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Engine Sizes, History, and Applications


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I'm thinking about picking up a Comanche pretty soon here, Tuesday actually. Still have yet to take a look at it, but it has always been one of the trucks that I've wanted. Comes with everything I'd need; small wheel base, robust engine (2.5 liter, too bad it's not the straight 6 though), 5 speed, four wheel drive. Small truck, but can do a hell of a lot.

There are some things I've been wondering though. I checked out some of the information on this forum and other forums on the Comanche, as well as Wikipedia. The engine that comes in this Jeep is the 2.5. Checked out Wiki for some information on the 2.5, apparently, it only comes in Jeep applications and some others. However, given that is an AMC engine, I'm wondering how many similarities, if any, it shares with the Dodge engines of the same day (Daytona's, Shadow's, Spirit's). I'm only linking the literage with the same literage as the K cars given Jeep/AMC's relationship with Chrysler.

Also, the availability of aftermarket seems a bit low, engine wise that is. I can see from the user pictures that there are plenty of suspension components that are available, and I'm alright with that.

Are there any common problems with the truck, transmission, drivetrain, brake, engine, electrical that I should be looking for? Something that's quite common with this truck that other vehicles may not experience?

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lol I'm hoping so. Small trucks are hard to come by up here, especially a Comanche. It's the only one in my town. Sounds like I'll need to find myself a good metal fabricator.

I haven't done a search yet, but has anyone gone the route of forced induction of any sort, whether turbo or super, on the 2.5? Or is something like that favored only on the 4.0? Too bad it's not the 2.1 turbo diesel, could have myself some fun with that!

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Something that's quite common with this truck that other vehicles may not experience?

Holes in the floor pans and an inexplicable Comanche addiction, once you have one they start to replicate and fill your yard up :thumbsup:

http://www.comancheclub.com/forums/viewtopic.php?f=3&t=26132

 

 

Ha Ha, Ive finally made an example of myself it seems :rotfl2:

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It's a good idea for a bolt-on kit, however, it's way too expensive. It's much easier to piece together a kit even including the fabrication process for the intercooler piping, turbo manifold, and so forth. Either way though, that certainly brights my day that there's one available. Only bad part, an MFI engine, not TBI. Also run into the problem of a bigger injector(s), higher flow fuel pump (though not that much higher, maybe a 190 LPH Walbro on a moderate 7-9 lbs of boost). Quite a bit to do, but I'm pretty sure it can be done for under $1,500.

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There is absolutely no relation between the AMC 2.5 and the Chrysler 2.5. Ive heard people talk about wanting to make the turbo from a Chry 2.5 work on an AMC 2.5, but have never seen one finished. Beyond that for forced induction it is all in what you can make of it yourself. There are a few performance items available though. Clifford performance makes an intake manifold that you could mount a 390cfm Holley 4 bbl carb to, or their own custom fuel injection setup, there are several companies that make headers including Clifford. Ive only found one place that lists a cam for the 2.5, but they have been "temporarily" closed for the last year and a half..... www.amotion.com they have (had) several different grinds available. Another thing for more power would be to remove the engine driven cooling fan and install an electric unit with a fan controller... I did this one myself. A cold air intake might help a little, and they say a throttle body spacer should help a little too, especially on the TBI models. A little port and polish, and a free flow or gutted cat converter and free flow muffler can only help too. There are those that say this will ruin the low end torque on this engine, but Ive noticed none of that myself. Its a great little engine as long as you don't expect too much out of it. Good luck with your truck, let us know what you end up doing!

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There are Chev 350's all around up here. That's the primary truck of choice, that and Fords. Not too much Mopar save for the Jeeps. Tons of Subies too...boxer swap? Nah, too heathen. Bloody pancake engines.

Anyway, I'd like to keep the drivetrain and the motor the same. Modify it for whatever it's purpose may be; rock crawling, mudding, DD, or something along those lines. Be nice to have a 300 WHP 350 with a blower on it though...but that'll be another project when/if I can afford it.

I read online at, Import Tuners I believe, that when you gut the cat, you actually lose horsepower/torque given that when the air flows into the catalytic converter, it 'hits' the sides and bounces back towards the outlet, thus hampering the total amount of flow. Best bet would be to get a high flow cat or just test pipe it completely. The test that they did it on (including the stock cat, hollowed cat, and high-flow cat) was a B18, or was it K20?, Integra. Of course, all engines, exhaust systems, and scavenging in the same place isn't the exact same from car to car, so I would imagine a couple dyno runs would provide the information.

http://www.importtuner.com/tech/impp_0904_hollowed_out_catalysts_make_power_fact_or_fiction/index.html

I took a quick peak of the truck as it sat in the school parking lot. From the distance it looked in pretty decent condition. Red in color. Needs some Hella fog lights on bottom though. Maybe some Rustoleum paint and a Rhino lined bed. And a completely chromed out interior with custom paint and decals. No, just kidding. Stock and stock for the interior.

