Fuel injection

[HalcyonS]

Has anyone tried, or thought about, replacing the carb with fuel injection?

[sastanley]

Has anyone tried, or thought about, replacing the carb with fuel injection?

Paging Dave Neptune......paging Dave Neptune.

HS, This discussion has gone around the way quite a bit, Dave is the authoritative source. I have had no trouble with my engine if the carb jet is clean and the advance weights work.

Dave works on dragsters and stuff...

[romantic comedy]

We could add a supercharger too.

[Wrsteinesq]

What's wrong with different ideas that build on the solid core of the A4? Electronic ignition and electrical fuel pumps were certainly never part of the original plan; but most of us think those are improvements. Likewise, freshwater cooling. Personally, I don't see anything wrong in identifying weak points in an otherwise strong design, and using some ingenuity to pursue that.

[joe_db]

Westebeke has a gasoline generator with fuel injection in the A4 HP range. That might be a good place to start.

[hanleyclifford]

What's wrong with different ideas that build on the solid core of the A4? Electronic ignition and electrical fuel pumps were certainly never part of the original plan; but most of us think those are improvements. Likewise, freshwater cooling. Personally, I don't see anything wrong in identifying weak points in an otherwise strong design, and using some ingenuity to pursue that.

I think fuel injection actually preceded carburation.

[Dave Neptune]

Hanley, you are correct! Fuel injection was the norm until carbs were developed to better atomize the fuel.

I will chime in on why it would be a waste of money on auxiliary displacement boat engine and not so much for power boats or cars sometime soon.

As far as fuel for the engine the best thing for an A-4 would be a much smaller carb. I have toyed with the idea of converting to down draft and using n old VW 36 horse carb, now that would really work. What would be best would be to find a far smaller updraft style.

Dave Neptune

[ndutton]

Dave, have you looked into outboard carburetors? Every one I've ever seen is a side draft, seems a 90° plenum would adapt it to our manifold nicely. Add a scavenge tube and a backfire flame arrestor and you're good.

For example:

http://www.ebay.com/itm/Outboard-Carburetor-Assembly-For-4-Stroke-20HP-25HP-Yamaha-Outboard-Motor-Engine-/171975427274?hash=item280a88c4ca:g:k7EAAOSwAYtWJ433&vxp=mtr

[lat 64]

Nothing wrong with tinkering, but…

A pressurized fuel system is contrary to safety in boats.

You could, however, put the pump right at the intake and have a fuel rail inside the head casting, then have the whole thing mechanically timed to squirt fuel directly into the combustion chamber to avoid any fuel accumulating in the intake(backfire safety issue).

May as well go with a heavier fuel since atomization is not critical now. I think stove oil would work.

Now just raise the compression pressures until the fuel ignites by itself and you've eliminated the dang electrical problems too.

guy, gals, I think I'm on to something!
Let' do a Kickstarter and make it happen!

[romantic comedy]

Dave, I have used 28 PCI and 28 PICT carbs (from VWs) on various engines over the years. A carb is just a carb.....(mostly)

We used to call the BMW motorcycle carbs " a brick with a hole in it". I am sure other carbs are called the same thing.

[joe_db]

Plenty of fuel injected gasoline inboards in boats now.
I think the safety issue may lay in making the EFI yourself

Nothing wrong with tinkering, but…

A pressurized fuel system is contrary to safety in boats.

You could, however, put the pump right at the intake and have a fuel rail inside the head casting, then have the whole thing mechanically timed to squirt fuel directly into the combustion chamber to avoid any fuel accumulating in the intake(backfire safety issue).

May as well go with a heavier fuel since atomization is not critical now. I think stove oil would work.

Now just raise the compression pressures until the fuel ignites by itself and you've eliminated the dang electrical problems too.

guy, gals, I think I'm on to something!
Let' do a Kickstarter and make it happen!

[lat 64]

Plenty of fuel injected gasoline inboards in boats now.
I think the safety issue may lay in making the EFI yourself

Hmm, now you got me thinkin'; just how does the regs deal with the pump location issue. I''ll dig in to it and get back.

[sastanley]

My step-father is the best 36-HP VW motor guy I know. He probably has enough parts to build three complete bugs right now, and that is after he had the 25 bug bodies hauled away years ago. He knows everything about them. I would guess he has more carbs than I have fingers.

[romantic comedy]

I had lots of bugs and buses. Just unloaded my last one. It was a 1967 split window bus. That was tough to do. I just dont want to be a slave to my possessions. Besides, it is just not fun to drive anymore. Too many idiots. A VW bus is not the safest vehicle..

[sastanley]

RC, I am sure he would say the same thing. His most "recent" VW is a 1979 Rabbit Diesel he used to commute to work before he retired. He still has it, but is has not moved in years.. His daily driver is a 2003 Chevy Silverado with a new motor, which replaced his 1979 Chevy 10.