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2.5 LITER PERFORMANCE MODS

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WARBED View Drop Down
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    Posted: Mar/05/2012 at 3:37pm
Have a 59 Rambler American really wanted to put a 4.0 into her, I even bought a 96 Grand Cherokee for a doner only to find the engine is way to long. I guess all I6 are not the same.  Other option 2.5 (150ci) AMC I4 engine 4.0 little sister, Stock she has 30hp over the original I6 so I should be off to a good start. Found a Cherokee with 2 2.5 engines one in the engine compartment and the original in the back.  I have allways dealt with AMC v8 and this is my first I4. I'm boring .030 with KBlack hyper pistons. Milling the head to help comp. will ballance and blueprint. cutting the crank for less resistance. roller rockers I have a bridged set off of a 401 and heard they interchange with the 4.0 so it should work with a 2.5. and this is were I get stuck. I need a performance intake, cam and headers and I run into road blocks does anyone know for sure who sells parts that I need. And by the way it's not the Iron Puke I mean duke.  It's the 150ci not the 151ci and parts will not interchange.  Does anyone regrind cams?          78 Pacer S/W 401/727/3.31 . 72 2dr Matador 401/727/3.91.   59 Rambler American 2dr SW ?/?/?.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote scott Quote  Post ReplyReply Direct Link To This Post Posted: Mar/05/2012 at 3:40pm
Some interesting 2.5 transmission info here: http://theamcforum.com/forum/25litre-amc-in-jeep-trans-swap-question_topic37552.html
Mopar Performance used to offer cams for the 2.5, along with a ported cylinder head. Some cam part #'s to search for: p4529657 p4529658 p4529659 p4529660. These #'s come out of the Mopar Jeep Engines Speed Secrets book from 1990.

Edited by scott - Mar/05/2012 at 3:48pm
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Post Options Post Options   Thanks (0) Thanks(0)   Quote carnuck Quote  Post ReplyReply Direct Link To This Post Posted: Mar/06/2012 at 12:58am
If going std trans, get an AX-15 from a Dakota with the 2.5L
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Post Options Post Options   Thanks (0) Thanks(0)   Quote farna Quote  Post ReplyReply Direct Link To This Post Posted: Mar/07/2012 at 8:00pm
ANY of the cam companies will regrind a cam for you. You'll have to call and talk to their tech people though. Mopar Performance has some good cams. I'd use the Phase II (middle) cam for a good street performer (http://www.southeastrt.net/catalog/index.php?cat=9&item=602). Borla makes a header for a Wrangler with 2.5L that might work, so does Banks (I like the Banks best -- http://www.a1jdm.com/product.html?id=banks-exhaust-manifold-91-02-jeep-wrangler-yj-tj-2-5l).

I don't think there are any 4V intakes for the little 2.5L, even a 390 4V would probably be too big though. You can get an older model (84-85) carb intake and adapt a nice Weber carb to it if you want a carb. The port injected four is probably the best though.  
Frank Swygert
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Post Options Post Options   Thanks (0) Thanks(0)   Quote carnuck Quote  Post ReplyReply Direct Link To This Post Posted: Mar/09/2012 at 12:47am
Mine worked very well with the Renix TBI. Larger throttlebody opening than the MPFI ones.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote threeelms Quote  Post ReplyReply Direct Link To This Post Posted: Sep/20/2021 at 5:45pm
How about ignition modifications. is there a points type distributer adaptable to the 2.5 ? ( for an engine swapped into a 49 Jeep )
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Post Options Post Options   Thanks (0) Thanks(0)   Quote tomj Quote  Post ReplyReply Direct Link To This Post Posted: Sep/21/2021 at 12:02am
How wide are the 2.5L intake installations? The engine compartment is very narrow, as well as short. Wider at the top of course. I'm very interested in how this engine fits.

1960 Rambler Super two-door wagon, OHV auto
1961 Roadster American, 195.6 OHV, T5
http://www.ramblerLore.com

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Post Options Post Options   Thanks (0) Thanks(0)   Quote farna Quote  Post ReplyReply Direct Link To This Post Posted: Sep/21/2021 at 5:59am
Old thread! WARBED has already put the Jeep 2.5L in his car, some pics and details in other posts he's made. The MPFI intake won't fit as it sticks out from the engine too far. The carb manifold fits (I think he has the carb?), I'm not sure about the TBI intake. If you cut the hump out of the driver's side the MPFI intake should fit though.
Frank Swygert
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Post Options Post Options   Thanks (0) Thanks(0)   Quote farna Quote  Post ReplyReply Direct Link To This Post Posted: Sep/21/2021 at 6:13am
I don't know about distributors. A Chevy HEI distributor from a 250 six fits an AMC six. I THINK the old 62-70 Chevy II 153 four uses the same distributor, as it is a shortened 250 six, and the AMC 2.5L uses the same distributor as an AMC six... I think (limited hands-on knowledge of the AMC four). If that's the case you should be able to find a six cylinder distributor and order a four cylinder cap for it. The six cylinder distributor is probably easier to find. A marine 153 (2.5L) or 181 (3.0L -- Vortec 3000) is the same engine with a larger bore and longer stroke. It was made 67-2013, modified in 91 for a one piece rear seal. 91+ uses a different flywheel and bolt pattern (required for the change in the block for the one piece seal).  I don't know when they changed from the 153 to the 181 (2.5 to 3.0). But an older one should have a points distributor, maybe even an HEI. The marine distributor will be a bit different as it has to be spark and moisture proof, but would still work in a car. Might be even better for an old Jeep -- ford deeper....
Frank Swygert
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Post Options Post Options   Thanks (0) Thanks(0)   Quote WARBED Quote  Post ReplyReply Direct Link To This Post Posted: Sep/21/2021 at 11:02pm
On the distributor I used a stock Motorcraft/Autolite that came on the 85 2.5 but ditched the ignition box and wired in a HEI module in its place and placed it on a aluminum heat sink close to the distributor. Its bolted to the frame and has air that travels through the frame keeping it all cooled. There is a sight how to convert Ford and Dodge modules to HEI. So far its been working flawlessly. As for the intake its also the one from a 85 Cherokee. Throttle body unit that I milled and made an adapter to facilitate a Holley/Weber/Motorcraft PINTO Two barrel progressive carburetor. Great carburetor. The only mod I had to do to make it fit is remove the EGR and plug the ports. As for transmission a 200R4/700R4 from a Chevy S10 with a 2.8, it has a 60deg bellhousing that is the same as the AMC 2.5 same bolt pattern. 3.1 Chevy Camaro flex plate and a home made pilot bushing. Used a 8.8 diff from an explorer shortened the drivers side by 3 inches and used a passenger axle. also the S10 driveshaft just bolted in, but did offset the diff back a few inches since the stock location just looked too far forward. anyways that is what I did when I had a lot of time for that kind of stuff. 
59 American 2dr S/W. 70 390 AMX. 70 232 javelin. Kelvinator fridge ice cold beer storage.
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