4.0 to 258 swap

I know that I'm going to need to rebuild an engine for my 89 XJ, either the
one in it or the one in the 88 XJ. Both are over 300,000 miles.

But I got to thunkin' ... since 99% of my driving is within 20 miles of
home, since I often tow a utility trailer to recycle various metals (about a
1/2 ton at a time), why not go with a 258 /4.2 from a YJ?

The 258 bore /stroke ratio is better suited for around town, trailer towing
and even snowplowing, should I decide to try it.

My plan is to do any drilling and tapping to mount all the Renix sensors
that the 4.2 block doesn't have a spot for and swap the head, exhaust and
intake from the 4.0.

Does anyone have info or a link I can check out?

Thanks in adavance.

Budd



--- Posted via news://freenews.netfront.net/ - Complaints to ---

Budd Cochran wrote:

> I know that I'm going to need to rebuild an engine for my 89 XJ, either
> the one in it or the one in the 88 XJ. Both are over 300,000 miles.
>
> But I got to thunkin' ... since 99% of my driving is within 20 miles of
> home, since I often tow a utility trailer to recycle various metals (about
> a 1/2 ton at a time), why not go with a 258 /4.2 from a YJ?
>
> The 258 bore /stroke ratio is better suited for around town, trailer
> towing and even snowplowing, should I decide to try it.
>
> My plan is to do any drilling and tapping to mount all the Renix sensors
> that the 4.2 block doesn't have a spot for and swap the head, exhaust and
> intake from the 4.0.
>
> Does anyone have info or a link I can check out?

Most common fix in a case like this is to re-build the 4.0 as a stroker -
google that. 258 crank/rods into a 4.0 carcass gives one helluva low end
without all the other grief. To drop the the Renix stuff into the 258
you'll still need the 4.0 head and manifolds with some odd water passages to
plug, etc.

--
Will Honea

"Will Honea" > wrote in message
...
> Budd Cochran wrote:
>
>> I know that I'm going to need to rebuild an engine for my 89 XJ, either
>> the one in it or the one in the 88 XJ. Both are over 300,000 miles.
>>
>> But I got to thunkin' ... since 99% of my driving is within 20 miles of
>> home, since I often tow a utility trailer to recycle various metals
>> (about
>> a 1/2 ton at a time), why not go with a 258 /4.2 from a YJ?
>>
>> The 258 bore /stroke ratio is better suited for around town, trailer
>> towing and even snowplowing, should I decide to try it.
>>
>> My plan is to do any drilling and tapping to mount all the Renix sensors
>> that the 4.2 block doesn't have a spot for and swap the head, exhaust and
>> intake from the 4.0.
>>
>> Does anyone have info or a link I can check out?
>
> Most common fix in a case like this is to re-build the 4.0 as a stroker -
> google that. 258 crank/rods into a 4.0 carcass gives one helluva low end
> without all the other grief. To drop the the Renix stuff into the 258
> you'll still need the 4.0 head and manifolds with some odd water passages
> to
> plug, etc.
>
> --
> Will Honea
>

Hmmm, interesting! And I notice the #727 crank casting from a YJ 258 has the
same snout as the 4.0 ... I think we might have a winner here.

Ok, off to the JY in a couple days to check on parts availability , for
cores if nothing else.

Thanks, Will.

Budd



--- Posted via news://freenews.netfront.net/ - Complaints to ---

Budd Cochran wrote:

> Hmmm, interesting! And I notice the #727 crank casting from a YJ 258 has
> the same snout as the 4.0 ... I think we might have a winner here.
>
> Ok, off to the JY in a couple days to check on parts availability , for
> cores if nothing else.

This was a popular project on the ng a few years back. If you can dig the
old messages out of the archives you'll find a bunch of discussion about the
stroker build - try something like 3-4 4 years back. ISTR that someone did
a dynamo test on his and the low end torque was amazing. For the reported
results and the price is caught my attention but I'm at a point now that all
the added performance would wasted on me. I fear that my rock climbing days
are over.

