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...

 

[CDW6212R]

http://www.superchevy.com/technical/engines_drivetrain/exhaust/0505phr_exh/

I found this article informative^^^
Exhaust discussions are always interesting.

That's interesting, but it's seriously complicated and misses the biggest issue for street vehicles.

The tuning issues are all factors related to the engine and everything forward of the collectors.

The key point that almost everyone does not get is that nothing beyond the collector* does anything except increase back pressure(and change the sound).
* Cross over point ideal(not back where everyone puts it(including OEM))

Tuning of an engine is done to match the engine needs(air and fuel), including the exhaust back pressure. If anything alters the airflow, new tuning is needed ideally. Back pressure is bad, it slows the flow, which means less airflow, less power possible.

Once the exhaust gets past the collector* area, there should ideally be no back pressure. That's why race cars never have anything past that if not required to by rules.

So the goal of any exhaust past the important point* is only to allow the gases out, not to suck them out. That is not possible past that one point*, so make the exhaust past that as big as will fit feasibly.

 

[QueenCitySleeper]

Ah I see. I was wondering what the idea was behind the large diameter pipes you are talking(2.5-3" ID). From what I understand, a well thought out collector can actually put a vacuum on the exhaust valves resulting in exhaust gas scavenging.

 

[CDW6212R]

Ah I see. I was wondering what the idea was behind the large diameter pipes you are talking(2.5-3" ID). From what I understand, a well thought out collector can actually put a vacuum on the exhaust valves resulting in exhaust gas scavenging.

Yes, for sure, but only at the collector area. Racers with new engines or headers, run the car at a track wide open, after painting the collectors with paint. They make the collector extra long with straight pipe, and the only proper location for a cross over is where the paint burns off the most. Racers cut off the collectors there, since they don't need the cross over. They just need to know how long to make the collectors(any shorter for them would lose power, any longer is a waste).

For any exhaust longer than the collectors for a race car, the cross over pipe should only go in that one place. Anywhere behind that doesn't create usable vacuum at the primary merge point(collector). You just want to not have restrictions beyond the cross over point.

 

[pufferfish]

well, i was wrong...the driver side was more difficult. there may be more room for the collector, but the primaries were harder. i had to redo the primaries a dozen times or more. one config worked to clear the steering shaft, but not the dipstick. the next worked for the dipstick, but not the steering shaft. then, they both fit well, but the primary was too close to the steering shaft bellows and would burn it. or there wasn't enough room to route the plug wires without burning them. once, it looked friggin sweet and then realized it was going to hit the brake line heat shield. AARRRGGG!

well, last night, i finally got a configuration that cleared the shaft and dipstick, doesn't get to close to the shaft bellows, and allows for standard plug wire routing. #2 had to be an over the top route, but it fits with good clearances. the problem is that i can't get the header in without removing the #2 pipe, then reattaching it once the header is in place. its always something!

i am going to run with it and figure out how to get it in there. if i could get the upper steering shaft to retract into the firewall, it would go in from the wheelwell. maybe an engine tilt would allow it to go in from the top? who knows. i will get it tacked up (its only held together with tape right now) and get it figured out.

for producing them, i'm now planning to self-manufacture. that company was griping about having to weld together 2 tubes per primary...i wish it was only 2 now. i have no idea how i am going to do it. it may prove to be more costly to tool up my garage than i could ever recoup. i am going to start with trying to find a company with a laser scanner CMM (coordinate measuring machine) to get the header shape into CAD, so i can develop primary tube paths and fixturing.

 

[pufferfish]

 

[R1dd1cK]

Looking awesome. I know of me and 2 others that would be interested in buying a set if it ever gets that far.

 

[CDW6212R]

Will either of the steering shafts collapse downward? I bought an early model shaft from Karl here, it;s supposed to be better than the later 98+ unit. If one will shorten when the top bolt is removed, maybe that would allow it to move aside just enough to pull it out the top(remove the bolt at the rack next). I'll go look at that shaft later, I have a dinner to go to shortly.

 

[pufferfish]

the lower steering shaft collapses and pivots out of the way. its the upper that seems to be fixed and is in my way.

 

[CDW6212R]

the lower steering shaft collapses and pivots out of the way. its the upper that seems to be fixed and is in my way.

Ah, I see.

Is it in the way just to install the header, or does it also affect where the pipes can run?

I have had to learn about the shaft components of the Mark VII's recently, when dealing with a leaking R&P. I found out that the 90-92's had the first two shaft systems of the Fox body cars. So the upper shaft would come out easily, and I found out that I could use a 94-04 Mustang shaft, to replace both of mine(with the 94-04 R&P).

