WBXOily

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

Moderators: User administrators, Moderators

WBXOily

Postby itchyfeet » 25 Nov 2017, 11:15

This is What2do's engine that was leaking oil from the spark plug hole, we checked compression and they were all low, not quite lower than VW min spec but that's not saying much, min is 8 bar If I remember ( my DG is 12-13 bar)

Figures were
No1 10 bar ( leaking oil out of plug hole)
No2 8,75 bar
No3 9 bar ( broken rings)
No4 11 bar

So it got removed and another engine fitted and now I'm going to take a look at what's wrong.

ImageP1040855 by Paul_Barr, on Flickr

ImageP1040856 by Paul_Barr, on Flickr
Last edited by itchyfeet on 25 Nov 2017, 12:29, edited 1 time in total.
1988 DG WBX LPG Tin Top
1989 DJ digijet WBX Holdsworth Villa 3 Pop Top
itchylinks
User avatar
itchyfeet
 
Posts: 10356
Joined: 23 Jul 2007, 17:24
Location: South Hampshire
80-90 Mem No: 12733

Re: WBXOily

Postby itchyfeet » 25 Nov 2017, 11:23

We pulled the heads off at his house and the first came with barrels, and two of the rings were broken on one piston, the other side came of OK.

Image20171118_143039 by Paul_Barr, on Flickr

So I took it home to play with and sneaked another of his old engines in while he wasn't looking :lol:

Image20171118_151853 by Paul_Barr, on Flickr
1988 DG WBX LPG Tin Top
1989 DJ digijet WBX Holdsworth Villa 3 Pop Top
itchylinks
User avatar
itchyfeet
 
Posts: 10356
Joined: 23 Jul 2007, 17:24
Location: South Hampshire
80-90 Mem No: 12733

Re: WBXOily

Postby itchyfeet » 25 Nov 2017, 11:29

on the bench today for a closer look

ImageP1080712 by Paul_Barr, on Flickr

and it's clear the rings didn't just break as the barrels came off because the barrel is scored.

ImageP1080717 by Paul_Barr, on Flickr

what's a bit strange to me is how clean the top of the pistons ( except broken ring piston) and heads are and yet what's all the crud in the spark plug?
I'd expect an oil burner to be black inside?
This is an LPG engine, plugs were changed 1 year ago.

ImageP1080718 by Paul_Barr, on Flickr

ImageP1080719 by Paul_Barr, on Flickr

ImageP1080721 by Paul_Barr, on Flickr

ImageP1080722 by Paul_Barr, on Flickr

ImageP1080723 by Paul_Barr, on Flickr

looks like some oil was leaking from a pushrod so not all being burnt

ImageP1080724 by Paul_Barr, on Flickr
1988 DG WBX LPG Tin Top
1989 DJ digijet WBX Holdsworth Villa 3 Pop Top
itchylinks
User avatar
itchyfeet
 
Posts: 10356
Joined: 23 Jul 2007, 17:24
Location: South Hampshire
80-90 Mem No: 12733

Re: WBXOily

Postby itchyfeet » 25 Nov 2017, 19:18

I want to take valves out to see if valve guides are worn.

Barrels need to come off head first , I use a floorboard lifter, it works for me to separate barrels, one side will move first then back and forth with chisel one side hammer the other until it comes off.

ImageP1080725 by Paul_Barr, on Flickr

ImageP1080726 by Paul_Barr, on Flickr

ImageP1080730 by Paul_Barr, on Flickr

the other barrel really needs a vice this was stuck on really well, needed to beat it with a lump hammer, studs stop it falling on floor when it finally moves.

ImageP1080737 by Paul_Barr, on Flickr

ImageP1080738 by Paul_Barr, on Flickr

I
1988 DG WBX LPG Tin Top
1989 DJ digijet WBX Holdsworth Villa 3 Pop Top
itchylinks
User avatar
itchyfeet
 
Posts: 10356
Joined: 23 Jul 2007, 17:24
Location: South Hampshire
80-90 Mem No: 12733

Re: WBXOily

Postby itchyfeet » 25 Nov 2017, 21:09

Easiest to give the springs a thump with a socket to loosen cotters
this is 1&2 side

ImageP1080777 by Paul_Barr, on Flickr

pretty oily on back of valves

ImageP1080779 by Paul_Barr, on Flickr

some bits of metal I made to help make the measurement

ImageP1080780 by Paul_Barr, on Flickr

worn but well in spec and less than other engines I have tested that don't burn oil.

