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HybridZ

Induction Project for my 406 SBC


pparaska

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Recently bought this on Ebay.

 

I'll be converting it to EFI, paying someone to weld in injector bungs, vacuum taps for MAP and IAC/PCV/Brakebooster vacuum, and fuel rail mounting tabs.

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injector_side.jpg

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injector_top.jpg

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injector_reartop.jpg

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I'll probably go to a more updated set of ram tubes, with a full 270 degree tapered opening (a la Vizard and TWM) to be able to fit it under the hood.

 

I'm thinking of a flat plate at the manifold/tube height and a box attached to the hood that has an opening in the firewall and an air filter in the cowl area. That way with the hood opened, you'll see the flat plate and stacks/tubes. :D

 

I guess the Holley dual plane (now on the 327), Vic Jr., and Offy CrossRam with twin 670 2bbl Holley TBIs to go on it will just have to go into storage after the Hilborn is on. :lol:

 

I'll be using a MegaSquirt ECU.

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Heck if I know. Busy around the house and at work lately. The Megasquirt is working on the bench, and I've got a design for adapting it to the Holley Projection harness so it'll be plug-n-play compatible. I just need to finish that (I have the parts) and put the MegaSquirt ECU in the Z and do some tuning.

 

Once that's worked out on the 327, I'll be able to bolt the Holley dual plane on the 406 (once installed) and start retuning.

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Sick Sick Sick Sick Sick Sick....

 

I Can NOT wait to see that puppy installed in the motor, in the car!

 

BTW, If all goes well, I'll have my new oil pan and Tranny in house by the end of the month!

 

Mike :D

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Pete,

 

That is going to be sweet! Are you going to weld the injector bungs on the outsides of the throttle bodies (not where the existing injector ports are)? Seems like you would have more room for injectors and fuel rails. I assume you are going to have some O-ring rails made (recommended). You'll have to fabricate some brackets to hold them on.

 

I was talking to a guy at the track yesterday with a Daytona coupe track car. He is running individual downdraft throttle bodies (over 700HP). Last year he had a fuel rail blow off while he was on the track. 50psi of fuel coming from a 1/2" fuel line made a BIG fire. Burned the whole front end of the car (would of been nice if the corner worker had a fire extinguisher that worked). The rail blew off because only a few threads of 1/4-20 bolt was holding it on. Make sure those fuel rails are secure! With hose barb injectors it's not a big issue, but with the o-ring style be carefull.

 

Now all you need is fresh can of tennis balls :D

 

Pete

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Pete,

 

Yeah, o-ring rails most likely. I'd imagine injectors that use o-rings instead of hose barbs are easier to find and cheaper. I'm probably going to need 36 lb/hr.

 

That must have been quite an ordeal. I will be very careful about the rail mounting! Thanks for the warning.

 

I've seen these Hilborn setups with the injectors on the inside. I think it looks cleaner that way:

 

SBChevy-327C8EL.jpg

new6.jpg

new4.jpg

 

So it seems to fit.

 

Here's a version with them done on the outside:

im003355.jpg

im003356a.jpg

 

Looks easier. I like the idea of using injectors with a threaded fuel connection, like above though! Stainless tubing somehow looks better on this old school setup!

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I like the top-most setup for sure. Everything is tucked in nice. Can hide all the wires in there too. The setup with the separate SS hose for each injector is probably not the best setup. I'd be concerned about any of those fittings letting go. Also, in traffic the fuel in those hoses could get hot, potentially causing problems. The shortest distance from the rail to the injector is always better for keeping the fuel cool.

 

Pick an injector that meets your realistic HP goals +10-15%. That way you will not sacrifice idle quality. That is iif you are running a mild cam where you could potentially have a good idle :D .

 

Pete

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Pete, I've got 42# injectors for my setup... I know they will be a little more than I need for the 383 stroker, but We figure they should be able to be used with plenty of headroom for an eventual Supercharger IF I ever decide to bolt one on!

 

Mike :D

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Reading over several sites about injector sizing is interesting.

Haltech's site gives the following:

 

http://www.haltech.com.au/injformula.htm

 

"Fuel Injection Sizing Formula

After much research it has been found that there are several different formulae used to determine injector size. It appears that most of the various formulae in use are basically identical, with only 2 real variables, being whether or not an 80% duty cycle is accounted for and what the desired Brake Specific Fuel Consumption (BSFC) should be. This is the formula with the correction based on the duty cycle:

 

Flow rate (lbs/hr) = Max Hp x BSFC / no. injectors x duty cycle

BSFC = 0.45 - 0.55 for naturally aspirated engines

0.55 - 0.65 for forced induction engines

 

Conversion from lbs/hr to cc/min = lbs/hr x 10.515

Simplified max Hp x 1.807 (nat) Simplified

max Hp x 2.136 (turbo)

 

Sourced from:

www.autospeed.com"

 

The following is what DD2000 engine astrology software says I'd have with a 10.5:1 406, Canfield heads that flow as I had them tested, the Cam Motion Cam that's on the way, large tube headers with mufflers (I'll be going to 1-3/4" headers), and an IR manifold that flows 2400cfm total.

 

That's 300cfm per stack, about what a good ram tube and 2-3/16" hilborn has been tested to, from what I've heard. 300 cfm may be too little, but let's be conservative. If you add another 100cfm per bore, you get 3200cfm total (what DD200 wants is total flow of all IR runners), and the peak HP goes up to 550hp instead of 525. Like I will be able to use all that anyway!