--
Will Honea

"Will Honea" > wrote in message
...
> Budd Cochran wrote:
>
>> Hmmm, interesting! And I notice the #727 crank casting from a YJ 258 has
>> the same snout as the 4.0 ... I think we might have a winner here.
>>
>> Ok, off to the JY in a couple days to check on parts availability , for
>> cores if nothing else.
>
> This was a popular project on the ng a few years back. If you can dig the
> old messages out of the archives you'll find a bunch of discussion about
> the
> stroker build - try something like 3-4 4 years back. ISTR that someone
> did
> a dynamo test on his and the low end torque was amazing. For the reported
> results and the price is caught my attention but I'm at a point now that
> all
> the added performance would wasted on me. I fear that my rock climbing
> days
> are over.
>
> --
> Will Honea
>

On the 20th, I'll be 65 myself and after a clown with a broke down crawler
in the local supermarket parking lot threatened to drive over my 95 Lebaron
in Moab one Jeep Safari, a few years back, I decided I wasn't interested in
it either.

It seemed to make him mad that a disabled person, me, actually had the nerve
to park in the handicapped space in front of his rig.

No, my off-roading is just getting back to some out-of-the-way fishin'
holes. But good torque just off idle is a plus when you need it.

When you have bigger pistons shoving down on longer crank arms torque
figures jump way up. My biggest concern with the swap is octane
requirements. If I could find pistons that would let me run 81 instead of
87, I'd be even happier.

Budd



--- Posted via news://freenews.netfront.net/ - Complaints to ---

Budd Cochran wrote:

> On the 20th, I'll be 65 myself and after a clown with a broke down crawler
> in the local supermarket parking lot threatened to drive over my 95
> Lebaron in Moab one Jeep Safari, a few years back, I decided I wasn't
> interested in it either.
>
> It seemed to make him mad that a disabled person, me, actually had the
> nerve to park in the handicapped space in front of his rig.
>
> No, my off-roading is just getting back to some out-of-the-way fishin'
> holes. But good torque just off idle is a plus when you need it.
>
> When you have bigger pistons shoving down on longer crank arms torque
> figures jump way up. My biggest concern with the swap is octane
> requirements. If I could find pistons that would let me run 81 instead of
> 87, I'd be even happier.

Well, I now qualify for minimum IRA distributions so I'm just slightly ahead
of you. I didn't remember any octane limitations on the stroker but wouldn't
doesn't surprise me. Could be close enough that stacked head gaskets would
work and I also recall that the pre-99 Renix heads were considerable
different than the MOPAR versions from 99 on so there are a few nits to
resolve on depending on which carcass you use.

I got hit with a sizable heart attack last summer and wound up with the
world's greatest wimp for a cardiologist so he keeps telling me what I can't
do despite stress tests in the full normal range so I'm pretty much in the
sit in the boat and cast category for now myself. Ironic isn't it that the
damned doctors keep harping on exercise while the rest of the world wants to
make things easier for you....

The other approach is to use the 4.0 pistons instead of the larger 458 ones.
That gives you a little less bore which will also drop the compression
ratio. Best I remember, the longer rods will fit and that solves some other
problems as well with block/head geometry. Back when this was a hot topic
there were also some custom ground cams around that would solve the knock
problems but that was a while back. The pre-89 Renix systems also include a
knock sensor which would probably serve the purpose as well.
--
Will Honea

