4.2 engine with 4.0 head
- Thread starter bob
- Start date
128000
The site Rene lists looks like a good one. If you are a little more into this conversion, there is a group on yahoo groups titled strokers (get your mind outta the gutter). In this group the discussion is along this general mod with the added possibility of changing rods and possibly pistons to create a stroker from the 4.2L engine (from what I've read the 258 is a 232 stroked already but these guys are going a step or two further). The result I've read about isn't so much a massive HP increase as it is low end to midrange torque grunt. Some of the info gets a little in depth but the knowledge there is pretty deep and thorough. http://groups.yahoo.com/group/strokers
FWIW
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Deny
81CJ-7; Jeep... it's an addiction; If it ain't broke, you didn't play hard enough; AND A bad day jeepin is better that a great day at work!
The site Rene lists looks like a good one. If you are a little more into this conversion, there is a group on yahoo groups titled strokers (get your mind outta the gutter). In this group the discussion is along this general mod with the added possibility of changing rods and possibly pistons to create a stroker from the 4.2L engine (from what I've read the 258 is a 232 stroked already but these guys are going a step or two further). The result I've read about isn't so much a massive HP increase as it is low end to midrange torque grunt. Some of the info gets a little in depth but the knowledge there is pretty deep and thorough. http://groups.yahoo.com/group/strokers
FWIW
------------------
Deny
81CJ-7; Jeep... it's an addiction; If it ain't broke, you didn't play hard enough; AND A bad day jeepin is better that a great day at work!
129000
Actually this opens up some interesting tech possibilities ,but first after reading the article two things , One they noted that the engine in question had 98,000 miles on it and looked better than they expected no carbon buildup etc ,This is characteristic of the jeep sixes as a matter of fact two of the print off road mags some years back did long term tests on Cherokees equipped with 4.0's and found that they " did not even fully break in or begin to achieve their best gas mileage until 50,000miles." Most automotive engines are designed for approx 100,000 miles before needing rework. so as you can surmise a 4.0 or 4.2 should last well beyond 100000 miles and my personal experience has born this out. And two if the manifold off of a 4.0 head will bolt up to a 4.2 head there is another way around the carter carb problem ( an involved and possibly expensive way but ultimately a much better solution -- MPFI )or grafting the mpfi or tbi setup from a donor (wrecked - junked etc)4.0 onto a 4.2 engine---hmmm
Keep in mind folks that the 258 and its younger brother the 4.0 have been around for a long time (the 258 anyway) reason -- they work ! and as any CJ owner will tell you they last almost forever. also remember that an inline six has design characteristics that lend themselves readily to longetivity and heavy duty use with an emphasis on torque production. V engines are good at something else- acceleration - Oh and reciprocating themselves to death.
happy motoring!
------------------
93 YJ & 2001 Cherokee Limited.Past Jeeps : 94 Cherokee Country,79 Cherokee Chief ,87 YJ Sahara,75 CJ5 Golden Eagle , 82 CJ7
Actually this opens up some interesting tech possibilities ,but first after reading the article two things , One they noted that the engine in question had 98,000 miles on it and looked better than they expected no carbon buildup etc ,This is characteristic of the jeep sixes as a matter of fact two of the print off road mags some years back did long term tests on Cherokees equipped with 4.0's and found that they " did not even fully break in or begin to achieve their best gas mileage until 50,000miles." Most automotive engines are designed for approx 100,000 miles before needing rework. so as you can surmise a 4.0 or 4.2 should last well beyond 100000 miles and my personal experience has born this out. And two if the manifold off of a 4.0 head will bolt up to a 4.2 head there is another way around the carter carb problem ( an involved and possibly expensive way but ultimately a much better solution -- MPFI )or grafting the mpfi or tbi setup from a donor (wrecked - junked etc)4.0 onto a 4.2 engine---hmmm
Keep in mind folks that the 258 and its younger brother the 4.0 have been around for a long time (the 258 anyway) reason -- they work ! and as any CJ owner will tell you they last almost forever. also remember that an inline six has design characteristics that lend themselves readily to longetivity and heavy duty use with an emphasis on torque production. V engines are good at something else- acceleration - Oh and reciprocating themselves to death.
happy motoring!