 

406_L2442-2501-12+4_Canfield215mineavg_IR2400_lth_105.gif

 

So using 525 MAX hp, .55 (lb/hr)/hp BSFC, 8 injectors and 85% duty cycle, you get:

 

525 hp * .55 (lb/hr)/hp * 0.85 duty cycle / 8 injectors = 30.7 lb/hr

 

adding 10% would be 33.7 lb/hr and adding 15% would be 35.3 lb/hr

 

I'm thinking 36 lb/hr (at 100% duty cycle as they usually are advertised) will be about right? If anything, it might be too much.

 

BTW, that cam has the same opening durations as the Comp Cams XS274S cam in my 327, and it's 244/250 @ .050" versus 236/242 for the XS274S. Lift is .570s ver .500/.510 for the XS274S, and the lash is less (.010 versus .016).

 

So with the increased cubes and the smoothing effect of IR, it ought to idle like a new Corvette. Note, DD2000 shows an incredible 470 lb-ft at 2000rpm, but it's known to be quite optimistic below 3000 rpm on a NA motor.

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I'd say 36lb/hr or 42lb/hr should be OK. I think even with the 42lb/hr you should be able to get a good idle with the Megasquirt. Get some high Z ones, so you don't need to run limiting resistors, or mess with the PWM mode (you can dissable it).

 

What kind of vacuum do you have at idle with your current motor? I would assume that it would be similar since you plan on using a similar cam. I'd start using the MAP sensor and VE table for load sensing with the Megasquirt first. The TPS would be doing acceleration enrichment only. From what I understand, it's easier to tuner than using the Aplha-N mode, with the TPS as load indication.

 

Not sure how you go about calibrating all of those TBs, but a single TPS is all you need for accel. enrichment.

 

Pete

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Pete,

Please keep us posted on what is involved. I have a set of Kinslers that I really want to run. The problem for me is that I know nothing about EFI. I have a vertex mag and no idea how or if it worked with the electronics, I was goinng to run the injection constant flow. Unfortunatley I don't have the room for a crank driven or even a belt driven fuel pump.

Joe

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Joe:

I've seen true mechanical Hilborn setups (both stack and birdcatchers) on "street" cars, but they are hardly streetable. You're dealing basically with an alpha-N type setup when you go mechanical, and the tuning aspects are not as simple as with alpha-N EFI. I'm sure there are mechanical injection gurus that can make a mechanical setup "work" on the street, but I doubt it's easy, if possible!

 

There are a few places that will take your Kinsler mech. FI setup and convert it, but I think anyone with some talent with a drill press and either a welder for AL or a tap can put bungs in. Someone makes externally pipe threaded injector bungs - that might be an easy way out.

 

Like others have said, come up with a good fuel rail and mounting scheme.

 

Then you need multiple taps/ports per stack below the throttle plates for each of the IAC, MAP, and PCV/BrakeBooster vacuum circuits, as well as small manifolds to run these to. Sizing of the taps/ports is important - too big a port/hose/manifold (volume) and you end with a bit of a plenum for sharing signals from cylinder to cylinder, which is what you're trying to get away from with an IR manifold. Again, drill and either tap, weld, braze, or epoxy tubes into each bore below the throttle plates. Run hoses from the ports to the small manifolds and hook your IAC, MAP, PCV/BrakeBooster to each of these three manifolds. I'm going to try to put some of this stuff under the manifold out of site.

 

You can either keep the barrel valve for the throttle linkage or build something to tie the sets of throttle shafts together. Put a TPS at the end of one of the throttle shafts.

 

So now you have injector bungs, fuel rails and mounts, IAC, MAP, TPS, PCV/BrakeBooster taken care of.

 

One last thing - these manifolds don't have a crossover/thermostat housing, so you need to adapt a remote one.

 

I believe that the large cap HEI distributor won't fit. The magneto does, but I'd get away from that for the street.

 

Air filtration is next.

 

Heavy - hey, it should be a torque monster once it's done!

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Pete,

Thanks for all the information. I can probably do the fabrication, its just the electronics that I'm uncomfortable with. I'm going to print your post, and hang it in the garage. I can't give up my mag though Its a Don Zig OXC, (external coil) off a top gas dragster and makes a huge amount of spark. Besides It looks much cooler than a distributor. :D

Joe

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Joe:

I understand wanting to keep the magneto - I enjoy the look of REAL nostalgic hotrod hardware, as long as it's the real thing! I've heard Magnetos aren't streetable, but there's probably a way to make them moreso.

 

[sidebar:

What torques me off is BS fake stuff:

http://www.alsblowers.com/streetinduction.html

I can't believe Don has his name on this carp!]

 

If you want to get into the electronics stuff (and all the rest of the stuff with EFI) the EASY way, get on the MegaSquirt forum http://www.msefi.com and start reading. There's alot of stuff in the archives (linked to Yahoo from msefi.com). Probably the best thing to do is read the MegaManual (on the http://www.msefi.com site also). It's not that bad, really. These guys (Bruce Bowling, Al Grippo, Lance, Eric, others) are really all about teaching people EFI and providing OPEN SOURCE hardware and software to do it. The entry fee is below $150 for the ECU kit. Software is freeware and VERY well supported.

 

MegaSquirt is the best way to learn about EFI, IMO.

 

Have fun!

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