While I don't see the difficulty in setting up a blow through, I do see the difficulty in making the head flow enough for the downsides of a draw through to matter any.
Using a draw though also frees up your carb options to whatever you want to build a manifold for. I doubt there's much tuning info out there for the ford 1bbl in forced induction apps.
oldopelguy wrote: But that would not be a dry draw through, now would it? A dry draw through would have the throttle upstream of the turbo but inject fuel downstream, meaning clearly not a carburetor. If you are going to run injection might as well do it conventionally. how hard are those integrated intake heads to get? Drill 6 holes, braze in some steel injector bungs, and add megasquirt. For carb plus turbo I think pressurizing a box around a carb with a turbo is the way to go.
You have my attention. Would megasquirt 1 be sufficient to run this set-up? Kits are about $200 so that's cheap enough. Hard part is the throttle body, what vehicle would be ideal to source one from? I googled universal throttle bodies and it looks like chinabay is selling cnc machined throttle bodies for about $90 - but junkyard would be much cheaper.
I had originally considered cutting the log off and brazing three manifolds on for triple SU carbs but realized that would be way too difficult to get right because each inlet is at a different angle and the manifold has an odd slope. I considered a tbi setup as well but that seemed like a waste of time too. I hadn't even considered brazing injector bungs in. That would be pretty easy.
Kenny_McCormic wrote: While I don't see the difficulty in setting up a blow through, I do see the difficulty in making the head flow enough for the downsides of a draw through to matter any. Using a draw though also frees up your carb options to whatever you want to build a manifold for. I doubt there's much tuning info out there for the ford 1bbl in forced induction apps.
That and replacement one barrels cost just as much as decent performance carbs...
Alternate idea, do a NA build, sawzall, hose clamps, BIKE CARBS.
^That is a nefariously cool idea. Nefarious because it is like giving someone a can of worms in gift wrap. But if it worked, it would be really cool.
In reply to Vigo:
In grade school, I always was that kid who gave everybody bad ideas while I stood back far away enough to avoid guilt by association and watched.
I would scour the yards for a TB in a similar size as the hole in the intake. Make sure it has a TPS sensor and an integrated throttle cable bracket to make it easier.
To adapt it, build a flat plate drilled to match the stock flange with counter-sunk holes and drill/tap it for the studs/bolts for the TB. Add some gaskets and you're golden.
The injectors can mount in brazed mounts in the intake, I think I saw some on eBay and other vendors. Fuel rail is available in bulk lengths online as well.
MS1 will work fine for this, even with boost.
I do like the idea of cutting the intake off to mount motorcycle carbs or TBs on the left over runners. Most mount with rubber hose and hose clamps. Tuning ITBs with MegaSquirt is more difficult than with a single TB, but the noise they make is very nice!
If going forced induction and EFI, why bother with hacking the head when you could just run a GM TBI draw through? The objective here is to make the most out of the integral intake manifold, putting a little TB over that little hole isn't going to help flow.
Kenny_McCormic wrote: While I don't see the difficulty in setting up a blow through, I do see the difficulty in making the head flow enough for the downsides of a draw through to matter any.
Before Ford started putting V8s in the Falcon, hotrodders were modifying the 144 head to take additional carburetors, both downdraft and sidedraft.
Picture that head with four small SUs hanging off the side.
IIRC with that and some other minor work, people more than doubled the engine's power output. The head itself is actually pretty nice.
There are tons of nice ideas in this thread, but I have to ask: why not just get a supercharger? A lot of superchargers work draw-through, they are cheap, and should match the torquey nature of the straight six.
oldopelguy wrote: Why would you do a dry draw through?
As above, fuel injection would be dry.
Sorry for what may be a stupid question, but how is the wastegate going to work in a draw-through application? Seems like you'd have to dump fuel outside the motor. If you recirculated it, you'd end up with a rich A/F mixture and possibly puddling.
As to intercooling, perhaps a water-to-air would work better. They are typically compact so that the air needn't be diverted through a big radiator.
turboswede wrote: I would scour the yards for a TB in a similar size as the hole in the intake. Make sure it has a TPS sensor and an integrated throttle cable bracket to make it easier.
