SRT Comanche build

[ghinmi]

Got tired of tripping over the busted up drain covers in the barn and made some new ones.  Had to put nice paint on them.

 

Cut the old exhaust off of the Comanche to free up space.  Must have been super quiet, 3 mufflers behind the 2.5 4 banger.  Whoever made it did a really nice job but unfortunately won't be right for my application.  Also, you can see my nice drain covers are already not so nice, haha.

 

Black Friday had some deals so I scooped up a lot of the turbo stuff.  Got a s257sxe with a .83 divided t4 housing, gen 3 VS 44mm wastegate, etc.  Also got parts to build the header.  Forgot to take pictures of most of it but did get the turbo.

 

This is where the scans are going to save a tremendous amount of time.  I've always built headers by eyeballing where the turbo should be and trying to connect the dots.  With this being a twin scroll header things get complicated in a hurry.  While I do have tons of space, trying to connect #1 and #4 to one half of the turbo and #2 and #3 to the other half really eats up space if you don't have a solid game plan.  With it all modelled up, I'll be able to cut all the elbows to the right angles and the straights to the right lengths ahead of time.  And fixture up both flanges on the welding table so I don't have to fabricate with it in the truck.

 

 

 

 

 

[ghinmi]

For fitment if the engine/trans it really helps to have a flat and square bottom on the oil pan.  All of the factory 2.4 pans are lumpy bumpy messes.  So now the Jeep Liberty pan is temporarily flat.

 

After many hours of shimming, checking, clearancing, refiguring, etc, this is where I have settled on final placement.  Motor is offset 1" off center to the passenger side with the transmission output remaining centered.  The AC compressor clears.  Won't have any issues with steering or axle at stock ride height.  Clears the hood.  Slight notch needed on the firewall pinch seam.  The alternator clears currently but I will trim some for future belt adjustment.  The biggie is the passenger upper control arm to starter clearance.  Will need something custom there.  Next to build is engine and transmission mounts.

 

 

 

 

 

[Salvagedcircuit]

You sir, are the right kind of crazy. Nice job!

[boxyjeep]

That this is really far back from the pics?  Is this for weight distribution?

[ghinmi]

Thanks guys!  Yes, it is pretty far back compared to a stock 4 cylinder truck for numerous reasons.  Weight distribution as you pointed out is a big deal.  Being a truck it's already front heavy so anything I can do helps.  But also the further back I mount it, the more room I get in front of the engine for piping, intercooler, radiator, etc.  And the further back I can get it the bigger I can make the sump on the oil pan without getting into the axle.  And will also allow me to lower the truck more than is typical because the oil pan is behind the steering linkage.  It's just a whole bunch of positives with very few downsides.

[ghinmi]

Made good progress on the engine mounts.  They're a combination of the factory 4 cylinder Jeep frame horns and 4 cylinder Dakota horns.  I'll be urethane filling the Dakota units to stiffen them up.

 

Driver side mount was easy.

 

Passenger side mount is more tricky because it has to clear the AC compressor and still leave room for the downpipe to pass between it and the starter.  Using just the top part of the Jeep frame horn and part of the Dakota and the rest will be scratch built.  Engine side mount will be tied into the custom ac compressor mount.  You can also see the starter to suspension clearance issue in this photo.

[ghinmi]

I call this the 'everything bracket'.  It pretty much mounts everything on that side of the engine.  AC compressor, belt tensioner, downpipe, and of course the engine mount.  The main structure is a repurposed PT Cruiser support brace for the intake manifold. 

 

 

 

I also filled both mounts with urethane to stiffen them up.  They won't be as stiff as full polyurethane mounts that I've used before.  Those might as well be solid mounts IMO.  Hopefully these are a nice compromise and soak up some vibrations and not let the engine move around too much.

 

With all the accessories mounted minus the alternator.  That needs some clearancing on the frame side.

 

In this photo you can see the space I have to work with for the downpipe to snake through between the engine mount and starter.  It'll be tight but it's going to wwork. I'm taking extra care to make sure this doesn't suck to work on in the future.

