WBX-Unknown

[tobydog]

Now cylinder 4 big end journal, can you see those three or four little marks on the left hand side

Reminds me of grinding with a clogged grinding wheel bouncing and causing localised burning? Or, lack of oil supply?

[itchyfeet]

cpuld have been dumped because of the nroken ring
did it have scores in the barrel?

[937carrera]

I only had a quick look in the barrel, didn't seem to be scored, so perhaps it broke upon removal, but I've never broken a ring on removal before.

On the journal, I understand what you're saying about a skip on a grinding wheel, very strange, no real signs of oil starvation on the bearing either.

[937carrera]

I have been spending quite a bit of time reading engine threads from itchylinks, not through them all yet. I haven't found so much about crankshaft condition, but interestingly T25converts thread http://forum.club8090.co.uk/viewtopic.php?f=37&t=120790 shows exactly the same issue on the same cam bearing.

There was a question in one of the threads from itchyfeet about measuring side to side movement at the little end. Well I did that already but I have discovered (from Bentley) that the wear limit of 0.7mm is just for axial play at the big end. Now I did try a 0.7mm feeler gauge in there yesterday and there was no way it would ever go in, at a guess I would say it was only 0.3mm. I can reassemble and check again, but at least we have a datapoint for the side to side movement, if no spec, other than 1.36mm shows the big end bearing is knackered . I think I have a CU crank on the shelf, so might measure that as a comparison.

Our friends at VW Heritage have a good picture of a new crank, so I'll use that to compare to the shape of my number 1 main bearing

[itchyfeet]

Sorry I don't understand why you think big end is knackered?
Ideally con rods with new shells should fall gently by their own weight
in practice they often dont.

Cam bearing often shot
main bearings usually ok you might find the standard bearings no better than your origional worn blue bearings

Worth changing big end shells IMO

I never found a spec for little end newuns the pin won't drop oit when oiled, worn pin always drops out if you can feel any play then consider what to do.

[937carrera]

Sorry I don't understand why you think big end is knackered?

My biggest concern is the flywheel edge of number 1 main bearing, the big end journals are in excellent condition, except for those pesky little marks on number 4 which I need to inspect further

Ideally con rods with new shells should fall gently by their own weight
in practice they often dont.

Yep, these used ones fell smoothly, but much more rapidly than new ones would

Cam bearing often shot
main bearings usually ok you might find the standard bearings no better than your origional worn blue bearings

I guess it's always that particular cam bearing too. This is where sharing the knowledge comes in, I hadn't seen this before on air cooled type 4 engines

What makes you say I have blue bearings, is it just that the journal measurement for the early and blue crankshafts is the same.

Any thoughts as to how an early crank is fitted to a late case - rebuilt at VW with new cases, did they go that far ??

Worth changing big end shells IMO

Absolutely, I knew that as soon as the first crankcase bolt was undone I was into cam, big end and main bearing shells almost regardless of what I found.

My dial bore gauge has just arrived, so barrel measurements are now possible. Only problem is I think is might be faulty as is I can't figure out how the small pin moves to operate the dial mechanism

[itchyfeet]

I suggest its a late crank and the paint is long gone if indeed a DG evr had paint.
I can't rember reading why there are late standard bearings, looks to me like DG may have been standard and 2.1 has the two colour ranges but I have not looked in a while, manuals suggest only blue and red for late so why std bearings?
perhaps you can find out?

[937carrera]

This is where my understanding had got to yesterday, courtesy of Haynes / Bentley

83-85, early crank

86 on, late crank

However according to ETKA all DF/DG crankshafts are the same part number, so perhaps there is no difference other than grinding tolerance, DJ etc were suffix B for the longer stroke.

late crank has three paint codes

Green paint indicated DJ

blue spot indicates main journal size for 1/2/3 is x9.99 to x9.98 (new to wear limit perhaps)
red spot indicates main journal size for 1/2/3 is x9.979 to x0.971

Then from Brickwerks, they have two types of main bearings

Single thrust https://www.brickwerks.co.uk/t3-parts/e ... -1985.html

Three piece thrust main bearings here https://www.brickwerks.co.uk/t3-parts/e ... x-all.html and separate thrust bearings, note the additional locating cutout https://www.brickwerks.co.uk/t3-parts/e ... x-all.html

Mine had the single thrust bearing arrangement........ or perhaps three thrust bearing arrangement with no thrust washers fitted, I suppose I should check the case, the single thrust bearing combines with the late case according to the width of the carse on top at the flywheel end is what has confused me (in particular). When did the late case design come in, '86 model year as per the bearings or later ?

I suppose the question is, if the cranks are the same and the case has the cutouts are both types acceptable.

By way of reference, I have just checked against the CU crank, main journals there measure x9.99 to x9.97, so essentially the full range of late red/blue WBX. Tolerances getting tighter as oils / engineering develop, but only for new build ?

Everything above is my understanding as of today, it might not all be right and is certainly incomplete knowledge

[itchyfeet]

oh I see now you have early bearings didn't spot that
I didn't know you could fit early bearings to a late case?
afaik the early and late DG crank is the same and the red/blue refers to 2.1

[937carrera]

Now you understand my confusion, welcome to the club

Red / blue is DG crank spec, green is good for a DJ. I think you have Bentley so page 137.

I'll need to take a look, but at this moment I believe you can fit early bearings to a late case, but not the other way round.

Further study of ETKA seems to indicate the red / blue crankshaft / bearing change happened 8/87, two years later than Bentley / BW would indicate.

[itchyfeet]

You can't believe bentley
you must go by the VW manual
We have the 2.1 manual but I don't have the VW 1.9 manual

[937carrera]

I thought Bentley was the nearest thing to factory manual, accepting it's US market.

Can you believe Haynes ?

Same picture as Bentley but at least references early and late thick / thin walled (i.e thrust) bearings in the text

Just looked at the DJ manual as well, same information at page 13-49, helpfully it also specifies the honing data for the big ends, which Haynes sort of references as a crankpin journal

Strangely enough I believe Brickwerks

[itchyfeet]

Bentley is a hash of all the VW manuals
I want to.see a VW DG manual

I think Bigherb has one...somebody must have it.

Haynes is well ....Haynes

[937carrera]

Some more case / crank information from the Samba

https://www.thesamba.com/vw/forum/viewt ... p?t=470096

second post

There are really only three differences between the early and late cases.

A. The early case uses a one piece #1 main bearing while the late case uses a #1 bearing with the thrust washers separated from the bearing.

B. The late case has an extra threaded boss for the second oil pressure switch on the 86-91 oil pressure system.

C. The late case has slightly more internal clearance for longer strokes.

and

Looked at that page in the Bentley regarding the use of the later cases for earlier engines. It shows the use of the later style #1 bearing with the early crank so it looks like the thrust surface is indeed the same between the two cranks. So, yeah, it looks like the 1.9 components will go in a late case with no problems.

and at Gowesty http://www.gowesty.com/tech-article-details.php?id=64, in US terms an early case is a 1.9, a late case a 2.1, we had the late case 1.9 too

Recycled knowledge / standing on the shoulders of giants, whatever you call it, I'll have more to tell tomorrow when I have another look at the motor

I assume you'll be whispering sweet nothings into Bigherbs ear

[bigbadbob76]

I assume you'll be whispering sweet nothings into Bigherbs ear

I would be too. Haha.

I seem to remember seeing something in (I think) the vw self study manual about "when replacing engine cases, use the same part no later cases for both 1.9 and 2.1." Or words to that effect. Suggesting early internals will fit in the later cases.