Aluminum Cyl. Head 4.0L
CF Veteran
Joined: Jun 2011
Posts: 2,858
Likes: 1
From: Nor-Cal
Year: 1990
Model: Cherokee
Engine: The venerable 4.0
Originally Posted by TrollHammer
Ok, think I found it. Cant be sure as my phone wont let me go to the next page, and I was wrong about the brand of stroker, but I believe this is the article that made me believe in the I6 ( well, more than I did).
http://www.jpmagazine.com/techarticl..._ii/index.html
http://www.jpmagazine.com/techarticl..._ii/index.html
CF Veteran
Joined: May 2008
Posts: 3,018
Likes: 23
Year: 1988
Model: Cherokee
Engine: AMC242
If it is the article I recall it was far more than 500. It was over 700, and the issue they had that stopped them from reaching for more was lack of fuel flow in the injectors. I need to look it up again, its my fav article. Mind you, they started with a titan stroker, pushed everything to what they though was the limit, turboed it, and had the water pump on electric. Like I said, want to read that one again.
Back on topic, if they go to the trouble of a new head, perhaps new design, I have a thought that might boost interest, sales, and performance by a large amount. How about if we make a hemi head for the 4.0? They had one overseas:
http://en.m.wikipedia.org/wiki/Chrysler_Hemi-6_Engine
It seems that this concept, as it was, would gain us 30-50 hp alone, looking at the displacement and horsepower.numbers. Most of these engines look to have high torque to horsepower ratios (numerically higher torque than horsepower) and horsepower to displacement somewhat near the renix, but carburated.
One in particular was only 20cc larger than the 4.0, but put out 302hp. It was at a 10:1 CR, though. Shows what such a head could do on a stroker, Id say.
As far as manufacturing and cost, this is what I see:
Aluminum: softer metal is easier and less costly to machine than cast iron or steel. Also, it seems to me that initial runs would not need to be cast. Modern CNC technology is more than up to turning out a head. Most of the same machining operations would be required regardless of whether or not the initial impressions were moulded into the blank. The coolant runners would be the most difficult, but as its aluminumband conducts heat better, this might not be an issue.
Cast iron/steel: would work the same strength wise as origional, and potentially stronger, but cast iron isnt as easy to be cast these days from what I hear. Also increases wear and tear on tooling.
It seems to me that the best idea would be to have the head material match the block, so that the expansion ratio matches. If I understand right this is one of the reasons the manifolds have a tendancy for cracking, at least in earlier engines.
As to the comment about the age of design of the inline six... It seems to.me that just because a configuration has been around for a while it doesnt mean its due for replacement. Each engine type has its bennifits and drawbacks: 4 cyl is cheap, has high RPM, and can be reliable as.it is simple. The V8 has high power density and high RPM, but usually lacks in low end torque compared.to the I6. The I6 may not have the highest red line but it has high reliability and high low end torque. This is why it is one of the more successful diesel formats as well.
The piston engine itself is an aging design, already surpassed in efficency by the gas turbine (jet engine). As far as.gasoline piston engines go, though it seems to.me.that the jeep I6 has a lot of untapped potential, and the only two things that can be done to maximize.that potential.are head work and maximizing displacement, at least without some sort of forced air.
So, as.for.my vote, if it means I can stick a HEMI sticker on the side.of my 4.0 XJ, Im all for a new head, even if its a shade pricy. CNC machine work shouldnt be that expensive these days, though, and last I priced steel and aluminum they werent all that far apart in price.
Back on topic, if they go to the trouble of a new head, perhaps new design, I have a thought that might boost interest, sales, and performance by a large amount. How about if we make a hemi head for the 4.0? They had one overseas:
http://en.m.wikipedia.org/wiki/Chrysler_Hemi-6_Engine
It seems that this concept, as it was, would gain us 30-50 hp alone, looking at the displacement and horsepower.numbers. Most of these engines look to have high torque to horsepower ratios (numerically higher torque than horsepower) and horsepower to displacement somewhat near the renix, but carburated.
One in particular was only 20cc larger than the 4.0, but put out 302hp. It was at a 10:1 CR, though. Shows what such a head could do on a stroker, Id say.
