• NAXJA is having its 18th annual March Membership Drive!!!
    Everyone who joins or renews during March will be entered into a drawing!
    More Information - Join/Renew
  • Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

Rebuilt Engine vs. Rebuilt Engine

tn_outside2003

NAXJA Forum User
Location
Tennessee
I have seen many threads where people say "Just purchase a long block and be done with it."

I can't seem to agree. I would like some input please. It is my opinion that ALL parts sold in parts stores are cheap parts, mostly made in China (etc), with Napa being the best of the bunch. As I get older and wiser I lean more towards OEM parts, purchased from discount retailers online.

So, my 2000 XJ 4.0 is at 170,000 miles and for various reasons (blown H. Gasket years ago, wearing head, worn main bearings, dropping oil pressure, intermittent misfires, etc) needs some engine work.

So.....if I need main bearings, rod bearings and a new head....many would say "buy a remanufactured long block and move on." But my logic is that those engines cost over $3,000 and are rebuilt completely with cheap Chinese parts. Probably the original cam and crank but otherwise all cheap Chinese valves, bearings, seals, rods, pistons?, rings, etc. All of this crap will wear out. It may take 50,000 miles, or even 90,000 miles. But that seems inferior to me. I simply would NOT rebuild an engine with a bunch of parts from O'Reilly. Would you??? And the major engine rebuilders sell exactly THAT. I would think that paying a sound mechanic labor to replace all of these parts with genuine Mopar parts (that I provide) is the better way to go. I have priced it out....it would cost about the same amount, or just a little more. This is with creative purchasing, a used, newer head, etc.

It seems to me that rebuilding my own engine, a known entity, with genuine Mopar parts would be INFINITELY better than buying some rebuilt engine with a bunch of junk parts. I am not concerned with the "3 year, unlimited mileage warranty." I want a "It will drive for 200,000 more miles" warranty.

What do you people think?

Thanks,

JG
 
I'm hesitant to buy a remanufactured long block as well. Frankly, I'm less concerned about using chinese parts for stuff like pistons since the bigger issue is the construction (Forged - best, Hypereutectic - good, Cast OEM - worst). The bigger problem (for me) is that many of the shops that build these combo's are quick turn shops that are more concerned about turning blocks around quickly than quality control. I have had much better luck with local shops who see my face and do what I ask.

Case in point, I bought a rebuilt Ford short block from one of the online shops simply because it was a great price even considering I was going to upgrade the rods/pistons. Upon taking it apart, I found steel shavings on the bearings. Thank goodness the crank was ok but I still had to take it in to get it polished and then spend additional hours with pipe cleaners and compressed air to make sure it was clean.

Rather than OEM, I have become a big fan of using aftermarket performance parts for things like this. A good set of forged pistons from someone like ICON (available with rings as a kit from Summit) and performance Clevite bearings work great and are stronger than stock. As for heads, I have become convinced that the only way to ensure you get a good product is to have a local shop do the work. Good quality guides and valves are key and I am not convinced on the current trend of boring out the existing guides and installing oversized valves. I want it done right which means someone local will get the business.

I have seen many threads where people say "Just purchase a long block and be done with it."

I can't seem to agree. I would like some input please. It is my opinion that ALL parts sold in parts stores are cheap parts, mostly made in China (etc), with Napa being the best of the bunch. As I get older and wiser I lean more towards OEM parts, purchased from discount retailers online.

So, my 2000 XJ 4.0 is at 170,000 miles and for various reasons (blown H. Gasket years ago, wearing head, worn main bearings, dropping oil pressure, intermittent misfires, etc) needs some engine work.

