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#1 even looks pretty low, and #6 isn't great. You've definitely got some problems going on.

Here's a pretty decent article for performing a leak down test: http://www.hotrod.com/articles/cylinder ... wn-tester/

I thought Autozone or Advance rented the tool, but I don't see it on their website; you may need to stop in and see. Really you just need to pressurize the cylinder somehow, I've even done it with just a trigger style compressor handle (with a rubber tip). You will likely hear air coming out somewhere immediately with whatever problem you've got. Likely you'll hear it either between the head and block (head gasket), in the valve cover (valves), or crankcase (rings/pistons).


aa

^^that. Just make sure whichever cylinder your checking is at TDC of compression.


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So my father in law and I are about at the point of ripping the 4.0 out and throwing another in. However, a friend is willing to sell me a working 350 for $50 and I can buy a Novak 350/ax15 adapter for $350.

Are there any benefits to keeping the 4.0 verses getting the 350?

Fuel injection is a pretty big one. After that... Probably splitting hairs with the exception that there will be a lot of nickel/dime costs with a motor swap.
Exhaust, radiator, hoses, electrical, fan shroud... That type stuff.



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Shagoneer wrote:So my father in law and I are about at the point of ripping the 4.0 out and throwing another in. However, a friend is willing to sell me a working 350 for $50 and I can buy a Novak 350/ax15 adapter for $350.

Are there any benefits to keeping the 4.0 verses getting the 350?

Going back to a carb would suck. Also don't forget about engine mounts and such that have to be put in. You have to completely cut out the i6 mounts and weld in new mounts. Then there is the radiator that will need to be changed out most likely, and complete exhaust. And personally I prefer the off idle torque of the i6 over the V8 for wheelin. And well, the fuel injection for offroading every day of the week.

Not using a chebby motor is a pretty huge benefit of keeping the 4.0L. haha

In all honesty, though, you're obviously going to get a lot more power out of the 350. As Ted mentioned, it's never as straightforward as buying the adapter and dropping it in. I'm a pretty huge fan of the 4.0L, even more so of the stroker options. AMC's straight 6 design is one of the best engines designed for a very long time. It's tough, cheap, easy to work on, and super reliable (any motor will blow up if mistreated).

I don't personally see any benefit to swapping in the 350, unless you were starting from nothing to being with.


aa

I also love the 4.0, however I've been offered a working engine with all of the accessories for $50. Simultaneously no one in my area is selling a 4.0 for less than $700.

Plus the cost of 350 accessories is much cheaper. You can get a basic 383 stroker for 499, a 4.7 stroker kit cost as much as a brand new 4.0.

If you want to go with the 350, thats fine. Just be aware that its not going to be a small or cheap project. Once you add in everything required, I would be surprised if the V8 swap ends up be cheaper than another 4.0. Much less just rebuilding your current 4.0.

Yup, that^^
We are supportive of whatever you choose to do man. Just trying to point out a 50.00 motor is gonna cost a good deal more to make work in both time and money.
You could always buy a used 4.2 cheap and use the crank to make your own stroker. That would give you a fresh 4.0 with more power that bolts right in.


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My other thought is to try to unload it and use the money to help buy an m715 that someone is selling in the area.

So I got a really good deal on this jeep (I'm assuming because of all the problems I didn't learn about till later) but how much would everyone value it at running and what would you value it at in its current state.

It has Mickey Thompson wheels and tires, custom rear bumper, the AX15 5 speed, and a twin stick D300.

Shagoneer wrote:I also love the 4.0, however I've been offered a working engine with all of the accessories for $50. Simultaneously no one in my area is selling a 4.0 for less than $700.

Plus the cost of 350 accessories is much cheaper. You can get a basic 383 stroker for 499, a 4.7 stroker kit cost as much as a brand new 4.0.

The last time I did an engine swap in a CJ it cost me ~$900. I already had the complete engine and the transmission adapter was $50. That was with me making the engine mounts and paying a radiator shop $75 to move the ports. Took me a month of work. $700 for a running 4.0 that you can just stab in is not a bad deal, considering a $50 engine may be worth every penny, but no more.

I found a decently priced 4.0 so I will be driving the 3 hours from Socorro NM to El Paso TX to pick it up next weekend. I'm planning on replacing all of the gaskets and cleaning it up before I install it. So the question becomes, what color do I paint the engine before dropping it in? I'm thinking maybe AMC blue with AMC red valve covers, just to be funny since it's an AMC body with a Chrysler era engine, or possibly just plain old black, or fire engine red.

Go blue!

The 4.0L was an AMC motor, not a Chryo motor. It belongs in blue.


aa

AMC originally designed it, but the later models like the one I'm working with were redesigned by Chrysler.

Shagoneer wrote:AMC originally designed it, but the later models like the one I'm working with were redesigned by Chrysler.

Not really redesigned. They just updated external parts of the engine. Such as the intake, fuel system, etc. You can still swap internals between the various versions.

I'll say it again for clarity: the 4.0L is an AMC engine, not Chrysler. AMC designed it but never had the money to put it into production. The only thing Chrysler did was try to squeeze a bit more mileage out of it over the years. Same engine, though.


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Cecil14 wrote:I'll say it again for clarity: the 4.0L is an AMC engine, not Chrysler. AMC designed it but never had the money to put it into production. The only thing Chrysler did was try to squeeze a bit more mileage out of it over the years. Same engine, though.


aa

AMC did put it into production. The first XJ to use it was entirely AMC. Chrysler bought them after the '87 XJ went into production.

Fair enough, forgot about those guys.


aa