Is it worth it to port match the intake manifold when doing head work?

Boooosted strangler

Boooosted strangler

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Hey guys I'm curious as too if anyone aside buying new has had or done themselves any small head work and port/polish intake manifold?? Benifits?? Worth the time and effort?? Back story on mine it's a 97 4.0 with 0630 head and I did my own turbo set up on it. AS i knew i would end up doing, i blew the head gasket. I just got the head off like an hour ago. I order a cosmetic MLS head gasket and ARP head studs...wondering if i will benefit from port and polish job or if it's a waste of time??? I also have a 68mm TB on the way as well...thanks in advance
 
Maybe @Jezza could be of help here as I know he builds turbo kits for our TJs and tears into the motors
 
“Worth” is HIGHLY subjective

When it comes to racing applications trying to squeeze every last bit of performance and flow numbers for ETs….sure

For a Wrangler?? Eh…..are you racing it?
 
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Not worth it in my opinion. Unless you are experienced in proper head porting you can do more damage than good. You won't see much for gains at low boost levels.
 
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Well I suppose how you define racing it??? Pretty much whatever I drive out of my fleet of junk any time I stop it's a drag race when I take back off again...lol...no I'm not racing it just something to tinker with in the garage when the wife is b/+$%ing at me....just learning alot and trying to apply what I learn I suppose, just seeing others opinions on the situation that's all...I'm hoping to some day pull 5-600 hp out my butt and blow it out the rear end of this ol girl...I hit 486hp rwhp last dyno tune hoping to edge up to 6 by next
 
I'm by no means an expert. And I agree with those that know much more than me that you won't gain much...but...you will gain experience and knowledge. And Jeep 4.0 stuff is plentiful and more affordable than most other engines/platforms.

So if you wanted to play around with porting... knowing full well the gains will be minimal...might be worth trying.

-Mac
 
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Definetly outside my experience but sharing I do recall that there was information out there on porting the head. Something along the lines of leaving the floor alone but working sides, upper and open things up around the bowl/ valve stem. However being boosted how much does that matter/ improve 🤷🏽‍♂️ I don’t know
 
JustDandee said:
Definetly outside my experience but sharing I do recall that there was information out there on porting the head. Something along the lines of leaving the floor alone but working sides, upper and open things up around the bowl/ valve stem. However being boosted how much does that matter/ improve 🤷🏽‍♂️ I don’t know
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There is a lot of experience required to port heads properly. Blending and bowls, short side radius, valve stem area, runner volume... certainly above my pay scale. It is my opinion as well that a few heads would need to be sacrificed to get that figured out. When boost comes into play it tends to mask bad flow to a point.
 
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Boooosted strangler said:
no I'm not racing it just something to tinker with in the garage when the wife is b/+$%ing at me....just learning alot and trying to apply what I learn I suppose, just seeing others opinions on the situation that's all...
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My opinion, if you want to try porting work for fun, go to the scrapyard and buy a handful of aluminum intakes and heads (brand/platform does not matter), then go at 'em and see what happens. If you think you're doing something right, take it to a flow bench and prove it. Then go back to the scrapyard and buy one for your engine so you can swap it on when you're done.
 
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From what little I know the good port guys will take an old head and segment it on a bandsaw to verify casting thickness and port cross section measurements.
 
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Jezza said:
From what little I know the good port guys will take an old head and segment it on a bandsaw to verify casting thickness and port cross section measurements.
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Lots of race shop have those sections sitting around. They can even pull a poly mold off the ports. Check out David Vizard's Utube channel if you want to see some of it, or if anyone wants to come to NC he runs a local engine building school.
 
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Well it's kinda late for all that, I am an impatient idiot and just dive into things head first and see what I come up with, some how every once in a while I make it happen...basically alls I did wast remove the rusty built up carbon,gasket matched it, along with the intake, using calipers to keep them the same. Then tapered from gasket match opening back towards the valves...I have a 72mm turbo on it, it should force the air in there regardless I'd like to hope..got alot of clean up work yet and smooth it out. Then on to MLS headgasket, ARP studs and torqueing her down, installing the rest and then seeing how she does forcing 14psi down her thought...she doesn't have any gag reflexes and i think she kinda likes it!! After the head gasket blew I started building up a 5.3 lm7 forged pistons, stoker kit, cam, ect..but I just couldn't quite pull the ol 4.0 ho out...so I figured get the parts I need and give her 1 more chance and hope she lasts...I don't need that kind of power in a jeep il save it for a lil hot rod...twin turbo lm7 can put out some power more than I can keep together in my swerving all over jeep
 
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Yeah I noticed casting defects on my intake too and considered die grinding with my carbide bit to match the gasket. I chickened out.

-Mac
 
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macleanflood said:
Yeah I noticed casting defects on my intake too and considered die grinding with my carbide bit to match the gasket. I chickened out.

-Mac
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By "defect" I assume you're talking about parting lines, casting flash etc. For the most part, that's stuff is insignificant until you start pushing the limits. What is significant is core-shift.

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macleanflood said:
Yeah I noticed casting defects on my intake too and considered die grinding with my carbide bit to match the gasket. I chickened out.

-Mac
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I remember the gist of an NMRA engine builders thoughts on gasket matching. You should never design a port based on a gasket. Gaskets are for sealing and nothing else.

Adding cross section at the gasket surfaces will need to be tapered larger all the way to the plenum.
 
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As always I dive 100 kinds of into it and start researching once I'm stumped, so we shall see what happens here pretty soon...I have the mls head gasket and arp stud torqued down still have the rest of assembly, but I stumbled on a really lucrative side job so jeeps on pause til I get this done and get that money...then just dumping it back into more jeep parts, finally getting 5.13 gears and probly a new clutch, and an aem a/f ratio gauge, and an electronic boost controller...
 
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