Head porting - JKowners.com : Jeep Wrangler JK Forum
 
LinkBack Thread Tools Display Modes
post #1 of 17 Old 10-07-2013, 09:51 PM Thread Starter
Wheeler
 
Join Date: Oct 2013
Age: 51
Posts: 12
Feedback: 0 reviews
Head porting

Hi I just bought a 08 jk. I'm looking to get lil more power out of it. My question has anybody done any cylinder head porting to theres and if so what kind of hp gains has anybody seen. Thank you for any help.
Babyjep is offline  
Sponsored Links
Advertisement
 
post #2 of 17 Old 10-08-2013, 02:24 PM
Wheeler
 
Join Date: Nov 2008
Posts: 70
Feedback: 0 reviews

There is not much you can do to a 3.8 to get more power over stock. CAI, throttle body, exhuast mods, porting/polishing, etc...all have been voted a waste of time and money.

Two exceptions seem to be, put a hemi in or supercharge the 3.8...real gain for the money spent.

NRA Lifetime member
It takes a special kind of stupid to think criminals will follow gun laws...

08 JK Red - NV241OR Tcase, Ripp GenII, 3"OME lift and Nitrocharger shocks, JKS F/R adj trackbars, Rockrawler UF adj CAs, Teraflex UR adj CAs, Ruggid Ridge Modular front bumper with M8000, Olympic rock rails and rear bumper, BFG KMs
rlanderton is offline  
post #3 of 17 Old 10-08-2013, 03:10 PM
JKO Addict!
 
ALASHA's Avatar
 
Join Date: Oct 2009
Location: Denver, CO
Posts: 8,257
Feedback: 0 reviews

Quote:
Originally Posted by rlanderton View Post
There is not much you can do to a 3.8 to get more power over stock. CAI, throttle body, exhuast mods, porting/polishing, etc...all have been voted a waste of time and money.

Two exceptions seem to be, put a hemi in or supercharge the 3.8...real gain for the money spent.
Noone has posted before and after numbers on a port job. Given how coarse the lower intake manifold is, I bet there would be some good improvements but the labor associated with tearing the motor down and building it back up may no be worth it...


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
ALASHA is offline  
Sponsored Links
Advertisement
 
post #4 of 17 Old 10-08-2013, 08:41 PM Thread Starter
Wheeler
 
Join Date: Oct 2013
Age: 51
Posts: 12
Feedback: 0 reviews

I build race engines for a living and have done extensive head porting. I have spent countless hours on a flow bench. On a typical v8 engine I can see with ported heads and intake, Heeders, cam and good exhaust a gain of 130 to 150 hp at the rear tires. I know this is a v6 motor so I'm not expecting those kind of gains. But I can't see why a gain of atleast 60 hp with ported heads , Heeders and good exhaust can't b reached. I just picked up a set of heads from my core supplier and going to b doing some work to them shortly here. I going to take my jeep to the chassis dyno here in the next few weeks to see what kind of numbers I get. Then do the work to it and I will post the results. I'm just curious that if I can get those kind of numbers still retain the mpg and emissions what kind of market there would b. thank you
Babyjep is offline  
post #5 of 17 Old 10-09-2013, 01:26 AM
Wheeler
 
Join Date: Sep 2013
Posts: 11
Feedback: 0 reviews

In for the results, and good luck!
agrims is offline  
post #6 of 17 Old 10-09-2013, 05:21 AM
Wheeler
 
Malan35's Avatar
 
Join Date: Mar 2012
Location: Palm Beach, Florida
Age: 27
Posts: 28
Feedback: 0 reviews

I have done some porting on my 3.8 heads. The key is not how much porting you do, but where you do it. With the porting, headers, exhaust, snorkel, and tune, I wouldnt be surprised if i picked up maybe 50HP. Dont do it expecting a race car, or even something that is moderately fast lol. The jeep is still a pig, just a little more manageable. If you are looking for real impressive power, I would pair this with a supercharger, or go straight for the v8 swap.

