Ok... Since a few of us have been spearheading the movement and almost everybody else on this particular forum is here because of it (with a few exceptions, don't worry guys, you'll come around.....)... I feel its time for a thread that is dedicated to exposing the myths of the IDI engine...

I have made a positive effort as far as every interest I have, to blow the conventional wisdom out of the water... Some things have done just that, and some have proven the status quo... I would like to use this thread as both a tool to explain the current status of the IDI, as well as a medium to solve the issues we all agree are problems with the platform.

This is not a forum for contention, but a forum for exploratory ideas only... You can disagree, but keep things civil.... The exchange of Ideas will prevail... That is my goal with this thread... hopefully we can all come to an agreement...

 

Here is one myth....

IDI injectors are set to different pop pressures depending on code...

All the codes pop at the same pressure.... I haven't had a set yet that popped consistently different than another...

Also, the nozzles/pintles themselves, are not different, aside from manufacturers...

 

Here is another...

The IDI block flexes enough to pop freeze plugs out...


No, the IDI block is one of the stoutest I have seen... However the Freeze plugs are the ****tiest I have seen...

Compare a BBC block to an IDI block sometime...

 

Myth: idi bottom end (main caps) can't handle hp numbers in the 300+ range and that they crack and leave your crank on the ground


Reality: have been proven to handle 350+hp for extended periods of time meaning thousands of miles

 

Fact......

 

Precups hurt power production...

Nope.... 2.81whp/cc is actually pretty damn good, even being a V8 diesel... That's better than most powerstrokes... Nothing there to say IDI is a limiting factor...

 

all 7.3 IDI engines suffer from cavitation.
can it happen? yes.
does it happen regularly? no
i have seen ONE 7.3 suffer from cavitation in the past 28 years, and that was on a 3 year old truck that was used and abused every day of it's life. in 3 years the truck had 165,000 miles put on it with only 3 oil changes, and still had the factory coolant in it. .

 

Myth: "I've heard the 7.3 is a better engine then the 6.9."

Fact: It's the same engine! A 7.3 is a bored out 6.9.

 

Myth: "IDI fuel injectors are expensive to replace."

Fact: You can replace an entire set of IDI injectors for the cost of one PowerStroke injector. Live it up!

 

Myth.....head studs need to be un-torqued as part of the install process.


Fact....torque them down in the oem sequence once and good to go.

 

myth: adding a turbo to an non turbo IDI will only blow it up.

 

myth: the more you turn the fuel screw up and more black smoke you make without adding any additional air,means massive power gains.

power doesn't come from smoke and mirrors.

myth: advance the engine timing as much as possible beyond 8 BTDC to gain lots of extra clatter because that's where the power and fuel economy is for all idi's regardless of the setup.

the more fuel you provide the engine with,the lower the timing wants to be.

myth: the idi's oil cooler was over engineered and therefore you'll never need to worry about oil temps when adding a turbo to a n/a idi.

the '93 and '94 turbo engines received an oil cooler with more cooling fins.
i had to installed an aux air oil cooler to keep oil temps below 240° (at the pan) on the grades.not only were the 260°+ oil temps no good for the engine,but it transferred the heat to my coolant,bringing down it's efficiency and putting needless stress on my cooling system.

myth: the 7.3l is so legendary that god used it to start the rotation of the earth.

this ones likely true.scientist just haven't proven it yet.

 

I like this post...

Both 7.3's I have (Jigblock and my IDIT) had perfect jacket-side cylinders, I saw no evidence of cavitation. I know that my IDIT hasn't been taken care of per the rule book either...

I think cavitation is a freak of nature core shift occurrence, exasperated by a bore job on a crappy block...

I think I posted in my thread recently, but by gasser standards (Yes I know...) Jigblock has plenty of meat for an overbore... It could probably go .020" over and take as much as my IDIT has.

I agree, cavitation is a way overblown issue...

 

THIS!

I don't care what sort of BS has been passed down the line... You simply do NOT need to cycle the studs...

My IDIT had 4 steps done on it, and a finish pass, it was even less than the instructions I pass out to my stud customers.... 85,105,125,150... It has arguably put the test on things as far as stock compression goes, and I never had one HG issue, even at 34psi and 180+cc of fuel...

You don't need to tighten/loosen the studs five times, that's uneeded wear and tear on the gasket... The studs don't stretch, they are NOT TTY head bolts....

Tighten them once and forget it...

 

...and along the lines of cavitation:

Myth: get a 6.9 because they don't suffer from cavitation. They are immune.

Fact: 6.9's do cavitate, and pumping toxic waste through your block (instead of clean coolant of the correct type and under the correct pressure) will have the same corrosive and catastrophic results... Eventually.