GM 250 Straight Six Turbo Fueling - Issues
Posted: Tue Dec 23, 2014 9:00 am
Guys
Quick recap so everyone can understand the issues I’ve been having, mostly because I was going off halfcocked. I had rebuilt a 63 C10 that had in it a mid 70’s 250 out of a nova (or similar). I wanted reliable starting and some performance to be able to keep up in traffic. I built myself a very nice plenum chamber with bell mouths and LS truck engine fuel injection equipment, I even built the injection so that it was staged i.e. three injectors near the valves and three into the velocity stacks. Sounds awesome when discussing in the Pub and looks awesome on the engine stand. However it is a poor design in reality. All to do with the outer cylinders being 240-480 degrees apart and shearing a Siamese inlet port.
OK recap over… see photo you can see I have three tubes in steal coming up from the head what I need to do is go to a ‘Throttle body injection’ type setup then into the three manifold tubes coming from the head. I would like this to be horizontal so that it will fit and easily tie up with the outlet of the intercooler. So my question is does anyone have any experience in mounting a GM throttle body then injecting directly after it. I am currently using the injectors out of the LS truck engine that I can get 250hp standard pressure or 355hp (calculated) by upping the injection pressure on six 25lb units. I could go for a smaller number of larger injectors to make the installation better there may also be some spray pattern issues with different injectors.
Basically I’m asking advice before I build this time.
also is it worth staging the injection on two banks?
Regards Steven
Quick recap so everyone can understand the issues I’ve been having, mostly because I was going off halfcocked. I had rebuilt a 63 C10 that had in it a mid 70’s 250 out of a nova (or similar). I wanted reliable starting and some performance to be able to keep up in traffic. I built myself a very nice plenum chamber with bell mouths and LS truck engine fuel injection equipment, I even built the injection so that it was staged i.e. three injectors near the valves and three into the velocity stacks. Sounds awesome when discussing in the Pub and looks awesome on the engine stand. However it is a poor design in reality. All to do with the outer cylinders being 240-480 degrees apart and shearing a Siamese inlet port.
OK recap over… see photo you can see I have three tubes in steal coming up from the head what I need to do is go to a ‘Throttle body injection’ type setup then into the three manifold tubes coming from the head. I would like this to be horizontal so that it will fit and easily tie up with the outlet of the intercooler. So my question is does anyone have any experience in mounting a GM throttle body then injecting directly after it. I am currently using the injectors out of the LS truck engine that I can get 250hp standard pressure or 355hp (calculated) by upping the injection pressure on six 25lb units. I could go for a smaller number of larger injectors to make the installation better there may also be some spray pattern issues with different injectors.
Basically I’m asking advice before I build this time.
also is it worth staging the injection on two banks?
Regards Steven