2007 2 Door JEEP Green
Teraflex 2.5" Coil-35" Toyo M/T-ACE Sliders-Smittybilt 8K-Rigid Duallies-Ridler-Spidertrax
Malan35 is offline  
post #7 of 17 Old 10-09-2013, 06:57 AM
Rock God
 
Join Date: Nov 2009
Location: Elkton, Maryland
Age: 37
Posts: 824
Feedback: 1 reviews

How impossible would it be to just swap in a 3.6? Or even a 4.7 instead of the Hemi?

I'd rather keep my stick shift, and I hear that's not possible with a Hemi.

On the thought of porting the 3.8. Do it if you've got spare time/parts, but I don't think you're going to see a huge gain or anything. I don't think anyone makes revised camshafts for these engines. So I don't know that I'd port the heads so much as smooth them up and remove some of the casting irregularities.

2008 Patriot Limited 4x4
2010 Jeep JK Sport 2dr/6spd/3.73's

Go visit
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
...and tell your friends!
SmurfJK is offline  
post #8 of 17 Old 10-09-2013, 07:20 AM
JKO Addict!
 
JKUnlimitedSport_2010's Avatar
 
Join Date: Aug 2010
Location: Selden, NY (Long Island)
Age: 33
Posts: 5,114
Garage
Feedback: 0 reviews

I'd like to see how this turns out!

-Marc
2010 JKU -- 3.5" RE Lift -- EVO LCAs -- ARTEC Truss and TB mount -- 17" Procomp 7069 -- 37" Maxxis Treps -- Heated Trucklite Headlights -- Synergy Drag flip -- Synergy TR -- Synergy bj's-- EVO 1/4 Pounder -- EVO Tire Carrier -- 4 gal rotopax -- TF Third Row -- China AEV Snorkel

Coming up:
D60 Front 99-04 Ford ARB w/ 5.38
14 Bolt rear ARB w/ 5.38
EVO Long Arm
40/42 MTR's
17" Spyderlock Beadlocks
JKUnlimitedSport_2010 is offline  
post #9 of 17 Old 10-09-2013, 07:45 AM
JKO Addict!
 
ALASHA's Avatar
 
Join Date: Oct 2009
Location: Denver, CO
Posts: 8,257
Feedback: 0 reviews

Quote:
Originally Posted by Babyjep View Post
I build race engines for a living and have done extensive head porting. I have spent countless hours on a flow bench. On a typical v8 engine I can see with ported heads and intake, Heeders, cam and good exhaust a gain of 130 to 150 hp at the rear tires. I know this is a v6 motor so I'm not expecting those kind of gains. But I can't see why a gain of atleast 60 hp with ported heads , Heeders and good exhaust can't b reached. I just picked up a set of heads from my core supplier and going to b doing some work to them shortly here. I going to take my jeep to the chassis dyno here in the next few weeks to see what kind of numbers I get. Then do the work to it and I will post the results. I'm just curious that if I can get those kind of numbers still retain the mpg and emissions what kind of market there would b. thank you
Headers dont work on the 3.8. I lost power slapping on a set of Borla long tubes. I dont know if that would change with a ported head but a supercharged 3.8 didnt like long tubes.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
ALASHA is offline  
post #10 of 17 Old 10-09-2013, 07:47 AM
JKO Addict!
 
ALASHA's Avatar
 
Join Date: Oct 2009
Location: Denver, CO
Posts: 8,257
Feedback: 0 reviews

Quote:
Originally Posted by SmurfJK View Post
How impossible would it be to just swap in a 3.6? Or even a 4.7 instead of the Hemi?

I'd rather keep my stick shift, and I hear that's not possible with a Hemi.

