2nd gen Explorer V8 headers

i am frustrated with Bob of TMH. i have been trying to get him to build me a set of his newest edition, the 1-1/2 to 1-5/8 stepped headers for my Mounty. we have talked on numerous occasions over the last 4 months and i still have no real date. communication is terrible. he has never called me back and 1 out of 10 times i try to call, he picks up. to his credit, he told me he wouldnt take a penny or promise shipment until he had a perfect set of headers. but i am putting my new engine in in 1 month and i need some friggin headers and the standard TM's won't flow enough.

well, necessity is the mother of invention, so i decided to come up with my own design. i did this before on my 351w based mounty project and it turned out well, so i thought i would give it a go with the 302 engine. so, i started by measuring and building the engine and engine bay obstructions in CAD. then, i designed my headers in 3D. gotta say they are pretty nice! i used a 1-5/8 primary to a 4 in 1 collector with a 2-1/2 exit, 2 bolt flange and a ball flange gasket donut. they exit near where the stockers do, but without a set of stockers in hand, measuring through the wheel well openings is the best i could do. doesn't really matter, because to take advantage of these headers, i will need a custom 2-1/2 y-pipe. the pipes all run down from the head flange. none of this up and over crap and no 2 piece bolt together primaries.

i am very satisfied with the clearances around parts and there are no kinks around the steering shaft. the DS header should go in easy enough with only disconnecting the steering shaft from the column and swinging it out. the PS header may be more difficult. hard to tell without actually trying it. it may have to go in from below by removing the starter, which wouldnt be so bad. the only sticky point is i dont think the dipstick will route through its normal path, but a SN95 mustang dipstick might work. easy enough to mess with after the fact.

ok, so my question here is would anyone be interested in buying a set of these for their 2nd gen? it would be nice to have an alternative to TMH, but i won't put in the extra effort to test, productionize and have them professionally built if there aren't any takers. this isn't a call for money or commitment, just an indication of potential customers. i will do my best to keep prices in line with the competition, so plan on 700-800 for a set with all the hardware and gaskets. maybe even a new dipstick and tube if needed. 1 size will fit all for these head flanges...same as every other aftermarket mustang header on the market. i think even the bung for EGR would be there regardless. i would just sell a longer flexible EGR tube separately (since the location would be farther away than the stocker).

here are some teaser pics of the model...

 

[ahodges]

I was thinking here again. I have AFR 185 heads on mine. Will the flange be different for all of these different heads? I know that felpro makes a gasket to fit the the ports on the 185's perfect. I can't remember the part number off the top of my head.

 

[pufferfish]

i can't find difinitive proof, but some searching indicates the afr185 and tfs190 use the same felpro 1415 gasket.

i am not planning to offer multiple flanges. TMH is the only header manufacturer to do this and there are only 2 options: small with the bolt holes centered with the port or small with the bolt holes offset 1/8". bob from TMH explained this to me a few years back. the gt-40 heads (not the p), positioned the bolt holes offset of the center of the port (can't remember if it was up or down). every other head, including aftermarket, had them centered. when you order specifically for afr's, you get the p head flange. if you order for edelbrock's, you get the p head flange. regardless, the flange's port shape was always the same.

the rest of the aftermarket doesn't worry about this because their flange ports start off larger than TMH's. so no differences in head port size or bolt hole location will produce a lip for the exhaust gasses to have to work around.

 

[ford99_1979]

ford99_1979,
i just looked at your cardomain. is that the stock intake elbow attached to that TFS intake? if so, that is your first point of restriction. you have to dump it (i know there are no options available...yet). again, pulling from mustang experience, the 347 with those 190 FAC heads needs a 75mm tb and an elbow to match. the MAF should ideally be >10mm larger than the tb. remember, it can only expell as much air as it brings in. you'll probably find 20hp on the intake side without changing the exhaust.