[ghinmi]

Another key piece of the puzzle showed up.  I had been waffling about doing a manual transmission just because none of the torque converter companies would work with me to get what I needed.  Edge pulled through big time.  Can't wait to see how it performs.

 

Spent the past two evenings creating a model of the two piece early PT Cruiser intake manifold.  It was necessary because I am going to heavily rework it and the computer helps me get angles and transitions correct.  More on this when I start the redesign this week.

[thecodemonk]

Loving seeing the progress on this!

[ghinmi]

On 12/14/2022 at 7:01 PM, thecodemonk said:

Loving seeing the progress on this!

Thank you!  Sometimes it seems like there's not much progress but it stacks up over time.

[ghinmi]

Here's the reason for making up a 3d model of the PT Cruiser intake.  I'm going to reuse most of it but cut up and flipped with a proper plenum and center inlet throttle body.  I needed to make sure all the transitions line up and that I could make it fit in the car before I started hacking and the computer helps a ton with that.  

 

In this picture, the red part is about 2.5" of the factory lower manifold.  Then the yellow is the part that will be cut off but flipped upside down to start a downward curve instead of up and over the top of the engine.  That will be chopped down as well as the upper intake runners (in blue) to result in a nice gentle bend and approximately 15" long runners.  Wish they could be a little longer but it'll still be far better than the other options for my application.  The plenum will be made from round tube and the throttle body adapter is the PT plenum (if you can even call it that) cut and modified.  I just threw a dummy model of a throttle body on there but it'll have a 64mm drive by wire unit off of a V6 dodge charger.

 

 

In this photo I've overlaid the factory PT Cruiser intake model with the new design.  Vastly different.

 

And finally, how it'll package into the truck. 

[ghinmi]

This is the moment of truth time.  Using the computer model to mark out my cut lines.  You can see in this picture how I've clamped the flange flat to my table and am marking the cut line with some blocks of steel and a razor.

 

Next I tipped it up to the desired angle and re-clamped it to the table.  Then I used a piece of metal rod sharpened to a point and clamped to a piece of metal to scribe a line all the way around at the same height as my first line.  This is my cut line.

 

A few minutes with the sawzall and there's no turning back.

 

Same process was done on the upper intake manifold to get the correct length and angle.  Joints cleaned and beveled, time to line up the pieces and weld together.

 

This is it all welded back together temporarily.  There will be more cuts.  But look at how nice the transition is!

 

 

In the next two photos you can see what all this work netted me.  What was once a 2 piece intake is now 1 and it sticks out of the hood.  That's where the second cut comes in.

 

[ghinmi]

Time to make this thing not stick through the hood.  Which means I've got to cut it apart, flip it, and reweld.  Marking up the cut.

 

Decent cut.  Also, with it cut here I'm able to get to the first set of welds inside the port and clean up any melt through.  That's the reason I did the fabrication in this order.

 

Fit back up and welded.  I'm very happy with how it is turning out so far.  Hopefully I'll be able to use some old school techniques to replicate the cast texture and make it look somewhat OEM.

 

 

And finally, sitting roughly in place in the truck.  I need to cut the old plenum off for it to bolt up.  Still waiting on material for the new plenum before work can resume.  But look at it compared to how it was!

 

[ghinmi]

Needed a little change of pace for a minute so I got back on the header build.  I've had the design finalized for a while on the computer.

 

The computer model helped so much.  I was able to cut all the parts ahead of time.  I had a bunch of people asking elsewhere about the cuts.  On my computer model I made a bunch of reference points and was able to transfer them onto the elbows on the granite table at work.  That's why they're all covered in layout dye.  Then I ran pinstripe tape around them connecting the dots and used it as the cut line.  Then cut them out with a thin 3" cutoff wheel.  Crude but very precise.  The header flange is from Treadstone and the collector is cast stainless from CX Racing.  The tight radius 1 1/2" sch10 elbows and pipe are from Treadstone as well.

 

Next step which I unfortunately didn't take photos of was that I marked out the header flange and collector locations on the work bench and clamped them down.  I taped the #2 primary together and it clicked right into place.  No grinding necessary.  I tacked it all together with just the #2 primary and bted it up to verify fitment.  Perfect.