"Will Honea" > wrote in message
...
> Budd Cochran wrote:
>
>> On the 20th, I'll be 65 myself and after a clown with a broke down
>> crawler
>> in the local supermarket parking lot threatened to drive over my 95
>> Lebaron in Moab one Jeep Safari, a few years back, I decided I wasn't
>> interested in it either.
>>
>> It seemed to make him mad that a disabled person, me, actually had the
>> nerve to park in the handicapped space in front of his rig.
>>
>> No, my off-roading is just getting back to some out-of-the-way fishin'
>> holes. But good torque just off idle is a plus when you need it.
>>
>> When you have bigger pistons shoving down on longer crank arms torque
>> figures jump way up. My biggest concern with the swap is octane
>> requirements. If I could find pistons that would let me run 81 instead of
>> 87, I'd be even happier.
>
> Well, I now qualify for minimum IRA distributions so I'm just slightly
> ahead
> of you. I didn't remember any octane limitations on the stroker but
> wouldn't
> doesn't surprise me. Could be close enough that stacked head gaskets
> would
> work and I also recall that the pre-99 Renix heads were considerable
> different than the MOPAR versions from 99 on so there are a few nits to
> resolve on depending on which carcass you use.
>
> I got hit with a sizable heart attack last summer and wound up with the
> world's greatest wimp for a cardiologist so he keeps telling me what I
> can't
> do despite stress tests in the full normal range so I'm pretty much in the
> sit in the boat and cast category for now myself. Ironic isn't it that
> the
> damned doctors keep harping on exercise while the rest of the world wants
> to
> make things easier for you....
>
> The other approach is to use the 4.0 pistons instead of the larger 458
> ones.
> That gives you a little less bore which will also drop the compression
> ratio. Best I remember, the longer rods will fit and that solves some
> other
> problems as well with block/head geometry. Back when this was a hot topic
> there were also some custom ground cams around that would solve the knock
> problems but that was a while back. The pre-89 Renix systems also include
> a
> knock sensor which would probably serve the purpose as well.
> --
> Will Honea
>
Get another cardiologist asap, Will. Or at least a good primary care
provider with some sense.

I've had eight heart episodses back when I was a youngster, 48, and that led
to a double bypass. Now I'm a Type 2 Diabetic along with the heart probs and
I'm a Polio Survivor (1952 epidemic).

Yet I work about 5-7 hours a day on what I feel like doing at my own pace
.... which is too slow to meet most jobs I've had in the past. My blood
sugars are excellent and my blood chemestry is that of a 25 year old, but
I've had medical providers that gave a hoot about me.

The 89 Renix's are supposed to have a knock sensor also ... I say supposed
because I'm finding more and more stuff that defies comprhension about it.
Last owner was a true non-mechanic.

If you meant 258 pistons, they would rattle in the bore a bit ... they bored
out the block to get back some cubic inches lost with the de-stroking for
the 4.0.

Higher compression pistons are easy to find but lower may be hard. Doubling
gaskets can work if the darn things are the steel composites, but the older
styles tend to blow pretty easy. I'll have to see what's available.

Budd



--- Posted via news://freenews.netfront.net/ - Complaints to ---

Budd Cochran wrote:

> Get another cardiologist asap, Will. Or at least a good primary care
> provider with some sense.

Step ahead of you there. I found a primary that I had as a student back
when I was on the EE faculty at the AF Academy. I also had him as a student
pilot before he opted for med school so we speak the same language.

> I've had eight heart episodses back when I was a youngster, 48, and that
> led to a double bypass. Now I'm a Type 2 Diabetic along with the heart
> probs and I'm a Polio Survivor (1952 epidemic).

This was my first encounter with coronary issues and I somehow missed the
polio gig growing up. My younger brother had it but he was the only one in
the family - who knows why. I did beat Hodgkins Lymphoma 15 years back but
this was a bit of a surprise - none of the usual indicators indicated any
major heart risks.

> Yet I work about 5-7 hours a day on what I feel like doing at my own pace
> ... which is too slow to meet most jobs I've had in the past. My blood
> sugars are excellent and my blood chemestry is that of a 25 year old, but
> I've had medical providers that gave a hoot about me.
>
> The 89 Renix's are supposed to have a knock sensor also ... I say supposed
> because I'm finding more and more stuff that defies comprhension about it.
> Last owner was a true non-mechanic.
>
> If you meant 258 pistons, they would rattle in the bore a bit ... they
> bored out the block to get back some cubic inches lost with the
> de-stroking for the 4.0.
>
> Higher compression pistons are easy to find but lower may be hard.
> Doubling gaskets can work if the darn things are the steel composites, but
> the older styles tend to blow pretty easy. I'll have to see what's
> available.

