chefdave

Hi
everyone would be interested in a setup using std manifolding. as my truck is a dolphin motorhome conversion extra power is good but has to bottom to mid range, which std manifolds should provide but fatter curve. cannot afford to swap engine at present. tempted by 3.0 diesel; 3.4 v6; lexus v8.

RSR

Search crossover delete. Lots of options and methods. Just ensure your passenger side ties into your main line before your 02 sensor.

LC engineering sells their crossover w/ their 3vze headers. It's ceramic coated and crosses under the tranny. Then you just need to fab up pipe from the headers to LC engineering crossover. Your call if you send our your fab pipes for ceramic coat, use ceramic paint, header wrap, heat shielding, combos thereof, etc...

chefdave

Hi rsr
would love to do that using std headers but my part of the world loads of welders but no one wants to frbricate manifold downpipes and crossover to rest of exhaust.
Nearest place is a four hour drive one way. Unfortunatley i cannot weld if i could tack welding and getting expert to finish welding would be my prefered option.

RSR

With the $200 LC engineering crossover, you should be able diy if you have basic welding skills.



You should be able to cut your existing drivers side down pipe and then weld a flange on at the cut to tie into the drivers side of the LC crossover.

And then on the passenger side if you use the factory crossover (cut at passenger header), you may have to cut to bend and then weld a plate onto the bend to repair... But then should only need a short pipe from the expansion chamber (cut before) to the LC header. Then weld a flange on.

Add the block off plate for factory crossover header tie in, and your good to go. Can't image no one would do, but you might need to remove the crossover on your own first -- make them more likely to do it I'd think.

EDIT: You'll also need to cut back your existing collector pipe (the one w/ the 02 sensor on it) and reweld a flange there too w/ the LC header...

The LC Catback system looks pretty decent too. Also stainless ceramic coated...

Turbo_4runner

I know this thread is kind of old but I'm in the process of tearing down my 3vze and definitely would be interested in a set of headers while I have everything stripped down.

RBX

Headers are most efficient when built correctly, and many cheaper headers are just longer pipes to a collector. There is an actual science to building them so that the engine benefits from new design.
That said, headers can give a nice benefit in hp or torque if built correctly.
I'm in no way an expert, but here is some reading:
http://www.carcraft.com/techarticles/header_basics/

Burns Stainless used to offer a service if you buy there mandrel bends. You send them you engine specs, fire order, cam lift and duration, and they will tell you how long each manifold tube needs to be before it hits the collector. This and you tell them you want more torque or high end hp.
Ceramic coating headers will help with heat under the hood.

RSR

Headers are a very marginal gain on this truck. Killing the existing crossover, and getting a good catback gives you at least 75% of the gains through doing your exhaust. And that's about a $500 - $750 project.

Whether paying an additional $600 to $800 plus the pain of removing existing manifolds, risking burnt fuel lines, burnt floor boards, etc, is worth it is up to you.

But you really won't see the full potential of the headers with fixing your intake which involves removing the heads and porting for oversized intake and exhaust valves...

By the time you price out the equivalent of a headgasket job (basically what you're looking at), maybe power profile grind cams, and the headers, you're basically at the cost of a 3.4 swap, which is the best power solution for 3.0s.

Also, the cat back exhaust from about the cat back can be used in a 3.4 swap. You'll probably want to swap in a cat with a size up of piping and also run that same size tube from collector to the cat...

Tom brown1212

About to get in to my yoto I have a 3vze and would love to put header on it .. what the cost

MaK92-4RnR

Unless the headers are less than 400 bucks, they're not worth it. Sure they sound cool, but offer no real benefit.

Learn from my mistake and do a 3.4

wrenchtech

I am pretty sure you cannot use the passenger side manifold on the driver side. While the manifold will "flip" and mount on the driver side head, It will end up being too long because the exhaust ports on the driver side head are offset farther towards the back of the vehicle as compared to the passenger side. If it fit at all, the outlet on the manifold end up right up against the firewall of the vehicle. This leaves absolutely no room to attach a downpipe. You can certainly use the original driver side exhaust manifold and block off one of the ports, but it seems like this would make a poor exhaust manifold with less than optimal flow characteristics. The question that remains unanswered in my mind is whether this is better or worse than the factory crossover set up. That said, there are aftermarket headers available from Doug Thorley that are smog legal, for around $600. For that kind of money, I think you could get a good start on a Lexus 1UZFE, 24 valve, dual overhead cam, V-8 engine swap. Which, by the way, would give you the same horsepower as a 3.4 with a TRD supercharger, but for thousands less $$$.



It is clear in this photo that the left manifold sits farther back. If you flip the right manifold over to the left side, the outlet end would be too long. It would either hit the firewall or leave to little room to attach a downpipe.