4.0 engine Build

Justin Bradford

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I am looking to turbo my car and wondering what I need for my internals and engine components.
I have access to a machine shop so can port the heads etc. I just would like to know any info about the limits of certain components like valve springs, rods, heads etc. any info would be helpful!
 

Juice

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Not many heavy 4.0 modders here. I seem to recall Explorer Express, guys modding explorers with the 4.0. But I cant find the site now. (Was going to go the xcharger route)

Generally, you can relatively safely double the hp with boost. And that puts you at the raged edge of "it should live". The closer you get to this power level the bigger the chance of blowing it up and a good safe tune is critical. So instead of forced induction, I coyote swapped mine.
 

Justin Bradford

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Yeah I was thinking about going the engine swap route at first. I wanted to swap in a first gen coyote since those are more n the cheaper side but a complete engine and trans are going for around 6k around here and I can't find any at at any junkyards in trucks or mustangs. I couldn't really find any 4.6 engines either except for in some crown vics that had been stripped of parts. The only engines that were cheap and plentiful were the 5.3s out of the Tahoes. That would only yield me around 310 stock and would require a lot more work. I already have a custom made twin turbo kit and at this point it will be cheaper to just put the kit on and build up the engine a little. Even without a built engine 400 hp isn't a bad number for these.
I would Like to do more since my free access to a tuner and a machine shop.
 

JimC

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Dave and Patty retired and so Xcharger closed down.

No need to build the engine, lots of boosted 4.0's running with lots of miles. My 2006 had the Xcharger Xtreme running about 15lbs of boost. I put 203,000 miles on it before I sold it, the guy I sold it to sold it with almost 250,000 all on the original stock engine. I know a lot of guys pushing more boost and with turbos who are getting 450 RWHP with no problems.

Look up the Mustang Collective on Facebook. You'll find a lot of 4.0 information from there.
 

Justin Bradford

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Yes I’ve done a bit of research on the topic and found that the max power most were getting on stock was between 400-450 crank. I’m looking to a bit higher and try and get maybe 500 whp if I can. I know that’s a bit ambitious but I believe that with possibly maybe rods or pistons depending on which is weaker, ported heads, and customs grind on the cam that I could get there. Just not sure on the internal components that give out and finding someone who has done internal work is proving difficult.
 

Juice

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Yes I’ve done a bit of research on the topic and found that the max power most were getting on stock was between 400-450 crank. I’m looking to a bit higher and try and get maybe 500 whp if I can. I know that’s a bit ambitious but I believe that with possibly maybe rods or pistons depending on which is weaker, ported heads, and customs grind on the cam that I could get there. Just not sure on the internal components that give out and finding someone who has done internal work is proving difficult.
Based on the HP level you want, you need forged crank, forged pistons and upgraded connecting rods. And than the block becomes the weak link. Porting is not a factor as far as strength of components, and valve springs are to be matched to cam and target rpms.
 

DieHarder

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Don't think X-chargers are available anymore but Modd box is. modd.me Probably lowest cost option. Of course turbos/centrificals out there as well.
 

Juice

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Don't think X-chargers are available anymore but Modd box is. modd.me Probably lowest cost option. Of course turbos/centrificals out there as well.
He wants to turbo it. I suggested explorer express as that is where I ended up looking to boost mine. And only for engine upgrades, not the supercharger itself. ;)
 

Justin Bradford

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Do you happen to know the limits of the internal components? As well as other websites to purchase the parts from. So far I’ve got Explorer Express, Morona Racing(not sure if I spelled that right) and SuperSix
 

Juice

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No, sorry. As I said, I went w/coyote. Practically the same weight as the 4.0.
 

JimC

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Do you happen to know the limits of the internal components? As well as other websites to purchase the parts from. So far I’ve got Explorer Express, Morona Racing(not sure if I spelled that right) and SuperSix
Explorer Express is not in business,and never carried any parts like that anyway - wasn't needed.
Be careful about Morana - lots of people reporting "issues" and non delivery of parts and some things that simply aren't available even though listed on his site.
 

