Hey guys. Looking for benefits on swapping an idi into a '72 250. Had an opportunity earlier this year to trade a rough '59 Galaxie for an '80's F350 with an idi in it. My brother talked me out of it, basically saying any idi is junk. He has had 2 DMax's, is currently building his second early Powerstroke, and also has a couple Cummins. So he's not Diesel illiterate, but he also thinks rolling coal is cool. Personally I think its wasteful and irresponsible, but I digress.
I've kinda regretted not making the trade, as idi trucks are still pretty cheap. Could probably find a whole truck for what it would cost to build my 360 into a 390. I'm not one looking for all out power and torque, I just really like diesels. I have since I was a kid, and right out of high school worked for a company that developed a diesel motorcycle for the military, also an idi.
What are the limitations of the idi Fords? As I said, not so interested in 1500 lb/ft of torque, but would an idi move a bit quicker than a tired 360? Is it a worthwhile swap into a bumpside.
Thanks.

 

Tough, cheap to maintain, and reliable are the first things that come to mind.

Certain blocks 83-early85 have the possibility of cracking if the block heaters are used, 7.3's can cavitate as the cylinder walls are thinner than the 6.9. Both of these issues are pretty rare however. Both my motors were early 85's and neither of them have cracked from using the block heater. My current engine has over 450k and wasn't properly maintained by the previous owner. I've got a few cylinders that could have better compression but there still within spec.

Being 21.5:1 compression they make great torque if you enjoy putting around, they don't care if you lug them and won't rattle apart or run hot like the cummins. You should be able to get double the fuel mileage compared to a 460, international did a hell of a job designing these things. Heavy bottom end and a full size oil cooler, large stock radiators (unsure if it'll fit in your rig however)

Other than the cost to rebuild I have no complaints. It does everything I need it to do and will tow anything I put behind it, just slow as I'm still non turbo. Plenty of power for me empty. A turbo and a maxed stock pump will net you around 250hp at the wheels which is more than a stock 7.3 powerstoke has.

Most people wanna go fast and pull whatever they want 80mph down the road, these are the people that give the idi a bad rep. There are plenty of people here that have added turbos and bigger pumps to get all the power they need out of them, however there pretty limited without extra dough once you cross the 300hp range.

The only really high maintenance item is glow plugs, and the pump and injectors should be changed every 100k (roughly 1200$)

 

I think the IDI is a good engine for you to consider for a swap into your Dentside.

When I bought my tuck I knew I wanted a diesel. Of course, everyone wants a 7.3l PSD so the prices are either sky high, or reasonable for a truck that's trashed. I didn't want to take a gamble on a 6.0l PSD because I've read horror stories. The 6.4l PSD has a worse reputation than the 6.0l and the 6.7l PSD was out of my price range. That meant that I had to look at older diesels.

 

Talk to a few injection shop owners in the real world. Although 100K gets passed all around IDI forums, injectors and pumps will perform perfectly a LOT longer than 100,000 miles. Unless you use veg oil or other such crap.
Mean Green 72, back in the day when diesels first came out in pickups, all of us that bought one was for the terrific towing mileage compared to a Ford 360, 390, or worse yet a 460.

 

Stock an IDI is better than a tired 360, i replaced a 400 with cam / intake / headers when i swapped my 79. The 400 had the edge empty, but couldnt touch the IDI towing. Drop a turbo on it and pick a number for power. Check out idiperformance.com I have their 110 pump, turbo kit, and s364 turbo. Out pulled our stock 2011 psd, empty, runs about like a 7.3 with chip and injectors, exhaust, intake etc. By rights given previous idi dyno sessions, i should be just around 400/ 850 at the flywheel. Also, the 7.3 psd is based HEAVILY off the 6.9/ 7.3 in the bottom end. NA IDI rods check out around 450, turbo rods, i would guess around 550-600 depending on setup.

 

I just converted my 1985 F-250 that had a 460 to a 6.9 IDI diesel. Being somewhat new to the diesel world, I can tell you my thoughts on doing a swap like this.

Personally I don't feel too much difference in acceleration in the IDI and my old 460. The 460 was a little bit quicker, but once you get the IDI going it's plenty fast and has some spunk. Not a lot - but it can move out of it's own way. The 6.9 IDI/7.3 IDI are as simple as they get. As long as you're getting fuel to the cylinders they're basically running. It really makes troubleshooting a whole lot easier. You either have fuel, or you don't. Your glowplugs are either working, or they're not. I really like how easy it is to diagnose issues.

My old 460 got about 8-9 MPG on a good day. I've been averaging anywhere from 14-16 with my IDI in town. I expect highway to be the same if I go over 65 - but I think at 55-60 on a straight road I'd probably average 18 with the 4 speed. My 6.9 IDI starts up great every day without missing a beat. My 460 could take a while. After the carb replacement it was pretty bulletproof too though I gotta say.

Final conclusion - I absolutely love my 6.9 and I wouldn't trade it for another diesel or another gas. I think the only thing I would replace it with would be another 6.9 or a 7.3L IDI with a turbo. Either way, you really can't beat it and since my swap I've fallen in love with a truck that I've loved for years all over again. For what you want, just something simple and reliable I think you should do the swap and you won't regret it. Your brother has no idea what he's talking about.

I mean really, you had me thinking that the minute you said he likes to roll coal.