I hear you on the elbow. It measures 70mm. on both ends IIRC. and I have an Accufab 70mm TB which helps return the throttle cable and cruise control etc. I had to cut and relocate the TB arm to match the push or pull throttle cable arrangement unique to the explorer.

Yes there is more than one bottleneck on my truck..... I have not seen a larger diameter elbow for this application that retains explorer throttle and cruise cable set-up. Someday I may look into it a bit more.

Re flange: Bob referred to the flange as Windsor type.

 

[pufferfish]

when i did the 408, i made my own elbow from 2 plates and a 3" exhaust tubing bend. i used a 94-95 BBK 75mm TB and grafted the stock explorer lever onto it. throttle cable and cc cable both mounted up perfectly with the original explorer bracket holding them. i had to make a few changes to this arrangement to make it work with the 347. the longer aftermarket intakes compared to the gt-40 makes the TB sit father out towards the passenger side, which makes the side mount IAC hit the oil fill tube. this wasn't an issue on the 351w block because the head was also farther out. so, i epoxied the IAC holes on the side and added a small mounting plate to the top with the same epoxy and drilled into the passeges to allow communication to the IAC in its new top mount location. its ugly, but it works. it also unshrouds the TPS, which is normally a PITA to adjust.

i also had to make a few adjustments to the elbow. particularly in the EGR department. the 408 was in a 98 with external EGR. the 347 is in an early 97, which has internal EGR. i cobbled together something to allow the EGR valve to exist in a relatively stock location and mechanically function so i don't trip codes, but it doesn't move any exhaust gasses through it.

if i find some time to rebuild the elbow, maybe i will make some extras

 

[ford99_1979]

Sounds like you covered all issues with the elbow you made. Make some extras. Haha

 

[pufferfish]

if i could find the perfect throttle body, that would be key to making it work. my epoxy job is fine for now, but it looks terrible and i never want to repeat it. any ideas? a 94-95 mustang TB without the IAC boss would be perfect (i can plumb the IAC into the elbow), but i can't find one. fox body TB's rotate the wrong way. any ideas? even chevy boy TB's are welcome if they will work!

 

[CDW6212R]

Another member(Ryan) here custom made an elbow also with 3" pipe, but he cut up the Explorer elbow to use the EGR boss, and both end plates. I tried to find his build thread showing it, but I couldn't find the right search words.

He used a 75mm Accufab TB for 86-93 Mustangs. I have that TB too, as does Andy on his 347. Ryan did that for his 302 in a 92 Explorer, very slick work. He also had to cut/weld the Explorer TB arm for the 75mm TB, but everything bolted up right.

 

[pufferfish]

so, the fox mustang TB does rotate the right direction to keep the throttle cable in the same location? i need to look into this.

 

[pufferfish]

this is my hodgepodge elbow and TB

 

[CDW6212R]

The examples of the members posting here all have the Explorer TB bracket and cables, EGR and computer/wiring. It's all stock parts from their trucks. They just altered the TB lever by welding a piece of the Explorer TB onto it. Not everyone does use the Fox TB, I found Ryan's thread where he showed how he made it. In his truck's thread, he used a 94/95 TB, and what looks like an Explorer bracket mounted flipped over to the right.

We can hunt the pictures of them in their threads. The custom elbow that Ryan made was the nicest, since he managed to carefully cut just the EGR boss and end flanges off cleanly. He did a lot of fitting to make the 3" pipe butt to them, and had a welder attach them. I have not saved any of those pictures, I guess I should. I had my elbow ported well, and myself opened the end to match the 75mm. It is obviously not ideal, I just wanted to get started. Fabbing a better elbow is the right way to do it.