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When I gutted my cat conv, I sleeved the inside of it to make a smooth flow through it. In my area, we have inspections, so at least the appearance of a converter has to be there.... but like I said, I had NO noticeable power loss, and it actually feels like it gets up and goes a bit quicker than it did before.... and the cat was in good shape when I removed... one of the cleaner ones Ive ever seen. If you don't have inspections, test pipe it, if you do, sleeve it inside and hit the road!

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How close to a sbc drivetrain swap would $1,500 get you? You can get used but servicable TBI 350's with tranny & t-case pretty cheap, $200 motor mounts, some custom exhaust,electronics, and a decent radiator?

 

You will have to do considerable floor pan modifications to fit a chevy trans in there if you choose to go manual. A common swap for them is the 700R4. Then again, the Chevy transfer case is setup for a passenger side drop, which is the opposite of what Comanche's having. That creates, again, major modifications to the floor pan.

 

What I'm doing is I got Novak adapters for the motor mounts and adapter to use an AX-15. This way, everything beyond the bellhousing will fit correctly with the 350. I had the AX-15 and NP231 laying around, plus found the adapter, bellhousing and all the brackets used so that kinda sealed the deal for me. My buddies boss has a ton of headers laying around so I grabbed a set of long tube headers from him (driver side is Chevelle, think the pass is Firebird). I'm in the process of putting in a new floor so everything has been yanked back out so I have no good test fitment pictures, unfortinately (new floor goes in this weekend, assuming the weather permits).

 

I have heard that a Ford 302 will bolt into the Comanche with minor modification and you can use a Ford 5 speed manual and transfer case. The longer transmission will limit the amount of modifications you need to do to the floor pan, but you will need to make up a mount for the trans (you can just make a top plate for the bolt holes on the trans then bolt it to your existing motor mount). I haven't tried this or really looked into this too much though, so I'm not sure how easy or hard it is.

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I noticed when I type anything into Google about Jeep Comanche OE parts or restoration parts, I don't get so much as anything for the Comanche. Are there any websites out there that list OE interior/exterior parts?

Took a quick glance at the Comanche tonight when I got done with work, it looks in decent condition, however, like many '87 vehicles, it does need a bit of work. Especially vehicles from Minnesota in the hands of a 17 year-old. Body is red, and the interior is burgundy (bleh). May think about doing a black interior swap or painting it...but I'm not so much with the paint.

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How close to a sbc drivetrain swap would $1,500 get you? You can get used but servicable TBI 350's with tranny & t-case pretty cheap, $200 motor mounts, some custom exhaust,electronics, and a decent radiator?

 

You will have to do considerable floor pan modifications to fit a chevy trans in there if you choose to go manual. A common swap for them is the 700R4. Then again, the Chevy transfer case is setup for a passenger side drop, which is the opposite of what Comanche's having. That creates, again, major modifications to the floor pan.

 

What I'm doing is I got Novak adapters for the motor mounts and adapter to use an AX-15. This way, everything beyond the bellhousing will fit correctly with the 350. I had the AX-15 and NP231 laying around, plus found the adapter, bellhousing and all the brackets used so that kinda sealed the deal for me. My buddies boss has a ton of headers laying around so I grabbed a set of long tube headers from him (driver side is Chevelle, think the pass is Firebird). I'm in the process of putting in a new floor so everything has been yanked back out so I have no good test fitment pictures, unfortinately (new floor goes in this weekend, assuming the weather permits).

 

I have heard that a Ford 302 will bolt into the Comanche with minor modification and you can use a Ford 5 speed manual and transfer case. The longer transmission will limit the amount of modifications you need to do to the floor pan, but you will need to make up a mount for the trans (you can just make a top plate for the bolt holes on the trans then bolt it to your existing motor mount). I haven't tried this or really looked into this too much though, so I'm not sure how easy or hard it is.

 

Only old ones. My 1994 Suburban had a driver side drop 241.

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GM switched to IFS in the 1/2 ton models in 1988 and along with the change came a driver's drop layout. The others went IFS in '90, IIRC. So most, if not all, GM's have been driver's drop every year for 23 model years, which is longer than any "modern" parts were used as a passenger drop. Factory 4x4 was pretty rare in the 60's. It is a safe bet, using sales numbers, that more driver's drop GM 4x's were made than passeneger drop, especially if you consider the S-series.

