My tired old 4.2 is fouling the #3 or #4 (I forget which -- haven't looked
in a very long time), and I am thinking the trouble is valve
guides/seals/stems, or any combination.

Instead of just replacing the seals, I was goiing to take this opportunity
to pull the head and swap in a 4.0. I did the Hesco fuel injection several
years ago -- early 2000 -- and installed a Borla header at that time, and
this made a huge difference in performance.

Clifford is not very far from my house, I could easily go there and get my
engine parts, but the checkbook is not bottomless so I need to get this done
on a shoestring. Clifford makes good stuff, but I assume they are probably
pricey. I am not considering a complete rebuild, only a head swap.

You guys that have made this change, how much did it cost and where did you
acquire your parts? Another thought -- does my Borla header for the 4.2 fit
the 4.0? The intake should be okay, shouldn't it?

PS
Due to work issues, my Jeep has not been out of the barn for a couple of
years. There is light at the end of the tunnel though, and I may be driving
my Jeep again to work across town. Since the Jeep has not been out, I have
to begin anew my observation of the plug problems, and other stuff that
needs attention ...

 

Jeff Strickland wrote:

> My tired old 4.2 is fouling the #3 or #4 (I forget which -- haven't looked
> in a very long time), and I am thinking the trouble is valve
> guides/seals/stems, or any combination.
>
> Instead of just replacing the seals, I was goiing to take this opportunity
> to pull the head and swap in a 4.0. I did the Hesco fuel injection several
> years ago -- early 2000 -- and installed a Borla header at that time, and
> this made a huge difference in performance.
>
> Clifford is not very far from my house, I could easily go there and get my
> engine parts, but the checkbook is not bottomless so I need to get this
> done on a shoestring. Clifford makes good stuff, but I assume they are
> probably pricey. I am not considering a complete rebuild, only a head
> swap.
>
> You guys that have made this change, how much did it cost and where did
> you acquire your parts? Another thought -- does my Borla header for the
> 4.2 fit the 4.0? The intake should be okay, shouldn't it?
>
> PS
> Due to work issues, my Jeep has not been out of the barn for a couple of
> years. There is light at the end of the tunnel though, and I may be
> driving my Jeep again to work across town. Since the Jeep has not been
> out, I have to begin anew my observation of the plug problems, and other
> stuff that needs attention ...

Jeff, I'm thinking that you'll have to re-do the Borla header with a head
change - was that in your figures?

I would like to see some experiences from past conversions as well but with
a couple of specifics. My main concern would be the plug used for the
off-pattern coolant holes - what was used and how did it stand up? I'm a
great fan of JB Weld but using it to plug a water jacket hole on the head
leaves me a tad skeptical.

--
Will Honea

--
Posted via a free Usenet account from http://www.teranews.com

 

"Will Honea" <whonea@yahoo.com> wrote in message
news:4787c492$0$26077$88260bb3@free.teranews.com.. .
> Jeff Strickland wrote:
>
>> My tired old 4.2 is fouling the #3 or #4 (I forget which -- haven't
>> looked
>> in a very long time), and I am thinking the trouble is valve
>> guides/seals/stems, or any combination.
>>
>> Instead of just replacing the seals, I was goiing to take this
>> opportunity
>> to pull the head and swap in a 4.0. I did the Hesco fuel injection
>> several
>> years ago -- early 2000 -- and installed a Borla header at that time, and
>> this made a huge difference in performance.
>>
>> Clifford is not very far from my house, I could easily go there and get
>> my
>> engine parts, but the checkbook is not bottomless so I need to get this
>> done on a shoestring. Clifford makes good stuff, but I assume they are
>> probably pricey. I am not considering a complete rebuild, only a head
>> swap.
>>
>> You guys that have made this change, how much did it cost and where did
>> you acquire your parts? Another thought -- does my Borla header for the
>> 4.2 fit the 4.0? The intake should be okay, shouldn't it?
>>
>> PS
>> Due to work issues, my Jeep has not been out of the barn for a couple of
>> years. There is light at the end of the tunnel though, and I may be
>> driving my Jeep again to work across town. Since the Jeep has not been
>> out, I have to begin anew my observation of the plug problems, and other
>> stuff that needs attention ...
>
> Jeff, I'm thinking that you'll have to re-do the Borla header with a head
> change - was that in your figures?
>

Well, my Borla has a lifetime warranty, and a crack. I'm planning on working
out an exchange. I bought it from a Jeep Shop in El Cajon (east of San
Diego), and I was going to see if that guy is still in business and work the
swap through him.

You are in the San Diego area, aren't you?



> I would like to see some experiences from past conversions as well but
> with
> a couple of specifics. My main concern would be the plug used for the
> off-pattern coolant holes - what was used and how did it stand up? I'm a
> great fan of JB Weld but using it to plug a water jacket hole on the head
> leaves me a tad skeptical.
>

That part is pretty easy. The holes in the block run into the head and
either align with the head, or with a blockage. So, the galleys in the block
are okay. The holes (galleys) in the head either align to galleys in the
block, or dump out onto the ground. The holes that dump get filled with
JBWeld. Well, maybe not JB Weld, but they get plugged. Coolant flows through
enough of the galleys to do its job, and the holes that do not align on the
head with holes in the block simply get plugged up.

