4.0 Rebuild $$$

[Beanmachine7000]

Hey guys, I'm looking to put a 4.0 in my BII and was looking at buying a junker Explorer and rebuilding the 4.0, I was wondering if anyone had any general estimates on what that would cost. I would keep the rotating assembly, but rebuild from the mains up... Get the block cleaned up and machined, maybe get it bored out, and new oversize pistons, new rings, new camshaft and bearings, entire new valve train along with reworked heads, gaskets, seals and such of course too... Any ideas?

Also, if anyone has any suggestions when I do this, to improve reliability or performance, I'd welcome those too... I'm really looking to do this right the first time, I don't want to tear into it again...

Thanks...

 

[Twizzler09]

http://www.northernautoparts.com/ProductModelDetail.cfm?ProductModelId=9794

$971.38 - for that rebuild kit.... might be cheaper out there but Northern Auto is my personal choice for stuff like that.

Thats about all I can help you with, machine work seems to vary greatly from place to place, so shop around and see if you can find a reputable place that runs a little under the norm. As for over-boring.... you probably wont even need to. From the 4.0s that I've seen torn down after months of sitting and 200k+ miles, the bottom end was still pristine and the factory cylinder hone still easily visible. If you do end up boring it out, its debatable, but .020" over is about the max that'd be "safe". Some say .030". Up to you...better safe than sorry imo.

Comp Cams makes a couple different camshafts you could use if you wanted to. Hit up their website and poke around still you find their "Ford V6" selections. Never used em myself but I hear they're pretty decent.

Thats my .02 for what its worth

 

[woodyedmiston]

I was just doing some figures in my head on the way home from a meeting. The machining costs, new pistons and rings, new rockers, new lifters, bearings, gaskets, will easily break a grand. If you spend $200 on a valve job for stock heads, the same for oil pump, water pump, and timing chain, you are at roughly $1500. New heads pushes it up further. At this point you haven't spent any money on a hot cam, induction repairs or upgrades, etc. etc.

There is only one reason in my mind to do all this yourself - and that it to know what quality of parts are going into the rebuild. You can purchase a Jasper rebuilt engine for about that money. One of the things I've heard MAKG say often is that when you to your own work, you have to be confident that you are not going to do something wrong during the process that is going to ruin all your hard work.

 

[Chris102371]

You generally don't have to replace a roller cam unless something has destroyed it,or you want a performance cam instead. Just a thought.

 

[JohnPi]

Why wouldn't you save yourself the hassle and just buy a known-good engine for $500, and drop it in? You find something in a wreaked truck with around 100k miles on it, you'd be good to go, in my opinion. I bought a '96 4.0L drivetrain (engine and transmission) for $250, with 75k on the clock.

I read about way too many people on this board with over 200k miles on their trucks to think that it's ever worth the money to rebuild an engine. Heck, I used to think that my engine was headed towards oblivion when it had "only" 175k miles on it (that's why I bought the $250 engine/trans combo). Over 75k later, I'm starting to wonder if the body will rust out before the engine gives out, and I sold the engine.

 

[fastpakr]

Why wouldn't you save yourself the hassle and just buy a known-good engine for $500, and drop it in? You find something in a wreaked truck with around 100k miles on it, you'd be good to go, in my opinion. I bought a '96 4.0L drivetrain (engine and transmission) for $250, with 75k on the clock.

I read about way too many people on this board with over 200k miles on their trucks to think that it's ever worth the money to rebuild an engine. Heck, I used to think that my engine was headed towards oblivion when it had "only" 175k miles on it (that's why I bought the $250 engine/trans combo). Over 75k later, I'm starting to wonder if the body will rust out before the engine gives out, and I sold the engine.

I completely agree. Rebuild a broken engine if you have no option. Otherwise, purchase a known good engine for a tiny fraction of the price and keep on trucking.

 

[CopyKat]

If the engine still runs good just throw a gasket kit into it ($80 shipped on e-bay) and consider it good. maybe get a rocker refresh kit for it and it should be good for many miles to come.

Even a running 4.0L from a junk yard shouldn't be more than $800-$1000

 

[Beanmachine7000]

Thanks guys... The reason I looked into rebuilding one is because the crappy junkyards around here don't have any (i'm serious) 4.0's that run... So I thought it might be cheaper to rebuild one rather buy one of those reman ones...

 

[turbo cat]

have you checked craigslist or ebay? you can probally still get one shipped to you for yunder 600$

 

[Beanmachine7000]

I think I might have actually run across one... It's only got 80k on it, and it's still running, but the girl who is getting rid of it is known to not take care of her car too well... I mean, she just had her oil changed 10+k miles after it was due... Plus, she's been running it with the check oil light on for a while (thinking it meant CHANGE OIL)... I'm just weighing my options...

 

[MAKG]

If it's not knocking, the oil pressure is OK, and it's consuming neither coolant nor oil excessively, it's probably fine.

Rebuilding is far too expensive -- and replacement far too labor-intensive -- to do if you don't know you need it.

It's good practice to figure out what's wrong with an engine BEFORE removing it from the vehicle. There are several diagnostic tests to do so. For instance, leakdown, compression, vacuum, etc. But from the information given, I don't see any reason to suspect ANY problem.

 

[Xploda]

I got my engine for 350$ and it had less than 80k on it scoped the cyl walls and you could still see all the cross hatch in it. real smooth. just the intake and other components where really worn so makes me worry that hey didn't maintain it all that well....but yet you can still see the machine work on the inside

 

[jasonl]

Has any body on here had new valve seats,guides,seals and a valve job done? If so about how much did it cost?

 

[Kylan]

Has any body on here had new valve seats,guides,seals and a valve job done? If so about how much did it cost?

I just did on a 351W and it cost $400

 

[98blownranger]

don't rework factory heads get new heads that are a thicker cast and have those done. or get a set all done right out of the box. supersix motorsports. Bird used to do really good heads. I had 2 sets of his