Hey everyone!
I'm a fellow 4x4'er, and am going to help my roommate swap a different motor into his Jeep. The current motor is shot.

What he has:

'73 CJ5 with a stock 258
Single barrel Carter :-(
Stock vacuum advance, points-type distributor
Stock manifolds
3-speed stick

What going in there: (as best we know)

'76 AMC Pacer <img src="/forums/images/graemlins/lol.gif" alt="" /> 258 (wish we had the Pacer!)
Stock electronic ignition distributor
2 barrel Carter
Stock manifolds (with air injection)
Funky Borg-Warner ignition box
Came out of auto-tranny car

The questions are:
Which parts should we swap over or upgrade?

CARB?
I don't know if we should even try to use the new 2bbl carb with the emission Cr*p. 2bbl would be nice, the single seems kind of weak.

Distributor?
Should we go with the older points distributor? Maybe the electronic distributor would be less maintanance and more relieable, but does it have smog junk built in, and might it be a PITA to hook up? Needs the Borg-Warner ignition box I assume.

Manifolds?
Leave on the 2bbl intake and exahaust, and plug the air injection?

How about upgrades? Maybe upgrade to an Offenhauser intake and a Weber? Or might a Weber bolt up to the Stock 2bbl intake manifold?

So, maybe, go with mechanical distributor, and Weber on stock manifolds?

Also, someone mentioned the motors being "internally or externally ballanced." Is that something I should concern myself with?


My buddy has a few bucks to spend, but this Jeep is a little bit of a beater, so he doesn't want to dump any money into that he doesn't have to.

So what do you all suggest for the noobs?

Thanks a lot, Brian.

here is a link to pics of both the motors, and whats on them...

http://www.pbase.com/brianmoore/just_truck_parts

Man, I was typin' & typin' and then asked myself, "where is this guy from?" Uh-oh, CA. You'll want to talk to the local testing guy about what they'd rather see under your hood, than what you'd rather have.

My personal vote - go all pacer. If you've got the coil, black box and the motor looks rather complete <img src="/forums/images/graemlins/smile.gif" alt="" /> Why not? You're going newer engine in older body. That carb is an early 2b, you'll do well with it. No plug o' wires to deal with. You could think about just swaping the long block, retaining your intake/exhaust set & ignition for ease of operation.
Less obviously you should think about replacing the clutch & pressure plate while it's all apart. Have the flywheel resurfaced and ask the machine shop if you should have it balanced differently due to it's auto duty. I'm unsure if those years where balanced differently.

Yeah I too would go all pacer...except for a few things.
First off will be the balance of the flywheel. Make sure to have the pacer balancer and flywheel.. These will be neded to keep the engine in balance.
Then I would keep my exhaust manifold. If you do not keep it the sniffer folks will insist you add a pump to it. (which really ain't so bad.)
Since the original jeep is so old I betcha the test ain't so bad. You might be ok by not even mentioning the engine change.
BTW that carb is one of their better carbs.
Big Jim

i know where i live the smog check list has a specific box for if its the right engine or not... it'll probably have to go to a ref. but if all the smog components are a atched and working proporly its a shoe in

Thanks a lot for the info guys!
I should have mentioned though, this Jeep is smog exempt. In CA, 1974 and back don't have to get smogged. :-)
Thats good to hear about the Pacer carb, I guess we'll keep it then.

About the flywheel though... The motor in the Jeep has a flywheel, but the Pacer motor is out of a auto-tranny car, so we only have it's flex plate and torque converter. Might there be a problem with just bolting on the Jeep's flywheel to the Pacer motor?

Is that part of the "internally or externally ballanced" deal?

Thanks again for the help
Brian. <img src="/forums/images/graemlins/cheers.gif" alt="" />

Whatcha need to do about the flywheel:
Check with your parts store for a new flywheel for each vehicle (of course with a clutch) And see if it would be the same one if you purchased it. If not then you MUST NOT use the old one! If you intentionally put your engine out of balance you will surely live to regret it. Lots of internal things are apt to handgrenade at ANY time.
Big Jim

Great idea about the flywheel Jim. Thanks.

So, does anyone have a wiring diagram for the ignition sys on this '76? I'm gonna have to figure it out if we're going with this electronic ignition.

The ignition box only has 5 wires coming out of it. One to ground, 2 to the distributor, and two going to each side of the coil.

I wonder if I just power up the coil, like on mechanical ignition, since there are no "spare" wires coming from the box.

thx,B.

Yeah that oughta work! Makes it an easy change over doesn't it.
Something I forgot to say about flywheels! There are different offsets in the things.. the reason is unclear but the starter is different when the flywheel changes. I found this in Wranglers. This may be part of the inside/outside balance devices. So look to the two you have now and measuer the distance from the block to the ring
gear. If they are the same you have a better chance! Also look to the spacing of the teeth to see if you can use your old starter on the new flywheel (if you need one).
Big Jim

Great,
Thanks for all the info guys.
It'll help a lot.
Brian.