Dual IP with a twist - Hello me brainstorm this out

[icanfixall]

The Stanadyne DB2 pumps on the chevy 6.2 and 6.5 diesels turns the oposite direction that ours does so maybe that can be used off the same drive gear or some mount capable of handleing two pumps.

 

[WisdomWarlord]

my only question is: will it still start in january?

In my experience, it shouldn't be an issue. My first personally owned diesel was a 1966 GMC Newlook (aka Fishbowl) transit bus with a 6V71 Detroit that started the same way, even in 0F, without a block heater... But it did take more cranking and sometimes a second ether pill.

 

[WisdomWarlord]

The Stanadyne DB2 pumps on the chevy 6.2 and 6.5 diesels turns the oposite direction that ours does so maybe that can be used off the same drive gear or some mount capable of handleing two pumps.

That's good to know. A little more flexibility in rotation might be useful.

 

[88 Ford]

That is actually a different way to think of doing two IPs. I have never never read about anyone talking about using the glow plug locations to mount a second set of injectors. Does the spray angle matter when it is spraying into a precup? I know it doesn't matter as much as in a DI engine but what bearing would it have on an IDI?

Also could the two injection pumps be mounted 90* out from each other on the same gear and then timed accordingly?

 

[racer30]

I would think you could start the engine on one IP timed for 8* then time the second IP for 10* so when running on both IP's the fire would already be started when the second shot was sent. Just Running one for a few seconds wouldn't create a problem. And run 10% or 20% oil in your fuel for lube. Let her rip...

 

[laserjock]

I was thinking about this a little last night. I think the slick way to do this would be to make the second set electronic. You could time it off a ferret type pic up and set your fuel curve for what ever you need. That way, you aren't cooking the pump by shutting off the fuel at idle. You aren't blowing smoke like crazy before the boost comes up because you can map it. You are going to have to find a different injector most likely anyway that will plug into the gp holes so why not look electronic. There are simple open source kits out there (Megasquirt comes to mind). It just makes sense to me. Hey if the appocolypse happens, you are just stuck on one IP.

This is an interesting discussion. As for the starting in January, a block heater goes a long way toward that but not always a tree around to plug into.

 

[Agnem]

I hate to burst your bubble, but as the owner of the Moose Museum of Mystery and Mayhem which travels to the IDI Weekends, and which one of the exhibits is a cutaway head, I can tell you that you will not have enough space in the head to cut a second injector in, unless your willing to build your own billet head. You will be into the cooling system in no time flat. The proper way to do what your trying to do (and much easier) is to put a T on the injector threads, and just run two lines to one injector.

Also, starting these on either is really not the best solution. Your Detroit did not have a 22.1:1 compression ratio, and these IDI's will combust either way before top dead center, which causes a lot of stress on the piston, connecting rod and journal bearings. Over time, your luck may run out doing it that way.

A dual IP build though is an idea I have been a supporter of for a while. Would love to see someone pull it off.

 

[justinray]

Mel, could you answer the question as to the lubing and cooling of the pump with the fss cut off?

 

[WisdomWarlord]

Mel,
I did some looking and realize that the glow plugs don't seem to have any threads in the precombustion cups, so assuming I can stuff a second injector into the head, I won't have to tap the inconel, just cast iron. Much easier!
You're saying that I won't have space to enlarge the glow plug hole to fit a second injector?
What if I drilled it out big and brazed in a sleeve that the injector mounts in? Kind like a helicoil?

As for running 2 injector lines to one injector, can the injector really flow enough fuel or will the single injector then be the next bottleneck to fuel flow? Also, If I staggered the timing, can the IP withstand having full fuel injector line pressure trying to flow back in? There will be a short period of time that only one IP is actually injecting fuel, and during this time the other IP will have to hold on and not let that high pressure fuel flow backwards.
Also, I am theorizing that 2 injectors per cylinder that are completely independent of each other will allow a more tunable and therefore a more streetable engine.

I do agree that improper use of ether will do harm, and the higher cr in the IDI is a special concern. But I'm also confident that done properly and used sparingly, the ether will be no more stressful to the IDI than it is to the old 2 stroke Detroits. Time will have to prove one of us right on that point.

At this stage of the project, I am making a lot of assumptions. Hopefully not to many of them rise to the level of SWAG (Scientific Wild Ass Guess), but it's possible. Please feel free to correct my SWAG

And I'd also like to hear anyone's thoughts on IP function while turning with the FSS off.

