4.0 Rebuild Thread

[HardRooster]

I have a 92 Explorer that started knocking just a few miles after I replaced the cylinder heads due to a blown head gasket. Pretty frustrating, but I'm here now, with the engine out, torn down and the damage found, spun No1 rod bearing due to a clogged oil feed hole in the con-rod. I'll get pics of all the carnage up in a few posts.

I've been researching the interwebz about this motor, and I've got an idea of what to do to rebuild this motor and give it a little more pep without making it an expensive project.

I should note, that I'll also be rebuilding the transmission, and maybe doing more work to the paint and body (I'm a professional painter/body man) if I'm feeling up to it, but those will all go in the appropriate forum sections.

Back to the motor, I've ordered up a list of parts, broken down on this spread sheet/screen shot (Updated 7/26);

Explorer Invoice2 by CASEY, on Flickr

The big difference will be the addition of the Comp Cams 410 grind, a minor port and polish job and headers. From ALLLLL the research I've done from people who've actually worked on these motors, those three changes will make a significant difference. Other things like throttle body, MAF sensor, cat-back exhaust are all back up singers on this stage. Also, those are things rather easily added later. It's much harder to go back and add a cam later.

Not listed on there is an air box modification. I'll probably do something like what I've seen in the tech section, maybe a cowl induction with a pipe run behind the fender. Just something to draw non-engine-bay-air.

So anyway, chime in with your experiences and advice, let me know if I'm missing something, or doing something needless. Pics and updated coming in the next couple hours.

 

[HardRooster]

If you want to know more about me, I introduced myself here: GOOD MORNING!

Engine Pics!

Lets see, where to start...Lets get right to it. Here is the bearing that got its little feelers hurt;

Exploder project by CASEY, on Flickr

Here you can see the Con-Rod oil feed blockage that led to the recently deceased bearing;

Exploder project by CASEY, on Flickr

The gutted block, still with all that fairly fresh copper gasket spray;

Exploder project by CASEY, on Flickr

Damage to the Crank Shaft, I've entered it into an exchange program where the contest winner gets to reject at least one crank shaft because the vendor sent the wrong year crank. But I'm dealing with a very friendly local Machine Shop, Sierra Engine and Machine here in Pioneer, so no complaints. Just patience;

Exploder project by CASEY, on Flickr

Engine part vomit all over my work bench;

Exploder project by CASEY, on Flickr

Lastly, a cheap, auction yard fork lift comes in handy for moving anything around . I would have pulled the motor with it, but the forklift doesn't fit in my tiny shop. A bigger shop is a future project, but don't look for those posts just yet (I also have a two post car lift, and nowhere to put it, first world hillbilly problems);

Exploder project by CASEY, on Flickr

 

[Marty'70]

Looks like you've got a good hold of things.

Sent from my QMV7B using Tapatalk

 

[HardRooster]

Got the correct crank in today, also realized I forgot to order piston rings, so I found a set of Sealed Power rings on eBay for $45. Add that to the list.

 

[2trux]

The clogged hole on the rod is the oil supply for the wrist pin in the piston. It does not feed oil to the rod bearing, that is supplied by the hole in the crankshaft which is supplied by the hole in the main bearing web. The most common cause for failure is putting in the main bearings incorrectly. Some mains only have the oil feed hole in one shell, if you put that in the cap side and the solid one in the block side you will not get oil pressure to that part of the crank.

 

[HardRooster]

The clogged hole on the rod is the oil supply for the wrist pin in the piston. It does not feed oil to the rod bearing, that is supplied by the hole in the crankshaft which is supplied by the hole in the main bearing web. The most common cause for failure is putting in the main bearings incorrectly. Some mains only have the oil feed hole in one shell, if you put that in the cap side and the solid one in the block side you will not get oil pressure to that part of the crank.

Ah ha. Good catch. Perhaps the clog is just debris from the failure then, forensic evidence so to speak?

Suppose it's irrelevant now.

I'll be waiting for the factory service manuals to arrive before I assemble anything, and brown Santa still has a lot of trips to make before I can really proceed. Got the headers in yesterday, that's always a fun feeling, driving up to see that box-o-parts in the driveway.

 

[HardRooster]

OK, so, port and polish, port-matching discussion time.

I now have aftermarket headers (Headman) and aftermarket cylinder heads (Fall Auto) and two different sets of aftermarket exhaust gaskets. (Headman and Fel-Pro)

None of it matches up, predictably.

The exhaust ports are shaped differently;

Untitled by CASEY, on Flickr

The Headman exhaust gasket is designed to match up with the headman header flange, and it does, but its way too small for either cylinder head;

Untitled by CASEY, on FlickrUntitled by CASEY, on Flickr

The Fel-Pro gasket matches the shape of the factory head very well, but cuts off the aftermarket head in a few spots;

Untitled by CASEY, on FlickrUntitled by CASEY, on Flickr

And the inside of the headers are where the welds are, and they're not all that pretty, lot of slag in there also;

Untitled by CASEY, on Flickr

The headers also have a couple extra o2 sensor ports that I'll just cut off/weld up. I just need the one.