------------------
93 YJ & 2001 Cherokee Limited.Past Jeeps : 94 Cherokee Country,79 Cherokee Chief ,87 YJ Sahara,75 CJ5 Golden Eagle , 82 CJ7
130000
<TABLE BORDER=0 ALIGN=CENTER WIDTH=85%><TR><TD><font size=-1>Quote:</font><HR></TD></TR><TR><TD><FONT SIZE=-1><BLOCKQUOTE><font face="Verdana, Arial" size="2[/IMG] And two if the manifold off of a 4.0 head will bolt up to a 4.2 head there is another way around the carter carb problem ( an involved and possibly expensive way but ultimately a much better solution -- MPFI )or grafting the mpfi or tbi setup from a donor (wrecked - junked etc)4.0 onto a 4.2 engine---hmmm
[/B]</font></BLOCKQUOTE></FONT></TD></TR><TR><TD><HR></TD></TR></TABLE>
On the strokers group I've noticed most are running MPI or at least TBI. The reoccurring statement made re: this addition to an older engine has been to take ALL the sensors involved with the system. If not the engine will not start. Just a thought... what about reliability in off camber positons? Gas mileage? Ease of starting? Any thoughts?
------------------
Deny
81CJ-7; Jeep... it's an addiction; If it ain't broke, you didn't play hard enough; AND A bad day jeepin is better that a great day at work!
<TABLE BORDER=0 ALIGN=CENTER WIDTH=85%><TR><TD><font size=-1>Quote:</font><HR></TD></TR><TR><TD><FONT SIZE=-1><BLOCKQUOTE><font face="Verdana, Arial" size="2[/IMG] And two if the manifold off of a 4.0 head will bolt up to a 4.2 head there is another way around the carter carb problem ( an involved and possibly expensive way but ultimately a much better solution -- MPFI )or grafting the mpfi or tbi setup from a donor (wrecked - junked etc)4.0 onto a 4.2 engine---hmmm
[/B]</font></BLOCKQUOTE></FONT></TD></TR><TR><TD><HR></TD></TR></TABLE>
On the strokers group I've noticed most are running MPI or at least TBI. The reoccurring statement made re: this addition to an older engine has been to take ALL the sensors involved with the system. If not the engine will not start. Just a thought... what about reliability in off camber positons? Gas mileage? Ease of starting? Any thoughts?
------------------
Deny
81CJ-7; Jeep... it's an addiction; If it ain't broke, you didn't play hard enough; AND A bad day jeepin is better that a great day at work!
131000
Oh the advantages of fuel injection over a carb are manyfold. A properly functioning mpi or tbi system will out perform at severe angles any carb,
let me put it this way the two vehicles I have that are FI 4cyl wrangler & 6 cyl cherokee both start easily run great and get good milage and perform offroad without any fuel related hicups. My two carburated vehicles 6cyl wrangler and 73 challenger dont like to start if its cold,either can be prone to "vapor lock" if its hot - surges if the jets become uncovererd due to fuel sloshing in the bowl,electric chokes that dont pulloff readily or completely oh yeah endless hours under the hood tuning and re-tuning, mazes of vacum hoses, etc etc,
I know that both Mopar performance and clifford research used to put out bolt on fuel injection kits for the 4.0 and 4.2 sixes but they were like 3 grand at the time worth it really but that price scared most people off ( most people spent it anyway getting their carters tuned, fixed, retuned, replaced,re-replaced retuned fixed agian etc etc).
Holly Pro-jection is better --and You dont want to get me started on Holly -- its not pretty.
Anyway ,yeah its my impression that FI is so much better but yeah you would need to get all of the sensors for the system to work correctly and the fuel curve would be off a little due to the increased displacement ( minor) but overall well worth it I think.