 

Uber trick bizarre set-ups are cool for car shows, but tend to suck if you use your jeep as a jeep.

 

Injected/auto/driver's drop combo's are plentiful and fairly cheap. The electronics have been figured out so DIY instructions or bolt-in stuff is readily available. Personally, I am not a chevy fan and never have been ( only little boys and weirdos wear bow ties), but when it comes to swaps "common and cheap" are great things. Just don't choose your wimmin by the same criteria used for swap parts...

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Every Chevy Dana 60 I've seen has been passenger side drop, guess they stopped putting those in in the late 80's/early 90's?

 

And the reason I chose a Chevy 350 was due to the cheapness and availability of the parts. The axles are going to be Ford axles while the trans/transfer are going to be Chrysler. It's going to be an odd mix but that's what AMC is. :yes:

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the GM Dana 60 is a SFA, so yes, it went away with the change to IFS. That is why you won't find a driver's drop GM D60. Dodge kept pass. drop D60/61's through 1993 before switching to driver's side, like Ford has always been. GM has not used a D60 front in over 20 years.

 

Chevy 350 is king because it is cheap, plentiful, and well researched. Can't fault you there, but the expense of adapting the chevy engine to a mopar tranny seems an unusual choice. If you want an AMC-patterned 727 with a driver's drop np208 attached, I know a guy who can hook you up cheap... :D

 

Interesting is that, as you point out, AMC had very few things that were AMC except engines. The trannies were always outsourced, and most of the axles were Dana, which were used by numerous manufacturers, foreign and domestic.

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The adapters and whatnot for the trans I got cheap, found everything I needed for $200, then just bought a flywheel and clutch (which I was going to replace no matter what choice I made since I had it all apart).

 

Just having that feeling of knowing the trans and transfer case are good, plus I don't need to customize the floor pan and linkages, gives me ease of mind (I took it out of my other Comanche after driving that for a while, that one is getting a full rebuild from the ground up so it doesn't need them).

 

Also for AMC, don't forget the GM steering columns and that crappy 2.8L we have! :fs1:

 

Thanks for the info. I'm way more of a Ford fan than a Chevy fan so never bothered looking up these things. That and I never had the reason since I found a set of Dana 60HP king pin and 10.25 ff axles from a Ford for cheap, won't be breaking them any time soon. :D

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As of tomorrow, I'll have the Comanche. Ah, nothing like a small, light, 4WD 5-speed truck. Now, apparently, all I have to do is find out what transmission it has (which one's the more robust?), order in an alternator and battery (since that's what is supposedly wrong with it, but going to do a load test before getting anything), grab some oil and a filter and be on my way.

Pretty sure that the transmission, differentials, and transfer case oils have never been changed so that's on a list of things to do. Same with the coolant. So much tuning up to take care of.

Oh, and there's no radio or speakers. F.

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I noticed when I type anything into Google about Jeep Comanche OE parts or restoration parts, I don't get so much as anything for the Comanche. Are there any websites out there that list OE interior/exterior parts?

 

 

no, not really. some random aftermarket crap, but it's not a valuable enough truck to justify quality restoration parts. a lot of stuff can interchange with Cherokees.

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Looking more along the lines of not completely doing a resto job on it, just getting some things cleaned up for decently cheap; rubber floor 'carpet', window roll-down knob, shifter console, and some other miscellaneous pieces. The maroon's getting to me, so I might just swap everything to black, or practice with some interior paint on some extra pieces of interior. Don't want it to look cheesy.

 

Anyway, here's some pictures.

 

 

 

 

It's not as big of a rust bucket as I thought it would be, especially for living its life in the midwest. Engine bay's dirty as hell of course, but nothing a little Simple Green and a pressure washer can't handle.

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I noticed when I type anything into Google about Jeep Comanche OE parts or restoration parts, I don't get so much as anything for the Comanche. Are there any websites out there that list OE interior/exterior parts?

 

 

no, not really. some random aftermarket crap, but it's not a valuable enough truck to justify quality restoration parts. a lot of stuff can interchange with Cherokees.

yeahthat.gif

 

XJs are pretty much rolling junkyards.

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Engine bay's dirty as hell of course, but nothing a little Simple Green and a pressure washer can't handle.

 

be extra careful with that pressure washer. there are some electronics in there that don't like getting wet (TPS, distributor, etc).

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Engine bay's dirty as hell of course, but nothing a little Simple Green and a pressure washer can't handle.

 

be extra careful with that pressure washer. there are some electronics in there that don't like getting wet (TPS, distributor, etc).

 

Plastic bags 'n' duct tape. I intended to wrap the throttle body, and most, if not all, of the main wiring in plastic bags and seal it off with some duct tape.

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