New Amateur Engine Rebuild Featuring a DJ2.1

[maxstu]

So the mindnumbing task of cleaning and measuring begins.
Starting with the pistons and blue spot sleeves while rest of engine sits at Thanet Engine Services..
Then it dawned on me l have a new set of SS/MV pistons on the shelf. I did try selling them but no takers. Ive also new 2.1 rings here too. A potential saving of labour and money.
Yet am l about to commit the ultimate WBX sacriledge by using these pistons instead of the original high compression DJ ones. Will l lose 12-15 bhp? This rebuilt engine will replace a very dead 1987 DG 1.9 auto LPG.

[Aidan]

unless you are running full fat 4* or E5 Superplus at 10' you don't get 112bhp out of a DJ even new
on E10 at 5' it's probably very similar to an MV; Digifant is a bit more clever than Digijet as it makes the most of the fuel available as ECU can control timing and fuelling, it would run on 3* back in the day
If you are running carb then I very much doubt you'd notice the difference

[Stesaw]

Speaking from someone who went from a 1.9DG to a 2.1DJ on a carb, there is a marked difference in power even running E10.
10 degrees vac off and plugged, with hot engine. With vac line on it seems to jump the timing quite a fair bit more at idle... I am using a DG dissy as I sold the DJ one like a muppet, live and learn. Does the DG dissy have more mechanical advance than DJ? can anyone confirm? (ill look it up, Ah Wiki says the DJ advances a bit more at around 2400. Probably fine to use though by look of it)
Granted I don't know how healthy the 1.9 was but it was a rebuild in 2017..(if I recall) so its still fairly fresh so it should have been healthy still. Although It did overheat badly once on my with a blown coolant line. I did get an MOT failure on emmisions on it and running rough which I put down to the overheating, although thinking about it it could have been the dodgy HT lead I found with the 2.1 not sparking all the time causing that..
Its annoying that its an early case otherwise I'd be pulling the 2.1 out and putting the innards in that 1.9 case as the DJ case was butchered by my local machine shop and the headbolts give me a constant twitch with them being barely helicoiled. Either way I suppose Ill pull the 1.9 apart to make sure the bearings are OK etc then get a seal kit and put it back together, give it a compression check and probably put it up for sale.

If the DJ pistons are in good nick Stu, I'd shove them in. You will get more bang for your buck that way. I'd say if you have new barrels I'd use them but depends if they'd suit the pistons... Part of me wanted a set of new barrels and pistons but the cost wasn't in my budget at the time and replacing the damaged ones with good used items was the only option.

[maxstu]

unless you are running full fat 4* or E5 Superplus at 10' you don't get 112bhp out of a DJ even new
on E10 at 5' it's probably very similar to an MV; Digifant is a bit more clever than Digijet as it makes the most of the fuel available as ECU can control timing and fuelling, it would run on 3* back in the day
If you are running carb then I very much doubt you'd notice the difference

I have road tested my DJ on both E5 @ 10' and E10 @ 5' and never noted any real world gain in power or any difference, apart from an additional 60p theft from each gallon.
This DJ engine will be replacing a DG on carb and LPG.

[maxstu]

[quote=Stesaw post_id=8334535 time=1719868595 user_id=45911

If the DJ pistons are in good nick Stu, I'd shove them in. You will get more bang for your buck that way. I'd say if you have new barrels I'd use them but depends if they'd suit the pistons... Part of me wanted a set of new barrels and pistons but the cost wasn't in my budget at the time and replacing the damaged ones with good used items was the only option.
[/quote]

Will clean them and measure and weigh them.
I dont have new sleeves/barrels, just MV/SS pistons. But Brickwerks do sell a set of MV/SS pistons, barrel, conrods and clips for under 300 quid. Could be a worth it for the barrels alone.
Just a thought.

Still can't get my head round why VW had two types of sleeves? Pink and blue spot.

[silverbullet]

Pink or blue denotes different running clearances, larger clearance for hot climate markets I would guess.
Using a pukka 2.1 cam or better will perk it up, even the original DJ/MV profile is very tame by modern standards.