Oh the advantages of fuel injection over a carb are manyfold. A properly functioning mpi or tbi system will out perform at severe angles any carb,
let me put it this way the two vehicles I have that are FI 4cyl wrangler & 6 cyl cherokee both start easily run great and get good milage and perform offroad without any fuel related hicups. My two carburated vehicles 6cyl wrangler and 73 challenger dont like to start if its cold,either can be prone to "vapor lock" if its hot - surges if the jets become uncovererd due to fuel sloshing in the bowl,electric chokes that dont pulloff readily or completely oh yeah endless hours under the hood tuning and re-tuning, mazes of vacum hoses, etc etc,
I know that both Mopar performance and clifford research used to put out bolt on fuel injection kits for the 4.0 and 4.2 sixes but they were like 3 grand at the time worth it really but that price scared most people off ( most people spent it anyway getting their carters tuned, fixed, retuned, replaced,re-replaced retuned fixed agian etc etc).
Holly Pro-jection is better --and You dont want to get me started on Holly -- its not pretty.
Anyway ,yeah its my impression that FI is so much better but yeah you would need to get all of the sensors for the system to work correctly and the fuel curve would be off a little due to the increased displacement ( minor) but overall well worth it I think.
132000
<TABLE BORDER=0 ALIGN=CENTER WIDTH=85%><TR><TD><font size=-1>Quote:</font><HR></TD></TR><TR><TD><FONT SIZE=-1><BLOCKQUOTE><font face="Verdana, Arial" size="2[/IMG]Originally posted by offctr:
Holly Pro-jection is better --and You dont want to get me started on Holly -- its not pretty.</font></BLOCKQUOTE></FONT></TD></TR><TR><TD><HR></TD></TR></TABLE>
If you would not mind, I would like to hear some discussion of Holley's system. I have a Carter BBS and it is a nightmare as you said
. I have been considering the change to FI but have also considered a 4B intake and a Holley 390 cfm with header and different exhhaust. If you would, give opinions of pro's and con's. What of the possibility of polishing the factory intake...worth the hassle?
Thanks,
------------------
Deny
81CJ-7; Jeep... it's an addiction; If it ain't broke, you didn't play hard enough; AND A bad day jeepin is better that a great day at work!
<TABLE BORDER=0 ALIGN=CENTER WIDTH=85%><TR><TD><font size=-1>Quote:</font><HR></TD></TR><TR><TD><FONT SIZE=-1><BLOCKQUOTE><font face="Verdana, Arial" size="2[/IMG]Originally posted by offctr:
Holly Pro-jection is better --and You dont want to get me started on Holly -- its not pretty.</font></BLOCKQUOTE></FONT></TD></TR><TR><TD><HR></TD></TR></TABLE>
Thanks,
------------------
Deny
81CJ-7; Jeep... it's an addiction; If it ain't broke, you didn't play hard enough; AND A bad day jeepin is better that a great day at work!
133000
Actually that was my feeble attempt at sarcasam , I put one of the original pro-jection TBI systems on an 86 dodge 4 by truck to get rid of the carter bbd that came as stock on the 318 and had given me no end of trouble as well as no horsepower for a v-8.
Anyway the holly system WAS an improvement but AT THAT TIME it was new to the market and the product had some teething problems holley heard all about from me , Now I can honestly say that I commended holley for moving fwd out of the carb era and bringing out a FI system that could supplant virtually any carb and any car enthusiast could install if so inclined however I suffered from poor instructions and a product that had not quite had all of the bug's worked out. That being said I have had no recent experience with the Holley product.
the one I did mess with once it was set up right and holley sent injectors that worked worked great.( keep in mind that was like 89 or 90 they may have improved it by now)
It may be a good way to go...