As far as manufacturing and cost, this is what I see:
Aluminum: softer metal is easier and less costly to machine than cast iron or steel. Also, it seems to me that initial runs would not need to be cast. Modern CNC technology is more than up to turning out a head. Most of the same machining operations would be required regardless of whether or not the initial impressions were moulded into the blank. The coolant runners would be the most difficult, but as its aluminumband conducts heat better, this might not be an issue.
Cast iron/steel: would work the same strength wise as origional, and potentially stronger, but cast iron isnt as easy to be cast these days from what I hear. Also increases wear and tear on tooling.
It seems to me that the best idea would be to have the head material match the block, so that the expansion ratio matches. If I understand right this is one of the reasons the manifolds have a tendancy for cracking, at least in earlier engines.
As to the comment about the age of design of the inline six... It seems to.me that just because a configuration has been around for a while it doesnt mean its due for replacement. Each engine type has its bennifits and drawbacks: 4 cyl is cheap, has high RPM, and can be reliable as.it is simple. The V8 has high power density and high RPM, but usually lacks in low end torque compared.to the I6. The I6 may not have the highest red line but it has high reliability and high low end torque. This is why it is one of the more successful diesel formats as well.
The piston engine itself is an aging design, already surpassed in efficency by the gas turbine (jet engine). As far as.gasoline piston engines go, though it seems to.me.that the jeep I6 has a lot of untapped potential, and the only two things that can be done to maximize.that potential.are head work and maximizing displacement, at least without some sort of forced air.
So, as.for.my vote, if it means I can stick a HEMI sticker on the side.of my 4.0 XJ, Im all for a new head, even if its a shade pricy. CNC machine work shouldnt be that expensive these days, though, and last I priced steel and aluminum they werent all that far apart in price.
Going to a cross-draught head alone is worth an increase in power output, because you are now free to optimize port design (since you have more room in between ports.) Elevating and canting the valves just adds to the boost there.
Also, since you're going to have to cant the valves to make either of those ideas work, and the locations of the lower valvetrain are already fixed, you may have issues with valve actuation - unless you decide to do something like adapt the CSRV (which is a useful idea - but now you have to figure out using the cam as an idler shaft and redesign the front end) or go with the Bosch "solenoid valve" design (which isn't finished yet, but will free up valve location immensely and should reduce parasitic drag through eliminating cam/tappet friction and assorted drag points in the upper valvetrain.)
Just eliminating internal friction will "free up" power - if you're not using it to operate the engine, you can use it at the wheels. That's why racers tend to use manual gearboxen as well - automatics take a significant amount of engine output to operate (hydraulic pumps are not cheap in terms of power consumption...) and just going to a "row-yer-own" frees up several hp/lb-ft to go to the rear wheels instead. That's why I'm keeping an eye on the Bosch solenoid valves, and why I'd really like to see the CSRV idea take off (Google it - Coates Spherical Rotary Valve.)
The CSRV is a proven design now - been out for a good 15 years that I know of - but it's not gained acceptance. The Bosch design is still in development, but has significant merit (much faster opening/closing time, no parasitic friction, no associated moving parts, able to adjust individual valve timing, ... Disadvantages? Electrical complexity, need for extra driver circuits in the ECU, additional wiring...
(But, you may be able to eliminate top-end lubrication - which can extend oil life, ref: CSRV [q.v.] and that would make replacement of the valves much simpler. Design them as "cartridge valves," like Honda did with the extra intake valve in the old CVCC engines ca. 1975-1985.)
Newbie
Joined: Nov 2011
Posts: 20
Likes: 0
Year: 1990
Model: Cherokee
i tell ya what my first stroker i built had a alu head from hesco running
10/1 on 89 oct it was in a 94 2wd xj and was a monster well worth the cost flows like crazy to 5300rpms build it right the first time ive learnd my lesson time and time agan by blowing up a few engings my self do it right the first time and be happy for a really long time good luck
10/1 on 89 oct it was in a 94 2wd xj and was a monster well worth the cost flows like crazy to 5300rpms build it right the first time ive learnd my lesson time and time agan by blowing up a few engings my self do it right the first time and be happy for a really long time good luck
CF Veteran
Joined: Jul 2009
Posts: 1,254
Likes: 11
From: London Ontario Canada
Year: 2000
Model: Cherokee
Engine: 4.0
Now these are the type of threads I relish. More like an XJ club for Mensa members. Whenever you can get into the actual science or even art of what makes our XJ's what I consider the epitome of the automotive field.
