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...