's one:

Go for it regarding the welded mount. On the driver's side, can't you mod the dipstick somehow to preclude having to muck with the header flange?

FYI, I'm about to finish my '04 Mach 1 donor based Mk IV today. Just need to re-attach front elephant ears, doors, and mirrors/visors/wings. Here's where I'm at now and you will be at some point:

[Alan_C]

Rick: Thanks for the reply, it appears I am the first to try to fit the JBA shorty headers to the DOHC engine. I am a bit surprised that I am the first, but I guess someone has to do it. Regarding the oil dip stick tube, I may be able to bend it to clear the header flange, but I am also concerned about heat transfer to the tube cooking oil within it. If I cut the flange, I can obtain a little bit of isolation between the tube and the header. Good to hear you are finishing up your build. Your build has been one of the ones I have watched the most since it is so similar to my own. You can't go wrong with the classic color combination you chose. I visited J Miller Customs a few weeks ago and talked with Jeff regarding paint for my car. I am looking for a color combination that is a little different, black cherry body color with dark metallic gray stripes. I expect to be in paint next summer.

Alan

[rick8928]

Alan,
Responded to your PM.

You know, I thought about other colors but in the end, blue with white stripes is the color combo I've had in my mind ever since '65 when I was 11 years old, had a cobra slot car that I used to race at the town's slot car racing emporium, and read that the Cobra team beat Ferrari for the world championship. It only took 47 years, but now I've got one!

I'm sure "the bat" would give you a perfect paint job, but if you're interested in saving money you might want to check out local auto body vocational training schools. I got my paint done for cost ($1500) at a local high school. It' s not perfect, but some of that was due to my timing (my build schedule ran right up against the end of the school year, and they had a lot of projects to finish before lights out). Besides, I was gonna settle for a rattle can flat black paint job in my garage, so this is perfection compared to that.

I'll finish loading any additional build pics plus some vids in my photobucket folder over the next week, so you can vicariously picture yourself next year at this time!

Good luck, and feel free to ask me any other questions and I'll try and help.

[Alan_C]

To all who might be considering the JBA shorty headers for their 4.6 DOHC mod motor build. I have tried, but the JBA shorty headers are enough different that I would not recommend to anyone else that they try this. The last straw was when I determined the drivers side header does not place the connector to the J-pipe in the same position as would the stock manifold. I do not have capability to modify headers to make them fit. For anyone who wishes to try, I will sell my set of headers with the drivers side header flange modified to not interfere with the oil dip stick tube for $300.

[RE63]

I have found it best to use the stock headers..Sandblast and paint the orginals and reuse them, I have had aftermarket headers leak. Nothing drives me crazy like an exhaust leak.

You haven't lived until you have removed the headers ona 4.6 roadster with the motor in..

again, I would recommend reusing the originals

Sorry I didn't chime in sooner.... I did not see your post until now.

headers for this are being sandblasted now.

[Alan_C]

Ron: Thanks for the feedback. Looks like we both had the same thing in mind for the engine, looks like twins to me. I will be sending out my stock manifolds for ceramic coating later this week.