two questions out there for the IDI owners

[no mufflers]

, 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

I think the moose mister that mell makes at Conestoga diesel has a different spray pattern. you might want to look at that.

 

[pelky350]

I think we need a video with the spray pattern of most the various options of injectors available because there are quite a few. Mel's moose mate and mister injectors with new tips I believe, type4 makes injectors, r and d has stock and stage ones with new tips and another company I can't remember the name it's like diesel power products or something makes stage1-2 injectors I heard just make a stream of fuel basically. It would be interesting to see them pop tested and see the spray pattern of them all.

 

[79jasper]

There are videos out there.
Not many side by side comparisons though.

Sent from my SAMSUNG-SM-G935A using Tapatalk

 

[Brennsky]

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.

You do have a point there on that, that was the one thing in my mind still a bit iffy about that alloy, i dont have any testing setup and wont for some time but i was going to make different sets of stainless alloys to see what results i get, 316 would make it more cost effective and cheaper to machine plus save tooling, there are other alloys of stainless i havent extensively read into all the finer details about yet so i might find something better, i would love 725 inco but man oh man will the piggy bank run dry haha

 

[Brennsky]

I think the moose mister that mell makes at Conestoga diesel has a different spray pattern. you might want to look at that.

Ill deffinitely check that out, the 7.3l idi shoots its fuel straight across the cylinder ,heres something to also note i noticed something peculiar about duetz diesels, they are direct injection but the injectors are indexed to shoot the fuel at an angle into the direction of the swirl effect i thought that was odd but it may also be a clue to something, theres only one way to find out ill have to test it eventually

 

[lotzagoodstuff]

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

Hey Brennsky: the pre-cup/injector theory is very interesting, but if you really want to make something that the IDI market will buy, I would kindly suggest reading Hydro-idi's comment. Do a search, there is a ton of buzz about the injector return caps, and somebody already made a log style that's got pretty mixed results, so the market is still open. Lots of IDI folks want something better than plastic, do a search and put your machinery towards a market that's clamoring for some upgraded return caps.

 

[ISPKI]

I am going to second the return cap idea. I have done caps twice on my idi and still have poor seals on a couple. Brand new viton rings too. Precision machined and DEBURRED caps made of 303ss would be a welcome improvement

 

[Brennsky]

I am going to second the return cap idea. I have done caps twice on my idi and still have poor seals on a couple. Brand new viton rings too. Precision machined and DEBURRED caps made of 303ss would be a welcome improvement

I looked at R&D's Injector return line rail they have and i notice one thing about it, wouldnt it take up some wrench turning room with that thing?, and when you mentioned making these are talking about reproducing a similar rail to R&D's, or would you want it in the original configuration like the old ones with the rubber line between, id imagine youd want a rail like R&D rail

 

[ISPKI]

I would want stainless steel caps with threaded flare fittings machined on them, then you could make NiCopp lines instead of this rubber ****. Nicopp would never need to be replaced.

 

[snicklas]

No, they are saying replicate the caps in Aluminum or Stainless, or brass..... we had a user here make a couple sets.... but they were a "government job".....

Here is one of the threads, to give you an idea.....

www.oilburners.net/threads/billet-aluminum-injector-cap.57625

 

[Brennsky]

oka

No, they are saying replicate the caps in Aluminum or Stainless, or brass..... we had a user here make a couple sets.... but they were a "government job".....

Here is one of the threads, to give you an idea.....

www.oilburners.net/threads/billet-aluminum-injector-cap.57625

that is pretty neat but theres one thing i see as a flaw but not a complete loss the rubber hose will last awhile but tbh i like ISPKI's idea because then you would have a more maintenance free solution, not only to mention less machine work involved= lower cost, the only thing you'd have to change are the o rings in time when they get old but thats not a biggy, nicopp is an excellent material for the return lines as its easy to form/flare

 

[jaluhn83]

IMHO no reason to mess with prechambers. Unless I'm missing something they're trouble free as is unless something catastrophic happens. Yes, they'l crack, but the cracks don't matter unless they penetrate the fire ring.

Increasing CR through increasing prechamber size is an interesting idea, but the size/shaping of the chambers is designed very specifically to interact with the rest of the cylinder for proper swirl, mixing, etc. The injector spray pattern is also matched to that flow. Changing the chamber shape stands to mess that up and I'd be worried about unintentional side effects there. Also not sure there's enough meat to do much without having strength problems.

I'd be interested in seeing some fluid flow modeling of the idi combustion system to see what is really the best way to optimize it for the higher air/fuel flow that comes form the turbo. Until that's done pretty much everything is guesswork. Not an easy project through.

Also do not think 316 SS is the optimal alloy - they probably speced inconel for a reason. I don't have any of my materials books here or time to dig into it, but I'm pretty sure high temperature performance of inconel is much superior to 316 - yes 316 may be rated to fairly high temps, but there's creep, strength loss, corrosion rates, etc etc. Austenitic SS is also a fairly poor thermal conductor - not what you want there.

 

[Macrobb]

On the return lines topic, 7 years ago or so I made myself a set while I was in machining school. Just made some aluminum cylinders with a hole bored out and a lip on top, and then drilled and tapped 1/16" NPT threads for little hose barbs.
The machining part worked, but I had trouble keeping burrs from nicking the O-rings.
Also still had trouble with sealing, despite using a tighter tolerance etc.

After I figured out that wheel bearing grease solves the leaking problem, I haven't worried about those caps or any others since. I just grab any old set of plastic caps(stock ones are getting brittle), and install them with a liberal helping of high-temp lithium grease.
It's almost a miracle when it comes to O-ring sealing. I've had no more issues since, even with disturbing the caps. I've done the procedure on 4 trucks so far, and had no issues with it.

Last time I had a leak on one after doing the caps, I pulled the cap to find... a pine needle! Just pulled the needle out, cleaned and re-greased the cap, and reinstalled. Done deal.
And that last truck, the 93 in my avatar... I just grabbed the absolute cheapest kit I could find on ebay. Still worked just fine; no issues with fit or finish, and no leaks(once I got the pine needle out).

As such, while I think metal return caps are cool... I personally don't think it matters anymore. A good set of hose should last 10+ years easily, and you'll probably need to replace the injectors themselves in that time.

 

[ISPKI]

On the return caps: i do not lkke how short the barb fittings are on the set i got. I used vaseline on viton o rings and it was still difficult to get them to seat. I work for a laser welding company so i could have the threaded fittings made separate and weld them on fairly easily.

I spoke to our metallurgist and he suggested 321 or 347 if you want to use that series of SS, Inco 660 if you have the $$$ should handle the environment better than 713.

 

[Clb]

You should do return caps.
I just opened up the diapco bs kit I got from
Somewhere here.
NOT MENTIONING WHO!
PERIOD.
This chit was a 2014 datecode.
Casting flash was crazy, including the ports inside for the hose conections.
B.S.
Cb out.