You know it...



I may have added a flare for maximum bling impact.

 

Wow, thats REAL pretty. No oil needed and washable right?

 

Correct. According to the website, 4 yr lifespan. Probably 3 for me, with all the dirt driven. But, still saves some money in the long run and should work really well.

I am running Mobil 1 full synthetic in this thing once I get to that point. Giving her every opportunity (besides supercharger and such) to really go.

 

Got a few more things today. Was able to sneak in the headers. In some ways, they were easy to fit than on the 3.0... in others, much harder. So difficult to access the bolts.

Anyway, I checked the fit and then welded some 3 bolt flanges onto the end... and painted 'em black with some high temp paint because I don't care for chrome:



Then I started to work on the rest of the exhaust. Only have one 180 degree mandrel bent piece of tube from Summit to make this work. Better than before, when I just had to miter cut and weld to get things to work:

Old stuff... that served it's purpose well:



Parts for the new routing:



I'll re-use my cat and muffler. Plan to make my own sensor mounts for O2's. Got the clutch line in, slave installed and bled. Maybe a few other loose ends tied up that I can't remember.

Back at it tomorrow... weather permitting.

 

Did you run it yet? Looks like you are close.

 

Great progress, Steve!

I'll bet that you're just about twitching to start it up!

Looking forward to hearing what you think, once you're running, again!

 

Very close. This weekend is the goal.

I have to finish exhaust, wire O2's, hook up the battery and a few other underhood connections, rear coolant lines, shift levers back on... I'll just keep plugging away.

 

I am anxious for sure. This will be a major project for me, so if she fires I'll be extremely stoked.

Once over that hurdle, I can't imagine I'll be depressed with the new found extra HP and torque.

 

Does anyone have any detail pics or can let me know which coolant line from the back of the 3.4 goes to which coolant line coming from the firewall on my '90?

I have 2 to hook up, and can't seem to find a coolant flow diagram online for the 3.4.

Thanks in advance.

 

the driver side coming from motor goes to the swich controling heat level entering heater core and the pass side coming from firewall goes to pass side going into block.

 

Good thing you can use your stock y pipe to conect the both i had to use a magnaflow to join my downeys together since i tossed the original. that 180degree bend should work great to make it work.

Looking good

 

Sweet. Thanks for the info. I may be tackling those lines as soon as tomorrow.

You lost me a bit on this one. I will be cutting that 180 bend into multiple, shorter bends and then do my best to make them all blend together. Before, I just got bends from the local Autozone. This time, I'll try and use this piece of mandrel bent to streamline the flow and get a better finished product. I'll be making my own "Y" pipe to tie the headers together. That will run under the tranny but above the front DS. Worked well on my 3.0 and kept everything tucked up out of harms way. The dual cases give me a fair amount of room to work with.

At least... that's the plan.

 

Haha i thought you were going to use the old exhaust to blend into aka tying into the old ypipe. What size pipe are you using? if the old is 2 1/4 and the new is 2 1/2 then i can see making your own ypipe but you could use the old ypipe it may be easier than making your own just IMO and if your using the stock diameter tubing.

I ran the downeys that same way and they should work and fit great. I flat bellied mine so the hardest part of mine was fitting it above my crossmember huge PITA but it worked.

 

Yes the duals definetly help with space lol

 

Since the Downey headers terminate at 2.5", I'll be running 2.5" back from them to the cat, muffler and out the end.

That's what I had on the 3.0 before, so hopefully it will work well for this application also.

 

They actualy advise not using any bigger than that and if at some point you supercharge or anything that would be optimal as for wheeling the smaller would give you a bit better with the low end torque however since you have duals youll be plenty set I would recomend the 2.5 as well. What kind of muffler do you have? Looks like a magnaflow

 

It's just a Summit Turbo muffler. I did have a Magnaflow a while back with the 3.0, but it was really loud.

Actually, the tone was probably all right... it just sucked having my 4Runner sounding like a V8 and pulling like a 3.slow.

 

I know what you mean haha. I liked the sound from my flowmaster so i stayed with that for now. My buddy had a magnaflow on his 3.0 pickup and when he sold it the guy said it sounded like a v8 and he was sold. thats funny that you said that.

Wont have to worry about not pulling its wait after the swap thats for sure

 

Rainy afternoon here today, but luckily got a fair amount done before hand.

Really glad I got that mandrel loop from Summit. Worked out very well, vast improvement over my 3.0 Y pipe.

The 3.0 headers went further back along the frame, causing me to run out of room and create this horrific "bend" off of the PS header. It did work, and cleared the DS. Before, when I had a local muffler shop do the job, they didn't cross over until behind the single transfer case, which put the cat at the rear axle. Believe it or not, my way was an improvement... at least to me.:



I had always planned it to be temporary until I got the 3.4. At least, I had always hoped to swap in a 3.4. Now, the much improved mandrel bent version:



The combination of the 3.4 headers being slightly shorter, my addition of the dual tranny and just a general improvement in my fabrication skills this Y pipe really came out well, IMO.



No closeups of the welds though, I still lack in that department, but getting better. They seem to hold up, so I guess that's the important part.

Nice and tight but no touching:



Was able to get it tucked up there pretty good. Should be mostly out of harms way on the trails. :



The rain then started to cramp my style. I was able to make space in the garage and plan to push it under cover to finish. Pretty much just have some wiring connections and coolant lines under the hood to figure out. If I get lucky with some off the shelf hose bends from Autozone, I should be in fairly good shape.

Who knows... may even be able to turn the key tomorrow afternoon.

 

Hell ya that y pipe looks way better. You should post the shop who did it before because that is rediculous.

You should think about adding a truss to the upper part of your front axle since that motor weighs a bit more. Plus they look sick and make the axle muh stonger