ImageP1080781 by Paul_Barr, on Flickr

3&4 side is just the same

ImageP1080783 by Paul_Barr, on Flickr

ImageP1080784 by Paul_Barr, on Flickr

ImageP1080795 by Paul_Barr, on Flickr

usual cracks between valves on three of four cylinders this is the worst so these heads can go back after a clean and valve grind :ok
1988 DG WBX LPG Tin Top
1989 DJ digijet WBX Holdsworth Villa 3 Pop Top
itchylinks
User avatar
itchyfeet
 
Posts: 10356
Joined: 23 Jul 2007, 17:24
Location: South Hampshire
80-90 Mem No: 12733

Re: WBXOily

Postby itchyfeet » 26 Nov 2017, 11:07

Next to remove pistons

all this has to come off, need to remove pulley to get old water pump bolts out, another reason not to store engines the pulley and flywheel rust

ImageP1080740 by Paul_Barr, on Flickr


an allen key just won't do it , they were stuck in well.

ImageP1080741 by Paul_Barr, on Flickr

rag around piston so you can't loose clip in sump ( I'm not rebuilding the bottom end oil pressure is good)

ImageP1080745 by Paul_Barr, on Flickr

as barrels are off the piston needs supporting, some bits of wood work
Pulled the pin with my home made M8 rawlbolt puller :D

ImageP1080747 by Paul_Barr, on Flickr

No 3 has a very bad burr on the circlip groove, this apparently happens from the pin bashing it, never coming out with that so out with the reamer
ImageP1080754 by Paul_Barr, on Flickr

ImageP1080756 by Paul_Barr, on Flickr

studs are A1 :ok

ImageP1080764 by Paul_Barr, on Flickr

other side out too

ImageP1080768 by Paul_Barr, on Flickr

again studs A1

ImageP1080769 by Paul_Barr, on Flickr
1988 DG WBX LPG Tin Top
1989 DJ digijet WBX Holdsworth Villa 3 Pop Top
itchylinks
User avatar
itchyfeet
 
Posts: 10356
Joined: 23 Jul 2007, 17:24
Location: South Hampshire
80-90 Mem No: 12733

Re: WBXOily

Postby itchyfeet » 26 Nov 2017, 17:17

pulled the tappets one side to check cam and while it's worn its OK and not too bad

ImageP1080771 by Paul_Barr, on Flickr


hello cheap oil filter alert

ImageP1080773 by Paul_Barr, on Flickr

broken bolt, what20do can drill that out :lol:
ImageP1080774 by Paul_Barr, on Flickr

mmm end float desperately needs setting, should be 0.07-0.13 this is 0.27

ImageP1080775 by Paul_Barr, on Flickr

rags in holes and back in the store until I have parts

ImageP1080776 by Paul_Barr, on Flickr
1988 DG WBX LPG Tin Top
1989 DJ digijet WBX Holdsworth Villa 3 Pop Top
itchylinks
User avatar
itchyfeet
 
Posts: 10356
Joined: 23 Jul 2007, 17:24
Location: South Hampshire
80-90 Mem No: 12733

Re: WBXOily

Postby what2do » 26 Nov 2017, 18:42

A1 studs - that's because I look after them, meticulously...
Why would the glass be anything other than half full?

'89 panel van, 1.9 DG.
what2do
 
Posts: 2741
Joined: 05 Oct 2012, 08:55
Location: Salisbury
80-90 Mem No: 11974

Re: WBXOily

Postby itchyfeet » 26 Nov 2017, 19:15

what2do wrote:A1 studs - that's because I look after them, meticulously...


yeh but you didn't know they were good before, you could have been meticulously looking after rusty old studs like these :rofl

ImageP1080183 by Paul_Barr, on Flickr
1988 DG WBX LPG Tin Top
1989 DJ digijet WBX Holdsworth Villa 3 Pop Top
itchylinks
User avatar
itchyfeet
 
Posts: 10356
Joined: 23 Jul 2007, 17:24
Location: South Hampshire
80-90 Mem No: 12733

Re: WBXOily

Postby itchyfeet » 26 Nov 2017, 21:42

piston and barrel check next

ImageP1080785 by Paul_Barr, on Flickr

ImageP1080788 by Paul_Barr, on Flickr

bore gauge isn't very accurate but it's better than nothing and accurate enough bearing in mind the difference between piston and barrel can be up to 0.2mm

ImageP1080790 by Paul_Barr, on Flickr

ImageP1080791 by Paul_Barr, on Flickr


No1 93.95/94.06 =0.11
No2 93.93/94.05 = 0.12
No3 93.88/94.07 = 0.19 ( broken ring)
No4 93.97/94.06 = 0.09

this is a bit worrying but it sealed before

ImageP1080792 by Paul_Barr, on Flickr

I think this could be the cause of low compression, this is way over the limit at 1.7mm at the top and ( where it actually runs) and 1.4mm at the bottom where you are supposed to measure ( who knows why because it never runs there)
I only checked No1 so far

