After several years, a couple of cross-country moves, effective poverty, considerable mind-changing, and other various tribulations, I'm finally ready to start on my Megasquirted turboed 292.
Does anyone have handy photos of the engine bay of a '67 to '72 Chevy pickup with a 292 installed? I'm particularlly interested in the clearance to the master and brake booster; especially so in this case as I'm planning use of a Hydraboost to eliminate vacuum worries.
Secondly, I'd like opinions on the various intake designs I've sketched in the attached file.
Because of the charge-robbing issue, I feel constrained to use throttle body injection. I'm considering use of motorcycle-type individual throttle body injection; either three or four barrels as needed.
The drawing shows top views of different intake shapes, which will be constructed of welded aluminum plate. The circles represent the locations where the side-draft TBs connect. Some TB mount locations are rotated to better line up the the pressure line coming back from the intercooler.
I can't seem to get the .JPG file to attach and wind up readable. I've forwarded it to the moderator for help, as I don't have a photo storage site. If anyone knows offhand how to post the picture, please advise.
I personally use Photobucket, it's free and easy. However, since Inliners has a limited bandwidth and some users are still on dial-up, I believe it's asked that you post links to pics, instead of attaching them in the thread.
I swiped that throttle body picture from the Megasquirt discussion board in a thread that lists different TBs from motorcycles and so on.
There are a lot of different variations. That particular photo shows a pair of 2 barrel castings bolted together. There are wide variations in size, some have auxiliary ports, some have 2 injectors per barrel, all kinds of things to differentiate. I chose this picture just for the structural aspect.
Some TBs have all barrels in one casting, some are individual castings, some are grouped.
In effect this is port injection in the original motorcycle application. But, it is also TB injection even though isolated because the injectors seem typically in front of the throttle plate; I guess for better low-speed atomization. (I don't pretend to know anything about the subject; I'm in the first stages of researching and learning about both FI and motorcycle-designed applications thereof.)
I hadn't really considered draw-through... Should I? I'm assuming that by blowing through a multiple TBs into a wet manifold I'd get better mmixing at the more usual throttle openings, but still have some all-out potential.
Once it's spun up the compressor will pulverise the fuel into suspension (if you're running much boost the heat generated will tend to drive the already pulverised fuel to an actual vapor, not always but it can).
Some say the draw through setups are lagy, I can't really compare as I've never had an engine with both.
FWIW a turbo for a draw through needs a carbon seal, not just the "dynamic" seal most turbos today run.
The thought I was having was the draw through might help with the mixture distribution issue EFI seems to have on siameese ports.
Well I did a TBI on a 194 inline in a 63 nova just took it all off a 4.3 v6 tbi, sensors, ecm made the harness.Need to add a EFI pump and a return EFI line (kit from jegs or summit$40). Have all the pin outs for the gm ecm and wire diagrams that I made cutting out stuff like the EGR, if you would like to see them let me know. Took me 2 months but most of it was reading and talking to others on how to do it. I did it for the nitrous as my turbo dreams were shattered with the shock towers in the way but with a truck I think you may be ok I know there is a turbo manifold on ebay now and there is the place that makes the 3.8sc manifold. hope this helps
Doug, Don't know if you still need the info on clearance for the hydraboost and ITBs. If you do, I can measure a hydraboost setup and the distance from the factory mounting of the master cyl to a inline. I have a 94 truck with hydraboost and a 67 with a inline.
A visit to hybridz.com might help you on your ITB questions, they have discussed that in depth in the past.
