Beta Spider 2000 engine rebuild/refurb

[mangocrazy]

It's been over a year since my Spider 2000's engine expired, while in the hands of a French garagiste, and I've only recently been able to get the engine repatriated and bolted to an engine stand. I'm unable to strip the engine at our place in Sheffield, as my workshop is in the cellar and the prospect of getting a fully built engine down (or up) the cellar steps fills me with dread and a sense of my own mortality...

So the engine is on a stand in the utility room in Stafford, where it will be dismantled, and then the individual components will be ferried back to Sheffield for further work. While cooking the Christmas dinner I managed (much to the dismay of my wife) to remove the cylinder head and take photos of same and on Boxing day the sump pan, oil pump and oil scavenge pipe were removed.

I'm still awaiting final proof of what it was that caused the engine to stop in a partially seized condition.The engine could be rotated back and forth a few degrees, but any more than that and the engine would lock up solid. My current thinking, based on what I've observed of the cylinder head, is that the exhaust valve on cylinder #1 dropped in (for reasons as yet unknown), bending the valve sufficiently to only allow a few degrees of engine rotation.

Equally disturbing are the witness marks on both valves and pistons on all cylinders that would seem to indicate running with incorrect valve timing. A couple of years ago I'd given the car to a (different) French garagiste to replace the cam belt and do an oil/filter change. I'm unsure whether the marks date from that time, or from the few minutes of running the car managed after having its water pump and cam belt replaced (the latter not on my instructions) by the garagiste in our village before it cried enough.

Any comments gratefully welcomed. Here come the photos, in the following order:

Cylinder head, with very obvious witness marks on valves.

Another view of the valves. Exhaust valve on far right looks suspiciously off axis compared to others.

Close up of valves on cylinders #1 and #2

Birds-eye view of the block/pistons. Again - notice witness marks.

View of block from an angle. State of bores looks pretty encouraging. No gouging or wear marks that I can see. Motor only has an indicated 60k miles on clock.

[HFStuart]

Kudos for getting the head off during Christmas dinner prep!

Those witness marks are bad, particularly on the valve cut - outs. I wouldn't be at all surprised to find four or more bent valves and possibly cracked piston skirts too.

I wonder if the belt was incorrectly tensioned and jumped a tooth or three and you're now stuck with the auxiliary shaft lobe fouling No.2 rod. Witness marks on the rod next to the top of the bolt ( or on the bolt head ) would be evident.

[peteracs]

Not sure I would get away with using the Utility room, no, definitely would never get that past the management, though if the only place.....

I think you are in for complete strip down and check each part and suspect as Stuart says, all the valves which have had contact will have some deformity and I guess the guides will need to be replaced as well, the bottom end should also be checked to see if that has sustained any damage as well as possible issues with the pistons.

Peter

[mangocrazy]

Yes, the more I look at those photos the worse it appears. I can't believe for a minute that the car could have run for hundreds of miles like that (i.e. since the cam belt was replaced by the 1st garagiste). It has to have happened during the brief period the engine was run after having the water pump and cam belt replaced back in November 2015.

I'm not as concerned as I would otherwise be about the valve/piston contact due to the fact that I'm intending to fit Eric Weston's old Evo head, and brand new pistons and rods. As long as the crank is undamaged I should still be OK (he said, optimistically). Having said that it's a real shame that what had been a very sweet-running engine up until that point could be so easily wrecked by careless work.

The engine itself will be stripped down to its last nut and bolt and then refurbished from the ground up. I'm planning to give the crank to GC to check out, drill and plug etc., as well as balance it to work with a VX flywheel and clutch I'm acquiring. If there's anything remotely amiss with the crank I know GC will find it...

[WestonE]

Graham

Definitely miss timing so expect 8 bent valves and maybe cracked valve guides. The pistons would probably be OK, but you would throw them away for the re bore this engine would be given for a re-build. It makes no sense to re-use the pistons at that age and mileage. So you have a sound crankcase and hopefully a sound crank for re-use. The head would be a reasonable base for a re-build with new guides and new valves.

At least you caught it before the rods broke or the pistons seized.

Eric     

[mangocrazy]

Graham

Definitely miss timing so expect 8 bent valves and maybe cracked valve guides. The pistons would probably be OK, but you would throw them away for the re bore this engine would be given for a re-build. It makes no sense to re-use the pistons at that age and mileage. So you have a sound crankcase and hopefully a sound crank for re-use. The head would be a reasonable base for a re-build with new guides and new valves.

At least you caught it before the rods broke or the pistons seized.

Eric     

Eric,

Yes, that's about what I'm expecting to find. The pistons will not be re-used, neither will the rods (I have some new GC Cunningham rods ready to use), so as long as the crank and block are OK it's not the end of the world. Very annoying, but not fatal.

How long would the engine be able to run in a condition like that? From the degree of mis-timing that's apparent from the photos I'm tending more and more to the view that it's the fault of the last garagiste I took it to (the one that replaced the water pump and cam belt). This would be consistent with his story that he left the car idling after completing his (botched) work and 'it just stopped and locked up'.