I wonder if we can do something similar with the Explorer column and steering shafts. Maybe pieces from another application will help to get the upper shaft out of the way for installing the header.

 

[pufferfish]

its just in the way when trying to get the header in. once it gets past the shaft, its golden. i am going to look at unbolting the column to see if that helps. if its too involved, its not going to be the solution.

 

[ahodges]

Oh wow.. I don't know where I've been during this thread. Guess I haven't had much time to surf the forum over the summer or winter until now. If you get these headers to completion and use a 2.5" collector I would be interested. I don't know how you would practically get a 3" pipe up through the hole between the oil pan and front axle on the drivers side. My exhaust shop didn't even want to do 2.5". Since the TM headers I have only had a 2.25" collector on them he ran a 2.25" pipe for a foot to get it out of the tight spot then went to 2.5" right away.

If I get a set of these headers then I would definately change my exhaust around.

 

[pufferfish]

your exhaust shop is a bunch of whining pansies. theres plenty of room for a 3" pipe there. i did that on the 408 install. the issue is actually the passenger side. frame to bellhousing is pretty tight there.

i think if i end up building these myself, it wouldn't be hard to make them with either collector size. the exhaust system i plan on developing will definitely be a true dual 2.5" though. i am convinced there is nothing to be gained by a dual 3".

 

[ahodges]

Haha, I won't disagree there! Lol. I'm friends with them though and they did a great job overall on my system, can't complain. They are used to doing semi truck exhaust work.

 

[CDW6212R]

its just in the way when trying to get the header in. once it gets past the shaft, its golden. i am going to look at unbolting the column to see if that helps. if its too involved, its not going to be the solution.

That's very good, you can disconnect the upper shaft then for the install.

I got the box out with the shaft(s) Karl sold me. I could take a picture to show, but basically the two shafts are similar in length, and a u-joint on one end.

The upper shaft has a large aluminum/steel u-joint with one bolt to hold it on. It does not collapse, but hopefully with the u-joint unbolted you can fish it upwards out of the way. I has to go out the back if removed, the inside is bigger than the hole.

Is the lower shaft too big in any way? I don't know if an aftermarket company would make some kind of replacement for a good enough price. The bottom joint feels very much like a double cardon u-joint. I'd say that's because the angle it bends at at the rack is large.

 

[pufferfish]

well there you go...they do semi stuff. a "tight" area to put a pipe on those is under 1'!just noticed you've got a blown 347. you could definitely use more exhaust flow to make that sucker move mountains you might be the perfect test case to see what gains you can get with bigger headers and exhaust. although, i think your biggest restriction to power production is the M90 in the EE kit. they can't flow enough for a healthy 347. i expect your kind of power out of mine n/a with a much smaller cam. of course, thats all talk until it gets on the rollers!

 

[ahodges]

well there you go...they do semi stuff. a "tight" area to put a pipe on those is under 1'!just noticed you've got a blown 347. you could definitely use more exhaust flow to make that sucker move mountains you might be the perfect test case to see what gains you can get with bigger headers and exhaust. although, i think your biggest restriction to power production is the M90 in the EE kit. they can't flow enough for a healthy 347. i expect your kind of power out of mine n/a with a much smaller cam. of course, thats all talk until it gets on the rollers!

Haha, yeah everything past the throttle body is maxed out for the power I'm making.. I would expect with you headers and a bigger supercharger I could make upwards of 500rwhp.. Maybe. To be honest I'm happy with how it is now (could always be better but not for cheap), but I may slowly improve it starting with headers.

 

[ford99_1979]

Pufferfish, if you come to the explorer market with these. Pencil me in there for a set. Although I have a body lift and that adds another set of problems with the steering shaft and clearance issues. To which I have already experienced with my TM Headers and the 3" bodylift.

 

[pufferfish]

Holy....! A 3" body lift?! Yeah, I bet you have all sorts of issues with that! What are you using for the steering shaft? Can't say it will work as is, but a #2 primary change may not be a big deal if I do theses " as needed".

 

[ford99_1979]

It's a stock steering shaft with the performance accessories steering shaft extension. It was a PITA to make work. I shaved the nut and bolt head on the extension sleeve. Some major "clearancing" on one of the primary tubes as well. It works.......

It would be nice to make the 347 breath better. I didn't realize at the time the TMH would be as much of a bottleneck for my 347 as there are. I was just happy that I could get headers made with the correct flange for the trick flow fast as cast 190 heads that Fordstrokers put on the motor. When I took my truck to a chassis dyno the owner noticed and mentioned that my headers were a restriction for that motor right away. The more I read about what you and others are saying, the more It makes sense to address.

Like I said if you get something ready pencil me down. Keep the body lift in mind.... LOL

 

[pufferfish]

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.