ImageP1080794 by Paul_Barr, on Flickr
1988 DG WBX LPG Tin Top
1989 DJ digijet WBX Holdsworth Villa 3 Pop Top
itchylinks
User avatar
itchyfeet
 
Posts: 10356
Joined: 23 Jul 2007, 17:24
Location: South Hampshire
80-90 Mem No: 12733

Re: WBXOily

Postby 937carrera » 26 Nov 2017, 23:53

You clearly know what you are doing, but don't forget, pistons are shaped along the height, and not generally round, neither are used bores, so you need to be sure that you are measuring in the right places and identifying whether it is the pistons, bores or both that are worn.
1981 RHD 2.0 Aircooled Leisuredrive project, CU engine
1990 RHD 1.9 Auto Sleeper with DF/DG engine
User avatar
937carrera
 
Posts: 1824
Joined: 05 Apr 2015, 19:29
Location: N Yorks.
80-90 Mem No: 16333

Re: WBXOily

Postby itchyfeet » 27 Nov 2017, 07:50

937carrera wrote:You clearly know what you are doing, but don't forget, pistons are shaped along the height, and not generally round, neither are used bores, so you need to be sure that you are measuring in the right places and identifying whether it is the pistons, bores or both that are worn.


interesting comment
VW manual state to measure in certain places which don't alwys make sense to me.

piston at skirt in vertical plane -seems logical its where wear is highest.

barrel is shown at top -logical because rings are there and wear is highest but not where piston skirt is and the spec of 0.2mm max is the difference
Also barrel measurement shown on horizontal axis - not logical to me ( I measure vertically because its worse)

Rings at base of barrel where they never run -not logical to me ( I measure at top also where its worse)

can you shed any light on this?
1988 DG WBX LPG Tin Top
1989 DJ digijet WBX Holdsworth Villa 3 Pop Top
itchylinks
User avatar
itchyfeet
 
Posts: 10356
Joined: 23 Jul 2007, 17:24
Location: South Hampshire
80-90 Mem No: 12733

Re: WBXOily

Postby 937carrera » 27 Nov 2017, 18:02

I'm getting to the limits of my understanding here, I'm not an engine builder, but have built a few and had a few race engines built for me, I even had to custom design some pistons when an engineering shop planed a block when I had told them not to. :cry:

I believe that pistons are not round when cold because you want them to be round when running and up to temperature and the material is not evenly distributed, largely because of the gudgeon pin. So they are cast / forged allowing for the differential expansion. Similarly the top of a piston is hotter that the lower area so the dimension above the first ring tends to be smaller - to a greater extent on turbocharged engines.

Bores are round when new, but, perhaps to a greater extent in boxer engines, they tend to wear oval.

I think it's best to simply measure where the manufacturer advises. They know where the measurements are being taken and what the wear limits when comparing those measuring points. If you are taking measurements at different points, the basis for the clearance calculation has changed so is the resulting answer of value ? It' a bit like measuring in inches or cm. Both function well as measures of distance, but you need to know which one to use at any point in time, (otherwise your Mars lander crashes) :oops:
1981 RHD 2.0 Aircooled Leisuredrive project, CU engine
1990 RHD 1.9 Auto Sleeper with DF/DG engine
User avatar
937carrera
 
Posts: 1824
Joined: 05 Apr 2015, 19:29
Location: N Yorks.
80-90 Mem No: 16333

Re: WBXOily

Postby itchyfeet » 27 Nov 2017, 18:55

Yes that's pretty much what I'm doing measuring where the VW manual tells me to.
I'm not building a race engine so as long as it looks Ok and within spec it goes back.
1988 DG WBX LPG Tin Top
1989 DJ digijet WBX Holdsworth Villa 3 Pop Top
itchylinks
User avatar
itchyfeet
 
Posts: 10356
Joined: 23 Jul 2007, 17:24
Location: South Hampshire
80-90 Mem No: 12733

Re: WBXOily

Postby 937carrera » 27 Nov 2017, 19:18

OK, with the concerns you expressed about compression I thought you were looking to replace pistons or barrels and the measurements were going to help you decide how far to go. I didn't want you to junk perfectly functional components.

Have you decided where the oil was coming from yet ?
1981 RHD 2.0 Aircooled Leisuredrive project, CU engine
1990 RHD 1.9 Auto Sleeper with DF/DG engine
User avatar
937carrera
 
Posts: 1824
Joined: 05 Apr 2015, 19:29
Location: N Yorks.
80-90 Mem No: 16333

Next

Return to Mechanical

Who is online

Users browsing this forum: 937carrera, captain Byrne, Cecil, Cmcalpine3, Dollytony, itchyfeet, Woodyyellow and 49 guests