My IDI build...

[IHDiesel445]

Hello all,

Haven't been on here in a while, but wanted to give you a heads up on a buildup I talked about a while back... I'm actually doing it.

The block, heads, crank, and rods are at the machine shop now. Here's what I'm doing:

7.3 block is being sleeved down to 6.9, piston height reduced by .050 to reduce compression to 17:1, head studs, fire rings, rods and pushrods hardened, stiffer valve springs, 75mm S400 turbo, water injection, and a pump and injectors built up (Agnem I'll be contacting you soon about a "Super" Moose pump and injectors).

My goal is 500hp... or close to it, at around 4500 rpm. A street driven sled puller is the object. I already have most of the parts (including the turbo setup), and will be custom fabricating the exhaust manifolds myself. Hope to have it running before summer is over. Just depends on how my crazy military schedule works out...

I'm trying to be the most powerful IDI on the road. Hope this piques some interest. I'll try to get photos posted soon.


Eric

 

[trapper]

 

[FordGuy100]

Sounds like an awesome build. That said....


Looking into mm^3 what a super moose pump will push fuel wise, it will probably be enough fuel to support 350hp at the crank. For 500hp you need more like 200-250mm^3/1000strokes. Super moose delievers 120mm^3

 

[6.9poweredscout]

mmmmm.....

-Jon

 

[Rot Box]

500hp IDI?!

I'll be watching this one!

 

[FORDF250HDXLT]

your going to need a custom ground cam to get your power band up where your after i should think.

 

[Diesel JD]

I'm glad somebody is finally doing this instead of just talking. So far Ive been just talking. I can't wait to see the finished version of this.

 

[icanfixall]

Sounds like a great build idea. What formula did you use to determine that 50 off the pistons will give you 17 to 1 compression ratio. Actually 20 is the max to be taken off any idi piston. Any more will result in top ring damage from exposure to the ignition hets. But see what happens. The Mahle engineers could be wrong...Please balance the rotating parts and line bore or hone the crank webs. When you removed the crank mains you would have seen some wear on one side of the bearings. That shows you how bad the factory machining was. Also the cylinders will need to be bored square with the crank so they don't drag sideways in the bores. Decking the block will help but no more than 5 thousands can be taken off. The most difficult part of balancing the power pulses is the precup chambers in the heads. Remove a precup and look at the really ruff maching the factory gives you. Matching all 8 is tuff but you can make a custom ball end mill for this. Yous size is your dicission. I made mine 1.168 in size. Porting the heads is something needed for better flow. The exhaust port has a tight turn in it on the floor just before the seat turn. That needs to be smoothed out some. All the ports are ruffly cut out. Clean them up and the flow will be increased lots. Hope this helps you make some informed dicissions for the most hp gains...

 

[FORDF250HDXLT]

well the goal of 500hp is of course very unrealistic.
fords new twin turbo 6.7l scorpion engine is just knocking on the 400hp door.
250hp idi at the rear wheels would be a huge achievement imho.the current "realistic" idi turbo dyno run here of 200 ponies is VERY impressive as is.
when it comes to diesels,its all about the torque anyway.for high hp builds for play trucks,you really cant beat starting with a 460.

 

[FordGuy100]

Example:

7.3 powerstroke with 160cc injectors (stage 1's or 2's). With the proper setup that 160mm^3 / 1000 strokes will put out about 375 maybe 400hp to the wheels.

Super moose will push 120 cc's of fuel, or in other words, 120mm^3/1000 strokes.

mm^3/1000 strokes is the same as cc/1000 strokes.

If the moose pump will push 90cc's of fuel, and makes in the range of 200-220hp that would be roughly (220hp/90cc) 2.44hp per cc of fuel. So...... 2.44hp (per cc) x 120cc's (super moose fuel supply) would be roughly 293hp at the wheels.

So I think a very liberal guess would be 300 rear wheel horsepower.

You can only get so much energy out of a cc of fuel. You can do other things to increase power, like propane though. Its all about da numbers.

500hp at the wheels would require (500hp / 2.44hp) 204cc's of fuel. That would be a very heavily modded pump that wouldnt be streetable (DB2).

I would alter your build to shave .020" off the pistons, and run a smaller turbo than that, as you wont need that much air to support 120cc's of fuel.

 

[Diesel JD]

I think to do this right so it will live a long time you need to have a set of custom slugs forged. I don't have the technical know how to say how they should be designed without a lot of help. If I ever build one, it's going to have a custom set of pistons 6.9 spec to bolt to IDI turbo rods and will be balanced to 4000 rpm and have a Russ cam in it. I still think the ultimate pump would be a DB4, not only because it n make more fuel when turned up for those track and dyno runs but that when it is set for daily driving the high injection pressures combined with an awesome nozzle like Moose Misters would wring out the most possible fuel economy. I think I'd be shooting for 18 or 18.5:1 compression. That's what the GM 6.5 crowd is doing. That makes more room for more boost without breaking stuff. It should also allow you to still start it with the glow plugs or block heater or just a whiff of ether. You go as low as 17:1 I bet it will run and may even start okay, but with decking the pistons out of factory acceptable limits, my money is you'll crack one or melt it down much sooner than you would with a stocker or one that was custom designed with that CR in mind.

 

[IHDiesel445]

My intention is to run it with a stock pump (turned up) for a while. I'm looking into building a DB2 (2 plunger) with a DB4 (4 plunger) rotor. This should move what I need. I'm one of those people that if I can't find what I want, I build it myself.

As for the pistons, I am using the reduced compression height pistons and milling from there to get .050 off. So I'm not actually taking .050 off the pistons. When the milling/balancing is done, they are going to have the tops ceramic coated to deal with the heat issue.

I want to work my way up gradually. My main goal for right now is to build a bottom end that will take whatever I throw at it. I'll worry about ridiculous fuel later. If the budget will support, then down the road an 8 cyl inline pump might be a possibility.

 

[seawalkersee]

I think with the IP in the factory position, you will not be able to get the results you want. I think where you throw the most power is where you will be eating GPs.

I do not know if you will kill the GPs when the pump is "just running" after it is heated up or if it only effects the GPs on the startup. My money is on an adjustable pump via RPM switch and cable that throws down some advance at a rpm...say 2000 or 2200. Now, if it kills the GPs, you of course would not want to do this.

Now Icanfixatonofstuff and I may not agree on some things, but I agree with him on what he posted there. Getting the heads ported is a must. The castings SUCK from the factory. Not only that, but the intake is very restrictive and needs to be opened up to breathe. I do not have any knowledge of the precup mod of which he speaks so I can not comment.

SWS

 

[dyoung14]

You want more power?

Take an old set of glow plugs chop the tips off, play with the timing advancing it till you find the most power possible, then give it all the fuel it can take, the downside is you will have to crank it on either, the reason you got to delete glowplugs for running crazy timing is it eats the tips off, trust me

 

[IHDiesel445]

Perhaps I should clear the air a little... I'm talking flywheel horsepower, not rear wheel.