IronMan0002005

I have been thinking about changing the motor in my 03 v6, looking to get a little more juice out of it without killing my gas mileage. I would like to put another V6 in it, and get about 300-400 horsepower out of it, while not getting insanely low gas mileage. This isn't anything I'm looking to do immediately, I'm not even sure if I will at this point, I'm just looking to see what might be available. I would like something that wouldn't be so big that I have to change the suspension, but I understand a lot of things will have to change (may need motor mount conversions, WILL need new gears in the transmission and clutch, etc.) I would like to see if anyone has built their own new motor and how it works for them, because I want to build it and put all of the individual pieces in it that I want. In a perfect world I would want something cheap, that I could build myself (with the help of my friends machine shop), that was a reasonable price to build, got decent gas mileage, I want the engine to be built tough as hell and be reliable, and wouldn't need TOO much of the original car to change. But I know I'm going to have to take compromises on many of these things, priorities being on the reliability and mileage/horsepower ratio, and I just want peoples experiences with them. What did you change it with? Did you do it yourself or did you take it somewhere, and what did it end up costing? How satisfied are you with what you changed? Did you encounter any problems along the way?

I have done a motor swap in my friends truck. We took his stock engine out of it and replaced it with a rebuilt supercharged Ford Lighting motor, so I'm familiar with the general information, I'm just curious to what engines would be compatible to swap and if they would be in the ranges that I would like. Any feedback is appreciated. Thanks in advance guys.

Stevo86

Ok here's the bottom line with performance parts and sports cars in general. As quality of parts goes up so does price, so if you want reliable horsepower it's going to cost money. Also, as horsepower increases so does gasoline consumption. In other words your dream of a cheap to build yet reliable 400 horsepower engine that still gets 20+ mpg just doesn't exist. Unless of course you want to buy a new coyote 5.0 but I don't think the get 20mpg.

Now if you wanna make it fun, get a supercharger kit for your v6 and call it a day. Or trade up to a v8 car.

IronMan0002005

I understand that there will be a compromise on all of these things. The truck engine that we changed out, he had to put $15k just into the engine, before he changed out the transmission and added the intercooler, triplepass radiator, and everything else to make he car run. And with that $15k, he got up to 600 hp and dropped down to 6 mpg. I know there are going to be trade offs, I just want to hear what others have done to their cars and what it cost them and what they gained out of it.

And I couldn't just bolt a supercharger to my stock, old, used v6 engine, I would blow the bottom end out of the motor and/or disentegrate the transmission. After I rebuilt the motor to handle the boost and the transmission to handle the torque I might as well have bought a new motor or car.

Just want experiences. What have you changed it for? What are the new specs? What was the cost? What problems did you encounter?

DeadBob

Really if you want gas mileage and power, the new 3.7L wouldn't be a bad place to start, it's what around 310HP? Get's around 30mpg highway, plus you're staying with a mustang engine, and well never seen a swap like that done before, would be quiet interesting, plus it's not that horribly expensive of an engine, but of course with that you'd need new mounts, shaft, gears, exhuast, transmission, ect.

DeadBob

Oh and of course all the electrical

IronMan0002005

I had actually considered that because the engine does fall within most of the specifications that I wanted, but as you said I would need a completely new transmission and everything else in the car, instead of just upgrading the stuff that I currently have. I may use that as a fall back plan though if I don't get any information on other engines that might work or there is nothing else that I like. If I use that I'll definitely let you guys know how it goes.

IronMan0002005

Would anyone know an approximate price of that engine or where I could find prices on them?

DeadBob

I looked around and found a few threads of people looking at dropping it into fox bodies, but everyone sees the same issue, it's hard to find the engine, most of the people who own cars with that engine are 40 year old women that have no clue how to drive fast and thus the car never gets wrecked, and they don't seem to really sell V6 crate motors

IronMan0002005

So I found the new 3.7 V6 for $4800, but it seems I'm going to have to change EVERYTHING in the car to make it compatible, and after replacing the entire drivetrain, conversions and adapters, and accessories to make that engine fit I might as well go buy the entire new car, so that idea got bumped down the list.

One of my friends recommended just buying a junked 3.8 out of a car and boring it out and rebuilding it to handle the extra power, but I can't find parts for this motor anywhere. I'm guessing nobody ever expected to soup up a V6 so there isn't a high market on parts for this engine. So if I did that everything would have to be custom, unless anyone knows where I could get parts to rebuild it.

So the question stands, does anyone know of anything to do with this engine to make it better? Or does anyone know of an engine that will be mostly compatible with the rest of the car (excluding the drivetrain which would obviously have to be upgraded to handle the extra power)? I'm almost considering trying to trade it up for a similar model GT because there seems to be a huge market for parts for that model. But this car kind of has sentimental value and so I was trying to stick to it.

IronMan0002005

And again I understand the whole increased price and gas for better performance. So if anyone has done anything with this, what did you do and what did it cost? Just trying to get ideas and estimates to see how much I really want to do this lol.