Beta Spider 2000 engine rebuild/refurb

[mangocrazy]

This engine has only run for a maximum of about 30 minutes in my ownership, all previous running was in the donor 2000 i.e. Coupe. One thing was obvious - the previous owner(s) were pretty cavalier about oil changes; all the aluminium interior surfaces are black. The photos can be misleading - on the photo of the block cylinder #1 is on the RH side. On the head photo cylinder #1 is on the LH side of the photo.

I now need to find some suitable material to plug up all the oil and coolant galleries before I start cleaning the block face. All work on the top end will be done at HQ in Sheffield. One thing I did notice was the difference in friction when undoing the cylinder head bolts. Some could almost be unscrewed by hand once initial tension was released, a couple made me reach for the rattle gun to fully undo them. So I can see plenty of thread tapping action in my future.

[mangocrazy]

One other thing I noticed on cylinders # 2 & 3 was a distinct line all round the bore about 15-20 mm below the block deck. Would this be as a result of blow-by past the top rings, or is this normal on an old and well-used (and abused) motor?

[WestonE]

Hi Nigel

I would expect a slight wear ridge you can feel. The carbon goes with the age/abuse but is most likely from the valve stem seals mostly. There are no hard score lines which would be broken rings. You probably had valves no longer sealing properly with a side dose of piston rings with plenty of wear. With your re-furb head it should work to get you home, but a full bottom end re-build will be the only way to long term performance/ reliability. That would need new oversize pistons and a re-bore.

Eric
I assume you did not do a leak down test before stripping it?   

[mangocrazy]

Hi Eric,

I (in)conveniently left my leak down test kit back in the UK (along with the 38mm impact socket), so I have no real data on how leaky or not the top end is. The complete top end (plus aux shaft) will be repatriated and once this head has been cleaned and vapour blasted I will compare it with the other spare head I have and use whichever is in better shape. I'm not going for perfection, just sufficient to get the car home with minimal risk of failure. I have a good set of valves, springs and head bolts to use (I acquired them from you along with the BW head about 10 years ago) so it's really a case of which head is in generally better shape (valve guides etc.) This refurb will just be a stop gap to get the car back to the UK. The engine I will be using longer term is the one sitting on the dolly back in the UK.

Is it worth cleaning up the bores to remove the carbon ridge or just leave well alone?

Graham

[mangocrazy]

The complete top end, along with aux shaft is now back on UK soil and it's time to find out what horrors lurk. The first thing I noticed was how black all the internal castings are. Clearly this motor has been run for extended periods without oil changes. I've stripped both camboxes today and to my relief the cams look in perfectly OK condition, as do the journals. There's no obvious wear between buckets and casting so that looks OK as well. However it did take more than a small amount of persuasion to get the cams to leave the housings - it was only once they were out that I discovered why. Where the cams run directly in the head at the camwheel end there were definite ridges of compacted old oil sludge on both cam and housing that was preventing the cams from sliding out as they would normally do.

I've marked up each of the shim buckets so they can go back in the same hole they were removed from - not sure if that is good practice or unnecessary? The shims have just been wiped off and put in a bag. Around half of the shims had either no size markings or were illegible.

Next step will be to strip the head, but that will probably have to wait a couple of days as Mrs Mango is flying off to the Philippines tomorrow and my time is spoken for...

[Nigel]

Graham,
It all sounds like good news.
Your approach to cam bucket position is good but probably not
required.
Sloppy mechanics put the shims in upside down. Size markings
should always be underneath so that they remain.
In any case you can measure the shims with a digital caliper or
micrometer.
The factory shims come in all sorts of weird sizes but most new ones are
supplied in 0.05mm increments.

Nigel

[mangocrazy]

Thanks Nigel. I'll be measuring up the shims in due course, but the ones that did have markings on seemed to cover a fairly wide range. Is it still possible to acquire a shim set for sensible money? And will a set of digital vernier calipers provide an accurate enough reading? I do have a metric micrometer but have a nasty feeling it's still in France...