On the thought of porting the 3.8. Do it if you've got spare time/parts, but I don't think you're going to see a huge gain or anything. I don't think anyone makes revised camshafts for these engines. So I don't know that I'd port the heads so much as smooth them up and remove some of the casting irregularities.
4.7 def isnt an option if you want to keep factory electronics. I bet the 3.6 is doable but will be pretty expensive. You need the motor and trans, ECU wiring and dash at the very least.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
ALASHA is offline  
post #11 of 17 Old 10-09-2013, 08:06 AM
Slow and Low
 
Co4Lo's Avatar
 
Join Date: Jun 2009
Location: Colorado Springs
Age: 46
Posts: 5,305
Feedback: 4 reviews

Quote:
Originally Posted by ALASHA View Post
Headers dont work on the 3.8. I lost power slapping on a set of Borla long tubes. I dont know if that would change with a ported head but a supercharged 3.8 didnt like long tubes.
I know your performance gains went backwards with the headers. But that may just be due to how your Jeep is set up or maybe the headers that you ran. I'm pretty sure there have been performance gains recorded on other JK's running long tubes. So I wouldn't rule them out for others based on your experience. Different setups do different things.
It will be interesting to see what kind of results are recorded when he ports these heads. And maybe even a pre/post header dyno run so we can see how the headers affect a ported head on his setup.
Co4Lo is offline  
post #12 of 17 Old 10-09-2013, 08:57 AM
Granite Guru
 
lank's Avatar
 
Join Date: Sep 2012
Location: Roanoke, VA
Posts: 428
Feedback: 0 reviews

Quote:
Originally Posted by Babyjep View Post
I'm just curious that if I can get those kind of numbers still retain the mpg and emissions what kind of market there would b. thank you
I personally don't care about peak horsepower. My JK has enough of that and I don't redline it very much anyway. More low end would be nice to have and would be something I'd be willing to pay money for.
lank is offline  
post #13 of 17 Old 10-09-2013, 07:29 PM Thread Starter
Wheeler
 
Join Date: Oct 2013
Age: 51
Posts: 12
Feedback: 0 reviews

I will for sure post the results of what I get out of it. I agree I'm not so worried about peak numbers the key here is a usable gain across a broad range of rpm. Most of the gain in flow numbers and hp numbers are gained in the first inch of the bowl. Under the valve seat and combustion area the more you relive and work that area is where you see the best results. I talked to the guy at comp cams that does our custom cams and they don't have a shelf cam but can custom grind one. Haha at a custom cost ) I'm trying to do this as cheap as possible to b able to give people lil more usable numbers
Babyjep is offline  
post #14 of 17 Old 10-09-2013, 07:50 PM
Rock God
 
Robnoxious1's Avatar
 
Join Date: Jul 2012
Location: Bakersfield CA
Posts: 620
Feedback: 0 reviews

Have you thought about regearing?
Robnoxious1 is offline  
post #15 of 17 Old 10-09-2013, 08:52 PM
JKO Addict!
 
thaduke2003's Avatar
 
Join Date: Apr 2009
Location: Upstate NY (I'm back, baby! :))
Age: 35
Posts: 2,145
Feedback: 1 reviews
Send a message via Yahoo to thaduke2003

Quote:
Originally Posted by Babyjep View Post
I build race engines for a living and have done extensive head porting. I have spent countless hours on a flow bench. On a typical v8 engine I can see with ported heads and intake, Heeders, cam and good exhaust a gain of 130 to 150 hp at the rear tires. I know this is a v6 motor so I'm not expecting those kind of gains. But I can't see why a gain of atleast 60 hp with ported heads , Heeders and good exhaust can't b reached. I just picked up a set of heads from my core supplier and going to b doing some work to them shortly here. I going to take my jeep to the chassis dyno here in the next few weeks to see what kind of numbers I get. Then do the work to it and I will post the results. I'm just curious that if I can get those kind of numbers still retain the mpg and emissions what kind of market there would b. thank you
60 HP? HAHAHAHAHAHAHAHA!! RIGHT... you're joking? You forgot the decimal point. I'm calling major BS on your experience if you think any OE head job can net you 60 BHP. Sorry mate, but there's NO head out there that's THAT choked up. I have built REAL race engines, and actually know what I'm doing. Maybe if you put some shitty OE heads on a fully built race big block that revs past 6K, you MIGHT be able to flow enough to pick up 60 BHP on a good day with the right cam (with no other changes). This is an anemic, low-revving 3.8L turd. Figure maybe 1-3 BHP from head work. The cam isn't there, the compression is low, and the entire assembly is junk. Save your money and time and re-gear. No amount of work short of completely re-engineering that rat turd is going to do you any good. And please, get real! Mark W.

