XJ 4.0 engine question

[anthonygubbin]

Thanks JJ for clearing up my questions about cyl heads. Now I need to know about short motors. If I want one the same as my 98 will I need to get a late 97-98 engine or can I get say a 96 short motor and build that up to go in to my 98? I want to keep eveything as is on a late 98 and not have to change belt tensioners, pully's and things like that.

Regards A

[Tezza]

Originally Posted by anthonygubbin

Thanks JJ for clearing up my questions about cyl heads. Now I need to know about short motors. If I want one the same as my 98 will I need to get a late 97-98 engine or can I get say a 96 short motor and build that up to go in to my 98? I want to keep eveything as is on a late 98 and not have to change belt tensioners, pully's and things like that.

Regards A

Post 96 blocks are stronger and your 98 will have a main bearing brace good idea if your running a light 4 counter wieght crank.
the 2000, 2001 engines are a great set up as a hole but I would not mix and match as I looked at a 2001 exhaust and the manifold would not even cover my ports. SMALL and the 331 heads crack on the earlier ones ok on the later Wranglers as they fixed the problem.
you can use a stock 96 cam as you will not get much benifit from a larger one on an OBDII.

[anthonygubbin]

Originally Posted by Tezza

Post 96 blocks are stronger and your 98 will have a main bearing brace good idea if your running a light 4 counter wieght crank.
the 2000, 2001 engines are a great set up as a hole but I would not mix and match as I looked at a 2001 exhaust and the manifold would not even cover my ports. SMALL and the 331 heads crack on the earlier ones ok on the later Wranglers as they fixed the problem.
you can use a stock 96 cam as you will not get much benifit from a larger one on an OBDII.

Thinking about possibly getting the old 4.2 crank on here for sale for a potential stroker build. Is that a good idea? So sounds like I should really be looking for a 98 block? Or will the more common 96 block be fine? Pre coil pack engines say 96-98 is there any different electrical things that will cause me problems, dizzy, sensors, etc?

Regards A

[junglejuice]

The late 95- blocks have extra bracing inside for NVH issues, the stud girdle is an add-on, I used to run one on my 95 OBD1 till I swapped it.
Any block from late 95 (OBD2) will have what you want, I have one here but it is most likely a little expensive when you add shipping to SA from here...

[anthonygubbin]

Thanks JJ. Now I know what I need to get. I should be able to get a short engine from our local Upullit pretty cheap. They often have 96s in there as update wrecks fetch a slighty higher price here in SA than they are willing to pay. Only problem I might run into is sorting the cam timing as the Upullit engine will have both the head and dizzy removed by the time I get one. Might have to work out a way to overcome that little one.

Regards A

[Tezza]

Originally Posted by anthonygubbin

Thinking about possibly getting the old 4.2 crank on here for sale for a potential stroker build. Is that a good idea? So sounds like I should really be looking for a 98 block? Or will the more common 96 block be fine? Pre coil pack engines say 96-98 is there any different electrical things that will cause me problems, dizzy, sensors, etc?

Regards A

Hey
There is a lot of different components especially when it comes to electrical but the blocks are interchangeable you could even put your 98 dizzy in the 4.2.
The most available 4.2 crank needs 10mm machined of the front or a washer space fitted otherwise it drops straight in.
As JJ said the later blocks are stronger and so are the cranks but the light 4 counterweight 4.2 cranks are not so rigid hence the need for the main bearing girdle, what happens is the harmonics transfer to the cam and you will end up with flogged out cam bearings and dizzy in no time flat if you drive it at over 3k rpm regularly.
Cheers Tezza

[anthonygubbin]

Where can you get a main bearing girdle? Also Are new cranks available or is the old 4.2 the go and get it machined? Lastly any idea if it would work out cheaper or about the same price to import a short motor 4.7 than it would to build one? You built one, didn't you Tezza?
It is sounding complicated I am beginning to think that building an engine might be beyond what I should attempt .

Regards A