Mechanical Fuel Injection, Because I Hate Electrons

One of the ideas my brain has recently latched onto is developing a mechanical fuel injection system to retrofit onto an old, carbureted engine. I know it's been done in the past, but I'm trying to develop a system that's a bit better, and also allows for the option of adding forced induction. Actually, that's kindof my main purpose- a draw through carb setup is limited to about 8 psi of boost, due to not being able to intercool it, and I'm a bit scared of trying to build a blow through carb.

So...EFI is TOTALLY off the table now for this thought experiment...how would you do a MECHANICAL FI system? Preferably this would be something that could be done using junkyard parts, or at least something OEM and thus somewhat reliable...perhaps an injector pump from an older diesel? Let's hear ideas.

I would try to swap in an existing gas MFI system, because designing your own is going to be a bitch. MFI is used in drag racing but the aftermarket systems for sale are designed for huge-displacement engines.

I think I'd keep it on carbs instead of mucking with MFI...

Didn't old corvettes( 60's) have a mechanical fuel injection system? If so that might be a good place to start

Look up K-Jetronic and Hilborn. Both are well known fuel injection systems with little to no electronic wizardry.

pres589 wrote: I think I'd keep it on carbs instead of mucking with MFI...

+1.

The Alfetta I race/wrench on is powered by a SPICA Mech Fuel Injection system. It has worked well for us so far.

Time to join the 21st century. Electronics beat mechanical every time. I had mechanical fuel injection on my old 911E. Incredibly complex. Be thankful for Megasquirt.

volvoclearinghouse wrote: Actually, that's kindof my main purpose- a draw through carb setup is limited to about 8 psi of boost, due to not being able to intercool it, and I'm a bit scared of trying to build a blow through carb.

Instead of blow-through, build a complete box around the carb? Then you don't have to worry about seals blowing and whatnot.

Volvo 240 Turbo= CIS made for boost

Electrical is not an option, for many reasons. Carbs are out.

I knew Chevy dabbled a bit in MFI for awhile there, but since it was mostly in 'vettes I'm betting parts are expensive and scarce.

Haven't heard of the SPICA system, that's something to check into. Also the K-jet.

Scared of the Hillman systems. I've read they were mostly used for WOT drag racing and have very poor drivability and fuel economy.

Argo1 wrote: Time to join the 21st century. Electronics beat mechanical every time. I had mechanical fuel injection on my old 911E. Incredibly complex. Be thankful for Megasquirt.

I was trying to not say it, and he said it first instead. It's time to get over hating electrons, or find someone who already has.. DIY'ing a mechanical fuel injection system at this point is reinventing the steel wheel.

In reply to mguar:

Thanks for the ideas...kindof what I was leaning towards. I'm wondering if a diesel injector pump would work? I know they have had issues with lubrication, perhaps I'd have to add an oiling system or just mix a bit of oil in with the gas, run like a 100:1 2 stroke mixture.

Diesels run MFI, the only difference is they always run lean, except at WOT. The butterfly valve compensates for that.

A carb box is the most typical way I've seen to deal with blow through forced induction...but you also have to deal with floats crushing. And if anything leaks...

Most sprint cars still use MFI. Check out kinsler.com and hilborn.com

Cone_Junky wrote: Volvo 240 Turbo= CIS made for boost

That was my first thought too. Or an Audi 5000 turbo CIS setup. Just block off one fuel line if you're running a 4cyl.

Yeah you can't roadside-fix EFI with a screwdriver like you could with a carb but it's not that bad and has a lot of upsides. The only thing I'd prefer MFI or carbs for now is an offroad vehicle, where submersion and breaking down in the middle of nowhere are potential problems.

Which isn't the 240 turbo fuel distributor basically a 6cyl fuel distributor with two lines blocked off?

Carb & a hat. Just saying.

The Kinsler website is definitely interesting. I'll look into that. My main concerns with FI were based on what I've read and heard about some MFI systems. People getting like 2mpg, only really working at WOT, that sort of thing. Are there people running turbos with MFI? I've seen superchargers. I'm also thinking about pretty high boost pressures.

Kugelfischer!

(Gesundheit)

I'm shocked that somebody would want to use a mechanical injection system for a turbo street machine today, but especially shocked that they'd want to do something different than what's already been done for decades. Talk about a glutton for punishment!!!

mguar wrote: Fuel Injection is actually a misnomer. It's actually fuel rejection.. The system delivers more fuel than you need and rejects what's not needed..

Just so you know, this doesn't really apply to modern fuel injection systems. They only supply as much fuel as required to keep adequate pressure at the injectors.

Bryce

Do what's always been done...get what's always been gotten.

Cone_Junky wrote: Volvo 240 Turbo= CIS made for boost

I was going to sugest adapting CIS, but honestly mastering your fear of electrons seems easier.

I am working with VCH on this idea, and I think some of you need some framework:

There are valid and good reasons for this choice, other than just hating electrons, and the carb-in-a-box isn't preferable for other reasons. This is not a street machine and a rulebook is in play.

So, let's stay within the framework of: How to best develop a MFI system for a high boost pressure four cylinder motor.

I want to know, for instance, how a MFI system would reference boost.