 

All the primaries tacked together.  Look at the perfect fitment.  Very impressed, all the computer time paid itself back when I was able to get this whole header cut and tacked in one afternoon after work.

 

All the dye cleaned off and prepped for welding.

 

I know I'm not the world's greatest welder.  But it's in one piece, stupid strong, and doesn't leak.  You can also see that I welded a divider in the collector to make it a twin scroll.  I still need to cut it off and weld it a little wider to match the gasket.

[ghinmi]

Header temporarily installed.

 

 

 

[ghinmi]

It was finally time to start transferring parts from the super rusty white truck to the good one.  I fired it up and it drove right out of the snowbank it's been sitting in, everything still functions and it's a great parts donor.

 

 

Dash removed.

 

Stripped down, she's a rusty girl.  The floors were full of expanding foam, license plates, and aluminum diamond plate sheets.  Just gross.

 

 

Then compared to the good Comanche.  The previous owner did a really thorough job with the sound deadening.

 

 

[ghinmi]

After getting the firewall I simulation swapped over, I inspected the HVAC box and installed it.  Unfortunately I didn't inspect it well enough and realized the heater core connection had a crack in it after it was all installed.  Had to tear it all back apart and source a new one.  A bit of wasted time but it went back together ok.

 

After the HVAC box was installed I modified the ECU mount for the Holley Terminator X Max.

 

 

Onward to identifying and labelling all the wiring.  I'm intending on keeping all the factory functionality but prune out the renix fuel injection and replace it with the Holley.

 

Then I encountered the fuse block.  Unfortunately it's gotten pretty melty at some point.  Very odd because everything functioned on the truck before I removed it.

 

The best solution was a new harness and luckily I had one.  So the swap starts.

 

 

And finally got the main part of the dash installed.  Also redid the instrument cluster and swapped over the body harness.

 

 

[boxyjeep]

Really excited to see how this turns out.  Also, I can really appreciate having the intake and exhaust manifolds on opposite sides of the engine.

 

For that fuse block, you can actually buy replacement terminals from Del City and just swap them over (assuming the plastic isn't too far gone).

[Warren99]

That thing looks amazing

[jpnjim]

Wow Ghinmi, you're killing it with this build!

Very nice work all around!

 

I miss reading your stuff on the AMC Forum, so I'm glad to see what you're doing with an MJ.

 

I have a couple questions though if you don't mind:

 

Is the PT Cruizer/SRT-4 (transverse) 2.4L block better/stronger, than a Liberty/TJ 2.4L block?

(or is the PT Cruizer/SRT-4 block the same as the KJ/TJ?)

 

I like the idea of this build (a lot!), and wondered if there would be a simpler way to get a PowerTech 2.4L Turbo into an MJ or an XJ.

Even if the transverse vs longitudinal blocks are all the same, I'd guess that the front engine accessory layout from a TJ/KJ may be a closer fit out of the box(?),

and something like an AR5, or MA5 transmission might work with the Libby/TJ NV1500 bell.

I'm not well versed in NV1500 bells, but I think a Supra R154 would even bolt up if input shafts could be swapped.

 

 

I know you are building this around an automatic, so that part wouldn't really apply to your build,

 and sorry to sidetrack this thread,

but I'm really interested in this swap and there's not a ton of info out there on these engines.

Thanks!

 

 

 

[ghinmi]

 

On 12/31/2022 at 12:34 PM, SoCalJeepComanche said:

Really excited to see how this turns out.  Also, I can really appreciate having the intake and exhaust manifolds on opposite sides of the engine.

 

For that fuse block, you can actually buy replacement terminals from Del City and just swap them over (assuming the plastic isn't too far gone).

Thanks everyone!  The plastic bulkhead was melted so I abandoned ship and swapped to the spare harness.  Luckily the spare only had three wires that had been modified for the radio.  And indeed, the manifolds on opposite sides makes a lot of things way simpler and cleaner.  But also takes up more space on the passenger side than before.

 

9 hours ago, jpnjim said:

Wow Ghinmi, you're killing it with this build!

