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1.9DG to 2.1DJ engine swap

Posted: 19 Apr 2024, 12:59
by keynsham1
I appreciate that the 1.9DG and 2.1DJ engines are different in terms of one being carbs and one fuel injection, different airboxes, air flow meters, ECU etc, but in principle if I wanted to swap engines are they fundamentally the same unit?

Re: 1.9DG to 2.1DJ engine swap

Posted: 19 Apr 2024, 13:50
by DoubleOSeven
Yes, the DJ will run on a Pierburg 2E3 too. Just need to add the oil warmer/cooler. All the other accessories from the DG, just put them back in. Air filter, air intake, it’s all the same. Don’t need the ECU if you’re not adding fuel injection. A 4-spanner difficulty upgrade.

Re: 1.9DG to 2.1DJ engine swap

Posted: 19 Apr 2024, 19:03
by maxstu
A few enlightened don't even both with an oil cooler when converting..
This is my next project. I have a rough DJ engine sitting under cover at the mo; and l have a 1987 auto DG LPG begging for more ponies.

Re: 1.9DG to 2.1DJ engine swap

Posted: 19 Apr 2024, 21:53
by Stesaw
rebuild 2 electric boogaloo.

But Yeah I've done the swap. I changed thermostat housings to accomodate the extra coolant line for the oil cooler. Generally when you get your hands on a 2.1 it will have the oil cooler on it anyway its there for a reason so you might as well renew it.. unless the previous owner had some external cooler.

You can run the DJ on a carb no problems. I'd love to go Fuel Injection but I want a swanky Marco Mansi kit with turbo.. but thats like $4000 there abouts + whatever shipping would be AND import tax from the US. Maybe I should make my own kit from speedshop etc :idea. I suppose adding a snail to a waterboxer isn't just as simple as bolting it on.

Re: 1.9DG to 2.1DJ engine swap

Posted: 20 Apr 2024, 09:30
by keynsham1
So If I just keep the carb DG setup, is the power and torque increase still worthwile? There is nothing wrong with my 1.9 DG So to bother I would want to notice an improvement !

Re: 1.9DG to 2.1DJ engine swap

Posted: 20 Apr 2024, 09:47
by Stesaw
I noticed a difference from the dg to dj in terms of grunt. But I've no idea how tired my 1.9 was.. it was a recon put in a few years ago so it should have been fairly fresh.. but no idea of who did the rebuild.

The 2.1 was also a semi rebuild with new rods, rings bearings and cam etc so.. it should run better...

Yes you can just plop the carb and manifold onto a 2.1 they are externally the same. You might have to swap the thermostat housing for the 2.1 variant for the oil cooler hose. The other hose for it attaches to the water pump.

I think the conversion is easier if you have a late 1.9 coolant setup rather than an early as I think you'd have to swap all the coolant pipes. Other people might be able to correct me on that though.

Re: 1.9DG to 2.1DJ engine swap

Posted: 20 Apr 2024, 10:50
by Mocki
Oh the difference is definitely worth it … the 2.1 performs much nicer than the 1.9 on the carb , I’ve made this change many years ago

Re: 1.9DG to 2.1DJ engine swap

Posted: 20 Apr 2024, 11:03
by DoubleOSeven
It’s a noticeable improvement both in torque and speed. What were slow 65mph motorway journeys with second thoughts about over taking lorries becomes a care free pleasurable experience. Like it should be.

I took my 2.1 MV to 95mph & a DJ has more horses.

Re: 1.9DG to 2.1DJ engine swap

Posted: 20 Apr 2024, 13:20
by shepster
You haven't got to swap any coolant pipes as the 'block ' is essentially the same.

You will need all the early cooling system swapping over to the dj obviously but it's there already, the oil cooler/warmer thing needs plumbing in admittedly and having the metal pipes from the donor engine helps but it's doable.

I've had a 2.1 running on lpg with carb for the best part 20yrs and it's been fine, well worth the upgrade in my opinion.

Re: 1.9DG to 2.1DJ engine swap

Posted: 20 Apr 2024, 15:26
by Robsey
I am still going through the motions of a early DF to DJ conversion.

I am retaining the early cooling and exhaust system, just grafting the 2.1 lump complete with injection into the space where the old 1.9 lump was.
More or less a DH or GW set-up but with a larger displacement.

I was planning on removing the oil cooler due to the limited space in that area.
I am presuming from the comments that this would be ill-advised.

But for the original poster -
Mechanically the engine and heads are a direct swap.

UPDATE - The DF intake system (Solex Carb and manifold) is far too restricted for a 2.1 engine due to the smaller port sizes in the manifold. So you would not really gain much ooomph. - for those that are interested in converting DF to DJ rather than DG to DJ.
The DG mafifold is a perfect fit, and so not restricted or strangled.

Re: 1.9DG to 2.1DJ engine swap

Posted: 21 Apr 2024, 11:15
by keynsham1
So realistically what is a 2.1 DJ with 150k miles an apparenty was seen running and in need of a full rebuild really worth?

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Re: 1.9DG to 2.1DJ engine swap

Posted: 21 Apr 2024, 12:10
by Mocki
If you cant see it running, have no idea if it leaks , over heats or knocks , no more than £200 in my book
Its parts .

Re: 1.9DG to 2.1DJ engine swap

Posted: 21 Apr 2024, 12:46
by philmcC
The 1.9 DG engine that I rebuilt lasted about 800 miles and disintegrated on the M 40 in some style. Following that Ian Holman built me a refurbished 2.1 DJ working on the carburettor. It has transformed my syncro. More power across the board no problem with hills very happy cruising around 60, and fuel economy okay. Would recommend. pjamcC

Re: 1.9DG to 2.1DJ engine swap

Posted: 21 Apr 2024, 14:06
by maxstu
keynsham1 wrote: 21 Apr 2024, 11:15 So realistically what is a 2.1 DJ with 150k miles an apparenty was seen running and in need of a full rebuild really worth?

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Not exactly well loved, is it? First check it is actually a DJ by asking for a photo of engine number. Any signs of tampering with block number walk away. I got caught out.

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As Mocki says, parts only. A couple of hundred quid. And that is still a gamble, as it may well end up in the bin if the cases are no good. High mileage is no indicator. As long as it has been well (nope) treated or rebuilt before.

Providing the heads, valves, pistons and sleeves cam, crankshaft and conrods are within tolerances, expect a bill for a DIY rebuild of around £600-1000.

Long long hours of cleaning and cleaning. And more cleaning.

Re: 1.9DG to 2.1DJ engine swap

Posted: 21 Apr 2024, 14:28
by Stesaw
cleaning *eye twitch* don't remind me..

well if youre gonna rebuild it, its new bearings all round which means new rods too. New piston rings, maybe a new camshaft if that one is shot...
Could go up to about 2-3k in parts.