Justin Bradford

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Not worth it to get a 3v at this point. Where I am right now I could only get a salvage title stock 3v/lightly modded for maybe 8-10k. I already have the turbo kit so even running stock motor I could make almost 100 more than a stock 3v. I know that a 3v would be a lot better for a power build but I’m going to just build this one up for the time being and maybe scoop up a 3v 4 or so years down the road. A GT at this point in time is simply not attainable with my goals for either a 4.0 or 4.6. Insurance would also kill me as a younger driver.
 

skwerl

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IMO go ahead and do what you want to do with this one. Use it as a learning experience or practice and have fun with it. Heck, 5 years down the road you'll be driving a blown 5.0 and you'll build it using the experience you gained working on this 4.0.
 

DieHarder

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Not worth it to get a 3v at this point. Where I am right now I could only get a salvage title stock 3v/lightly modded for maybe 8-10k. I already have the turbo kit so even running stock motor I could make almost 100 more than a stock 3v. I know that a 3v would be a lot better for a power build but I’m going to just build this one up for the time being and maybe scoop up a 3v 4 or so years down the road. A GT at this point in time is simply not attainable with my goals for either a 4.0 or 4.6. Insurance would also kill me as a younger driver.

Insurance is based on the VIN. They don't know what's in it.
 

Flapjack

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Here are my thoughts on modding the 4.0L. I was one of the first batch to start modding mine back in 2005 and had a ProCharger P1SC kit ordered the day it came out. I eventually bumped it to a D1SC (SO much better), then did Super Six Motorsports heads and cams (Tom is still around and in business, and is your BEST source of info). Total power with heads and cams @ 14psi was 440 RWHP. Good for a V6? Sure, but there are some caveats here.

Anything over 400 RWHP is pushing it. The only reason I ran that much boost for as long as I did was because I lived at 6500ft (Colorado Springs). While we only have 91 octane here, the altitude makes detonation less of a worry. Unless you plan on using aftermarket/forged rods (which weren't available when I built, but are now), that kind of power leaves little room for error. With that, though... you're also talking about forged pistons, and a seriously PITA engine build. This is really just not worth the hassle, IMHO. Get a 4.6L 3v. There's no way they are 8-10k. Whoever's giving you that price is smoking crack. A quick search at autowrecking.com (first result in my search) showed $1600. You'll also need a PCM ($200-500), the GT engine wiring harness ($200 from Ford, but that was years ago), a transmission ($1000-1500), and a few other odds and ends. This may sound like a lot, but you are going to spending a LOT more than that on building a 4.0L up.

The other thing I cannot understate is the 4.0L is just a shitty sounding engine with "good" cams. You can look at youtube.com/cabuzzi for some of my old 4.0L videos. Outside of the first heads and cams video (which was with open headers), they all sound like shit/rice. I made revision after revision to my exhaust, trying to find something tolerable. I eventually said fuck it and decided to do a 3v 4.6L swap (don't ask me why I chose the 5.4L 3v, though...). The shitty sound of the 4.0L was the #1 reason I swapped to a V8.

I would recommend one of two courses:

#1 - Keep the 4.0L stock and get a decent power adder, but keep it no more than 10-12psi. That should net you 300-350 RWHP. You'll be happy.

#2 - Swap in a 4.6L 3v, drive it around for a bit, and decide where you wanna go from there. You should be able to do 450-500 RWHP on the stock block with turbo without much hassle (as long as you don't get an engine with 50 million miles on it). Later on, you can consider building that and bumping up the boost, after doing supporting mods.

Regardless of what you do, just keep in mind, you WILL blow the 4.0L stock 7.5" rear end. Even with a Detroit TrueTrac, I still smoked it the first time I got good traction at the track. I've seen it happen on the street, too. The 7.5" is just hard to make strong. Gone are the days when brand new 8.5" GT takeoffs were common at nearly every reseller. You'd have to get one used now, and that is also a mixed bag (depending on how the car was driven).
 

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