Air cooled Carbed VS Air cooled FI Versus Watercooled

So being a layman I was wondering if buying an A/C FI engine eliminates maintainence issue's on a A/C carbed engine and whether it then offers the same advantage as a watercooled engine.Now I've heard that the carbed engines sound better. But I've also read that the aircooled FI offer more power.Usually I thought that for people who go watercooled are doing so for more power and less maintainence then a an A/C engine. If this is in fact the case could you then go with a smaller A/C FI engine(say 1776 VS 1915) and get similar power with more reliability?Also doesn't an FI engine offer better cold start characteristics then a carbed engine. Would it also get better gas mileage?Is it easier to tune? I was reading on the CB websight that you can tune an A/C FI engine while your driving.But since I don't yet own a speedster how much of the mechanical maintainence would I be eliminating?

FI's biggest advantages are it's extreme tuning resolution. Unfortunately, this is also it's biggest dis-advantage since the system must be set up and initially tuned to be effective.

What is your experience?? Carbs or FI?

Jake-I haven't owned a carbed car in yrs. When I owned Alfa's they were all FI(Bosch L Jetronic). I replaced all my old hoses with silicon,replaced my cold start valve and temperature sensor,learned how to tweek the AFM and had my ECU reprogrammed for a higher rev limit. I never had too many running issues with the old GTV6. My Spider had spica injection which I never touched. So this is a new ball of wax for me.I'm therefore a little wary of a carbed engine. I'm more of the Ron Popeel philosophy(set it and forget it).Which is why FI sounds more appealing then having to play around with carbs.Correct me if I'm wrong but it would seem to me that an FI engine runs more efficiently once it's properly set up.Wouldn't the air/fuel mixture more be presicely mixed resulting in better fuel burning and better mileage and more power? A lot of people who had Alfa Spiders with the Spica Injection converted to carbs using a Webber Kit.The car did not have more power but sounded better.It seems to me sound can be compensated for by using a more aggresdsive exhaust and intake. But again I don't know much about air cooled VW engines.

Yes, EFI will run more effi ciently once set up and properly tuned over the range that it will be used. Due to the resolution of EFI systems it is quite common for tuning to be necessary often during the first full year of operation s weather condituions vary with the seasons.

EFI opens doors that would otherwise be locked, when installed onto a properly configured engine.

I see some people that use EFI because they can't understand carbs- if you can't manipulate carbs, you damn sure can't tune EFI!1

75% of what we build is equipped with FI and I have to support these engines...The FI system thats used is certainly the determining factor.

Aircooled engines are not meant to be "set and forgot", no matter how hard you try it won't be as effective as a 2008 Modern car.

But are there simpler FI systems out there for aircooled engines?

The arrangement I use is THE simplest, it doesn't even require a PC to interface and change the enrichment.

Paul, based upon my recent conversion from a CB Performance air cooled 2.1L with solid lifters and dual Weber 44 IDF carburetors to a Subaru water cooled 2.5L with fuel injection...

Fuel injection eliminates carburetor maintenance issues of clogged idle jets, the need to adjust float level, idle mixture, accelerator pump and idle speed, synchronizing multiple carburetors, experimenting with idle, main and air correction jet sizes and venturi sizes, tearing the top off the carburetor to remove water and dirt from the float bowl, and likely some additional maintenance tasks I've forgotten about. In theory, the precision of fuel injection should yield improvements in performance and efficiency when compared to carburetors on an air cooled motor, but I've witnessed some who struggled with their fuel injection conversion and moved back to carburetors. Carburetor and fuel injection both must be tuned appropriately for the motor, though fuel injection is more of a set-once-and-forget, assuming you get the tuning right the first time.

An air cooled motor with solid lifters requires periodic valve adjustment. An air cooled motor with hydraulic lifters requires less maintenance (assuming you don't have an hydraulic lifter failure), more in line with a typical water cooled motor. Fuel injection should make it easier to cold start, though I've rarely had any issues starting a carburetor motor with a manual choke or no choke at all.

Preference for the sound of carburetors vs fuel injection is in the ear of the beholder. If you want your car to sound like a, say, an original 1958 Speedster, you may be happier with a carburetor.

By converting to a larger, contemporary water cooled motor designed for fuel injection, I'm benefiting from significant improvements in torque, horsepower and gas mileage, and hopefully lower maintenance and higher reliability. This makes the car less "correct", straying from the original, but it's my daily driver, so low maintenance is important to me. And the acceleration :-)

Rayner,

Wow engine swap on an almost new IM! I would love some of the details of your swap and pics if you have the time.

Questions:

Who did the swap?

What was the general install cost + engine cost?

You got around the computer subbie engine codes?

Did you lose back seat space?

What are your driving impressions before and after?

Thanks
Dave

Dave, I'll post some photos and details when I return from travels in mid-August.

Engine purchased from Outfront Motorsports http://www.outfrontmotorsports.com/homepage.htm. Installation performed by Vintage Spyders http://www.outfrontmotorsports.com/homepage.htm. Both are located in southern California. Please check with both companies for an estimate of acquisition and installation costs - depending on what you wish to do, the costs can vary quite a bit.

Outfront provides a wiring harness and aftermarket engine management computer (with mapping) as part of the package, so factory engine codes aren't an issue. No loss of backseat space, the Subaru motor bolts up to a plate on the VW transmission, fits easily into the engine compartment.

Only have a few days of driving experience with the new motor, but can volunteer that it hauls a**. Low RPM torque is wonderful, the motor spins up fast. I'm having to re-program how I shift, to accommodate the availability of additional torque across the RPM range, which is a great thing. Thanks for your interest.

You mistakenly listed Outfronts web site twice.

This is the web site for Vintage Spyders http://www.vintagespyders.com/

Dave:

My son and I will be installing a Golf, 1.8 litre in-line watercooled EFI engine in the flared CMC kit we'll be building throughout the Winter. It bolts to a modified aircooled VW transaxle and has the radiator up under the nose of the car. We'll be posting regularly on progress as we proceed but, so far, all we've done is tear the 1971 pan apart and found LOTS of rust to contend with. I don't yet know what he'll be running for an EFI system - I'm leaving that up to Chris, as he knows those things inside and out and all I know are carburetors (new school versus old school, but at least this old dog will learn a few new tricks!)

My son wants to run the turbo version of the 1.8 Golf (the later GTI version) so I'm designing the pan attributes to manage more than 200 ft. lbs. of torque (that should hold it).

Stay tuned through the Winter.....should be an interesting build (if we ever get past the rust).

gn

Thanks Rayner and Gordon,

Both of your projects are interesting. I have an 02 1.8 turbo Passat and I must say I do love that wagon, get around 30 mpg all the time and even with the heavy Passat it goes nice, pop that in a 1800+ lbs vehicle (aprox 1/2 the weight)it boggles the mind. I am sure you will have braking and suspension built to match.


Cheers
Dave