So.....if I need main bearings, rod bearings and a new head....many would say "buy a remanufactured long block and move on." But my logic is that those engines cost over $3,000 and are rebuilt completely with cheap Chinese parts. Probably the original cam and crank but otherwise all cheap Chinese valves, bearings, seals, rods, pistons?, rings, etc. All of this crap will wear out. It may take 50,000 miles, or even 90,000 miles. But that seems inferior to me. I simply would NOT rebuild an engine with a bunch of parts from O'Reilly. Would you??? And the major engine rebuilders sell exactly THAT. I would think that paying a sound mechanic labor to replace all of these parts with genuine Mopar parts (that I provide) is the better way to go. I have priced it out....it would cost about the same amount, or just a little more. This is with creative purchasing, a used, newer head, etc.

It seems to me that rebuilding my own engine, a known entity, with genuine Mopar parts would be INFINITELY better than buying some rebuilt engine with a bunch of junk parts. I am not concerned with the "3 year, unlimited mileage warranty." I want a "It will drive for 200,000 more miles" warranty.

What do you people think?

Thanks,

JG
 
Hummm....performance parts.
Thanks for the info.

Something to consider. My mechanic indicated that pulling the pistons, having the cylinders polished, and putting new pistons in was "not an option." I think that means too much labor and not enough quick profit.

Hummm.....
 
Here is something to keep in mind. One of the "parts" that can be ordered is a crank kit. The kit comes with a replacement crankshaft and matching bearings the crank having been turned.

Why mention this? Because an end of production YJ crank kit (that has the long nose for the serpentine belt) costs about the same as the XJ kit. Installing the YJ crank takes the 4.0L to 4.5L in displacement. As the block is going to get bored anyway, might as well go for more than enough to just clean the cylinders.

Done properly, building a stroker engine is not much more expensive than a simple rebuild of the 4.0L.

In defense of your mechanic, doing an "in frame" rebuild is never a good idea. As the engine ages, the cylinders wear out as the iron is being scraped by the steel rings. This causes the bores to enlarge and form a taper as well. The degree of wear is what determines how gig the new pistons have to be. So, he is correct. Doing a slap and dash will have a very bad result. For starters, the rings may never seat and they will leak compression as well...

AS is always the case, there are no short cuts that give an acceptable result. The question for you is, what displacement do you want to wind up at? One thing I can state without any qualms is that that engine will never displace 4 litres again.

OK, I will put a caveat on that, it is possible to bore out the block and sleeve it back to stock but why on earth would anyone do that to a 4 litre...
 
FYI I work at NAPA and they use ATK for the reman engines now. skip the middle man and go straight to ATK, they're quality rebuilds and were a big sponsor of the jeepspeed racing series so they know jeep engines well.
 
I used a autozone longblock and it lasted for years in a buggy, that now is still doing good.
http://www.autozone.com/autozone/pa...9i2Z9enw6?itemIdentifier=561305_804124_11266_

and then with a current coupon code you get 20% off and only 100$ to your door frieght. Your out about 1650$ (after you return your core). With a 3yr warranty.

I do, on occasion, purchase BRAND NAME products at AZ--brake cleaner, oil, not a lot else. I NEVER PURCHASE AZ BRAND PARTS. This is based on personal experience as well as watching a number of shops that FAILED from using AZ parts--comebacks destroyed them.

AZ is one of those "caveat emptor" places.

I will be 62 in February, learned mechanics from my Father--33 years with Ford Motor Corp., and his "side job" was a service station with full auto repair shop. I was ASE certified in the early 70s, worked for dealerships, independent shops, and have owned and operated my own shops. Junk parts will put you out of business. Don't buy junk parts.
 
if you think autozone builds their own long block then so be it.

But you can buy an ATX or other even, long block from autozone. The only thing autozone has into any long block they offer, is the buying power, so you save $.
 
THANKS for the responses. A lot to think about.

I do not want a stroker. This is a daily driver and I want gas mileage more than performance. I simply do not need more HP, torque, or performance. I don't think I have ever had the pedal pressed to the floor for more than a second in over 10 years.

I think I will put my new (used) head on the motor and see how it works. Then I may have the oil pan pulled if necessary. If all the bearings are smoked.....I am not sure what direction to take. JUST bearings and a head will most certainly work. But the engine will still have worn cam, cam bearings, rods, pistons, rings, timing chain/gears, etc. Hummm......

