1.9DG head pitting - recoverable?

[FannyBawz]

Hi all

I have a DG engine which I was going to use to replace my current slower than slow DF in my camper. This DG has no compression on one cylinder and it seemed to be the exhaust valve, so I removed the head, and found some pitting which (to me) looked pretty bad. I've not checked the valve or seat yet since I thought this pitting might make the head(s) a write off anyway.

What do you think, are these usuable/repairable? Even if these pits aren't causing compression leaks they look to me as though they would prevent the liners making a watertight seal to the head, and water getting into the cylinders? Then again I've never worked on a VW engine before so can't say for sure!

The first three pictures are of the cylinder with no compression, the last picture is of the other cylinder which has (at least some) compression.




This is the working cylinder:


Thanks

David

[ajsimmo]

I'm afraid that looks like it's a gonner. Something has been hammering about in the combustion chamber and mullered the head. What state's the piston in?
I'd put a good used head on (and maybe pistons/barrels/ new tappets) and probably same the other side too as a minimum while you're in there. Then look at the cam, etc etc...

[itchyfeet]

yes that seal surface is too far gone for the water jacket o ring on the barrel.

not sure that would explain no compression but might if it corroded the compression seal.

You shoulds as a minimum replace the lower liner seals on the barrels, this can be done by removing pistons and barrels together so you don't break pistion rings, people who don't regret it later when coolant leaks into the oil.

[FannyBawz]

Piston crown shows the same damage as the combustion chamber, but the bore looks surprisingly good, there's no scratches as you'd expect if loose metal was bouncing around the cylinder. Maybe that damage is from an old problem that was fixed?

Typically, I got my left and right and back and front mixed up with these pictures, the chamber with the bad pitting is actually the one holding compression and the "better" looking one is not, but that could be unrelated.

In any case, it sounds like I could never rely on this head sealing properly. Ah well. I've posted in the wanted section for replacement heads, hopefully someone will have a couple spare.

Thanks for your advice so far, much appreciated!

David

[ajsimmo]

What's your budget in reviving this engine?

Uninvited metal has gatecrashed the party - are you planning to check everywhere for damage? After all, it's the better looking one with no compression, so something else going on there!
I have heads, pistons, barrels, cases, cranks, conrods & cams that are serviceable. You can come and rummage for what you need, but I'd suggest a full strip down to assess first. And if you're then going that far, why not pop 2.1 crank, cam and MV pistons in instead? (MV because I'm keeping all my DJ sets!)

[FannyBawz]

I was hoping to keep the budget low to be honest! Since this engine is for a high top camper going fast isn't my plan, I just want it to have enough poke so I can hold 60mph on the motorway and the DF just isn't cutting it, DG seemed like a straightforward swap without having to set up any injection systems etc. See where that idea got me lol.

Of course stripping this engine right down will only cost me time and I suppose it would be a sensible precaution.

What's the benefit of the 2.1 parts? Does it raise the compression?

I'm in Scotland btw so you're quite a long way from me unfortunately, unless you'd be willing to post some parts?

Thanks

David

What's your budget in reviving this engine?

Uninvited metal has gatecrashed the party - are you planning to check everywhere for damage? After all, it's the better looking one with no compression, so something else going on there!
I have heads, pistons, barrels, cases, cranks, conrods & cams that are serviceable. You can come and rummage for what you need, but I'd suggest a full strip down to assess first. And if you're then going that far, why not pop 2.1 crank, cam and MV pistons in instead? (MV because I'm keeping all my DJ sets!)

[ajsimmo]

Can I just go back to your first post. You say your DF is too slow? What's up with it? It might be easier, and cheaper, to just get it running right. When they're on song a good DF goes pretty well.
Have you done a compression test?

[ChrisTriple]

I have DF pop top, she nips along at a steady 60! Ok so she's a bit slow up the hills. How fast do you want to go?

[FannyBawz]

I haven't done a compression test yet but going to borrow one this weekend and check before starting to take the engine out. Both exhaust studs have snapped on no.2 cylinder so it's blowing pretty badly.

I'm not looking to make this into a fast van by any stretch, it managed to hold about 55-60 on the motorway and that would be quite acceptable to me but every time the slightest incline appeared it really struggles even to stay at 50, and I have to drop it into 3rd for that. It didn't sound too happy but that may just have been the blowing exhaust. This van is a fixed hi-top so wind resistance won't help either.

So I thought, since I'm going to be dropping the engine anyway, might as well look at getting something with just a little more power, but keep things as simple as possible (so avoid fuel injection etc), which led me to the DG engine idea. Unfortunately my first donor engine has a bad head as you can see (although the other head looks much better). Another idea I considered was putting a set of DG heads and carb onto the DF...

There's probably no end of potential upgrade routes here, but I'm open to suggestions for the best way to proceed!

Thanks

David

[itchyfeet]

If it were me I'd build up the DG but keep the DF as a spare, once you have done it swapping an engine isn't too bad, if the new DG is a duffer ( you won't know for sure until you run it) then you can put the DF back

To get the extra power you will need the DG dizzy, carb, manufold, throttle linkage, throttle cable, if it's a late van thermostat housing and water pipe.

smiffo had a DG fitted with DF carb and dizzy, this thread describes the changes he needed for the extra power.


https://club8090.co.uk/forum/viewtopic.php?f=37&t=147477" onclick="window.open(this.href);return false;

[kevtherev]

The DG will struggle with gradients and hills.
The DJ 2.1 can use a pierburg from a DG, lots of us have gone this way.
Or you can go out of the VW loop with a Subaru.
If it was me I'd get the DF running properly.
DF's when running right are ok.
Then fix the DG head issue.

Old VW campers are campers, bhp just doesn't figure.
It's a big change from DF to DG as itchy feet shows.

[FannyBawz]

Thanks for that link, lot of good information there (and some stuff I hadn't thought about).

I'm picking up another DG engine on Saturday, once I check the condition of that one and get compression test results from the DF hopefully I'll have a better idea what direction to go in here. I'm probably going to end up having to strip both DG engines down (and maybe also the DF!) to see which one would be the best replacement. At least I shouldn't be short of spare parts...

[itchyfeet]

Not much in the DF of any use so keep it in the van until you get a DG built up is my advice.
Do a compression test on the DF so you have an idea of condition.
check ignition is set right DF is After TDC, check twin vaccum dizzy unit works too.

Is it early or late exhaust? Where have the studs snapped? can you get a couple of gaskes wedged in the gap with some gun gum around as a temporary fix?

Some DG engine porn here...
http://s1145.photobucket.com/user/paul_ ... LPG_Engine" onclick="window.open(this.href);return false;

[ghost123uk]

Slightly off topic alert

Some DG engine porn here...
http://s1145.photobucket.com/user/paul_ ... LPG_Engine" onclick="window.open(this.href);return false;

I've mentioned your legendary huge collection of useful T25 related photographs before, and now we have access to the entire collection
A picture is worth a thousand words they say, one could spend hours easily just learning stuff by looking at that pictorial archive
Not sure why, but I particularly like this pic -> http://s1145.photobucket.com/user/paul_ ... sort=3&o=4" onclick="window.open(this.href);return false;

[FannyBawz]

That's an impressive collection of pictures. Looks like you cut some castings in half there?

It's a 1983 van so early exhaust, one stud looks like it has snapped with maybe a quarter inch sticking out, just enough to keep the flange on, the other has snapped off flush or maybe inside the head, I can't tell at the moment. The old gasket is still there but it's slipped out of alignment and is badly bent out of shape, I'll try and get it put roughly back into position, or maybe just cut it off and try wedging a couple of new ones in as you suggest.