Wonder if any of you out there has ventured into swapping from an old Pushrod Motor (460 CID) to a Modular Motor (4.6L) in a mid 80's F250?
I need to get rid of the tired old gas guzzling 460 and I have low mileage Cross-Drilled 4.6L Engine & Automatic Trans (not sure of the Model) from a wrecked 99 F150. Just not real sure on availabilty of parts for this conversion?

I'm not completely ignorant to the conversion world but most of my experience is in Ponies (64 1/2 to 93). My most recent venture was putting a GT40P into an 1982 GT T-Top Mustang. This required the installation of a Painless Wiring System and a Stand Alone Engine Management Platform. This retro didn't require any mods for the Trans as I stuck with the original SR-4 Speed (didn't want to spend the money for a Tremac). Also required some creative Exhaust work as at the time of the conversion there wasn't much marketed yet and the upgrade from a 7.4" to an 8.8" Rearend (Hp reasons).

So any suggestions or advice as to what I may be or need to look at for this one will be greatly appreciated.

 

You might also post this in 87-96 as those years are closer to your target engine,
there might be more people who can help ya.

BTW could ya fill out the rest of your profile for me so we can see where you're at? Click
on User CP in the top-left corner.

 

I believe there are harnesses available through Ford Motorsport that may help. The biggest issue will be some sort of ECM and if you want to connect to the stock guages.. Engine perches will most likely have to be customized. the 4.6 is actually around the same physical size as the 460 so no real worries there.

 

Why in the world would you want to do this? Those tiny motors performed poorly in trucks from day 1. Getting rid of a cheap $ per HP engine that makes big power and factory block and heads good to upwards of 700 HP to some tiny little toy motor. It boggles the mind. You'll spend a lot of time and money and not get any gains over a 385 series engine. To each his own, but this sounds like an expensive mistake. Hell, I know folks who are pulling mod motors to replace those new heaps of anemic junk with 460 based packages.

In any event, it'll be as simple as fabbing up some mounts, depending on how different the mod motor mounts are from the 460 mounts and modifying the crossmember to mount whatever trans you run to it. You might have clearance issues with heater box on pass side and brake booster on drivers side. The mod motors are a bit wider than a 460, but slightly shorter (not as tall). Oil pan may or may not be a problem too. Aside from that it's just wiring it up. So really shouldn't be too difficult of a swap, just makes absolutely no sense to do it.

 

Archion,
As far as stock Gauges goes I was planning on adding in original Analog Senders and Switches to accommodate those and utilize the later Sensors and such for the EEC. I'm just aware if there is an aftermarket Management System out there that was suited for this swap or would address the later Transmission? Fab'ing and locating the later Powertrains in early Models is always somewhat challenging, but as stated "Where there's a Will, There is a Way".

 

cadunkle,
Its called living in the 21st Century where Parts and Mods are readily available at reasonable costs, not to mention the has savings from 10mpg to 25mpg. I can go buy a complete Mod Motor cheaper than a Big Block.

 

The stock 96-98 Mustang harness and ECU with coipacks vs the Later COP system would be best. It doesn't require the dash to perform any of its functions and the transmission from those years uses a gear still.

Mounts and harness will have to be custom to use the 99 engine.

 

because, as he noted, nobody wants em'.

if you want 21st century, buy a new truck.

straight up, the savings you will see in gas, will take years, if not decades to pay for the whole thing. (every little part you need will nickel and dime you to the poor house.)

I found that out the hard way swapping a 300 six in to replace a tired 302...

If I was going to go to that expense, and trouble, I think the ecoboost might turn out to be a decent engine...

 

A mod motor isn't magicly going to double your fuel mileage in an 80's F250, in my experience they are hard pressed to break 20 in a 97+F150 which undoubtedly has much better aerodynamics than an 80-96. A fair comparison for weight and probably aerodynamics would be a 5.4L Superduty, anyone I know who has one complains of them being completely guttless and have mileage figures in the 10-15 range.

For half of what you will spend making that mod motor work, you can freshen up that 460, bump the compression, port the heads, toss in a new cam and some headers, and have boatloads of torque right where you need it, and at least have power to make the crappy fuel mileage worth it. A Mod motor swap, you'll have spent a pile of money, still have mediocre fuel mileage, and have crap for torque at a decent rpm.

If you want good fuel mileage, go diesel.

 

Wow, just wow. There are so many things wrong with these two sentences that I am not sure where to start, so I'll take it from the top...

The 21st century, eh? Why don't you buy a 2000-something truck then? That being said, let's run down a few quick facts...

- The 385 series cam be built on a budget comparable to going through a small block.
- Dollar per HP, the 385 series is the cheapest Ford engine to build.
- Performance parts are plentiful for the 385 series
- New parts are being designed all the time, including extensively modified heads, shaft rockers, roller cams, roller cam bearings, aftermarket blocks, and many others.