 

IDI's are easy to work on, cheap to work on, and last forever. With a turbo, they perform really well. I take my IDI up the mountains all the time. Prior to the turbo, it was slow up the grades, but it always got up there. With the turbo, I can cruise up the grades at 70+mph.

You don't need any fancy tools. A standard mechanics tool set can fix 99% of that engine. No crappy electronics to deal with. No expensive computer tools to buy. Most IDI parts are cheap to obtain. If you have a torque wrench and socket set, you are basically set.

Also, if the engine does have a failure, you can usually limp it anywhere. they survive a lot of wear and tear. Once I limped my cracked block 7.3 from Newfoundland to Los Angeles in the heat of July.

Compare that to a new diesel, which on paper gets more HP, but they fail after 100K and cost 10-20x as much. I was talking to Justin at R&D IDI Performance last year about this. Either you blow $25,000 on a newer diesel, or buy a used IDI for $4000 and invest a few grand on a turbo kit, new IP, injectors, fuel filter, and tranny upgrades. You'll end up tens of thousands of dollars ahead, and not have the huge maintenance expenses the new diesel trucks require.

 

not to mention that you don't need to Urinate in a special tank either

IDI is obsolete and inefficient compared to DI engines, and that is probably why they generally last longer... newer ain't always better.

'course I know folks that can destroy an Anvil in the middle of a Cotton Field too.....

this paints a good picture ... Indirect vs Direct Injection Diesels

 

i knew he did not know what he was talking about as soon as i read he likes duramax and cummings.

 

"higher thermal efficiency" this is true, give or take 10%

"lower nox and particulate emissions" False

"lower noise vibration and harshness" VERY false

"greater high altitude performance" False

The article alludes to the newer vehicles the DI engines are in, if they have a cat / dpf, are common rail, turbo vs NA, newer, whatever, then its apples to oranges anyway. However engine to engine, IDI to DI theyre quite similar except for noise and vibration, IDI wins hands down there until you get to modern common rail with compacted iron / graphite blocks. Dyno tests have proven that IDIs actually have the edge in hp / cc of fuel injected over the 7.3 psd and 5.9 cummins. IDI's do seem to be a tad more air hungry though, probably due to the better flowing heads.

Everyone mentions the $$ involved, it really doesnt have to be that expensive, you can get over 250whp pretty dang easy and close to 400whp for a bit more. Once you start trying to go over that is when things become murky and expensive.

 

"lower nox and particulate emissions" False <<<== yeah that is my opinion also ... if the newer were so much cleaner they wouldn't need DEF and VW wouldn't have had to Lie to everyone

I think they are just stating lower because the newer all have additional systems to lower NOX

they tell me that new 3.0 is really quiet, I've not seen one yet.... and I can tell ya right now I don't want one

I guess this post really has nothing to do with IDI either

 

That was my assumption as well. I think the 3.0 is probably going to be a good engine, dont know that i want one either though. TBH, im sure a 6.7 probably is a hell of a lot cleaner than an old idi, they have i think 6 injector events per combustion now? That being said, its not like IDIs were dirty engines, that was the whole point of the prechamber, is it offers better atomization than direct injection, allowing for a cleaner, quieter burn. With the advent of better computer systems DI was comparable with IDI. As far as nox emissions however, that is simply a matter of timing, if you are advanced, they make of a ton of nox, retarded, hardly any. Im not sure how or why, but ive read this mentioned in a few articles regarding tuning 6.5s.


OP: As a talking point, you could ask your brother what the first diesel engine EVER in the 9's was, then no doubt correct him that it was not a cummins, but was in fact a 7.3 IDI.

 

The newer emissions is a scam and a half. I'm sure the very people lobbying behind the scenes to get stricter emissions are the very people that make and sell all that expensive failure prone equipment.

New engines flow a ton more cfm's for one, then add on top that the whole egr/cat/dpf/urea treatment system only makes them on average twice as clean.

Then we get into the fuel mileage which is absolutely horrible compared to older emission free diesels. I think most engines could get double the fuel economy if they were designed to breathe and run instead of being choked down.

Burning twice the fuel to be twice as clean doesn't get you anything but higher fuel prices at the pump due to demand.

Nox is mainly generated with high egt's too though.

It used to be called global warming and the main offenders were nox, methane, freon and cfc's...now it's called "climate change" because they found out they cherry picked the data for the global warming and there saying now just the output of co2 is enough to ruin the world. Every decade some guy somewhere comes out saying how we only have ten years left, yet somehow every ten years were still here and the sky hasn't called yet.

 

I'm petty certain IDI's have the loudest idle of any diesel out there... But I like em that way!

The ones equipped with a ZF had a dual mass flywheel from factory that had it's issues. But there's a solid flywheel kit to eliminate it.

There's a mod called TYP4 that can be done to allow any 383 series transmission to be used. It requires some drilling.

Of course there's adapters made to adapt close to any transmission on there.

 

we have a deleted 6.7 in work. average weight is 11,000 lbs.
and at that weight it still gets 14 MPH. and blows zero smoke. before delete, it was lucky to get 14 mpg empty
i was stopped at an emissions checkpoint a few months ago and they saw no muffler. the inspector asked me if it was deleted and i told him yes it was.
and it passed every test they threw at it, because there was no tunes added to up the power.
the inspector let me go without any tickets too, because it passed all the tests. even without a muffler it is still quiet unless you stand on it.