More efficient alternative to a 2.1i engine?

[centro]

Due to the ridiculous and almost daily rise in petrol prices, I am weighing up the options and was wondering about swapping my 2.1. Injection DJ engine for for a petrol engine which is more efficient. What would be my options and what sort of mpg could I expect?

[Cableguy]

From what I've read on here, the gti engine would fit the bill.

[silverbullet]

AGG-type swaps need a ful-house of diesel parts and they are getting expensive and rare. Your DJ is high-compression, so would convert well to LPG (gas likes high comp. ratios for a better burn as it's over 100 octane)

Have you considered an aftermarket sequential injection system? Megasquirt is very popular and well-supported and seq. gas injection systems are also popular (they run piggyback on the engine ecu, so you need to sort that first)

All of the later VW petrol engines are sequential and leaner-burn, which is why they are so much more efficient. Unless of course, your DJ is in need of a rebuild?

What are the compressions like, have you had it tested for emissions, does it use/burn oil? I know it's not compulsory at MOT but it can tell you a lot about the engine's health. After 20 years you can't expect a large-bore engine like these to have a lot of piston ring tension left, so they get thirsty and inefficient due to blow-by at the cylinder wall.

I'm convinced that modern engine management on a rebuilt wbx would be a real eye-opener...

[mrhutch]

I'm convinced that modern engine management on a rebuilt wbx would be a real eye-opener...

me too Ian!

[centro]

It doesnt burn oil and has had no issues with emissions at MOT. The previous owner did a top-end rebuild about 4 years ago.

I know very little about mechanics and engines, so have been googling some of the terms you mention in order to understand them.

I reckon I get 20 – 24 mpg, which isn't great, but seems about right for a 2.1 petrol injection. This is on only going to get more expensive to run. I used to drive it every day to work, but now its twice a week. I get the train on the other days. I would hate to get rid of the van and would rather find an alternative solution to the fuel economy issue in order to keep it.

I suppose my only options are convert to LPG or install an engine like a suburu or other compatible VW engine which is more fuel efficient.

How does Megasquirt work? and what would the effect on MPG roughly be ?

[silverbullet]

For MS the engine will need a toothed trigger wheel on the front pulley and a bracket to carry a sensor, so the ecu knows which injector to fire first in the 1-4-3-2 sequence (did I get that right?) This is an in-situ fitting for most engines.

MS also dispenses with the old MAF/flap meter, as it measures air flow into the engine with a MAP sensor inside the ecu, which measures air pressure/depression in the inlet manifold.

A new engine loom, fresh sensors, fixed dizzy to keep it simple (MS can be fuel-only but why bother, you'll lose mpg) and that's the end of the DIY. Then it needs mapping to sort the fuelling and ignition out, so you get a man in with his laptop and a head full of experience. 2-3 hours would see that done.

The thing is, a healthy wbx is the engine that the vehicle was designed for, it fits and it's a very light engine by any measure (Subarus are a good 15 kg heavier at least) and it's just about the quietest, smoothest 4 cylinder engine out there.

OK so watercooled flat-fours aren't fashionable or "scene" but if yours would do more like 28-30 mpg for about £600 outlay and no engine swap aggro, why change it?

[centro]

Sounds interesting. Anyone on here gone the MS route?

[jim potter]

im going ME7 .. ill let you all know hows it goes.. im just gathering parts then the fun will begin.

[silverbullet]

ME7...is that the Emerald system?

[PetenAli]

This is going to be a really useful thread for me. I am just setting about building a new 2.1 DJ having picked up most of the bits from Dave at Futbus. I had thought long and hard about going down the Subaru route but finally decided that I own VWs because I like and can understand (up to a point) VW flat fours.

My plan is to try and rebuild the engine to a standard approaching that of tencentlife in the States who is one of the gurus as far as I can tell. I'm still getting to grips with all that he does to his engines which he is confident enough to guarantee for two years / 24k miles if an external oil cooler is fitted.

My first two questions in relation to Megasquirt are:

Can you keep the original injectors? I am just about to send a set off for a refurb but don't want to if they are not going to be needed.

Is there a good internet source of info on Megasquirt?

Thanks,

Pete

[silverbullet]

Injectors can stay afaik. they use a standard Bosch loom plug and since flow rates were specced for a standard engine, they'll be ok with more efficient management as it'll use less fuel.

The web is your friend. Phil (?) at "extra-efi" was very helpful with my daft questions.

http://www.extraefi.co.uk/" onclick="window.open(this.href);return false;

I can help you with the few internal machining mods that are necessary for a good strong wbx. pm me

[centro]

This is all bit too complex for me – I have no knowledge of engines, aprt from changing the oil!

I think this is a job for someone else.

[silverbullet]

Have a word with Hutch and Elvis (they know more than me about these sort of conversions, I like building engines) I'm still planning my build but it will based around a 2.1 and be running Megasquirt, I'll be taking the advice of those more experienced too, but I have played around with basic efi for a while (old Rover/Lucas 4CU on Vitesse V8's mostly)
It's really all about connecting the relevant sensors and a supply to the correct ecu inputs, the guy who sets up the fuel maps with his laptop does the clever bit. You've got most of what's needed on the DJ already.

[PetenAli]

Injectors can stay afaik. they use a standard Bosch loom plug and since flow rates were specced for a standard engine, they'll be ok with more efficient management as it'll use less fuel.

The web is your friend. Phil (?) at "extra-efi" was very helpful with my daft questions.

http://www.extraefi.co.uk/" onclick="window.open(this.href);return false;

I can help you with the few internal machining mods that are necessary for a good strong wbx. pm me

Thanks silverbullet. PM on its way.

[centro]

Is this the same sort of thing as megasquirt? or am I completey confused ?

http://www.vwspeedshop.com/product.php? ... 496&page=1" onclick="window.open(this.href);return false;