I can't wait for the next post by someone who has actuality studied why whatever he has posted on works then the "My buddy Bubba told me this is how it works and I always believe him" answers.
I started checking out the Hemi Six stuff as I have relatives "Down Under" I could get stuff from until i read the years and block it was based on.
DAMN!
But do please continue on the aluminum head issue. Fascinating reading here!
BTW Kelly please update your site. I'm going to start adding to my library from your suggested list but noticed a lot of other info is from 2-3 years ago. NOT a criticism just greedy for new knowledge.
I can't wait for the next post by someone who has actuality studied why whatever he has posted on works then the "My buddy Bubba told me this is how it works and I always believe him" answers.
I started checking out the Hemi Six stuff as I have relatives "Down Under" I could get stuff from until i read the years and block it was based on.
DAMN!
But do please continue on the aluminum head issue. Fascinating reading here!
BTW Kelly please update your site. I'm going to start adding to my library from your suggested list but noticed a lot of other info is from 2-3 years ago. NOT a criticism just greedy for new knowledge.
CF Veteran
Joined: Jun 2010
Posts: 1,220
Likes: 5
From: Arkansas
Year: 1987 & 1996
Model: Cherokee
Engine: 4.0
http://www.luckyoffroad.com/forum/showthread.php?t=566
I just found this write up on a manifold swap for the HO.
Since this thread has turned into a HP thread heres a great read with dyno numbers
to verify the gains.
Might have some help for heat issues too.
I just found this write up on a manifold swap for the HO.
Since this thread has turned into a HP thread heres a great read with dyno numbers
to verify the gains.
Might have some help for heat issues too.
CF Veteran
Joined: May 2008
Posts: 3,018
Likes: 23
Year: 1988
Model: Cherokee
Engine: AMC242
Now these are the type of threads I relish. More like an XJ club for Mensa members. Whenever you can get into the actual science or even art of what makes our XJ's what I consider the epitome of the automotive field.
I can't wait for the next post by someone who has actuality studied why whatever he has posted on works then the "My buddy Bubba told me this is how it works and I always believe him" answers.
I started checking out the Hemi Six stuff as I have relatives "Down Under" I could get stuff from until i read the years and block it was based on.
DAMN!
But do please continue on the aluminum head issue. Fascinating reading here!
BTW Kelly please update your site. I'm going to start adding to my library from your suggested list but noticed a lot of other info is from 2-3 years ago. NOT a criticism just greedy for new knowledge.
I can't wait for the next post by someone who has actuality studied why whatever he has posted on works then the "My buddy Bubba told me this is how it works and I always believe him" answers.
I started checking out the Hemi Six stuff as I have relatives "Down Under" I could get stuff from until i read the years and block it was based on.
DAMN!
But do please continue on the aluminum head issue. Fascinating reading here!
BTW Kelly please update your site. I'm going to start adding to my library from your suggested list but noticed a lot of other info is from 2-3 years ago. NOT a criticism just greedy for new knowledge.
As far as the Hemi Six that ChryCo did down in Oz - I'm not sure if that was still based on the standard LG/RG block pattern (that used for the 170/198/225 Slant six. The 170 used the LG, the 198 used both, and the 225 used the RG with the higher deck. It's worth noting that the RG225 was also done in die-cast aluminum for a couple of years - sometime in the 1970's, I think. I'd have to check my notes. If it was, it would be interesting to get a couple of those heads and sets of pistons (if they share the bore used - if not, perhaps Keith Black can stomp something up for us?)
Seasoned Member
Joined: Jan 2011
Posts: 387
Likes: 1
From: CT
Year: 96
Model: Cherokee
Engine: 4.0
Cool build but not anything amazing. I would certainly hope a big stroker, turbo motor would make 700hp. Hell there's a million 2 liter civics making that. I had to laugh out loud when they claimed to be "invading NASCAR territory". NASCAR engines are around 2.5 hp/cui naturally aspirated while sticking to a mile long list or rules and restrictions.
