What donor engine for a 4.6 stroker build?

Bammo68

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Later this year I want to start building a 4.6L stroker. My current 4.0 (1999 TJ Auto) is in good condition (despite recent coolant issues!) and I want to have the new one built and ready to swap straight in so using my existing engine isn't an option.

So if I'm going to find a donor engine to do a complete rebuild on, what should I look for? I'm guessing the first thing is to avoid a 2000-2001 head, right? I don't know yet how far I will take the stroker build but I thinking it will be a mild build so unlikely to be a new aftermarket head for instance.

Would it matter if the donor core was a - say - 1996 engine out of an XJ or a 2005 out of a TJ? Given I want the swap to be as easy as possible I want to avoid complicating factors like different engine mounts or manifold layout...
 

SvtLdr

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I've searched a few times on this topic and haven't found consistent answers. I'm interested to learn what recommendations you receive.
 

OldBuzzard

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First: I haven't built a stroker, I'm just mentioning a few things.

You could look for a 2000-2001 engine with the TUPY head. Just look in the oil filler hole, it's there in big letters.

In the US, federal emissions law says you must replace an engine with one from the same year or newer. State laws vary, depending on how they handle emissions inspections, if any. Do you have laws like that in Australia? Do you have emission inspections in your area?

If you'll be keeping your PCM (computer) to run the thing, you might want to stick with compatible years.

The 2005-2006 engines have a lot of differences to the older ones. You might not want to try to tackle those differences.
 
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JHammett

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If you have a 1999 you can source a block from:

-1987-2001 Cherokee XJ
-1991-1999 Wrangler YJ/TJ
-1993-1998 Grand Cherokee ZJ
-1987-1992 Comanche MJ

1999+ Grand Cherokee WJ and newer TJs have a different block and the mounts/accessories are different.

Is there anyway to know if you have the early or late model 99? From my understanding there is not a clear date since they used the older model parts until they ran out, right?

Is there a serial number or stamp on the block to know? I would love to know, just in case I end up in a similar spot one day!
 

jeepguy03

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The 2000-2001 engine block will fit fine, and if you can find a TUPY head it will work, but the TUPY head also has the smaller exhaust ports for the emissions changes on those engines, IMO it really isn't worth the effort to find a TUPY head since so many other years of 4.0L engine will work without the headache of trying to find one without the crack susceptible head.

As far as regulations, most of those are there so that you don't stick a carbureted Chevy 350 in a 2005 Jeep. If you use an engine block from a 1987 XJ and everything else from the 1999 you will be fine.
 

jeepguy03

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Is there anyway to know if you have the early or late model 99? From my understanding there is not a clear date since they used the older model parts until they ran out, right?

Is there a serial number or stamp on the block to know? I would love to know, just in case I end up in a similar spot one day!

The easiest way to tell isn't from the block itself, but from the ignition/emissions systems. The later 4.0L found in the WJ and newer TJs will have the coil rail ignition instead of the distributor, as well as the California emissions with 3 cat convertors or on some 49 state vehicles with that engine you will see they have a two piece exhaust manifold and only 1 cat convertor. All had the coil rail ignition though.
 

NskLJ

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Later this year I want to start building a 4.6L stroker. My current 4.0 (1999 TJ Auto) is in good condition (despite recent coolant issues!) and I want to have the new one built and ready to swap straight in so using my existing engine isn't an option.

So if I'm going to find a donor engine to do a complete rebuild on, what should I look for? I'm guessing the first thing is to avoid a 2000-2001 head, right? I don't know yet how far I will take the stroker build but I thinking it will be a mild build so unlikely to be a new aftermarket head for instance.

Would it matter if the donor core was a - say - 1996 engine out of an XJ or a 2005 out of a TJ? Given I want the swap to be as easy as possible I want to avoid complicating factors like different engine mounts or manifold layout...

Here is a link to get started. The second is a stroker forums. Russ Pottenger is the guy to talk to from my research.
 

JHammett

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The easiest way to tell isn't from the block itself, but from the ignition/emissions systems. The later 4.0L found in the WJ and newer TJs will have the coil rail ignition instead of the distributor, as well as the California emissions with 3 cat convertors or on some 49 state vehicles with that engine you will see they have a two piece exhaust manifold and only 1 cat convertor. All had the coil rail ignition though.

So I have the one piece exhaust manifold as well as a distributer, which means I have the earlier model that matches earlier TJs/ YJs. Thanks!
 

Wildman

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First: I haven't built a stroker, I'm just mentioning a few things.

You could look for a 2000-2001 engine with the TUPY head. Just look in the oil filler hole, it's there in big letters.

In the US, federal emissions law says you must replace an engine with one from the same year or newer. State laws vary, depending on how they handle emissions inspections, if any. Do you have laws like that in Australia? Do you have emission inspections in your area?

If you'll be keeping your PCM (computer) to run the thing, you might want to stick with compatible years.

The 2005-2006 engines have a lot of differences to the older ones. You might not want to try to tackle those differences.

When stating that it must be the same year or newer engine this doesn't refer to the manufacture date of the engine block.

Example: I have a 1997 Jeep TJ so by federal emissions regulations I'm required to swap in 1997 or newer engine when doing an engine swap. But this is referring to the emissions system of that engine family. The engine block I have in my TJ is from 1996 but I'm using a 1998 Dodge PCM & am running 1998 emissions system on my TJ. So don't confuse the wording when they say engine in being just the engine block.
What the rules are meaning is that you can't swap in a 1995 Chevy 5.7 & it's emissions system. If Chevy made the 5.7 in 1997 and you swapped in it's emissions system the year the block was manufactured doesn't matter.

In this case the OP is asking which engine block is the better choice. So as long as he retains the emissions system from his TJ the year of the block doesn't matter.