 

[icanfixall]

I was waiting for Mel to discuss the pics of the head cut away that Rus did for him. As Mel said. There just isn't enough room to support another injecter. As for the threads. They are about 2 1/2 inches away from the precups. As for welding up the head with a sleeve. I'm thinking a very special cast iron welder is needed for that. Years ago I know of one but can't find the saved article about him or his shop. He never allowed anyone to watch him work on cast iron. When he was done there was no way to see where he repaired a cast iron block. He ground it down and then did a praprity step to make the cast iron finish look the same as the rest of the block. It was an amazing finished product. I think I saved a hard copy of the precup cut away head pics. Will have to look around this mess and post it if I still have it..

 

[laserjock]

If timed appropriately, would it matter where in the cylinder the fuel is injected? If ignition is happening in the precup, supposing ignition has occured and the flame front is moving along, it would seem to my uneducated brain on this subject that additional fuel could be added to the cylinder at large and not have to go through the precup. Does that make any sense to anyone else that knows more than I do about IDI cylinder heads and flame fronts and etc. etc. etc.? I could see where it might not be completely optimal but it may not need to be for a significant gain. Ah mental ************... These types of threads keep me sane by letting me think about anything besides what I'm doing. Keep up the good work guys.

 

[88 Ford]

Mel,
I did some looking and realize that the glow plugs don't seem to have any threads in the precombustion cups, so assuming I can stuff a second injector into the head, I won't have to tap the inconel, just cast iron. Much easier!
You're saying that I won't have space to enlarge the glow plug hole to fit a second injector?
What if I drilled it out big and brazed in a sleeve that the injector mounts in? Kind like a helicoil?

As for running 2 injector lines to one injector, can the injector really flow enough fuel or will the single injector then be the next bottleneck to fuel flow? Also, If I staggered the timing, can the IP withstand having full fuel injector line pressure trying to flow back in? There will be a short period of time that only one IP is actually injecting fuel, and during this time the other IP will have to hold on and not let that high pressure fuel flow backwards.
Also, I am theorizing that 2 injectors per cylinder that are completely independent of each other will allow a more tunable and therefore a more streetable engine.

I do agree that improper use of ether will do harm, and the higher cr in the IDI is a special concern. But I'm also confident that done properly and used sparingly, the ether will be no more stressful to the IDI than it is to the old 2 stroke Detroits. Time will have to prove one of us right on that point.

At this stage of the project, I am making a lot of assumptions. Hopefully not to many of them rise to the level of SWAG (Scientific Wild Ass Guess), but it's possible. Please feel free to correct my SWAG

And I'd also like to hear anyone's thoughts on IP function while turning with the FSS off.

It was mentioned earlier in the thread, I posted the Diesel Power article about the Cummins running two injection pumps running different timing. I tried to look up more info on that build but couldn't find anything on it. It would be interesting to talk to that guy and the guy who built the Chevy 6.5.

Also for flow reasons, instead of doing a T at the injectors, I would bring them into a Y. There would be a lot less turbulence at the injector if you decide to go that route than there would be with a T.

 

[88 Ford]

If timed appropriately, would it matter where in the cylinder the fuel is injected? If ignition is happening in the precup, supposing ignition has occured and the flame front is moving along, it would seem to my uneducated brain on this subject that additional fuel could be added to the cylinder at large and not have to go through the precup. Does that make any sense to anyone else that knows more than I do about IDI cylinder heads and flame fronts and etc. etc. etc.? I could see where it might not be completely optimal but it may not need to be for a significant gain. Ah mental ************... These types of threads keep me sane by letting me think about anything besides what I'm doing. Keep up the good work guys.

I was thinking about that too. I kind of doubt the spray pattern will matter much since the original injector will initiate the injection process. I guess just a long as the fuel doesn't wash the cylinders down it should be good I would think.

 

[Agnem]

As for spinning the pump with the FSS off, that is not an issue. The primary pump inside runs whenever the pump spins, and this pushes fuel through the pump, and cools and lubricates everything. The metering valve will not have any fuel flowing past it, but that won't matter as the pistons just won't operate without the fuel pressure. Yes, the injector definitely can be a bottle neck, but so can the lines. You would have to upgrade the lines to a larger size if you T them at the pumps through a manifold or something. Then you will have trouble with the nut and thread size at the injector. The larger lines have larger nuts. These will not fit the injector. T'ing at the injector is what the tractor pullers do. It's not uncommon for 6 cylinder inline guys to run a 12 cylinder IP with a custom cam firing 2 plungers at once, both T'd at the injector. As for one IP having to block the pressure of another due to offset firing, not a problem. The pumps possess a metering valve that seals off the injector line once injection has taken place.

 

[typ4]

You might be able to machine the glow plug hole to accept a pencil type injector, would need a way to clamp it down and also seat it at the bottom. Interesting thought. Stacking a GM pump on the front of the timing cover would be the easy part of the whole process. Or making a new casting for another ford pump, you could just run it with a cam gear, it should mesh perfectly with the IP gear.