CF Veteran
Joined: Jun 2011
Posts: 2,858
Likes: 1
From: Nor-Cal
Year: 1990
Model: Cherokee
Engine: The venerable 4.0
Originally Posted by ClaytonXJ
Cool build but not anything amazing. I would certainly hope a big stroker, turbo motor would make 700hp. Hell there's a million 2 liter civics making that. I had to laugh out loud when they claimed to be "invading NASCAR territory". NASCAR engines are around 2.5 hp/cui naturally aspirated while sticking to a mile long list or rules and restrictions.
Seasoned Member
Joined: Jan 2011
Posts: 387
Likes: 1
From: CT
Year: 96
Model: Cherokee
Engine: 4.0
I hate rice more than anyone. Maybe I exagerated a little on the Civic part.. Just saying. I do have a friend with a 2.* 1st gen talon that gets driven on the street all the time and makes 838awhp. There are a bunch of street driven evos around here making north of 600 to the tires as well. Just saying 700 hp at the crank from a custom built 5.0L with a decent size turbo on race gas and meth is far from amazing. 118 octane doesn't sound too street friendly either.
Last edited by ClaytonXJ; Nov 14, 2011 at 01:17 PM.
Registered Users
Joined: Jul 2011
Posts: 618
Likes: 0
From: 92392
Model: Cherokee
That Zj that was posted was a dog! Not to be an *** in anyway, but that guy hogged his head out to get good flow number. Belled out his exhaust ports something nasty...which causes revision for those of you who didn't know. Revision - exhaust being sucked back into the head..so burning exhaust vs fresh intake air.
He got his flow numbers way to high and had no torque down low where it needed to be. I'm not surprised about that gain he got, but look where he got them..4600rpm!
I'm sorry but I don't wheel at 4600rpm.
Now I know alot of people think about bigger valves as helping flow..well they do but they don't. The cost vs return in power isn't there because our port design..or head in general don't flow enough to make use of those bigger valves! Theres money better spent, bigger valves will help but you'd never notice the difference! Spend that money on roller rockers or valve springs & a cam...now theres something that will matter!
I personally stuck with my Renix head to make it easy, its been ported decently, I gained a little flow at lower lift which is great & more and more the higher the lift got! You wanna increase flow all over, not shift the flow up higher. I achieved that!
Home ported head, gasket matched & stepped, & stock size swirl polished & uncut SS valves from Mopar. The swirl polish & uncut will help flow without using bigger valves which is why I went with them vs something bigger!
Stepping the head means exactly that, on the intake side, the intake manifold port should be slightly smaller that the head port..so it flow straight in with no ledges/ridges to disturb flow! On the exhaust side the header should be ported or opened up to be just a bit bigger than the actual exhaust port..this is so theres no ridges/ledges! I'm not talking about a huge difference either, just very minor..its basically gasket matching!
I'll be using stock valve springs, a comp 200 cam & those bolt on roller rockers. I also unshrouded the valves by doing a .60 overbore which will also help flow, and give a more efficient burn..a spruced up stocker was the goal.
I think an aluminum head would be great if you can get on with stock valve train..maybe valves that were polished & uncut for around $700-750 but it won't happen. And for that 750 your gonna spend on it, you could DIY port your old head, or leave it alone & gasket match & step it. And then add a simple 6psi turbo kit. You should end up with more power from the turbo!
This is exactly why I left mine a spruced up stock with a compression ratio of 8.89 vs the stock 8.81
My motors more efficient, flows better & makes more power even though its got a stock compression ratio. Once I add in 8-10lbs it'll be even better!
Build for a purpose!
He got his flow numbers way to high and had no torque down low where it needed to be. I'm not surprised about that gain he got, but look where he got them..4600rpm!
I'm sorry but I don't wheel at 4600rpm.
Now I know alot of people think about bigger valves as helping flow..well they do but they don't. The cost vs return in power isn't there because our port design..or head in general don't flow enough to make use of those bigger valves! Theres money better spent, bigger valves will help but you'd never notice the difference! Spend that money on roller rockers or valve springs & a cam...now theres something that will matter!
