Port Matching A 2.5L Intake Manifold To A 4.0L Throttle Body
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- čas přidán 7. 09. 2024
- Swapping to a 4.0L Throttle Body goes hand in hand with boring the 2.5L intake manifold. Although the 4.0L TB works fine without boring the manifold you can easily increase your flow just a bit more by grinding out that pesky aluminum wall that certainly creates all kinds of turbulence.
Be sure to wash out the manifold thoroughly before you reinstall it on your engine!!
While you have the manifold off you might as well swap the injectors... Check out my video where I do just that!
• Do 4 Port Injectors Ma...
Also watch me swap the 2.5L Throttle Body for a 4.0L:
• Installing a 4.0L Thro...
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#Jeep #JeepWrangler #4cyl
Don’t forget to up your coil pack voltage, it will really get the iridiums firing. Cooler plugs would help too.
I’ve got a 2.9 stroker kit in my 2.5L. Been a busy guy, just terrible with the video stuff. I’m glad someone else is getting to it.
hey man if you want to do the video thing but need help with the editing (that's what really takes the time), I can help you out if I can post the video on my channel. You can take all the credit of course lol!
At WOT these engines run rich naturally based on the tune, so bigger throttle and bored intake and better injection spray pattern WILL gain you some power gains near the top end. Not real practical for daily 3k rpm shifts, but more power is more power! It’s also a great supporting mod to do when you add a header and get some bigger valves in it. Then you can really use that CFM rate throughout the powerband.
Your on the right track, don’t forget your TB spacer plate mod to buy. You can get the air raid brand or jeepers and creepers brand.
I have heard others mention the TB spacer. What does the spacer accomplish, as apposed to the TB flat on the gasket?
@@heatmizer-jim6762 from what I understand it cools the air a bit. Also supposed to increase the velocity by causing a swirl effect. Does it work? I don’t know. I’ve seen some work good for some applications and not so much for others.
Thanks for the 2.5L love. :)
It is incredibly hard to tell. but it is the "correct" thing to do if you have a 4.0L throttle body
Thanks for the video, was going to do that with my reman engine install!
Another great video! Learning so much from you. Thx
Honestly, when I started watching this I thought it was going to be you showing your intake pictures of a family reunion or a vacation video on a cruise ship.
Lol that might have worked too
Thank you! You are the first, and as far as all the clips I've seen, the only one to explain the relationship between the TB and the intake valves. SO to make sure I understand, because I'm kinda slow: by installing the 4.0 TB, and porting the intake manifold to match, while not increasing air volume, except at full throttle, we are decreasing air-flow-resistance? Allowing the four-squirreled beast to breathe better. Correct?
Yes that is the theory. You are also changing the amount of air into the engine per throttle position. So it should 'feel' faster because 10% throttle before meant X amount of air whereas 10% throttle now is X plus a little more. Being that the jeep is fuel injected and the throttle position is recorded in the PCM doing this will have a slight affect on you fuel trims as well but nothing that the feedback loop can't account for. The overall theory here is reduced air resistance but keep in mind everything else that is happening in the system.
4:55 the valve Gap is what controls the air amount .. one of many ways around this ☝️ 👀 look in changing your Rocker arm ball bearing type with different clearance 1.5 1.6 it changes the valve clearance . FYI
I assume when you dremel the bore of you manifold theres significant aluminum shavings that fall into the manifold. How did you go about cleaning the shavings out? Did you use vacuums? Shoot compressed air into it?
Both, yes. You can also run water though it and dry it off before re-installing. Just whatever it takes to get the shavings out.
Computer is going to hold back the motor. 1.6 rocker arms are the best bang for the dollar.
By the same logic the computer would prevent the rocker arms from adding power as well. Neither is true reducing restrictions is helpful however you slice it and the computer really has nothing to do with it. I do agree that 1.6 rocker arms are a good mod and will make more power but porting the intake manifold is free so if porting makes any power at all and costs nothing then it provides more bang for the buck. However I would argue that the 1.6 rockers are more worth the time/ effort.
@@JeepSheepTV there are videos that go mod by mod on a dyno. Only the rockers as any significant increases.
I see that these improvements has fallen off, The power commander 3, it seems a limited amount of a computer modification are not available... or is there? Now in the end of 2021
There is a small group of people working on an aftermarket ECU and I'll be digging into it soon. The best I've done for this engine is re-gearing, supercharging, and moving the IAT sensor. I have videos for the last 2
So the gains with a 4.0 tb, spacer, and ported manifold all together total 24hp, but is that by themselves, or does that include other mods like 12hole injectors, header and full exhaust? What could one expect by running EVERYTHING? Injectors, header and exhaust, tb, spacer, ported manifold, intake, 180* thermostat, and anything else I'm forgetting.
I currently have all of those things minus the thermostat and tb spacer. My injectors are 4 hole instead of 12 because I read that there wasn't much difference between the two. I have also regeared to 4.11s which made a huge difference in how it drives. I will be making one more modification before I put it on a dyno and then we will find out what the difference really is.
@@JeepSheepTV definitely post up an update video with final results. Ive got a 96 XJ with the 2.5 that I'll be building on. Bone stock right now and in desperate need of maintenance, so I might as well just jump right into the upgrades instead of doing it twice. The 4 hole and 12 hole injectors are pretty much the same price on Ebay, so I might as well just jump for the finer spray pattern, also gonna dig up a spare manifold to prep for the tb swap.
