Headers Without Intake Manifold. Worth It?

I've had a set of headers hanging on the wall for I dont know how many years now because I was told it wasn't worth installing them until I was ready to put an intake manifold on there at the same time. I can understand why, but the more I stare at them I can't help but wonder if it might be worth installing them now and just doing the intake sometime in the future. Will I get any significant performance increase with headers alone? And secondly, can they be installed without pulling the engine?

 

I ran headers with an iron intake and 2bbl for years. Ran fine, will likely lean it some.

 

Not a big fan of tubing headers. Especially on a Jeep. Noisy, hot, fragile, expensive, leaky race car tech. Otherwise they are great. Yes, you will get more power with headers, even with the factory intake.

 

Most headers do nothing below 3500RPM's other than crack and leak. Personally, unless you have a specific need (I run fenderwell headers for steering clearances) or running a high revving engine, your better off with stock manifolds. If you are looking for more flow, you can open up your existing system and reap some benefits without any of the drawbacks of headers.

 

Interesting. I'm definitely a 99% low rpm guy. I'm mostly asking out of interest in getting more power in general, including low rpm. Sounds like headers are the wrong way to go.

 

What do you mean by open up the existing system?

 

Not sure if you are running a single stock system or a dual system, but,
You can increase the diameter of the existing pipe(s). This increases the breathing ability of the system without having to change it and keeps the stock manifolds, which will breath just fine for a stock or mildly modified engine. If you wind up replacing the exhaust system, I like to recommend a single or double flange in the area of the transmission and transfer case. A single flange will split the exhaust. A double flange will allow you to remove a section of the exhaust pipe, allowing easier access to the bell housing, starter, transmission, and t case.

You can also run a glass pack or low restriction turbo style muffler.

 

I have had fenderwell headers on mine since 1992, several good reasons. Easy to get the transmission, bellhousing or transfercase out or to work on anything underneath. Mine do not leak and are not rusty even after all these years. Are they loud, moderate rumble until you hit the throttle. Mine runs fine no noticeable loss of low end power. I run 2 Hush Thrush mufflers on mine.

 

I went to headers when I did my power steering
way before the internet . just a bunch of junk yard visits
on my third set now , same mufflers

 

If you want some low RPM, start with a HEI ignition if you haven't already, that will help the whole range. On these little V6 engines, mostly headers just make noise until you wind it way out. I pulled the headers off mine and put the cast manifolds back on and got more low end for my trouble.
Yanking out the thermostatic bypass valve will improve flow and reduce the risk of it jamming closed.

 

Already done on the HEI, one of my favorite upgrades. Haven't heard about removing the thermostat though, is that safe?

 

I think I am in the other camp I spent near on 3 weeks designing and building a Set of TRI Y headers for my 134L Maybe the only set in the country I know the only set like mine. I had guys who build race car and hot rod headers helping me on line. They will increase my mid range HP and Torque. Running a 2.25" Mandrell bent exhaust with a little Duramax muffler









Granted I have a one of a kind Cast aluminum intake and Weber DGV-5A carb

I'll let you know how it comes out in about a month when I have the engine started and tuned.

 

I am thinking this is what teletech is referring to...

 

That's the very item. Located at the bottom of the passenger side manifold. You can remove the whole assembly or just cut out the butterfly and shaft and tap the shaft holes for plugs.
They don't cost that much flow when they are working right and don't fail all that often, but if you want more flow and are willing to much with headers then it's not a bad step in the direction of power that won't hurt your bottom end.
If looking for flow, also make sure you have removed the air injection nozzles if your vehicle was so-equipped so that's not impairing things.

 

That much effort and I'd have been tempted to go EFI, turbo (take advantage of the low compression of the flat-head), or both. That said, that is an absolutely lovely header you have made there, very high production value indeed.
The 4-cylinder I suspect would benefit more from a header than the uneven-fire V6 and it's reputation for poor scavenging, made much worse by the fact most folks who run headers on the V6 do a dual exhaust. Of course if you are building a motor with a cam that helps as well.

 

As to running an EFI that could be in the future Turbo no not my thing plus they do squat for bottom end. A small blower type super charger sure those are right off idle all the way through but again not a thing I want to invest in.

I have already done the old school stuff. Shaved the head .035" decked the block .007" increasing the compression ratio and then a .060" over bore for an additional 6cu in. Plus other things.

 

In the spirit of keeping it a little old-school but still getting past some of the carb issues, I've fantasized a couple times about slapping a mechanical-injection on, Bosch k-jetronic or such.
Whoops, getting off topic here. I'll step away and let others weigh in on the V6 headers. I will add that I really enjoy NOT sucking so much exhaust, so if you do run headers I advocate for not running the outside-the-rails dual exhaust that seems like the obvious thing to do but rather have a good shop come up with a real, single exhaust system for you. It's pretty easy if you have only the front tank, but if you have the back fuel tank, PTO, overdrive, etc. it gets pretty crowded under there!

 

That looks great. Nice job.

 

I have installed headers on my 2A with my stock 225 since the beginning,1983.
I have dual exhaust out the back quarters with some type of "quiet" torpedo type mufflers.
For me, when I ran the sand dunes, the mufflers always came off. To me, the V6 just came alive with open headers and stock carburetor.
Granted, not everyone will get to experience the difference. You can crunch the numbers all day long if you want to.
If you are planning on rock crawling, outside the frame headers may not be for you as they are vulnerable to rock damage.
I say run headers if you want on a stock engine set-up and be happy.

 

Definitely a beautiful set of custom headers, however, they are not a tri Y design. Tri Y headers have the front two and rear two cylinders connecting, forming 2 Y's. they then come together forming the third Y. The cylinder pairs help scavenge by opposing pulses.

Edit:
I just revisited your post and the third picture definitely shows two collectors. Sorry for the mixup.