I personally stuck with my Renix head to make it easy, its been ported decently, I gained a little flow at lower lift which is great & more and more the higher the lift got! You wanna increase flow all over, not shift the flow up higher. I achieved that!
Home ported head, gasket matched & stepped, & stock size swirl polished & uncut SS valves from Mopar. The swirl polish & uncut will help flow without using bigger valves which is why I went with them vs something bigger!
Stepping the head means exactly that, on the intake side, the intake manifold port should be slightly smaller that the head port..so it flow straight in with no ledges/ridges to disturb flow! On the exhaust side the header should be ported or opened up to be just a bit bigger than the actual exhaust port..this is so theres no ridges/ledges! I'm not talking about a huge difference either, just very minor..its basically gasket matching!
I'll be using stock valve springs, a comp 200 cam & those bolt on roller rockers. I also unshrouded the valves by doing a .60 overbore which will also help flow, and give a more efficient burn..a spruced up stocker was the goal.
I think an aluminum head would be great if you can get on with stock valve train..maybe valves that were polished & uncut for around $700-750 but it won't happen. And for that 750 your gonna spend on it, you could DIY port your old head, or leave it alone & gasket match & step it. And then add a simple 6psi turbo kit. You should end up with more power from the turbo!
This is exactly why I left mine a spruced up stock with a compression ratio of 8.89 vs the stock 8.81
My motors more efficient, flows better & makes more power even though its got a stock compression ratio. Once I add in 8-10lbs it'll be even better!
Build for a purpose!
Member
Joined: Oct 2011
Posts: 168
Likes: 0
From: memphis tenn
Year: 1988
Model: Cherokee
Engine: 4.0
Originally Posted by Kamaran
That Zj that was posted was a dog! Not to be an *** in anyway, but that guy hogged his head out to get good flow number. Belled out his exhaust ports something nasty...which causes revision for those of you who didn't know. Revision - exhaust being sucked back into the head..so burning exhaust vs fresh intake air.
He got his flow numbers way to high and had no torque down low where it needed to be. I'm not surprised about that gain he got, but look where he got them..4600rpm!
I'm sorry but I don't wheel at 4600rpm.
Now I know alot of people think about bigger valves as helping flow..well they do but they don't. The cost vs return in power isn't there because our port design..or head in general don't flow enough to make use of those bigger valves! Theres money better spent, bigger valves will help but you'd never notice the difference! Spend that money on roller rockers or valve springs & a cam...now theres something that will matter!
I personally stuck with my Renix head to make it easy, its been ported decently, I gained a little flow at lower lift which is great & more and more the higher the lift got! You wanna increase flow all over, not shift the flow up higher. I achieved that!
Home ported head, gasket matched & stepped, & stock size swirl polished & uncut SS valves from Mopar. The swirl polish & uncut will help flow without using bigger valves which is why I went with them vs something bigger!
Stepping the head means exactly that, on the intake side, the intake manifold port should be slightly smaller that the head port..so it flow straight in with no ledges/ridges to disturb flow! On the exhaust side the header should be ported or opened up to be just a bit bigger than the actual exhaust port..this is so theres no ridges/ledges! I'm not talking about a huge difference either, just very minor..its basically gasket matching!
I'll be using stock valve springs, a comp 200 cam & those bolt on roller rockers. I also unshrouded the valves by doing a .60 overbore which will also help flow, and give a more efficient burn..a spruced up stocker was the goal.
I think an aluminum head would be great if you can get on with stock valve train..maybe valves that were polished & uncut for around $700-750 but it won't happen. And for that 750 your gonna spend on it, you could DIY port your old head, or leave it alone & gasket match & step it. And then add a simple 6psi turbo kit. You should end up with more power from the turbo!
This is exactly why I left mine a spruced up stock with a compression ratio of 8.89 vs the stock 8.81
My motors more efficient, flows better & makes more power even though its got a stock compression ratio. Once I add in 8-10lbs it'll be even better!
Build for a purpose!
He got his flow numbers way to high and had no torque down low where it needed to be. I'm not surprised about that gain he got, but look where he got them..4600rpm!
I'm sorry but I don't wheel at 4600rpm.