Any recommendations on an ignition upgrade to go with, or is stock sufficient in this case?
@@theconstantevolution For sure, I have videos for most of my mods so feel free to take a look at those and don't hesitate to ask questions! We are here to help!
@@JeepSheepTV any word on the update video?
@@theconstantevolution its gonna be a while, I have one more mod to do before I throw the jeep on a dyno.
I'm new to your channel and was wondering, could you add a turbo to the 2.5l?
You could, but I chose to supercharge it. I have a whole series on it
So did this make a difference?
did this make a noticable difference, as you said a simple install made no difference?
No, mods like this would take a dyno to understand the any hp gains. I believe 4wheeler did a dyno test a while back and found 2-5 hp gains. The biggest difference for the 2 mods mentioned is an increase in responsiveness off idle and I do notice that.
On the subject of air needed by an engine there is a simple mathematical equation at least for older vehicles that manufacturers used to use to determine the CFM requirement of the engine to put the correct size carburetor on a specific application CFM stands for cubic feet per minute it's basically how much air can flow through something like a throttle body or carburetor the math ematic equation that I'll put on here is for a street engine only needing an 85% efficiency rating I'll use your Jeep engine as an example to show you what the CFM requirements are for your engine first you start with how many cubic inches the engine is yours translates to 150 cubic inches then times that by the red line of the engine or the maximum rpm operational which on your engine is 5550 RPM times that by 85% divide it by 3 4 5 6 it should look like this 150x5550x85%/3456=204.75 CFM requirement. And on a full racing engine you would replace 85% with 110% efficiency rating what I like to do on my performance Street engine which means it has a mild cam upgraded intake and exhaust you want to hit it somewhere in the middle between 85% and 110% to get a good CFM flow for your throttle weatherby carburetor or throttle body at 234.75. This is a approximate guideline not an exact equation meaning there are other factors that come into play like /stroke /compression ratio etc but you are correct in the fact that no matter how big you put of a throttle body and or intake manifold the air still has to make its way past the intake valve and into the cylinder what would basically be happening on an old engine is you would be doing what's called over carburetion by putting too big of a carburetor on the vehicle will cause it to bog because it can't use all the air it's receiving but the reason you don't notice much of a difference is because the computer system will compensate and adjust your fuel and air mixture accordingly so the only real way to get more air into your engine and make use of a larger throttle body would be to put a larger lift and longer duration camshaft along with if available larger valves in addition porting and polishing the cylinder head you would definitely notice a horsepower gain after all of that. Then of course there's always a turbocharger kit lol the only way to get a lot of horsepower out of that engine but your gas mileage will suffer greatly LOL not to mention adding more moving parts to your drivetrain.
That is a wonderful response! I have seen that equation in my engine classes when I was at school. The only adjustment I would make is I would drop the rpm because in reality this engine only ever sees a max of 4500 and that's rare it's more 3000-3500.
@@JeepSheepTV yes very true and that would reduce some bogging but it would definitely help to open up those valves a little longer in a little further lol I know the struggle I own a 1996 Dodge Dakota 2 wheel drive with the AMC 2.5 l it's the first year of the AMC inline 4 and the last year of the first gen body style. Minds rated for 120 horsepower at 139 pound feet of torque not terribly impressive but I'm pleased to say it still runs like a champ at 238000 plus milesI'm going to be replacing the exhaust manifold because it has a hairline crack developing on it and the intake gasket is leaking on number 3 intake Port really bad causing my idle to fluctuate at times other than that I drive it daily to work and it never seems to let me down I also have the 5-speed ax15 transmission. I'm only getting 18 miles to a gallon but I'm guessing it's due to my intake leak I drive it rather conservatively and the truck is rated for at least 22 miles per gallon highway we will see! After I fix the intake leak lol.
I find your videos to be very entertaining and to have a lot of valuable information I found your channel today actually when I was researching stuff for my Dakota I always research for Jeeps because there are way more Jeeps running around with my engine then there are Dodge Dakotas LOL I actually have been working for a dealership for 14 years about eight of those as a technician I started out at the Chrysler Jeep and Dodge store in Phoenix Arizona I also worked at the Alfa Romeo and Fiat dealer under the same company and now work at a all makes all models used car facility reconditioning used vehicles. in my eight and a half years I spent at the Chrysler Jeep and Dodge dealer I saw a lot of crazy stuff come through the doors and many of them were these 2.5 l AMC engines they are the little engines that can believe it or not I've seen these things that were so worn out it sounded like a ball peen hammer bouncing around inside the engine and they were still somehow driving great Little engines and I always look forward to learning new things each day even though I've been doing this so many years worked on so many cars there's always something new I learn each day.
You get much better head mileage than I do! I'm sure much of that has to do with gearing and wind resistance. My engine had roughly 200k on it before I replaced it and although it had 50psi of compression and knocked loudly it never left me stranded and always started. These engines are very difficult to kill. Thanks for the complement and keep coming back for more!
Hey what year is you Jeep??
This red beauty was made in 1994.
I see you are not subscribed... whats going on my friend? lol
you mean grinding out by hand, NOT boring totally different process