MV downgrade to DG (running a 1.9 with Digifant)

Big lumps of metals and spanners. Including servicing and fluids.

Moderators: User administrators, Moderators

Post Reply
dn-j
Posts: 3
Joined: 11 Jun 2020, 13:29
80-90 Mem No: 0

MV downgrade to DG (running a 1.9 with Digifant)

Post by dn-j »

Hi All,

I plan to take the 2.1 MV out of my syncro for a rebuild, and so that I can take my time with it, I want to install another engine in the meantime.

I have a spare 1.9 DG that I acquired.  So the question is, can I install the DG as-is and run it on the MV's Digifant system?  The Digifant has lambda control so hopefully it will automatically fuel as required for the smaller displacement?  Has anyone done this before and what were the results?

The alternative would presumably be to rebuild the 1.9 DG as a 2.1.  I understand that this should be possible with a bit of clearance work on the crankcase?  I plan to strip down and do a light rebuild on the DG before it goes into the vehicle (as practice for the MV rebuild), so I could do the upgrade to 2.1 spec at that point.  But I would rather not get involved in purchasing new crank, pistons, etc. for a engine that is only a temporary stop-gap - easier if I can keep it as a stock 1.9.

Thanks!
 
2.1MV Doka Syncro LHD
 

User avatar
Aidan
Trader
Posts: 5297
Joined: 11 Oct 2005, 19:21
80-90 Mem No: 742
Location: Llanfyllin, mid Wales : )
Contact:

Re: MV downgrade to DG (running a 1.9 with Digifant)

Post by Aidan »

I don't know from having done it, but I reckon the Digifant will cope just fine on the DG, because it is a bit more adaptive than DigiJet with the feedback from the Lambda and the ability of the ECU to control both fuelling and timing; you might just have to play around with the initial timing a little bit, but we do that running LPG and generally I can find a compromise setting that works for both LPG and 95 RON petrol, 8-9 degrees worked well for me

User avatar
ajsimmo
Trader
Posts: 2118
Joined: 23 Mar 2009, 14:06
80-90 Mem No: 6542
Location: Isle of Arran
Contact:

Re: MV downgrade to DG (running a 1.9 with Digifant)

Post by ajsimmo »

I've run a DG on Digijet very successfully, but not Digifant. However, I agree with Aidan that it should deal with it very well, for the reasons given.

Sent from my ONEPLUS A3003 using Tapatalk

The Campershack - Just T3s
WBX Rebuilds, Upgrades & Engine conversions

User avatar
maxstu
Posts: 2611
Joined: 07 Feb 2008, 01:05
80-90 Mem No: 3946
Location: Margate

Re: MV downgrade to DG (running a 1.9 with Digifant)

Post by maxstu »

Im doing a similar exchange in late summer. Putting in a temporary early DG while giving a top end refresh on the DJ. Have been reassured by many on here it will be fine. In fact, l believe it is designated as a SP. 1.9 fuel injected...is that right?

Good luck with the rebuild :ok
MaxStu
1989 DJ 2.1 Auto Leisuredrive rusty bucket.
"Blissfully happy in your presence".

User avatar
ajsimmo
Trader
Posts: 2118
Joined: 23 Mar 2009, 14:06
80-90 Mem No: 6542
Location: Isle of Arran
Contact:

Re: MV downgrade to DG (running a 1.9 with Digifant)

Post by ajsimmo »

Not SP, that's on a carb. It's either a GW or DH.
It's identical to a DG, but puts out a (claimed) 90bhp on digijet.

Sent from my ONEPLUS A3003 using Tapatalk

The Campershack - Just T3s
WBX Rebuilds, Upgrades & Engine conversions

User avatar
maxstu
Posts: 2611
Joined: 07 Feb 2008, 01:05
80-90 Mem No: 3946
Location: Margate

Re: MV downgrade to DG (running a 1.9 with Digifant)

Post by maxstu »

ajsimmo wrote: 28 Mar 2021, 20:26 Not SP, that's on a carb. It's either a GW or DH.
It's identical to a DG, but puts out a (claimed) 90bhp on digijet.

