two questions out there for the IDI owners

[icanfixall]

Sounds intriguing really. Many do not know that the power stroke 7.3 pistons fit our turbo idi rods and the bore size is the same as our 7.3 idi. So... If we had a cone type precup with a provision for the glow plug in it you might be looking a nice modification. I know very well what Inconel is. I used it with the tig weld process to repair steam turbine stationary diaphrams and the blades on them. the steam erodes the metal on the blades and actually cuts the sealing surfaces between the upper and lower case halves. We tig welded them and finally machined them back to oem standards. Reason we used inconel was it resists the steam erosion better than what Westinghouse or GE manufactured in the first place..
I don't know what our compression ratio would be using the power stroke pistons either. I do know the power stroke engines use a minimum injection pressure of 20,000 lbs where we in the idi community use around 1850 to around 2300 lbs. This forum does know of an idi that was made into a direct injected diesel. It made about 1100 hp too. So much that the freeze plugs would pop out because of block twisting. So the rubber type plugs were used. I recall hypermax had a lot to do with this engine. Had a nice twin turbo on a custom intake manifold too. Not sure what the injection pump was. I'm sure someone has saved the article and pics of it too.

 

[CDX825]

I don't know how big of market you would have but as I recall you can no longer get all the pre cups. From what I recall the ones used in the 6.9 are no longer available but the 7.3 style ones were.

The idea of better replacement is certainly appealing as well.

 

[ISPKI]

I would be surprised if 316L could hold up where inco (even 713 alloy) could not. 316L is alloyed for corrosion resistance, not necessarily heat and shock resistance, although it's structure makes it better at these tasks than 304L. A different grade of inco would most likely be the best direction to head in, or stellite, maybe hastalloy would be a good thing to look into as well. From what I recall, Stellite is extremely shock and heat tolerant but also difficult to machine as it contains tungsten. a 718 or 725 inco would probably be worth looking into rather than 316L.

 

[Hydro-idi]

I got a full set of brand new pre-cups from a parts distributor last year. For the life of me I can't remember what the name of that shop was. They were reasonably priced from what I remember. Around ~$20 apiece and they had plenty of them. Got them back east. I'll try and dig up the name of this shop.
Aside from them, nobody else carries them that I know of.

 

[Hydro-idi]

Found it! Looked at last year's bank statement to find it.

http://www.dieselcastwelding.com/

 

[79jasper]

Yep. Also the only company that sells new heads, iirc.

Sent from my SAMSUNG-SM-G935A using Tapatalk

 

[OLDBULL8]

I personally don't think there is a market for them to make it worth while. In all my years on IDI forums (16), I can recall maybe only 6 or 8 people that needed them. There has been many a million precups made, and they seem to do the job.

The precups would have to be cast, I don't know how they could ever be just machined, the angle and size of the injection spout and cavity was engineered thru trial and dyno testing. The rough cavity surface that comes from casting helps with the fuel atomization, in fact according to Ford, the injectors don't have to have a spray pattern, fuel injection can be a straight stream.

 

[Brennsky]

I personally don't think there is a market for them to make it worth while. In all my years on IDI forums (16), I can recall maybe only 6 or 8 people that needed them. There has been many a million precups made, and they seem to do the job.
The precups would have to be cast, I don't know how they could ever be just machined, the angle and size of the injection spout and cavity was engineered thru trial and dyno testing. The rough cavity surface that comes from casting helps with the fuel atomization, in fact according to Ford, the injectors don't have to have a spray pattern, fuel injection can be a straight stream.

Thankyou for the input on that topic, i could easily pull off the machining of these precups up with a 3d cnc milling machine so undoubtly its doable, however the surface finish is another matter but it can be copied through machining work, i just had noticed this as an issue not being able to get prechambers myself i figured there must be others out there as well

 

[Brennsky]

Found it! Looked at last year's bank statement to find it.

http://www.dieselcastwelding.com/

Thankyou for this article as well

 

[Brennsky]

Sounds intriguing really. Many do not know that the power stroke 7.3 pistons fit our turbo idi rods and the bore size is the same as our 7.3 idi. So... If we had a cone type precup with a provision for the glow plug in it you might be looking a nice modification. I know very well what Inconel is. I used it with the tig weld process to repair steam turbine stationary diaphrams and the blades on them. the steam erodes the metal on the blades and actually cuts the sealing surfaces between the upper and lower case halves. We tig welded them and finally machined them back to oem standards. Reason we used inconel was it resists the steam erosion better than what Westinghouse or GE manufactured in the first place..
I don't know what our compression ratio would be using the power stroke pistons either. I do know the power stroke engines use a minimum injection pressure of 20,000 lbs where we in the idi community use around 1850 to around 2300 lbs. This forum does know of an idi that was made into a direct injected diesel. It made about 1100 hp too. So much that the freeze plugs would pop out because of block twisting. So the rubber type plugs were used. I recall hypermax had a lot to do with this engine. Had a nice twin turbo on a custom intake manifold too. Not sure what the injection pump was. I'm sure someone has saved the article and pics of it too.