The advantage of the 4.0L head is that the intake track is straighter. At
the intake valve on the 4.2 head, the mixture has to make a hard-90 degree
turn, which has an adverse affect on the total air flow. The turbulance
caused by the hard turn reduces air flow, or something like that. On the 4.0
head, the intake comes in at a level about 2 inches above the valve, so the
turn is not so sharp, and airflow is improved as a result.

The idea is similar to the olden days when they used to port and polish the
intake manifold to make them smoother and cleaner. The 4.2 head has the
ports set about 1/4" higher than the valve seat, so the sharp corner needs
to be cleaned up. The 4.0 head has the port coming in at a level about 2
1/4" above the valve seat, so they can create an angled turn instead of a
straight 90.

In any case, I already have fuel injection that is supposed to fit directly
on a 4.0 head.

 

Jeff Strickland wrote:

>
> "Will Honea" <whonea@yahoo.com> wrote in message
> news:4787c492$0$26077$88260bb3@free.teranews.com.. .
>> Jeff Strickland wrote:
>>
>>> My tired old 4.2 is fouling the #3 or #4 (I forget which -- haven't
>>> looked
>>> in a very long time), and I am thinking the trouble is valve
>>> guides/seals/stems, or any combination.
>>>
>>> Instead of just replacing the seals, I was goiing to take this
>>> opportunity
>>> to pull the head and swap in a 4.0. I did the Hesco fuel injection
>>> several
>>> years ago -- early 2000 -- and installed a Borla header at that time,
>>> and this made a huge difference in performance.
>>>
>>> Clifford is not very far from my house, I could easily go there and get
>>> my
>>> engine parts, but the checkbook is not bottomless so I need to get this
>>> done on a shoestring. Clifford makes good stuff, but I assume they are
>>> probably pricey. I am not considering a complete rebuild, only a head
>>> swap.
>>>
>>> You guys that have made this change, how much did it cost and where did
>>> you acquire your parts? Another thought -- does my Borla header for the
>>> 4.2 fit the 4.0? The intake should be okay, shouldn't it?
>>>
>>> PS
>>> Due to work issues, my Jeep has not been out of the barn for a couple of
>>> years. There is light at the end of the tunnel though, and I may be
>>> driving my Jeep again to work across town. Since the Jeep has not been
>>> out, I have to begin anew my observation of the plug problems, and other
>>> stuff that needs attention ...
>>
>> Jeff, I'm thinking that you'll have to re-do the Borla header with a head
>> change - was that in your figures?
>>
>
> Well, my Borla has a lifetime warranty, and a crack. I'm planning on
> working out an exchange. I bought it from a Jeep Shop in El Cajon (east of
> San Diego), and I was going to see if that guy is still in business and
> work the swap through him.
>
> You are in the San Diego area, aren't you?

Nope, Colorado Springs. Wife has family is San Diego so I get out there
every so often

>> I would like to see some experiences from past conversions as well but
>> with
>> a couple of specifics. My main concern would be the plug used for the
>> off-pattern coolant holes - what was used and how did it stand up? I'm a
>> great fan of JB Weld but using it to plug a water jacket hole on the head
>> leaves me a tad skeptical.
>>
>
> That part is pretty easy. The holes in the block run into the head and
> either align with the head, or with a blockage. So, the galleys in the
> block are okay. The holes (galleys) in the head either align to galleys in
> the block, or dump out onto the ground. The holes that dump get filled
> with JBWeld. Well, maybe not JB Weld, but they get plugged. Coolant flows
> through enough of the galleys to do its job, and the holes that do not
> align on the head with holes in the block simply get plugged up.

No issues with the flow but those gallies that vent to the ground would
bother me. I think I would be looking at something I was more comfortable
with than JB Weld. I've never seen the actual hole in question, but if the
sides are long enough I'd be inclined to pour lead or bronze in there.
I've also seen people use aluminum but I'm not sure how they got adhesion.

> The advantage of the 4.0L head is that the intake track is straighter. At
> the intake valve on the 4.2 head, the mixture has to make a hard-90 degree
> turn, which has an adverse affect on the total air flow. The turbulance
> caused by the hard turn reduces air flow, or something like that. On the
> 4.0 head, the intake comes in at a level about 2 inches above the valve,
> so the turn is not so sharp, and airflow is improved as a result.
>
> The idea is similar to the olden days when they used to port and polish
> the intake manifold to make them smoother and cleaner. The 4.2 head has
> the ports set about 1/4" higher than the valve seat, so the sharp corner
> needs to be cleaned up. The 4.0 head has the port coming in at a level
> about 2 1/4" above the valve seat, so they can create an angled turn
> instead of a straight 90.
>
> In any case, I already have fuel injection that is supposed to fit
> directly on a 4.0 head.

No question of the advantages. The 4.0 (HO/post-Renix) intake manifold is
also a huge step up - mush better flow pattern at the port than the early
4.0.

Sounds like you could make out like a bandit on that header as well -
sometimes you win one.

--
Will Honea

--
Posted via a free Usenet account from http://www.teranews.com