Sent from my ONEPLUS A3003 using Tapatalk

Ah yes! GW. That's the one. I easily confuse myself nowadays. SP is Zoona's Swiss speccd engine.

:ok
MaxStu
1989 DJ 2.1 Auto Leisuredrive rusty bucket.
"Blissfully happy in your presence".

dn-j
Posts: 3
Joined: 11 Jun 2020, 13:29
80-90 Mem No: 0

Re: MV downgrade to DG (running a 1.9 with Digifant)

Post by dn-j »

Thanks all, sounds like the DG+Digifant should work fine.

It will be a few months yet, but I will post back here when I have the DG installed, with some info on how well it runs with Digifant.  It's only a temporary solution, so as long as it's reasonably driveable then that's good enough.

Next question - am I right in saying that I will need to tap an extra oil pressure port in the DG case for the MV's sensors?  Or I could presumably run a T-piece instead.  Are there any other mods that I will need to make to the DG for it to be accommodated into an MV/Digifant setup?

Cheers.
2.1MV Doka Syncro LHD
 

User avatar
Mocki
Membership Admin
Posts: 15801
Joined: 29 Sep 2005, 09:27
80-90 Mem No: 428
Location: Mansfield tel/txt 07947137911
Contact:

Re: MV downgrade to DG (running a 1.9 with Digifant)

Post by Mocki »

Is it a early DG ? If so it won’t have the second oil pressure port , but you can defeat the buzzer with the wiring .
late DGs have the second port and will be the same as your MV 
Steve
tel / txt 07947137911
Image
just one shade of very fast grey
________________

1989 2.1LpgWBX HiTop Leisuredrive Camper

User avatar
Aidan
Trader
Posts: 5297
Joined: 11 Oct 2005, 19:21
80-90 Mem No: 742
Location: Llanfyllin, mid Wales : )
Contact:

Re: MV downgrade to DG (running a 1.9 with Digifant)

Post by Aidan »

oil pressure isn't part of engine management, it's just to talk to the dash dynamic oil pressure system, as Steve says can be defeated if the block hasn't got the second tapping to the oilway.
If you are fitting the full later plumbing you'll have to change the oil filter fitting to the long one to take the oil warmer cooler and use the 2.1 thermostat housing with the temp2 sensor

dn-j
Posts: 3
Joined: 11 Jun 2020, 13:29
80-90 Mem No: 0

Re: MV downgrade to DG (running a 1.9 with Digifant)

Post by dn-j »

Mocki wrote: 29 Mar 2021, 16:49 Is it a early DG ? If so it won’t have the second oil pressure port , but you can defeat the buzzer with the wiring .
late DGs have the second port and will be the same as your MV 

Good question!  As I understand it, the primary oil pressure port that all engine types have, is the one under the pushrod tubes, and the second one that is only on the MV and later DG engines is the one between the alternator and water pump pulleys?

If that is correct, then can someone confirm that blanking plug shown in the following photo, above the engine mounting stud, is the one?  If so, then it looks like it's a later DG.

Image

As an aside, the cast numbers on the casings are 025 101 101 B and 025 101 102 B.  There is a post from Rocky Jennings that I saw on The Samba that says that the "B" suffix denotes a 2.1 engine.  But since this is definitely a 1.9/DG engine, I guess that he meant to say that the B denotes "a 2.1 or a later 1.9"?
 
2.1MV Doka Syncro LHD
 

User avatar
Mocki
Membership Admin
Posts: 15801
Joined: 29 Sep 2005, 09:27
80-90 Mem No: 428
Location: Mansfield tel/txt 07947137911
Contact:

Re: MV downgrade to DG (running a 1.9 with Digifant)

Post by Mocki »

Yep that’s where the second sender should be . 
all later wbx have this port , early don’t . 

Image
Steve
tel / txt 07947137911
Image
just one shade of very fast grey
________________

1989 2.1LpgWBX HiTop Leisuredrive Camper

Post Reply