[maxstu]

Pink or blue denotes different running clearances, larger clearance for hot climate markets I would guess.
Using a pukka 2.1 cam or better will perk it up, even the original DJ/MV profile is very tame by modern standards.

Okay and thanks.
Picking up re-ground crank tomorrow. Both big ends and crankshaft journals now US 0.5mm.
Report on camshaft is it's worn but useable.

So what is a pukka cam and have you a cunning plan, Ian? The cam gear is in great condition btw.

My driving style leans toward low down grunt and torque as a preference. I rarely drive above 65mph on motorway in any vehicle.... part from when on two wheels.

Is there an old git George Cole wearing trilby in a Jag type of cam available?

[cobblers]

Definitely following this, cheers for taking the time to do photos!

I'm also interested in cam stuff as I'll be building one of these soon.
My intention was to stick with a decent DJ/MV cam if possible, but I do have an CB performance cam I picked up a while ago. That opens up it's own can of worms - it's a beetle type cam so I'd need a different drive gear and I've read that these can be a bit noisier on account of not being matched to the gear on the crank like a proper DJ cam would be? I'd rather a smoother quieter engine than a revvier one with a noisy valvetrain and a few more HP.

[maxstu]

Thanks Cobblers...
I'm not going photo intensive with this rebuild. I did it last time and it adds about 50 percent to the task. Much of the time l post to ask guidance from forum users' instead of me showing how to do what.
But l'm keen to learn and hopefully help other T25 owners'. This is my third engine build in four years. Starting with a top end refresh in 2021 to a full one in 2022. And there is another one after this!
Will pick up cases, heads, crank and camshaft tomorrow morning. Then post photos and start the process of ordering parts.

Calling Mr Silverbullet. Re cam. Can you advise please?

Meanwhile two hours of piston cleaning today.
Two down. Two to go....

The piston ring grooves will get additional cleaning later.



My chip shop vinegar dispenser. Ideal for short squirts of oil.

[silverbullet]

I don't know if I have any 2.1 or improved cams left, got to admit that I ran the stock down.
Thing is, because they all come on a Type 1 3-bolt iron blank you have to use an adaptor and dial in the timing ysing a DTI and crank protractor, then drill and tap the cam gear to secure. Its not a DIY job and has to be done as part of a dry build in the case before the final wash and assembly.

[Stesaw]

I might have missed, but did you have a chat with Andrew about a cam Stu?

[maxstu]

I don't know if I have any 2.1 or improved cams left, got to admit that I ran the stock down.
Thing is, because they all come on a Type 1 3-bolt iron blank you have to use an adaptor and dial in the timing ysing a DTI and crank protractor, then drill and tap the cam gear to secure. Its not a DIY job and has to be done as part of a dry build in the case before the final wash and assembly.

Okay and thanks for the explaination.

[maxstu]

I might have missed, but did you have a chat with Andrew about a cam Stu?

No. Perhaps not yet, anyhow.
But reading Silverbullets post it seems it isa case of shipping engine cases and internals to whomever does the deed.
Not keen to go down that road at the mo.

The cam...

[silverbullet]

That is goosed. They aren't regrindable because the case hardening has worn through. A reprofile will rapidly wear, I have seen how they fail and it doesn't take long at all.

[maxstu]

That is goosed. They aren't regrindable because the case hardening has worn through. A reprofile will rapidly wear, I have seen how they fail and it doesn't take long at all.

Okay and much appreciated.
Time to take stock of this very unsatisfactory situation.
So, l have a recently purchased 1987 DG1.9 Autosleeper camper, with a snapped head stud.
I also have a very suspect DJ2.1 engine with a reground to US .5mm crankshaft and a crappy camshaft.
And then l have an early DG1.9 engine in bits waiting for new crank bearings.
And lastly l have an additional early DG1.9 crankshaft and camshaft sitting on the shelves.

I must be mad!!