Back in a '94 YJ! Well, after I sink $$$$ into it...
thaduke2003 is offline  
post #16 of 17 Old 10-09-2013, 10:07 PM Thread Starter
Wheeler
 
Join Date: Oct 2013
Age: 51
Posts: 12
Feedback: 0 reviews

Ok this is why I'm asking questions bout this I know that for a fact on a dyno that a ls1 will gain 145 hp with that kind of work but I don't argue with stupid people so enough said thank you mark w someone with the experience you have and knowledge wouldn't talk down and act like other people are stupid. Am I right. You have good day and would appreciate if yea kept your intelligent responses in your own posts thank you
Babyjep is offline  
post #17 of 17 Old 10-09-2013, 10:32 PM
JKO Addict!
 
thaduke2003's Avatar
 
Join Date: Apr 2009
Location: Upstate NY (I'm back, baby! :))
Age: 35
Posts: 2,145
Feedback: 1 reviews
Send a message via Yahoo to thaduke2003

I only call BS when I smell it, man. A "typical" V8 puts out, say, 225-350 WHP at the wheels. You're telling me you believe you're adding ~50% with porting, cams, exhaust work, and an intake? Why aren't you writing books for engineers to use? Why haven't I heard of you?

I have been building engines, both race and street, since I was 17. I started out in Subarus (because my first Subie's timing belt broke, and I wanted to fix it. Little did I know...), and have worked with Fords, Chevys, Hondas, Subarus all both in street and racing configurations. I know what an engine can and cannot do.

Now, if by "typical" V8, you mean an LS truck engine (notoriously plugged up), you MIGHT get your 125 WHP out of it with a head swap (no mere port job, mind you, but perhaps even that on the aftermarket heads, or a CNC jobbie), big cam, race fuel, intake, TB work, long-tube tuned headers and a free-flowing exhaust, and a fair bit of ECU tuning. But please don't BS a BS'er- you really wanted us to believe that you, having spent "countless hours on a flow bench" thought that a low-compression (9.6:1), low-revving (sub-6K), 3.8L engine that is rated AT THE CRANK for 205 BHP (with accessories, but no drivetrain) could gain 60 WHP (that's at the wheels, after your ~10-18% parasitic drivetrain loss) with just some head work and exhaust? I think you need to head back to the flow bench. Step 1: self-educate: http://www.allpar.com/mopar/38-40.html

I am NOT someone who is out to belittle you, or anyone else, to feel smarter, or make myself feel good. I am not trying to insult you, or make myself look awesome. Sorry, but I'm intelligent enough to not need the internet to do that. I simply don't abide by bullshit, and can't stand how many people out there belittle my profession by calling themselves "engine builders" and "technicians" and spew forth bullshit all day long on the internet. You BS'ed, I called you on it. I had a laugh. You likely got red in the face. So it goes.

Long story short, forget making any more power from the 3.8L. It's a joke of an engine, and it's barely adequate. Spend your time paring down unnecessary weight or on re-gearing the rig (that's about the only way to get any "performance" out of the 3.8L). A programmer isn't awful, and will help with fuel economy, if nothing else. If you really want to throw time and money at it, look into a Hemi swap, or the LS swap. Either will net you some nice power, but at the cost of about what you'll pay for the whole damn rig Either way, remember: "power" and "3.8L" only go together with a negative in there Mark W.

Back in a '94 YJ! Well, after I sink $$$$ into it...
thaduke2003 is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the JKowners.com : Jeep Wrangler JK Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome