WBX

[Mr Bean]

[quote="itchyfeet"]Was it an Aircooled CS?

Sorry only just picked this question up.
No it is a 2.1 watercooled Digijet . I don't know whether they are riveted or bolted but it has lasted so far. Apparently it broke the crankcase. I thought it was a thrown rod as the engine rotated bacwards but klunked to a dead stop if rotated backwards.
CS

[itchyfeet]

2.1 cam looks the same as the one above i.e rivited, assuming they put a WBX cam in it of course.
It's possible to fit a 3 bolt cam with adapter described here
https://club8090.co.uk/forum/viewtopic.php?f=12&t=140840" onclick="window.open(this.href);return false;
Just possible Elite are modding cam gears to bolt on to keep costs down.

pic from CJH on post above

[CJH]

pic from CJH on post above

That's actually one of Silverbullet's I think. Just for completeness, another one of Silverbullet's photos shows how a 4-hole riveted cam gear attaches to a 3-hole cam, via a vernier adapter. The adapter allows the cam to be timed accurately. Both the adapter and cam are tapped to take bolts - two different sized bolts are needed, some metric and some imperial. They're all button head socket screws. For some reason I can't repost that photo, so here's a link to the relevant post.

https://club8090.co.uk/forum/viewtopic.p ... 5#p8063442" onclick="window.open(this.href);return false;

Here's a photo of mine from one of many test assemblies. It shows my cam advanced by 4 degrees.


With the two sets of bolts there's scope for the gear ending up slightly off-centre, so the instructions describe how to 'budge' it, by assembling hand tight, then running the crank backwards and checking for the cam lifting out of the bearings to identify any tight spots, then using a wooden mallet I think to tap it away from the tight spot to centre it.

[itchyfeet]

Thanks Chris

it's those fixings from the gear wheel to adapter I'm interested in because thats basically the same as the mod I just did to enabe Joe Blogs to swap a cam gear in his shed
Looks like 10.9, do you remember the thread and torque setting?
you say you stripped the hex and bought new bolts so I assume you have the old ones still?
Not sure the point of the washer?

[CJH]

The washer is to ensure the protruding threads don't foul the other side. My memory is a bit hazy - I suspect that when I rounded the hex socket (it's small and quite difficult to get a bit that fits really snuggly) I replaced them with slightly shorter bolts, but don't quote me until I've checked my facts. I'll check the thread and torque settings too.

Aaah - the haziness is clearing - I think I replaced them with cap head bolts that had a bigger hex socket. Maybe

Facts to follow.

[CJH]

OK, facts checked. The bolts that were supplied with the kit to hold the ring gear to the vernier adapter were M6x16 10.9 dome head. The washer was necessary to prevent the protruding threads from fouling. M6 dome head bolts have only a 4mm hex socket, and even the moderate torque (12-14 lb-ft = 18Nm) required was too much for any of the 4mm hex bits that I own - they would round the socket in the bolt before the required torque was reached.

I replaced them with M6 x 14 12.9 cap head. The cap head means that the socket is bigger (5mm) and deeper. I went for 12.9 not because the strength is needed in this application, but because I thought there'd be less chance of the sockets rounding, but in fact the step up to a 5mm socket was probably enough to prevent this anyway. The 14mm length meant I could dispense with the washers and still have less thread protruding than the 16mm+washer.

The cap heads are slightly proud of the ring gear, but there's plenty of room in the case on that side of the cam gear - it's the other side that's short of space.

[itchyfeet]

Thanks for the pics.

The cap heads are slightly proud of the ring gear, but there's plenty of room in the case on that side

Have you test fitted with an oil pump, there is about 2mm from the gear to the back of pump if you are lucky?
Steel rule is 1mm thick

Is it just 4 off M6?

P1040652 by Paul_Barr, on Flickr

[CJH]

Have you test fitted with an oil pump, there is about 2mm from the gear to the back of pump if you are lucky?

Yes - the cap heads are on a different radius from the protrusion on the back of the oil pump. If the cap heads were wider, like your bolts, there might be a problem, but yours are lower profile than my cap heads so I guess they fit behind the pump ok.

Is it just 4 off M6?

Yes, 4 off M16x14x1.0 for the ring gear. 3 off 5/16-24 for the vernier adapter-to-cam.

[CJH]

Your photo has just appeared. Your pump is different - I guess that's the original pump? Mine's a pump for a 3-bolt cam, maybe that's the difference.

[itchyfeet]

Yes I was missing the fact you were using a different pump
does the pump for a 3 bolt cam give less delivery as it's less deep?
possibly already discussed but I haven't read your thread yet.

I think you mean M6 not M16 ^^ there was me worrying 4xM7 was not enough.

[CJH]

Yes I was missing the fact you were using a different pump
does the pump for a 3 bolt cam give less delivery as it's less deep?
possibly already discussed but I haven't read your thread yet.

I am not aware of a difference in delivery - my pump has 26mm gears, which I think is the same as the standard pump. There was some discussion of the pumps, I think on Silverbullet's cam thread*, where I think he determined that it might be feasible to machine down the standard pump to work with a 3-bolt cam, so I think the internals are the same and it's just the housing that's different.

I think you mean M6 not M16 ^^ there was me worrying 4xM7 was not enough.

I do indeed. Clumsy fingers.

*EDIT: Discussion of oil pumps here.

[itchyfeet]

Thanks Chris
I wonder how many people are fitting Aircooled 3 bolt cams to WBX?
I suspect not many now but as soon as the NOS WBX cams are exhausted it will become the norm.

[itchyfeet]

I'm replacing head seals, so far so good.

Any update Kev?
is that the 2.1 you bought?

[Jawin89]

Great info on all this guys.

I'm beginning to realise how lucky I was that my new NOS cam was the same as my old cam

[CJH]

Thanks Chris
I wonder how many people are fitting Aircooled 3 bolt cams to WBX?
I suspect not many now but as soon as the NOS WBX cams are exhausted it will become the norm.

I would have thought the profile of the Aircooled cam is different from the WBX, so unlikely to be a good choice - there's a significant difference between the 2.1 and the 1.9 (and even a different version for the DF) (see here). There were some VW 2.1 cams available a year or so ago*, but I think they were reprofiled Aircooled cams. There are a few aftermarket cams available - Silverbullet's for one, but there are others - but I believe they are all made from 3-hole blanks. I must admit I've only looked for 2.1 cams, so I don't know what the situation is for 1.9 cams.

*EDIT: They're still available at VW Heritage.