Graham

[WestonE]

Graham

The last garage for sure. If this had been given load and revs it would be in many broken pieces.

Eric

[Neil-yaj396]

What I don't understand is that he should have heard a 'tinging' noise as soon as he started it up and/or the belt slipped. Every apprentice mechanic must learn that you have to be dead careful on first start up after a belt change? Especially a relatively complex one like the Beta's. Then again, I guess people are just careless.

[mangocrazy]

Yes, the more I look at it the more I regard it as a complete clusterf***. Greed compounded by stupidity and arrogance. The second garagiste was more interested in pointing out faults the previous guy had made (he'd omitted to secure the water pipe to the back of the bracket that has the pointers for the cam wheels) and was urging me to go and get my money back. If he'd paid more attention himself he wouldn't find himself in receipt of a large bill when I return to the village in April...

What really winds me up is that I did not ask him to replace the cam belt; he simply did that so he could bump the bill up. The cam belt had been changed only a thousand miles or so previously and the mileage it had been changed at was clearly written on the cam cover. I only wanted a new water pump fitting. As a result of this he's caused me a countless amount of inconvenience and a great deal of expense. I think I may be asking a French friend of mine to compose a letter to a solicitor.

I haven't stripped the head yet (been more concerned with getting the sump off and cleaned up), but when I do (probably first week of Jan) I'll post pictures up. If I've learned anything from this little episode it's to only allow people I know and trust near my Beta. Either that or do the job myself.

Thanks for everyone's help and comments.

[mangocrazy]

Since I last posted I've managed to make some more progress stripping the engine down in fact the block, shorn of all its studs and ancillaries, is sitting in my van waiting to go to the local engine overhaulers to go in their hot wash. The crank has been removed and appears in generally good health, although I will only be sure of that once Guy Croft has pronounced on its status. When I measured the end float in situ it was 0.18mm (0.007") which is apparently right in the middle of acceptable tolerance (0.002" to 0.012"). This encouraged me...

I've sourced a 228mm VX flywheel from Millieman (thanks!) and that, along with the sump (sans OE baffle plates), clutch gearbox-mounted bracket, flywheel plates and other bits and bobs have been sent for blasting.

I stil haven't got round to stripping the cylinder head, and I may not do so for a while yet, as I'm very tempted to take the head 'as is' to the French garagiste that caused this whole sorry mess and confront him with it.

Now that all the bits are back in Sheffield I'll try and take some pics to illustrate progress.

[mangocrazy]

Just a quick pic of the crank and the main bearing shells, bolts and caps bagged up. I was thinking of photographing all the bearing shells individually, but as none of them will be re-used I didn't really see the point. I can't feel any ridges or wear marks in the crank journals, so hopefully it's fit for re-use. There are signs of discolouration, but I'm hoping they will polish out.

[WestonE]

Graham

Good Luck with the crank. It looks OK, but you will only know once GC has measured it.

Eric

[mangocrazy]

Yes, planning to visit GC this coming Thursday with the crank. I'v just got all the parts back from the blasters and all looks good so I think we're ready. Presumably GC will need the crank, flywheel and clutch outer for balancing purposes? Guy did say he'd be able to check the important dimensions while I waited so I should know on the day whether it's viable or not.

[mangocrazy]

I travelled over to Lincoln today and spent a very enjoyable and instructive morning with GC. The good news is that my crankshaft passed all of Guy's measuring routines with flying colours, has been given the GC seal of approval and is fit for purpose. That was a real relief, I must say. It was instructive to watch Guy testing the crank for runout with it mounted on a pair of V blocks and a dial gauge on the centre journal. As far as I could see there was zero runout, and the only time the dial fluctuated was when Guy had to apply pressure to turn the crank. What surprised me was the degree of deflection when Guy pressed with only mild force on the centre of the crank - it registered 10 thou deflection. So the crank is with Guy now to work his magic.

I mentioned to Guy that I was taking the block to an engine reconditioner in Sheffield to have it hot washed, and he suggested taking it to a place that he uses exclusively for such work (and a lot of other machining operations). As I was only using the Sheffield firm because they were local, and the firm Guy recommended (Stanwood Engineering) were on the way back to Sheffield (they're based in Bawtry, about 20 miles from Sheffield), I was happy to take him up on that. I was so glad I did - they have a tremendous operation, with some hugely impressive computer-controlled machinery and they also do a lot of motorbike stuff, so I can see a variety of ways in which I can use their services.

They will definitely be boring the block to suit my new Vick Auto-sourced 10:1 pistons; what was particularly impressive was the way that Phil was able to assure me that there would be sufficient meat for my 84.4mm pistons in the standard bores when overbored just by running his fingers around the bore tops. Apparently bore # 4 is the worst, but they should be able to accomodate any slight discrepancy. The're having an open day on August Bank Holiday Monday, and are expecting a lot of classic cars and bikes, so that sounds like a must-see.

Stanwood will be knocking out the core plugs, hot washing the block in a solution that is completely friendly to the auxiliary shaft bearings, then ultrasonically cleaning the block, and finally facing off the top deck to ensure it's completely flat. With that done, it should be ready for boring to suit my pistons.