Now I know alot of people think about bigger valves as helping flow..well they do but they don't. The cost vs return in power isn't there because our port design..or head in general don't flow enough to make use of those bigger valves! Theres money better spent, bigger valves will help but you'd never notice the difference! Spend that money on roller rockers or valve springs & a cam...now theres something that will matter!
I personally stuck with my Renix head to make it easy, its been ported decently, I gained a little flow at lower lift which is great & more and more the higher the lift got! You wanna increase flow all over, not shift the flow up higher. I achieved that!
Home ported head, gasket matched & stepped, & stock size swirl polished & uncut SS valves from Mopar. The swirl polish & uncut will help flow without using bigger valves which is why I went with them vs something bigger!
Stepping the head means exactly that, on the intake side, the intake manifold port should be slightly smaller that the head port..so it flow straight in with no ledges/ridges to disturb flow! On the exhaust side the header should be ported or opened up to be just a bit bigger than the actual exhaust port..this is so theres no ridges/ledges! I'm not talking about a huge difference either, just very minor..its basically gasket matching!
I'll be using stock valve springs, a comp 200 cam & those bolt on roller rockers. I also unshrouded the valves by doing a .60 overbore which will also help flow, and give a more efficient burn..a spruced up stocker was the goal.
I think an aluminum head would be great if you can get on with stock valve train..maybe valves that were polished & uncut for around $700-750 but it won't happen. And for that 750 your gonna spend on it, you could DIY port your old head, or leave it alone & gasket match & step it. And then add a simple 6psi turbo kit. You should end up with more power from the turbo!
This is exactly why I left mine a spruced up stock with a compression ratio of 8.89 vs the stock 8.81
My motors more efficient, flows better & makes more power even though its got a stock compression ratio. Once I add in 8-10lbs it'll be even better!
Build for a purpose!
I love it homeslice
CF Veteran
Joined: Jun 2011
Posts: 2,858
Likes: 1
From: Nor-Cal
Year: 1990
Model: Cherokee
Engine: The venerable 4.0
Mild port and bowl work and a good 3 angle valve job along with a mild cam will wake the 4.0 right up. All possible for DIY in your garage. Except the valve job...
Seasoned Member
Joined: Jun 2010
Posts: 360
Likes: 0
From: Central Washington
Year: 91 xj, 93 xj, 93 zj, 94 zj
Model: Cherokee
Engine: 2x I6, 2x v8
I'd love to see a hemi - or even a pentroof - head for the 6-242, but the problem there is that you're in for designing more than a cylinder head at that point. You must lay out and design a new intake setup, because a hemi or pentroof head must be a cross-draught (and the AMC sixes have all been side-draught heads.)
Going to a cross-draught head alone is worth an increase in power output, because you are now free to optimize port design (since you have more room in between ports.) Elevating and canting the valves just adds to the boost there.
Going to a cross-draught head alone is worth an increase in power output, because you are now free to optimize port design (since you have more room in between ports.) Elevating and canting the valves just adds to the boost there.
http://en.m.wikipedia.org/wiki/Chrysler_Hemi-6_Engine
Sure, it loses the port optimization of having a cross flow, but if done right it wouldn't need new intake/exhaust work, it would seem to me, which is a more DYI install situation.
At the same time, what you say would be better power wise, and might be worth the extra bucks if the exhaust and intake adaptions were included in the kit.
I'm not familiar with the CVCC modular system, but combining it with soleniod valves and whatnot makes a nice mental picture: a cylinder head that includes the cooling jacket and main upper surface, and then a modular system for each cylinder: an exhaust/spark module bolted on one side, and an injection/intake valve module for the other side. Not that I would like a lot of electronic stuff that can't be worked on on the trail, but individual electronic throttles for each cylinder (air tuning) would be interesting, and then you'd just have a electrical cable for each module and a fuel and air line, no intake manifold. That's getting crazy though, I guess.
(edit) Ok, found this:
http://grassrootsmotorsports.com/for...g/32113/page1/
and it sounds about like what I was thinking, however, I had forgot that it would be best to get other work done along the way (guides and whatnot), so perhaps I'm not feeling as cool about it. That is unless my dad has the tools already. Never know what he's got.
Last edited by TrollHammer; Nov 17, 2011 at 03:13 PM.