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4.0 i-6 DIFFERENCES?

bcmaxx

bcmaxx

NAXJA Forum User
Location
The West Kootenays,B.C. Canada
Will a 88 xj 4.0 bottom end bolt into a 97 tj with a 4.0?
 
Do you mean like a short block? Use 88 block with the 97 head?
 
I was involved in a yj swap that used an 88 or so xj block with the 94, I think it was, head and accessories. the biggest problem we had in BFE South Carolina was finding the right pilot bushing for the crank IIRC.
 
Ghost is correct in the biggest difference will be the pilot bushing if you have a manual tranny(all true CJs, YJs, and TJs do). The older ba10s and ax15s had a .59" ID pilot bearing and the newer ax15s have a .75" ID pilot bearing. Your 97 won't be using the Knock sensor that's on the driver's side of the 88 block. Probably some other minutiae that you'll be able to address.
 
I have an early 90's maybe 89 block with a later HO head on it and it bolted into my 96 perfect, as far as I know nothing changed on the block until 01 when they moved stuff around drilled bosses wise (but that was putting an 01 wj motor into an 00 XJ) blocks should be the same with your situation
 
H8PVMT said:
I have an early 90's maybe 89 block with a later HO head on it and it bolted into my 96 perfect, as far as I know nothing changed on the block until 01 when they moved stuff around drilled bosses wise (but that was putting an 01 wj motor into an 00 XJ) blocks should be the same with your situation
Click to expand...

That's what I believe to be true also. Should be obvious to the naked eye. Kinda weird that they made those changes to the block so close to the end of production, isn't it?
 
it was more for the grand cherokee and wrangler lines than cherokee
 
not to hi jack a thread or nothing but how many heads did the xj come with and what is the most desireable one. i know everyone is hot for the 99 intake but if i want to do a stoker can i use my renix motor or do i need something from a newer year. i know there is info all over the place but i was just looking for some basic info.
 
You can stroke a Renix and use a Renix head. The HO heads do flow better at higher RPMs though. You can use an HO head #7120 and matchport your head and intake manifold to each other quite easily.
 
Head casting number by years
Look hear for a lot more info
Information from: Scribd-Jeep Engine and Cam-Tech Specs
http://www.scribd.com/doc/15418414/jeep-Engine-and-Cam-specs
It is easy to determine what head you have. On the driver’s side, about halfway down the cylinder head clean the lip of the head with a rag or solvent if really greasy. With a good light, you can read the casting number of the head.
The stock cylinder head is cast iron and weighs 60lb. The valve head diameter is 1.91" intake/1.50" exhaust.
Casting numbers are as follows:
Year............Casting No
1987-90......2686
1991-95......7120
1996-99......0630
2000-01......0331

The early '87-'90 non-HO heads have low intake ports that flow rather poorly. The later HO heads have
higher intake ports that flow more air by allowing a straighter shot into the cylinders. The '91-'95 HO
heads with casting no.7120 have the highest intake and exhaust port airflows, especially at lower valve
lifts where it is most important, and are the best for performance. The '96-'99 0630 heads are almost identical except that they don't have a port for the coolant temp gauge sending unit.
 
ok will the 7120 head bolt on to the renix motor? or it that a dumb idea? and if so will the 99+ intake fit on the 7120 head?
 
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