Will a 91 block drop right in to my 89 truck?

[coolwind57]

So my 89' Renix engine essentially took a dump.  Cracked cylinder head and now I discovered a bad piston/cylinder.

 

I had bought a 1994 cylinder head (7120) and had a valve job and resurface done on it before I discovered the bad cylinder wall/piston (yea, I know...dumb mistake of not catching the bad block).  I had port matched the 7120 head to mate with my 89 Renix intake manifold.

 

My 89 block is a 53005535 by the way.

 

There's a dude nearby that has a freshly machined, ready-to-go 53008405 block.  Its my understanding that these blocks are from 91-01 XJs.  It's bored .40" over.  I've got pics and video of it. 

 

Will this block fit in my 1989 Comanche?  I'm trying to think of what would not make it a plug and play...Motor mounts, Knock sensor, oil filter housing, water pump, maybe?

 

If it'll go in with no problem, then the plan would be to put on my 7120 cylinder head and run my Renix intake setup. 

 

Anything come to mind with this idea, fellas?

 

[coolwind57]

I forgot about the distributor, which is different and I just so happen to have one for the 91-01 engines my my garage.  I assume it'll plug and play with my existing renix ignition parts.

[89 MJ]

Use all of your Renix parts on the HO block. I’ve done a write up on this in Tech and Cruiser has it on his website. It’s entirely bolt in, but you’ll have to use your Renix accessories, distributor, intake, exhaust, etc. 

[coolwind57]

1 minute ago, 89 MJ said:

Use all of your Renix parts on the HO block. I’ve done a write up on this in Tech and Cruiser has it on his website. It’s entirely bolt in, but you’ll have to use your Renix accessories, distributor, intake, exhaust, etc. 

Ah sweet, man.  Thanks.  He's going to assemble a complete short block for  about $2500. 

[coolwind57]

47 minutes ago, 89 MJ said:

Use all of your Renix parts on the HO block. I’ve done a write up on this in Tech and Cruiser has it on his website. It’s entirely bolt in, but you’ll have to use your Renix accessories, distributor, intake, exhaust, etc. 

I've looked over Cruiser's page but I can't find your write up in Tech.  Know where I can find it?

 

[89 MJ]

1 hour ago, coolwind57 said:

I've looked over Cruiser's page but I can't find your write up in Tech.  Know where I can find it?

 

It was buried back on page 7. Here you are:

 

[cruiser54]

CRUISER'S MOSTLY RENIX TIPS

HO INTO RENIX SWAP

OCTOBER 31, 2015 SALAD 86 COMMENTS EDIT

 

This swap is easier than some will lead you to believe. And generally Pooh-poohed by those who have never done it. Those of us who have done it, like myself, will share with you the things that need to be done for a successful swap. Just think of it as swapping in a long block.

• XJ Cherokee and ZJ Grand Cherokee 4.0L engine blocks interchange.
• 2000+ TJ Wrangler and WJ Grand Cherokee 4.0L engine blocks interchange.
• YJ and 1997-1999 4.0L TJ blocks will interchange in XJ/ZJ
• XJ/ZJ blocks, and the 2000+ TJ/WJ blocks do not interchange without significant modifications.

TJ/WJ 4.0L Engine blocks underwent clean sheet design changes effective in the 1999 WJ Grand and 2000 TJ Wrangler. These blocks are not interchangeable with XJ/ZJ engine blocks. The reason is motor mount bolt holes and belt driven accessory mounting bolt holes are in different locations, or not present at all, TJ/WJ vs. XJ/ZJ.

Now that we know which engines we can use, let’s get down to business.

The HO and Renix have some differences but none that can’t be overcome very easily.

One running change was that the rear of the head was no longer drilled and tapped for the temperature gauge sender beginning in the 96 model year. The sender can be relocated to the threaded hole in the thermostat housing taken from an HO engine. You’ll have to extend the wire to that location. Some brave souls even drill and tap the HO head at the rear for the sender.

You will be using the intake and exhaust manifolds from your Renix, along with all your sensors and wiring. Since the intake ports of the HO are slightly different, you use a new Renix gasket. Exhaust ports are identical.

An alternative on exhaust manifolds:

As far as exhaust, you can use the Renix exhaust manifold and be fine.
If you want to use the HO exhaust manifold, you must go with an HO headpipe and screw your O2 sensor into that headpipe. Standard Renix harness is plenty long to do so.
A bung can be welded into the HO manifold to accept the EGR tube.

You will need to use your Renix distributor as it is different than the HO design. See Tips #12 – Setting Your 4.0 to #1 TDC and #13 – Distributor Indexing to be sure you get the distributor installed correctly.

The flywheel or flexplate from the Renix must be used so your CPS gets the correct signals. The valve cover from the Renix allows you to keep your CCV system intact and requires no modifications.

The HO block will have a plug in the coolant galley on the driver’s side of the block, closest to the front, which needs to be removed so your Coolant Temp Sensor can be installed in it’s place just as it is on the Renix. It requires a 5/16” square drive or a modified 3/8” drive that has been ground down to fit. Do this before installing the engine.

As for the knock sensor, which is located just above the oil pan on the driver’s side of the engine about mid way, all the blocks I’ve seen are threaded for it. If not, I’ve heard they may be drilled but not tapped. Tap the hole if that’s the case.