[SanRemo78]

I won't be trusting a set of digital vernier callipers unless they're modified to take a point reading in the centre of the shim, if you've got parallel jaws you'll read a high point at the edge. I doubt it'd take much to superglue a couple of pads onto a cheapie set from Aldi?
Guy

[peteracs]

Hi Graham

I would forget vernier calipers and buy a decent cheap second hand micrometer off Ebay. Imperial are usually little money and you can get quality ones with calibration parts as a set.

On the shims as Nigel says they are available and listed for various manuf eg Fiat. Cost about £4 each from memory.

Peter

[mangocrazy]

Hi Guy, Peter,

When I was removing the shims from the buckets it appeared to me that the bearing surface on the underside of the shim was the outer circle that bears onto the bucket, and that it is the shim thickness at this point that should be measured. The centre portion of the underside of the shim is never in contact with anything and as such is irrelevant. The only way to measure the true (working) thickness of the shim is by taking a reading from the bearing surfaces, surely?

I'm pretty sure I do have a set of imperial (non-digital) micrometers, but that leads me down the imperial/metric conversion rabbit hole. I think it's time to start scanning ebay for metric digital micrometers...

Graham

[peteracs]

Hi Graham

Interesting point, maybe measure across to see variance?

On the imperial to metric conversion, Google is your friend. I simply measured all my shims, made a list and converted, though all I have are still legible. I had no issues. The only issue I did have was that new shims do come in .05mm increments which can mean at the limit of tolerance which is what I had on one of mine. Yes you can get them ground down, but not a DIY job.

Peter

[mangocrazy]

Today I took a trip to Clay Cross to the (new) premises where Stanwood Engineering have relocated to. Jon has had something of a Eureka moment in the last couple of years and realised that he'd much prefer to be a one-man band rather than an employer/part time engineer and has downsized his operation. All of his previous employees have found suitable work elsewhere and Jon can now concentrate on what he does best - working on race/sports engines. He also now works less than 5 minutes away from home, compared to over an hour each way. Definitely a quality of life improvement.

I took a box of engine parts down to him for his inspection and he confirmed within a couple of seconds of looking at the suspect cylinder head and gasket that there had indeed been failure of the gasket in at least 2 places. This was a welcome relief to me as it confirmed that I wasn't going (completely) mad and my diagnosis was correct. I had expected to see chunks of gasket missing, but Jon pointed out at least two areas of carbon build up on the fire rings that should by rights have been clean and shiny. It does help when you know what you're looking for.

So Jon will clean and pressure test this head and the spare one I have and will clean up and lap the valves in and generally prep the head ready for me to take down to France and re-fit to the block. I'll need to drop off the remaining pieces of valve gear and required seals and gaskets next week and then Jon can crack on.

As an aside, I was intending to give Jon the bare head, but I only managed to dismantle the four inlet valves using a brand new (and quite expensive) Laser valve spring compressor before the tool became completely unuseable. The T-bar that you screw in to compress the valve springs galled to the extent that it was impossible to move it forward or back. I've tried contacting Laser after-sales service and have been much less than impressed by the response. The response has either been silence (when using their online contact form) or 'I'll get the service department to call you back'. I've had no call-back, unsurprisingly.

[mangocrazy]

These are the areas on the head gasket that Jon reckoned had failed. With the benefit of hindsight it's fairly clear where gases had been escaping past the fire rings.

[mangocrazy]

Jon rang me up this morning (I was impressed - working on a Sunday) with some not-so-good news. He was at a loss to explain how he hadn't seen this before, and to be honest I should have spotted this as well; an almost complete break in one of the cam journals on the inlet cambox/cam housing just where the cover stud screws in. I can only assume that the fault was present but only showed itself after the cleaning operations Jon undertook.