I have no idea where you're getting this 25 MPG figure from. Keep dreaming, it's not going to happen. You'll be working that little toy engine real hard in a heavy truck and it will show in the MPG. It'll be a slug and get terrible MPG. Expect mid teens at best, and even that might be a bit optimistic. I hope you have at least 4.10:1 gears becasue that itty bitty toy engine won't want to push a heavy truck at highway speed at low RPM.

If you want good MPG look at a 7.3, or a 4bt/6bt swap. Either that or get something that's not a truck.

For comparison sake, when my F-250 Supercab 4x4 was stock with a 351w/C6 and 3.55:1 it managed 15-16 MPG highway at 65-70 MPH. Putting a ZF5 behind the 351 got me 17 highway. Now with 460/ZF5 it's 12.5 MPG at 70-75 MPH (and 10 MPG towing 5000 lbs at 70 MPH), but that's also with 4" lift, 35" tires, Dana 60 and + nearly 1000 lbs more weight than when it was stock. For comparison my Galaxie gets 17 MPG highway at 80 MPH with a stockish 460, C6, and 3:1 rear.

My 460 puts out about 425 HP/550 ft/lbs. I would wager that if I put the truck back to stock height it would get about 16 MPG, maybe more with the overdrive. If I built and tuned the engine for peak MPG I could probably squeeze about 20 MPG out of a 460 based engine in an '80-'96 truck. That's about as good as you're gonna get without going to a diesel.

My suggestion is do some real number crunching if you're doing this for fuel efficiency (i.e. to save money). How much is your mod motor going to cost, total package? Everything from how much the motor/trans cost you, to whatever needs to be done to it to inspect, freshen up, and reseal, etc. What is it going to cost you to convert it to work in the truck? Consider everything... Mounts, crossmembers, oil pan, oil filter, pickup tube, driveshafts, clearance issues, wiring, computers, etc. Your best estimate + a contingency of 5%-10% for all the little BS items that come up in an engine swap.

Then if your 460 is in good running condition, well you know that'll cost you nothing. How much gas can the price of that mod motor conversion buy you? Probably a lot. So price out a conversion from whatever trans you have to a ZF5/NV4500/E4od/whatever your preferred overdrive trans is. Plan on a gain of 2-3 MPG highway.

If your 460 is worn out and needs rebuilding, it's a great opportunity to do it better and shoot for mid-high teens for MPG. For comparison sake, when I did my 460 conversion it cost me $2500, $500 of that was for the conversion and $2000 was to build a 425 HP/550 ft/lbs engine, including buying a complete engine to build ($400). So for you to build a comparable engine would run ballpark of $1600, since your truck is already set up for a 460 and you already have the core to build. Are you really going to spend less than $1600 on the mod motor?

Also run some projections of estimated MPG with all your options (realistic MPG, not dreamland 25 MPG), see where the break even point is on all your choices. As others have stated, it'll probably be many years in the future.

I just think you're barking up the wrong tree here. If you throw us some more details on the truck and what your goals for MPG, power, range, etc. are we have help you come up with a plan that's gonna get you there. A 4.6 is just going to be a disappointment.

 

If you are absolutely adamant about swapping a Modular into your rig, then I suggest you take a look at this. Quint's Bronco Project While it isn't an exact swap to an 80-86, this shows a lot of the fab work that had to be done to get a 5.4 into an old bronco.

Whatever you do, enjoy yourself.

 

Guys, Guys, Guys,
I don't think nor have I ever thought that a 4.6L would add to a 7.5L. I know I will be sacrificing a large amount of torque, but as I previously stated this Truck isn't a pulling rig. There are plenty of "Non-Destructive" "Bolt-On" Power Adders that will help compensate (not replace) the loss. I do thank everyone for the concern and did learn a few new things with all of your replies.

To address a previous comment about about relative costs, I already have both complete arrangements so those cost pretty much wash out. The old Big Blocks and buildable Engines are getting rarer by the day in my parts. I live in the desert southwest and building this Engine will require Boring .060" and we all know that they are drastically weakened and prone to running Hot after that. I believe this Block and/or Head is already damaged, blowing Coolant Hoses and sprays Oil from almost every orifice under load.

I just thought or hoped that someone out there had already performed this (or relatively similar) and could offer insight as to what parts (OEM & Aftermarket) that can be used to make the arrangement fit, work and operate properly.

 

I know alot about Mod motors, but only in Mustangs and Fox-body swaps.

AFAIK you will be among the first.

 

Personnally I would stay away from a Mod engine just for the swap issues. If I was going to go through all the work of putting a Mod engine in an older truck like ours I would put a diesel in it and get much better fuel economy with much better power/torque. I drove 4 different trucks with that 4.6L in it and the best I ever got for mileage was around 18 on the highway and that was with overdrive and the cruise set at 60 going on flat ground. But its really up to you in the end. I wouldnt want the 460 because of the mileage either so it seems to me your in a catch 22 with those two motors. I dont want to sound like a jerk but the GT40 motor into a mustang is a cake job. This will not be a cake job in regards to the swap. Just so you know before hand.

 

With me too, Ponies anyways. This will be my first venture into Mod Motors, all previous swaps were with Pushrod Motors. Just really wanted to try something new and different.

Thanks.