So I'm pulling the top end off my IDI to do studs and gaskets after the one head bolt went missing...

I decided while I have everything apart, I might as well spruce up the performance a bit, but without adding a turbocharger.

Right now I'm considering Stan's Long-Tube Headers (but I haven't really heard much about and how well they work) with a true dual side-exit exhaust, and I'm also looking into the Type4 cam. Are there any other mods that can be done somewhat cheaply to bring up the power a bit? What's the consensus on head porting? This outfit offers head porting service for the IDIs:

6.9L / 7.3L IDI Head Porting Service

I know stock on the 6.9L is 170 HP and around 330-340 ft-lbs tq... Is it possible to get 200 hp out of it at the block, and close to 400 ft-lbs tq?

Also, has any one supercharged a 6.9L? I know they fit superchargers to the GM 6.2/6.5. Eaton style blower with a water to air inter-cooler (Lightning setup) would be pretty neato.

 

You want to get near 200hp without a turbo?? Sorry not happening. If you are gonna stud it, port it, ect. why not put a turbo on? You won't see real results until you see boost. All those other little things can help, not gonna give you 200hp though. In fact, with my intercooler, turbo and increased fuel, I might be just about at the 200hp 400ft/lbs of torque range. Not sure though, no dyno.

I'd stud it and turbo it and get power.

 

Have to agree that a turbo is what you really need. With studs and some porting, you could crank the boost and get more power. Would a supercharger work? I suppose it could, but the limit with a surpercharger is you are always compressing. A turbo spools up when needed due to the extra heat energy in exhaust when you step on it. A turbo is much more efficient. Typically supercharger adds low-end, you already have enough of that.

 

Floored,

For what you would spend on the heads for a stage 1 or 2 upgrade (not to mention the add-ons), you could get a used turbo and add instant power, with better fuel mileage. Turbos on these trucks are proven. If you don't go crazy with boost and monitor your EGTs' it will give you unequaled performance, and reliability. My 93 7.3 has all the power I need with a Sidewinder and 3.5" exhaust
Next I am adding a intercooler to try to milk some more MPGs' out of her. The turbo install isn't that hard if you find a complete kit.

Give it some thought.

Mac.

 

I'm definitely installing ARP studs.

My buddy suggested I build a set up for twins...

I was actually kicking around the idea of getting a set of flanges and assorted bends and building turbo headers... bringing the manifolds up the sides, mounting two turbos on each side above the valve covers with a cowl induction hood to clear. That's about the only way they'd fit. Only thing is, I've never heard of it being done, and I'm not sure how two smaller turbos would work out.

If I were to turbocharge it, I'd be building it from scratch pretty much.

Any thoughts?

 

I just want to know how a head bolt went missing, there has to be a story here.
It has been claimed that stans headers give little gain by some, guys that have bought them said different, I never used them so can't say one way or the other.
I do know going to larger true duals helps a lot, I also know the driverside exhaust manifold is crazy restricted on the back cylinder, so I have to believe that the headers help.

I still want to know HOW a head bolt went missing.

 

You and me both. First time I've even heard of a missing head bolt, but there it is plain as day. I didn't stick anything down the hole to see if it was snapped off or completely missing, but I'll find out when I pull the head. Hopefully it didn't warp the head or burn part of the head/block away.

 

I have seen many broken headbolts, most I have seen were on the older cummins that were turned up. All that I have personally still had the bolt in the hole though. If it isn't broke off, I would be inclined to belive that it was never installed. lol

 

Hahaha... I have to say, these things are tough. When I first got the truck it didn't make much noise. I thought okay, noisy vacuum pump? Then it started making what sounded like an exhaust manifold gasket so I ordered the gaskets and figured I'd wait until I had a little time off to do it. It got really bad really quick and started to run rough, so upon further investigation I had it running with the hood open and saw smoke shoot out off to the passenger side. I'm looking, and looking and then I see a hole in the head, and I'm like... is that... missing a head bolt? Seriously?

My buddies had a pretty good chuckle over that. Being Chevy fans, an onslaught of jokes headed my way but all I had to say was... It ran with critical pieces missing. Built Ford tough. I guess more specifically, built Ford tough with International stuff.

 

Porting the heads is a waste of time on these engines. Id be willing to bet that the heads stock, flow more Air/Exhaust, than what the engine moves at redline. That means that you will see no increase in power, just wasted effort. Valve jobs help move the Air/Exhaust past the valve more efficiently, and may be worth it on a highly tuned setup, but as far as porting goes, its simply a waste of time.

The best thing you can do to an IDI, is Turbo it. Supercharging is a waste of energy, and you dont get the load controlled benefits of a Turbo. If your Turbo is not spooling up fast enough for you (Jesus, how low do you want said boost??), its because your setup isnt dialed in. Turbo's are put on almost all diesel engines for a reason, they are the most efficient, and best suited power adder, plain and simple.

To the OP, your best bet would be to Stud it, Turbo it, Cam it and Pump it, youll a lot more satisfaction from that, then to build a "Hi-Po" N/A engine.

 

Pretty much agree with wha you say Racindummy, but there are many people that don't want to spend that much, and can get by with out a turbo.
if you are not going to run a turbo head studs are a waist of money.
Just a free flowing exhaust and free up the air intake makes a lot of difference in these engines.
People have to keep them a long time to make it actually worth while to spend the bucks, a turbo and related parts cost, and many don't keep them that long.

 

Was that supposed to be an insult?

Turbo's are really not that bad. I couldnt sell my factory ATS kit, COMPLETE, for more than $500, and you can sink that into useless N/A upgrades in no time.

All im saying is a Turbo is the most bang for the buck, and thats un-arguable.

 

Why would you consider that as an insult, and what is a useless upgrade. I have a turbo on my dually, But don't have a need for it the one I just drive, I do have open exhaust on it though. I know how much a used turbo cost, I have an extra setup in case I ever have a need for it. I know there probably have been some, but I have never seen a set of cheap used head studs, and I wouldn't consider a turbo on a 6.9 without them, then if you don't upgrade the exhaust, you have not done much with a turbo.

There are a lot of people that don't need to spend the bucks for a turbo, that can benifit from some cheaper upgrades.

 

I think he's referring to the way you misspelled his user name, "Racindummy". I'm sure it was a typo and there was no insult meant.

Personally, I like the idea of a turbo, but I also like the simplicity of a naturally aspirated engine and the fact that there isn't much room to work under the hood once you've got a turbo on there. Unless you remotely mount the turbo/turbos, and seems to me that would have it's own unique set of problems, like oil routing and return. Also, most of the turbo kits that are used that I have personally seen for sale, seem pretty beat for that price range ($500-$1000) and may or may not be missing components.

It just seems hard to believe that with a cam, headers and a full exhaust, 20-30 HP couldn't be tacked on. It's been said that the Type4 cam will give you close to 12% increase in power, and at a lower power band... So right there that takes a good running 170 HP up to ~190 HP. Of course this is on paper.

Remember, I'm also talking about getting 200 HP at the block, not rear wheels.

 

I have never dino'ed one of these, but my but dyno can tell the difference with just good exhaust over stock, and this was when they were new. A lot of these rigs are running around with the original stock exhaust that is about half stopped up. newer free flowing exhaust would make you think you were driving a different rig.

I am sorry to you racindrummin. I totally misread your handle and ment no disrespect or surely wasn't trying to insult you. I didn't even notice it until fiftyfordfloored pointed it out.
At least now I know why you thought I was trying to insult you.