Dual IP with a twist - Hello me brainstorm this out

[88 Ford]

Another thing that would help with tuneabilty would be to have the smoke puff limiters to regulate the fuel before the boost comes on. You won't need a crap ton of fuel until you do have that boost. It would effectively work the same as AFC on a Cummins.

 

[WisdomWarlord]

Another thing that would help with tuneabilty would be to have the smoke puff limiters to regulate the fuel before the boost comes on. You won't need a crap ton of fuel until you do have that boost. It would effectively work the same as AFC on a Cummins.

I am playing with the idea of a stepper motor controlled by a simple microcontroller that monitors manifold pressure, throttle position, vehicle speed and EGT, that handles the second IP. For someone not familiar with basic electronics it may sound a bit pie-in-the-sky, but it's actually pretty simple, with all off-the-shelf components. Choosing the right components and interfacing them together will take some time and trial-and-error, but with enough patience, it's very doable.

With that setup, I figure I can control excessive smoke and high EGT's, and still have a pretty solid 300hp even if the second IP fails. Not to bad for a derated engine huh?

 

[justinray]

To aid in the bottleneck at the injector, you could stagger the timing of the pumps, set the primary to the nominal 9-9.5*, and the secondary to 20* or 0*, that would ensure the pumps weren't bottlenecking the injector. Not sure which would work better though.

 

[riotwarrior]

if running dual pumps, what about higher pop pressures? Not sure if the pumps can do it but *** worth a try...more fuel better atomized right?

 

[justinray]

I thought about that too, but anything over 2000 would put excess stress on the pump(s) and return lines. That's not based on any hard facts that I can point at or link to except pump dynamics showing the relation to pressure output and pump stress.

 

[aofarrell2]

Well what a interesting read, considering a project of mine I've been working on. It would be interesting to see dual IPs on one of these, typ4s idea of using a pencil type injector was a great one, IMO it would work great, they are cheap and IPs to match are cheap. One word here, if you use a pencil type injector, remember that it is designed for DI, not IDI. Same goes for the pump to match the pencil injectors. Too much pressure from a injector designed for DI on a IDI precup could cause trouble. Now if you used it for DI setup, something like a pump off of a 8 cyl JD diesel would work great with them, JD used alot of RoosaMaster pencil injectors and Stanadyne pumps to match, they are cheap to get, and easy to modify. One note: if you do that remove the shim on the fuel screw, JD shims them, and I don't think theyd give enough fuel when shimmed. Also, AFAIK, most roosamaster pencil injectors are designed for high-pressure DI systems, they wouldn't pop or atomize properly at lower pressures used on IDI setups.

Another idea to throw in here, is that the second IP throttle doesnt have to be mechanically operated entirely. Instead, have the first pump run at normal naturally aspirated settings. Then, you can easily make a valve that detects boost, all it is is a simple spring loaded valve that operates the throttle on the second pump based on PSI in intake manifold, a interlock that is operated by the accelerator peddle prevents too much fuel. Just throwing it out there!

I personally have been working on a new IP for gasoline engines, it is installed in place of the distributor, and I'm trying to make it as inexpensive as possible, allowing gassers to upgrade to DI instead of port injection (87 octane turbo gasoline engine at last!) - and I wanted two injections per stroke, so this is why I stopped in here, cause it was along my lines . If it works, it could easily be converted to be used on diesel engines like the IDI, as it is designed for 8 cyl engines.

And since I've already opened my mouth, another idea to share here... Someone mentioned custom heads, and I was puzzling over EGTs the other day. Now I don't know much about the IDI heads, so don't take this thought like I know everything. I wonder if a custom head could be made for the IDI that decreases the comp ratio, has 4 valves per cylinder, and has one or two injector holes, the head could lower the comp ratio to allow more boost, but if it was DI it won't affect starting performance, so you could make the head DI, and convert it to a DI pumping setup. Granted, you would need a new intake manifold and exhaust manifold, but I don't think that would be hard to fab up, but then you could also get rid of the hat style turbo thingy at the top of the intake and go to something more convenient and readily available. I know some people who could make high-quality custom heads like that, given a good design. I know it would take a lot of thinking and planning, but just thought I'd throw that out there. The cam etc wouldn't need to be changed, and 4valves would allow it to breathe better, making it stay cooler Sorry if I hacked the thread, I just thought it was along the lines of the thread...

 

[laserjock]

Stacking the two pumps in parallel won't increase the pressure just the fuel volume. I would think so long as the injector is ported large enough to handle the volume, you actually could synchronize the pumps. Not sure if that's better or worse than sequential shots.

 

[Kevin 007]

Hmmm, one pump can cause enough hassle, don't think I would want two

 

[WisdomWarlord]

Hmmm, one pump can cause enough hassle, don't think I would want two

Lol, one of many reasons I want 2 independent fuel injection systems. The engine will be able to run off either or both, so if one dies, the other is there to take up the slack.

 

[justinray]

Im not worried about a pressure increase from an extra pump, I was talking about pressure increase from a higher pop pressure injector. Also don't know if an injector could be machined to flow twice the flow all at once, it may be possible, I just don't see it atomizing if it's drilled out enough to flow the volume, so unless you staggered them, you would have to take the trade off between poor atomization, and bottlenecking at the injector. Just my SWAG there.

 

[WisdomWarlord]

Im not worried about a pressure increase from an extra pump, I was talking about pressure increase from a higher pop pressure injector. Also don't know if an injector could be machined to flow twice the flow all at once, it may be possible, I just don't see it atomizing if it's drilled out enough to flow the volume, so unless you staggered them, you would have to take the trade off between poor atomization, and bottlenecking at the injector. Just my SWAG there.

All worries about injector and line bottlenecks are solved with a dual injector setup.

 

[88 Ford]

I am playing with the idea of a stepper motor controlled by a simple microcontroller that monitors manifold pressure, throttle position, vehicle speed and EGT, that handles the second IP. For someone not familiar with basic electronics it may sound a bit pie-in-the-sky, but it's actually pretty simple, with all off-the-shelf components. Choosing the right components and interfacing them together will take some time and trial-and-error, but with enough patience, it's very doable.

With that setup, I figure I can control excessive smoke and high EGT's, and still have a pretty solid 300hp even if the second IP fails. Not to bad for a derated engine huh?

That sounds kind of similar to how a Ds4 works off a Chevy 6.5. I know a Db4 can be made to work using some Db2 parts. I wonder if the Ds4 can be made to work the same way? Or you could piggyback it like was mentioned before since it turns the opposite way. The way it works is pretty similar to what you mentioned though...

 

[bbjordan]

subscribed

 

[justinray]

If we're set on the extra injector idea, and know we cant drill out the glowplug hole, what about putting a nipple in the threads then an adapter to the injector threads? It would mess with the compression ratio, and kinda be a weird spray but possibly the easiest way?

 

[riotwarrior]

U know it would be easier to just do an inline pump I tell ya for all the work involved.