 I do wonder whether my efforts in drifting out the inlet camshaft caused the fracture; I remember it needing a fair amount of (controlled) violence to drift the cam out of the housing. This was down to the very considerable burnt oil and gum deposits that were effectively glueing the cam in place; a legacy of non-existent oil changes by the previous owner(s).

So what to do? I'm not at all sure that this fracture can be repaired by alloy welding. I do know a pair of very, very good welders, but welding cast aluminium is always a lottery especilally when it's been in continuous contact with oil. There would also be potential distortion issues. So I guess I need a replacement inlet cam box/cam housing. Does anyone have such an item they'd be willing to part with? I'll put an entry in the 'Parts wanted' section as well.

Oh well - I should have known it was never going to be as simple as it looked. There is also a degree of time pressure as I'll be heading back to France in the first week of September and I need all the various parts ready by then. In an ideal world I'd receive it in time to let Jon build the complete head/camboxes assembly up prior to travelling, but the first step is to actually acquire a replacement.

[peteracs]

Pm sent

Peter

[mangocrazy]

The refurbished cylinder head came back from Stanwood in the last week of August and was duly packed into the van with a load of other kit; Jon had cleaned up a lot of very manky parts, lapped the valves in, reassembled all the valve train, shimmed up the valves and basically presented me with a top end nearly ready to fit back onto the block (after it's been properly cleaned up). I drove down earlier this week (in the middle of the heatwave with no air-con) and all the Beta stuff has been off-loaded. So all I'm waiting for now is for Nigel to arrive in Montpellier tomorrow morning whereupon I'll drive him back to Pouzolles and we can formulate A Plan.

And probably drink some wine in our spare time...   

Anyway, here's the head on the bench.

[WestonE]

I assume you have fiber washers for the cam box lid bolt screw things and assorted gaskets ready? Enjoy sunny France!

Cheers

Eric
From Heatwave UK!

[peteracs]

Hi Graham

You did well to get Jon to do all that!

Hope all goes well in France, is the plan to drive the car back this time or leave over there?

Peter

[mangocrazy]

Eriic,

Yes I've brought the cointents of more than one gasket set with me which includes the fibre washers, plus some sheet gasket material. In fact if there's an outside possibility I might need it, I've brought it with me...

Graham

Peter,

I came down in the van so will return the same way. Once the Spider is mobile again it will need a Controle Technique (the old one has expired) and I want to build up confidence in the car before travelling back to the UK in it, so hopefully I can repatriate the car in Spring 2024.

Graham

[mangocrazy]

Nigel and I are officially feeling deflated, and that's the most polite term I could come up with...

As part of the block prep and cleaning I ran an M10 x 1.25 tap down the threads in the block to clean out any crud and make them ready to accept the head bolts. Nine of the threads cleaned up very nicely, but one gave serious cause for concern - the one between cyls 3 and 4 on the inlet side. When I ran the tap down it there was consistent resistance to the tap, nearly all the way down. This reminded me that when undoing the head bolts back in May one bolt had been particularly difficult to remove and had needed me to use quite serious force to unwind it. After tapping it I tried a head bolt in the thread and discovered a worrying amount of slop. It only started to straighten up and fly right towards the end of the thread.

We decided to carry on and torque the head up (as per GC's instructions) and all bolts passed muster at 20 lb/ft. When we upped the torque to 40 lb/ft Nigel (who was wielding the torque wrench) came to the iffy bolt, tightened it up until nearly at torque, at which point it just went floppier than a floppy thing. Many imprecations and bad language followed, as you can imagine.

So now we need to try and track down a supplier of an M10 x 1.25 helicoil kit in a part of France where engineering suppliers are few and far between. I've enlisted the services of a Brit ex-pat I know who runs a number of old cars and he wiil try and track down a source for a Helicoil kit.

So not the best of news to report. Both of us want to get this thing buttoned up and finished before Nigel flies home on Thursday, so tomorrow will be crucial if we are to achieve this.

No-one ever said it would be easy...