This is tough. I could CARE LESS about the warranty on rebuilt engines. Most people sell the vehicle in less than three years OR the vehicles are "buggys" which run up very few miles. This is my DAILY DRIVER. I STILL lean towards pulling the motor and having it rebuilt, from the ground up, if necessary.

No one here has convinced me that I should purchase a rebuilt. ATK....same as Jasper as far as I am concerned. Just another shop that throws together rebuilts as fast as they can turn them around. With chinese parts. Who wants to replace their motor, for free, two years later? Too much LABOR, time, and labor expense. If the original motor lasted 170,000...then so should the rebuild. And I have NEVER seen a rebuild run up that many miles.

PLEASE feel free to correct me. I DID ask for opinions.

Thanks!!!

JG
 
all things being equal, i would rather have my own rebuild done than buy one in a box. i have installed several "crate motors" for people over the years. stock and performance, and you really do get what you pay for. i'd never trust anything "stock" in my own vehicle because mass production shoots for a "high percentage" of success. conversely i'd easily trust a high performance build from a reputable manufacturer, though i'd probably still pull it apart and inspect the crank and cylinders myself.
i say give the local engine shop your business. compare pricing on performance parts to OEM and consider the performance part to be just a little better for the most part, even if you dont want more power. they wont necessarily make your fuel economy worse, including a stroker crank.
a quick head swap, new main bearings, and fresh gas will just undermine your desire of reliable longevity.
a full rebuild isnt always required, but in the case of a high milage 4.0L i say you are wasting your $$ if you dont have the cylinders trued up and filled with new pistons by a guy who knows you are watching him and expecting quality workmanship.
 
@ sidriptide.
Thank you.

Sort of my feelings. But my honest mechanic around the corner does not want to get involved in a motor rebuild. Hummm....I may have to convince him. I do have a plan B mechanic...also very honest...but he is quite old and runs a small, country shop with a dog laying around and fat men sitting around chewing tobacco. CLEARLY a great shop.....seriously. But a bit out-dated for my tastes. Again....hummmmm......
 
Last edited:
Something to consider. My mechanic indicated that pulling the pistons, having the cylinders polished, and putting new pistons in was "not an option." I think that means too much labor and not enough quick profit.

No. What this means is that with a high mileage engine is that the bore is too worn for a simple hone(its not polish) and drop in new pistons. You will have piston slap an burn oil. If you are hesitant about some of the big rebuild houses (rightful so) have a good local machine shop do the rebuild. Spec good bearings such as Clevite or King. Use speed pro hypereutetic pistons pistons, Felpro or Victor gaskets, good quality valves and Hylift lifters. There isn't much selection for our engines.

An engine rebuild is not something a mechanic usually does. The mechanic may install the engine, but usually the rebuild part is left up to a machine shop. Some machine shops do both.
 
I just installed an engine in my 2000. I did TONS of research on ATK, Jasper etc. Any parts store engine is going to be an ATK. Jasper is overpriced, IMO. Also, their long blocks came with the factory 0331 head which I did not want.

I ended up buying a reman head from J&C enterprises on ebay. As for the long block, I used a local builder here that has a great reputation. I paid $1600 for the long block. As for parts, I don't know what or where the internals are from. But I trust this shop over the other online or mass production places. I have about $24-2500 in parts and fluids. And I replaced the radiator, hoses, everything I could.

I did the install myself and used a HD fel pro headgasket (something a purchased long block wont have). Also used all other fel pro gaskets on the rest, and was able to prelube the cam, lifters etc too. I felt better about doing to work myself because I got to take time and clean everything and make sure it was done right. Any mechanic will throw the old dirty parts back on as it's all about the bottom line. Something to think about.

Find a local builder/machine shop with a good reputation.
 
Correction, I paid $1600 for the SHORT block. The aftermarket thick casting to replace my 0331 head was $400 shipped.

If you have any questions fire away, I just went through all this.
 
Back
Top