So - it finally feels like real progress is being made, after all the false starts.

[mangocrazy]

Heartened by the progress made yesterday, when I got home from work I decided to start the necessary modification of the auxiliary shaft, by cutting off and plugging the lobe used to drive the mechanical fuel pump. Photos shown below:

The unmolested shaft sitting on my vice:

The shaft wedged between two blocks of wood, ready to have its nose cut off:

Now in his books, Guy always uses a hacksaw to do the cutting. Personally, ever since I've discovered the delights of an angle grinder, I've always found it equally accurate, a lot quicker and a lot less hassle to use a cutting wheel in the grinder. Here's a pic of a cutting wheel for steel that I can heartily recommend; it's quite simply the best I've ever used. It's only 0.8mm in cross-section so cuts very quickly and cleanly and generates far less heat than thicker discs. And below is the end result. Actual cutting time was no more than than a minute or two, followed up with the results of a quick clean up with a flap disc:

With the lobe cut off, I measured the internal diameter of the oilway with a digital vernier. It came out at pretty much exactly 6.8mm. I was fairly sure that 6.8mm was the recommended tapping clearance for an M8 x 1.25 tap, but needed to check in my trusty Zeus handbook (shown).

Looking in the ISO metric coarse threads, I found the answer. I realise the flash has burned out the heading line, but if you follow the line for O.Dia. of 8.0, under the tapping drill column you will see 6.8mm, for a thread pitch of 1.25 (standard M8 coarse thread pitch). So the oilway hole is the perfect size for tapping for an M8 grub screw. I measured how much depth of oilway there was before encountering the cross drilling, and it worked out at at least half an inch (12.5mm), so tapping to a depth of 8 or 9mm and using an M8 x 10mm grub screw would be about right, leaving a millimetre or two of the grub screw sitting proud of the surface.

I checked on eBay and a pack of 5 M8 x 10mm high tensile (14.9) grub screws costs a miserly £1.10 including postage. That will do me fine. I just need to check that I have an M8 x 1.25 plug tap and then I'll be good to go.

[mangocrazy]

Paid Stanwood Engineering in Bawtry another visit today, taking them a selection of camshafts, camboxes, cambox covers, cam buckets, and various seal housings and sundry items. I also took them my Vick Auto 10:1 84.4mm pistons as reference for when boring the block. If bore no 4 is outside limits they can resleeve that particular bore quite easily. The block itself has been through their hot wash and is virtually unrecognisable from the manky old thing it was previously. Even the core plugs have come up as new, and very much look as if they're stainless items. If so I probably won't bother replacing them.

Next step is the ultrasonic bath, which apparently removes the requirement to re-tap stud holes. The threads to clamp the head down will definitely have a tap run down them, but Jonathan reckoned for everything else it probably wouldn't be necessary. All the other bits will be getting the hot wash and ultrasonic treatment.

They've also said they are happy to do a 'short' engine build if required. If I go doen that route I'll do all the block preparation, dressing and deburring, following GC's detailed instructions in his books and will then hand the parts over for them to assemble crankshaft, rods, pistons, aux shaft etc. If nothing else, it saves me buying piston ring compressors. It all depends on price, of course.

Getting quite excited now... 

[WestonE]

Hi Graham

Great progress. I suggest you check every thread is clean and complete with a tap and be aware core plugs normally rust from the inside out and I have never seen a stainless set. I hope a flex hone will be used and you are right the head bolt threads MUST be cleaned out with a tap. I recommend the full bolt pack from GC for a neat job including the studs and nuts for the sump in place of bolts.

I have found sandblasting and silver spray painting the seals covers give a nice finish as long as you do not blast or paint the machined seal contact faces.

Eric 

[mangocrazy]

Hi Eric,

Yes for the amount of time it takes, it seems silly not to run a tap down all the threads. The ultrasonic will have cleaned most of the crud out so it should be very simple to do. I think I'll get a fibre optic probe to have a look at the back of the core plugs. I have a complete set ready to go on, so it's no sweat to replace them. I'll check on the flex hone, but I doubt GC would trust his reboring to anyone that didn't do that finishing op. I've got to ring them tomorrow so will check.

I was thinking about painting the aluminium seal covers in the same shade I use for the block. Once they've come out of the ultrasonic bath they should be in a perfect state for paint. Bare aluminium always goes 'furry' over time if left untreated anyway. I'm currently thinking of painting the block silver, but that may change. I prefer a lighter shade, if only to quickly show up any possible oil leaks.

So you'd recommend using studs and nuts rather than bolts on the sump? I was planning on using A4 stainless bolts for the sump, but am open to suggestions.

[WestonE]

Graham

I like the studs option on the sump because the nyloc nuts mean the sump stays fully attached in a way bolts never manage and it is easier to fit.

Eric

[mangocrazy]

Eric,

Yes understand your point. I hadn't thought of using studs and Nylocs, and M6 nylocs in A4 stainless are readily available. I'll do same with mine. For added security you could Loctite the studs in place, as well. Nothing would work loose then.

Graham