The TBI you are describing is from an early Ford Tempo
It will bolt in and hook to the existing linkage. Problem is finding an injector for it that will flow enough fuel for more than 100whp.
I am going to sacrifice one and cut out the restrictor plate and see what happens. Some injectors gain ~40% that way.
That would be about perfect with port injectors. Easy hook up for a hose from the intercooler too.
I need to find one of those just to fiddle with...
Vigo wrote: I agree with OP on the simplicity of the draw-through approach. If you could get the turbo put up right beside the intake manifold and basically discharing right into it through a short 90 degree turn, it would be a really tidy setup and you wouldnt have to do any vac/boost related mods to the carb, just fuel tuning. I'm on board with the whole idea.
And drill the head for injector bungs and mega squirt it too...
Vigo wrote: Yep, get yoself a t3 turbo from an 84-87 non-intercooled dodge 2.2, or use some kind of T3 center section and buy the rebuild kit for said dodge to get the proper seals. If you do decide to use the whole dodge turbo, port the wastegate orifice in the turbine housing as much as the puck will allow to mitigate the possibility of boost creep on the larger motor.
Where would you recommend getting said rebuild kit(s) from? I'm not interested in Fleabay sources.
Mind blown DitchDigger... good work...
This may be a stupid question and oldopelguy kind of answered it but I'm going to double check. Can I use a tbi unit and remove the injector to use as just a throttle body? Then still do port injection?
kreb wrote: Sorry for what may be a stupid question, but how is the wastegate going to work in a draw-through application? Seems like you'd have to dump fuel outside the motor. If you recirculated it, you'd end up with a rich A/F mixture and possibly puddling.
Wastegates are on the exhaust side.
turbofiend wrote: Mind blown DitchDigger... good work... This may be a stupid question and oldopelguy kind of answered it but I'm going to double check. Can I use a tbi unit and remove the injector to use as just a throttle body? Then still do port injection?
Of course. Just close off the hole.
Heck, I've got a carburetor and I'm port injected.
Or use it for the fuel part of your nitrous boost!
turboswede wrote:
Of course. Just close off the hole.
I thought that was the case but I didn't want to assume. Cool.
oldopelguy wrote: Or use it for the fuel part of your nitrous boost!
Hmmmm.....good thinking lol!
OK Since I am also building a boosted Ford 200 I will chime in more and throw some thoughts and findings out there.
This is a large log 200 head
As you can see the Tempo TBI unit sits on there like it was made for it.
The injector just sits in the hat
but the injector is also the problem. I have not found one that flows more than 56lb/min. There is supposedly a Taurus 64 pounder but that isn't big enough either. The regulator is adjustable (pop out the cap and there is a socket set screw in there) and I think fuel pressure is ~14-15 psi.
The GM TBI injector is just there to show difference (I was really hoping it would work)
Earlier you mentioned machining the log for a weber. If you had that in mind I might suggest instead machining it for a GM two barrel TBI unit.
That would be perfect but quite a bit more fab work. None of it hard but just more of everything. Plenty of fuel injector options too.
OK now to the one everybody keeps suggesting. Machining the head for port injectors. The ideal plan, sadly no where near as easy as it sounds.
not so bad on the first couple of cylinders. Sure you can't even hope to aim for the back of the valve but who cares. The fuel is gonna make it in there just fine. Problem being the log is angled up so the runners get progressively longer and taller towards the 6th cylinder. No way to fit Bosch style injectors. Skinny little ones are required.
Tight fit.
If you tried to set the injector at the same height as the first injectors it would have to sit at an angle that would interfere with the valve cover. OK then mill down and braze in a steel injector holder, right?
Cool but again to keep the injectors at the same height the runners would have progressively less volume.
Stick them way out of the head then? Perhaps not a bad idea because of another issue. This log is intentionally heated by the exhaust. There are heat sinks in the siamesed center exhaust port that transfer heat up. That damn thing gets HOT.
How about the backside of the log?
I am still not sure how I am going about fueling mine. I am still building the bottom end so I have a while. Right now I plan on removing the restrictor plate in the stock tempo injector and sending it to witchhunter for a flow test. I am still looking into port injection too. Just have to decide on the cleanest way.
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