My whole gist of this discussion was to bring to the forefront a discourse on the feasability of using a more modern devloped system (4.0 EFI ) on an older piece of iron (the 258) in an attempt to alleiviate some of that motors known weak points specificly the carter carb,and what would be nesscesary to do so.
as far as aftermarket goes there are plenty of custom and mass produced FI systems out there and as the myth of incomprehensibility on fuel injectons part and the myth of simplicity on carburators parts goes away ( I always hear people say that carbs are simple and work and that FI is too complex and too hard to understand ) there will inevitably be more , for now ther are basiclly 3-4 options .
1 mopar performance MPI KIT
2 the Holley projection system
3 a stripped system from a later model 4.0 ltr.
4 a custom MPFI system .
each has thier own advantages and drawbacks and price range
the MPI is around 16-1700 dollars right now
the Holley I dont know what they are asking for that right now.
a stripped system probably around 5-700 bucks more or less depending on source avialability etc
and last but not least how much do you have ?
Anyway it comes down to this I guess if you are going to spend the money why would you spend it on 1960's-70's technology that never really worked right anyway ( the carb was always a compromise) when you can spend your money on something that will solve your problems for sure ? if you are going to put a Holley carb on you jeep find someone who knows how to tune holleys they can be a bear jets ,metering blocks ,diaphrams yada yada yada Personally dont like em and that's all I can say about holleys carbs in public.
I guess in the end it is each one of us's own decision as to what we are comfortable with under the hood --- Ill take Fuel injection any day.
------------------
93 YJ & 2001 Cherokee Limited.Past Jeeps : 94 Cherokee Country,79 Cherokee Chief ,87 YJ Sahara,75 CJ5 Golden Eagle , 82 CJ7
Actually that was my feeble attempt at sarcasam , I put one of the original pro-jection TBI systems on an 86 dodge 4 by truck to get rid of the carter bbd that came as stock on the 318 and had given me no end of trouble as well as no horsepower for a v-8.
Anyway the holly system WAS an improvement but AT THAT TIME it was new to the market and the product had some teething problems holley heard all about from me , Now I can honestly say that I commended holley for moving fwd out of the carb era and bringing out a FI system that could supplant virtually any carb and any car enthusiast could install if so inclined however I suffered from poor instructions and a product that had not quite had all of the bug's worked out. That being said I have had no recent experience with the Holley product.
the one I did mess with once it was set up right and holley sent injectors that worked worked great.( keep in mind that was like 89 or 90 they may have improved it by now)
It may be a good way to go...
My whole gist of this discussion was to bring to the forefront a discourse on the feasability of using a more modern devloped system (4.0 EFI ) on an older piece of iron (the 258) in an attempt to alleiviate some of that motors known weak points specificly the carter carb,and what would be nesscesary to do so.
as far as aftermarket goes there are plenty of custom and mass produced FI systems out there and as the myth of incomprehensibility on fuel injectons part and the myth of simplicity on carburators parts goes away ( I always hear people say that carbs are simple and work and that FI is too complex and too hard to understand ) there will inevitably be more , for now ther are basiclly 3-4 options .
1 mopar performance MPI KIT
2 the Holley projection system
3 a stripped system from a later model 4.0 ltr.
4 a custom MPFI system .
each has thier own advantages and drawbacks and price range
the MPI is around 16-1700 dollars right now
the Holley I dont know what they are asking for that right now.
a stripped system probably around 5-700 bucks more or less depending on source avialability etc
and last but not least how much do you have ?
Anyway it comes down to this I guess if you are going to spend the money why would you spend it on 1960's-70's technology that never really worked right anyway ( the carb was always a compromise) when you can spend your money on something that will solve your problems for sure ? if you are going to put a Holley carb on you jeep find someone who knows how to tune holleys they can be a bear jets ,metering blocks ,diaphrams yada yada yada Personally dont like em and that's all I can say about holleys carbs in public.
I guess in the end it is each one of us's own decision as to what we are comfortable with under the hood --- Ill take Fuel injection any day.
------------------
93 YJ & 2001 Cherokee Limited.Past Jeeps : 94 Cherokee Country,79 Cherokee Chief ,87 YJ Sahara,75 CJ5 Golden Eagle , 82 CJ7
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