I'm not fond of the head spacers myself. The reason I point out the MOPAR
heads is that they are ported way better than the pre-Chrysler ones. At one
point I was looking to swap the MOPAR MPI system into mine but by the time I
worked out all the water jacket issues it wasn't worth the problems to me.
From looking at the late model I had sitting around I'm pretty sure that the
knock sensor went away post 89 - doesn't show up on in the factory manuals I
have.

--
Will Honea

"Will Honea" > wrote in message
...
> Budd Cochran wrote:
>
>> Get another cardiologist asap, Will. Or at least a good primary care
>> provider with some sense.
>
> Step ahead of you there. I found a primary that I had as a student back
> when I was on the EE faculty at the AF Academy. I also had him as a
> student
> pilot before he opted for med school so we speak the same language.
>
>> I've had eight heart episodses back when I was a youngster, 48, and that
>> led to a double bypass. Now I'm a Type 2 Diabetic along with the heart
>> probs and I'm a Polio Survivor (1952 epidemic).
>
> This was my first encounter with coronary issues and I somehow missed the
> polio gig growing up. My younger brother had it but he was the only one
> in
> the family - who knows why. I did beat Hodgkins Lymphoma 15 years back
> but
> this was a bit of a surprise - none of the usual indicators indicated any
> major heart risks.
>
>> Yet I work about 5-7 hours a day on what I feel like doing at my own pace
>> ... which is too slow to meet most jobs I've had in the past. My blood
>> sugars are excellent and my blood chemestry is that of a 25 year old, but
>> I've had medical providers that gave a hoot about me.
>>
>> The 89 Renix's are supposed to have a knock sensor also ... I say
>> supposed
>> because I'm finding more and more stuff that defies comprhension about
>> it.
>> Last owner was a true non-mechanic.
>>
>> If you meant 258 pistons, they would rattle in the bore a bit ... they
>> bored out the block to get back some cubic inches lost with the
>> de-stroking for the 4.0.
>>
>> Higher compression pistons are easy to find but lower may be hard.
>> Doubling gaskets can work if the darn things are the steel composites,
>> but
>> the older styles tend to blow pretty easy. I'll have to see what's
>> available.
>
> I'm not fond of the head spacers myself. The reason I point out the MOPAR
> heads is that they are ported way better than the pre-Chrysler ones. At
> one
> point I was looking to swap the MOPAR MPI system into mine but by the time
> I
> worked out all the water jacket issues it wasn't worth the problems to me.
> From looking at the late model I had sitting around I'm pretty sure that
> the
> knock sensor went away post 89 - doesn't show up on in the factory manuals
> I
> have.
>
> --
> Will Honea
>

My mom believed I caught the Polio bug from a drainage that ran by the house
back in Indiana when we lived in a small rural community. A couple kids
"downstream" died from Polio about the same time.

When the weather clears a bit, I've got to swap the front driveshaft from
the 88 into the 89 to fix a bad set of u-joints and the vibration that goes
with them. No it's not "death wobble". While I'm under there I'll take a
peek for the knock sensor.

I'll probably use the original head as it flows well enough for my use, but
I'm thinking of going to Ford 4.6 injectors to gain a bit of mpg.

Are you still in the C. Springs area? I'm in Canon.

Budd



--- Posted via news://freenews.netfront.net/ - Complaints to ---

Budd Cochran wrote:

> Are you still in the C. Springs area? I'm in Canon.

Yeah, can't seem to get out of here dispite 25 years trying to get back home
to Austin. Something about a wife....

My pending project is a paint job. Between the collection of dents, dings
and the Colorado sunhine it's getting pretty ratty. I'm also looking for a
new seat. It's an 88 MJ so about any year XJ bench seat will work but those
long runs to South Texas have about finished off the original (200k miles)
and I'm getting fond of the creature comforts.

Give me a shout if you get up this way. There are a couple of boneyards
here with fair Jeep collections.

--
Will Honea