Very nice work all around!

 

I miss reading your stuff on the AMC Forum, so I'm glad to see what you're doing with an MJ.

 

I have a couple questions though if you don't mind:

 

Is the PT Cruizer/SRT-4 (transverse) 2.4L block better/stronger, than a Liberty/TJ 2.4L block?

(or is the PT Cruizer/SRT-4 block the same as the KJ/TJ?)

 

I like the idea of this build (a lot!), and wondered if there would be a simpler way to get a PowerTech 2.4L Turbo into an MJ or an XJ.

Even if the transverse vs longitudinal blocks are all the same, I'd guess that the front engine accessory layout from a TJ/KJ may be a closer fit out of the box(?),

and something like an AR5, or MA5 transmission might work with the Libby/TJ NV1500 bell.

I'm not well versed in NV1500 bells, but I think a Supra R154 would even bolt up if input shafts could be swapped.

 

 

I know you are building this around an automatic, so that part wouldn't really apply to your build,

 and sorry to sidetrack this thread,

but I'm really interested in this swap and there's not a ton of info out there on these engines.

Thanks!

 

 

 

Small world!  I remember your screen name from the other forums.

 

Regarding the Liberty/Wrangler 2.4, it's got some stuff that's more convenient but some things are more of a challenge.

 

The blocks are very similar with some key differences.  The turbo engines have piston oil squirters, the turbo oil drain back, better material valves, etc.  But the Jeep engines have more conventional engine mounts.  The front accessory drive is where things get sticky.  The accessory locations are very favorable BUT interfere with the #1 intake runner.  So the Jeep engines have a very poor design and will not hold up to boost.  No real way around that without moving the accessories around.  Also, the Jeeps have a steel oil pan and more conventional oil pump which would be less work.  But the oil pump is discontinued and also a lower volume than the turbo engines.

 

Long story short, a Jeep 2.4 would be a relatively simple swap if you kept it stock and were ok with getting beat by stock 4.0 rigs.  But as soon as you add boost and try to make power all the parts that made it a simple swap become problematic.  Unfortunately this swap is just a lot of work no matter how you slice it.  I knew that going in and I enjoy the challenge.

 

You're correct on the bellhousing stuff.  People have used the Jeep bellhousing to put the ar5 and ax15 behind them.  I had considered it but the issue is that you're stuck with the Jeep dual mass flywheel that I don't trust with decent power.  And there's no off the shelf replacement.  Which is why I ultimately decided to adapt to Ford modular.  I'll be able to bolt on any of the auto or manual options from the flywheel back.  Just in case I end up hating the automatic.

[ghinmi]

I spent many days with the factory wiring book sifting through the factory engine bay wiring harness.  Lots of things that needed to be deleted and/or re-evaluated.

 

I spent entirely too many months trying to find an aftermarket radio that didn't look terrible.  Settled on a boat radio.  It fits the look alright and has Bluetooth and all that.  I just can't stand flashy radios in old cars.

 

 

 

Next step for the interior would be carpet but I had to figure out the shifter situation first.  I flipped the sheet metal tunnel cover which moved the shifter hole back a little bit.  Then the 01-04 Mustang shifter slid right into the perfect location.  A couple rivnuts and it's mounted.  Then after the carpet goes in I can start scanning the area and designing a center console.

 

[neohic]

Got a link for that boat radio?

[ghinmi]

3 hours ago, neohic said:

Got a link for that boat radio?

https://www.crutchfield.com/S-PsWfKbYgoFB/p_049MDR20/MB-Quart-MDR2-0.html

[ghinmi]

Upon assembly of the interior I found that somewhere along the line the mounting bosses had been broken out of the lower driver side interior panel.  Someone had replaced the hardware with wide head screws which kind of work but provide nothing to tighten against so they would loosen up over time.  I designed and printed these drop in replacements for the broken ones and some support pieces to make the non-broken ones match.  Not exactly OEM but they repair an otherwise presentable panel.

 

 

 

 

 

 

 

 

 

I also have the new carpet mostly installed now.  I was really hoping to reuse the original from the parts truck but it was just too far gone from the floors being missing.