If you could pull up any info on that or if someone else could shed some light i would like to see that

 

[Brennsky]

I would be surprised if 316L could hold up where inco (even 713 alloy) could not. 316L is alloyed for corrosion resistance, not necessarily heat and shock resistance, although it's structure makes it better at these tasks than 304L. A different grade of inco would most likely be the best direction to head in, or stellite, maybe hastalloy would be a good thing to look into as well. From what I recall, Stellite is extremely shock and heat tolerant but also difficult to machine as it contains tungsten. a 718 or 725 inco would probably be worth looking into rather than 316L.

316l is an austenitic stainless steel that has resistance to carbide precipitation from constant heatings, its continuous heat duty is rated for 1650 degrees fahrenheit before its stress to crack or rupture begins as well as the elongation of the metal from pressures under heat stress, this alloy can withstand pressures well above what the compression ratio creates in the 7.3l idi, the 7.3l idi exhaust temperature is topped out at 1200 degrees but exhaust temperature tells you very little of the inside chamber temperature, the precups will normally at tops be at 400 to 500 degrees or normally closer to the coolant temp so 316l is more than sufficient for a prechamber without any issues of intergranular corrosion and remember sulfer cannot create corrosion without water

 

[Brennsky]

I don't know how big of market you would have but as I recall you can no longer get all the pre cups. From what I recall the ones used in the 6.9 are no longer available but the 7.3 style ones were.

The idea of better replacement is certainly appealing as well.

Ill take note of your input, im starting to realize there may not be much of a market for this part out there but im still going to give it a shot for myself for testing, i may even go as far as modifying the spray patterns as ive noticed other idi diesel engines of other makes spraying finer mists for better fuel economy it would seem

 

[Hydro-idi]

It sounds like you have the machinery & skills to make custom parts. How about making some billet (or some other material) injector return caps . Now there's definitely a market for them depending on how much they cost.
I've been wanting a set for a long time, and some members have made them successfully....but never made enough to put them on the market for the rest of us.
Not a big fan of R&D's return line rail thingy he made. Metal return caps would be better IMO. Sorry for being off topic

 

[Brennsky]

could a pre-cup be made to be more open making more space in the head, and dropping the compression ratio just a little bit for those wanting to run higher boost numbers? I dunno if it's possible or not but just a thought

Good question, from my judgement and understanding the prechambers play a role in the timing of the combustion process of diesel fuel, basically there was a thermal dynamic engineer at ford who sat down and with mathematics determined the precup size/cubic inches as well as its spray pattern for the proper atomization/timing of ignition, the spray pattern could in theory be messed with and may yield some interesting results but the precup chamber itself cannot be distorted or changed because its purpose seems to be for helping with the atomization, notice how the injector sprays at an angle into the precup, its creates a swirl effect in the precup, once the fuel fills up the precup it shoots out into the cylinder and the fire normally starts in the cumbustion chamber and works its way back up into the prechamber where any other fuel may be, for instance look at mercedes benz one of the finer makers in diesels and notice how the 300d and the 300sdl have precups similiar as to the spray nozzle on a direct injection diesel, spray pattern could do one of 3 things either increase your fuel economy or reduce your fuel or increase the combustion timing if the fuel gets atomized faster, just my two cents and understanding on it

 

[ISPKI]

316l is an austenitic stainless steel that has resistance to carbide precipitation from constant heatings, its continuous heat duty is rated for 1650 degrees fahrenheit before its stress to crack or rupture begins as well as the elongation of the metal from pressures under heat stress, this alloy can withstand pressures well above what the compression ratio creates in the 7.3l idi, the 7.3l idi exhaust temperature is topped out at 1200 degrees but exhaust temperature tells you very little of the inside chamber temperature, the precups will normally at tops be at 400 to 500 degrees or normally closer to the coolant temp so 316l is more than sufficient for a prechamber without any issues of intergranular corrosion and remember sulfer cannot create corrosion without water

But there is water vapor when you have combustion inside an ICE, and 316's corrosion resistance ends far short of 400 degree environments. Inco 725 is tougher and capable of surviving in environments up to 1300 degrees.