'73 Jeep CJ5 with 360. Engine rebuild or crate?

I have a 1973 CJ5 with a 360, that needs a new engine. Actually I'm doing a frame-up restoration, and a friend of mine said that I should buy a rebuilt short-block rather than rebuilding it myself. He says that by the time I spend the money on the machining and new parts for everything up from the crankshaft to the valve rockers, then I could save money by buying a short block.

What thinkest thou?

I am not going to overbore or make a racing engine out of it. The specs on the factory 360 are fine. I am going to put performance intake, headers, carb, maybe cam, etc...

So... Get the block machined, heads magna-fluxed, re-valved, ported and polished, or just buy a rebuilt short-block?

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Perplexed?

 

Cheapest route would be to find a good running but rusty wagoneer and just swap over.

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Yes, cheapest is another used engine.

What's wrong with the engine you have now? A restoration does not require a new engine. Anyway, the CJ only came with the 304 - it's already not the right engine, so you're not restoring.

I would evaluate the current engine first. Hot idle oil pressure is critical to these engines. Bad HIOP comes from cam bearings falling apart, or from timing cover/oil pump wear, combined with normal bearing wear.

If you want to save money, I suggest that you learn more about what goes wrong with these engines. There is some discussion here, and a lot on the Wagoneer (IFSJA and FSJN) and the AMC forums.

 

A few other things -

Rebuilts (or remanufacture) are always over-bored and fitted with new pistons. This is required to straighten the bore taper. You can reuse your old pistons, but that's not rebuilt - maybe instead "overhauled."

Porting and polishing is strictly race car stuff. It's an expensive reman that features port work.

A short block does not include cylinder heads.

To me, a crate engine is a new engine on a pallet. They don't exist any more for the AMCs. You can buy a Chevy crate engine though.

Hey - first post! Welcome from Boston!

 

I would a agree with your friend...........at least to a point.

Yes , it is costly to strip one down, have it boiled out, check the deck for flatness, bore it out, buy new pistons, pins & rings, re-size the rods, grind the crank, install new cam bearings, maybe a new camshaft & lifters, new timing gears & oil pump and maybe even a new timing cover , gasket & seal set Etc, and reassemble..............in either case your heads will also need to be freshened up, checked for flatness & cracks, grind the valves & seats, replace the springs, rebuild the rocker shafts etc. and reassemble and NO you don't need to port and polish these stock heads.......
If you were to find a rebuilt short block from a reputable re-builder with a reasonable warranty these guys can sell these far cheaper than an individual can do one by themselves................Of course if your a Do it yourself kind of guy then do it yourself.....or as others have mentioned perhaps a used motor that you can hear run while checking the oil pressure , do a leak down & compression test and get some history on it may also fill your needs.

 

Mmm. Not sure if that tells the whole story.

You can probably get an assembled factory-built short block for a price that may be less than the cost of the machine work. Someplace like Autozone will give you a good price. These engines are "remanufactured" - the cores are brought in and broken down into their reusable parts. These parts are refurbished and placed in stock. When the company needs to replenish their inventory, they pull parts from stock and build the engines as if they were beng built at the factory.

The main problem with spec'ing the work at a shop of your choice is deciding what work needs to be done. The shop will always err on the side of caution and recommend procedures that may or may not be needed in every case. Once you do everything that the shop recommends, you may end up spending more on the engine than you would have if you had bought a factory reman. Knowledge and experience matters here.

The factory engines come with a warranty - the factory expects a certain number of failures within the warranty. You'll probably get a good engine, but if you don't you need to be sure the builder will cover replacement even if you installed the engine yourself.

If you go the route of building the engine yourself, you have the opportunity to check the work of the machine shop before you put the engine together. Many engine builders prefer this because they trust their own skills more than the skills of the factory workers. You take on a different kind of risk if you assemble the engine yourself.

I suggest you get some prices. Autozone or similar will be a good base to judge against. Go to a local machine shop and see if they offer locally assembled engines, or if they only sell factory engines. They might give you a good price to rebuild your core.

 

It's cool to say you built your own motor, but time is money. My '79 CJ-5 came with a rebuilt 360 in it when I bought it. It's an ATK. 4 wheel drive hardware is a dealer and they have the long block for just over $2k. Chances are you could get a running Wagoneer for that money, but it's still a used motor. ATK motor has a 3 year unlimited mile warranty according to the link.
http://www.4wd.com/Jeep-Engine-Perf...=46&t_pt=4337&t_pn=ATKDA14#overview_Container

 

Just my 2 cents, but bulk commercial engine builders are assembling those motors as fast as possible using the cheapest components that will get them past the warranty. Over the years, I had to re-learn that lesson a couple of times. I wouldn't hesitate to tear it down and rebuild it. You then know what every piece of it is and that it was put together right. And if it isn't put together right, the responsible person is close at hand---

Lots of good literature floating around-start reading. At least enough of it so you can talk head to head with the machinest. I believe allison on here just put a 401 together and he would certainly be a good source to have a conversation with.

Bottom line for me is yes, I would buy a crate motor, as in a brand new one from GM, Ford, Chrysler, but not a chance I will buy another "rebuilt" from anyone-at least not something I would be planning to run as received.

 

Here's an example of what's available in my area for the do-it-yourself guy.
A long block is about $1,500.
You can probably find comparable prices in your area if you shop around.
As for the used motor route--From time to time I can get running motors starting at $100.
I have one on the stand that I got for $100. Was running when removed (about 112,000 miles on it). I took the intake and oil pan off to inspect it. Looks like it's camshaft time. otherwise looks good.
Other 360's I bought for $50/each were disassembled. Other than the need for a valve job, they were useable as to bearing and cylinder wear.
Your results may vary.

http://theengineshopinc.com/shop_specials.htm