Anyway, so here's my thought...Dangerous I know...

1) I want to use the Fel-Pro gasket, which I will have to trim a tiny bit to match the new head.

2) I want to weld up the headers (tube to flange) from the outside.

3) I want to take my slightly trimmed Fel-Pro gasket and port match both the header and the heads to this new-slightly-modified gasket.

4) I want to smooth the inner welds, well, smooth that whole entry area, even if it means re-welding it to give myself adequate material. It should be noted that the Fel-Pro gasket is significantly larger than the Headman flange, so there will be a lot of material to remove from the flange...so I'll have to be really careful not to get into the tubes.

Am I off my rocker arm here?

 

[HardRooster]

Got the block all honed out, cleaned up, gaskets surfaces cleaned and ready to start accepting new bits, mostly just waiting on Brown Santa to finish my July Christmas. Apparently, the cam wont be here for another month. Boo!

Untitled by CASEY, on Flickr

 

[HardRooster]

Still waiting on the camshaft, which isn't scheduled to ship until Aug 23rd. So putting the rotating assembly together is as far as I can go on the bottom end for now.

Cleaned up the pistons in the parts washer, then used my gasket surface tool on the piston tops to clean off all the carbon deposits from the factory pistons.

Untitled by CASEY, on Flickr

Using the piston to set the ring flush for measurements;

Untitled by CASEY, on Flickr

Ring Specs from the Factory Service Manual;

Untitled by CASEY, on Flickr

All measurements were on the high end, but within spec, .022-.023;

Untitled by CASEY, on Flickr

The FSM has some very specific procedures to follow regarding installing the crankshaft, so I'm glad I have it. You're supposed to install the three main bearing caps, fully torqued down first, and save the main bearing cap with the thrust bearing for last. Finger tighten, then pry the crank forward, while you pry the cap back, and torque to spec. That's a two hand job, so no pics of that.

There's also a spot where I'm told to apply silicone to the rear main bearing cap, in the corner. The description left a little to the imagination, and there wasn't a photo, so this is what I came up with. If it's wrong let me know, it's not too late to go back and correct it;

Untitled by CASEY, on Flickr

Main Bearing Specs;

Untitled by CASEY, on Flickr

Plastigauge for the main's (and the con-rods) all fell within service limits, which is good considering the crank and bearings are all provided by a machine shop. The crank kit even came with a silver seal rear main sleeve, which is a nice bonus. That will have to wait for the engine to be on a hoist to install though, as the rear of the crank shaft is inaccessible thanks to the engine stand;

Untitled by CASEY, on Flickr

Got a little lazy with the pics after that point. No pics of con rod plastigauge, ring installation, or piston install, which was made easy by my pretty cool, inexpensive ring compressor (which also came with a ring installer) I got from Amazon. I did manage to get a pic of torqueing the con rods;

Untitled by CASEY, on Flickr

So we will now just skip ahead to the completed rotating assembly. Quick recap, manually honed and cross hatched cylinders, retained cam bearings and freeze plugs, new Clevite main and rod bearings, crank shaft came on exchange after mine was damaged due to spun bearing, Retained factory con-rods and pistons, new Sealed Power Rings. Project is now waiting on the cam shaft, so the engine is in a trash bag to keep it clean. I'll probably start porting the heads next while I wait;

Untitled by CASEY, on Flickr

 

[HardRooster]

I've been busy the past couple weeks, and I'll likely be a little busy coming up, but I got my Cam in, and I had the time and motivation to install it today. Nothing to it really, it's just kinda cool to be putting in a little something special, Comp Cams 410.

Untitled by CASEY, on Flickr

New timing chain, everything else reused;

Untitled by CASEY, on Flickr

 

[HardRooster]

Just a bit more time killing work today, got the bottom end handled, cleaned up the old oil pump and windage tray, installed a new Melling pick-up. Then put on the timing cover, new oil seal, got the oil pan on, the oil filter adapter, etc. Back under the bag. My shop compressor is currently out of service, and I really don't like running the big diesel compressor for little work, so I'm waiting to install a new compressor pump so I can get back to the port and polish job on the heads.

Untitled by CASEY, on Flickr

 

[Josh B]

Nice thread Rooster

 

[Jim Oaks]

Did you use the stock pushrods?

 

[bobbywalter]

2017


I would run all new pushrods from trend on anything over 50 k miles or ate more then a few quarts of coolant. This thing likely failed from coolant contamination.

With the cam..... all new valvetrain and double check with degree wheel ..... is key to making horsepower.