Here's a link to Ryan's elbow thread, and I bumped it.
http://www.explorerforum.com/forums/showthread.php?t=328687

 

[ahodges]

Yep I used a BBK 75mm TB made for an 86-? mustang. It doesn't have the correct pull on it but it isn't that big of a deal to change it to pull from the bottom side towards the front of the truck. The IAC mounts on top. This is rotated 90 degrees from how it is used on a mustang. I wish I would have taken a picture of the TB and elbow. I also used the stock elbow, blocked off the EGR port, and ported it out to 75mm on the TB side and 70mm on the supercharger side. I did my best to carry it throught the 90 but I'm sure it isn't perfect.

 

[pufferfish]

that engine bay looks good! i checked out some aftermarket fox mustang TB's and some have bolt on levers. that would be awesome! since i am a sheet metal kind of guy, i could easily create a new lever to work perfectly! i think i am going to buy a new 75mm and clean sheet my elbow. just added one more thing to my ever growing list!

 

[ahodges]

that engine bay looks good! i checked out some aftermarket fox mustang TB's and some have bolt on levers. that would be awesome! since i am a sheet metal kind of guy, i could easily create a new lever to work perfectly! i think i am going to buy a new 75mm and clean sheet my elbow. just added one more thing to my ever growing list!

Thanks! Let me know about those elbows as well as the headers when you get around to selling them!

 

[pufferfish]

i ordered a TB and brought the original elbow into my office to get dimensions. im going to get it into cad and then put a deign together. i would like to be able to develop one elbow to work with both EGR styles. we will see.

as for the headers, i am in the middle of getting prices to have them 3D scanned so i can get them into cad and develop the final product. i have been thinking about how to self-manufacture them. i have some ideas. i already had a tube "shaper" made up to form the tube ends to match the rectangular flange shape. i need to create 8 fixtures to repeatably weld up the primaries. i also need a cutting jig so that the pipes are cut to the right length and angle. this is all a huge challenge! it will be fun!

 

[tmsoko]

Great progress! Your headers are looking real nice. Something I learned when I made mine was to use band clamps at the joints. Made it a lot "stronger" while mocking up and easy to twist things to fit as you go. These are going to be excellent!

 

[pufferfish]

do the band clamps work for bend to bend coupling? one handy part about painters tape is that once you have it set where you want it, just slit off a strip on either side of the pipe to reveal the metal butt connection so it can be tac welded together.

 

[tmsoko]

They worked pretty well on all joints. It got a little tricky when I used sections from the "donut" bend that had a bend radius equally to tube diameter, but otherwise good.

Yeah, the tape is good to allow immediate tack welding as you said.

Everything has its good / bad points.

Looking good!

 

[pufferfish]

well, the mockup headers are going to get 3D scanned next week. they get scanned in a couple of hours, then they need a couple of weeks to compile the scanner data into a model. in that time, i will be full welding them up and start getting my exhaust system mocked up. making progress!

also, i have been gung ho on this elbow and throttle lever for a fox TB. the lever was cake. got a drawing made up and just need to find out how much my sheet metal fabricator will charge to make them. the elbow is a bit trickier. i started with billet aluminum flanges, since the 97 has internal EGR passages. the quote back was ridiculous. my cost in having parts made was over $500/set. thats before welding labor and finishing! so unless y'all want to pay a grand for a 75mm elbow, it isn't happening. back to good ol' sheet metal. the 98+ is easy. just a mount and a single communication port from the EGR valve to the inside of the elbow. even got mounting points for the whatchamajiggers that control and monitor the EGR valve. the 97 is harder, since it needs one port from the upper intake to the EGR and then a second from the EGR to the inside of the elbow. looks like my thought of having one for both versions is no bueno.

 

[CDW6212R]

That's good progress, I hope it all goes smoothly. I look forward to how the parts all turn out.

 

[tmsoko]

When I did my 90mm throttle body elbow, I took a cast aluminum explorer elbow and cut off both flanges with my bandsaw, then took an off the shelf cast aluminum 3.5" elbow I got on eBay cut it down a bit and then welded it up.

Something like this: http://www.ebay.com/itm/170338907236?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649