Beta Spider 2000 engine rebuild/refurb

[rossocorsa]

I think it would get too hot to be reliable. The pipes do fit normally, last time I looked mark had a VX bottom pipe refurbished for sale that would be a solution.

[mangocrazy]

Not sure that would help as you then only have one support for each pipe. The heat from the exhaust also adds to the complication.

Peter

The pipe would be supported at both ends, with only a short flexible mid section, but I agree it's definitely inferior to a full metal construction. Agree that exhaust heat adss an extra layer of concern. I'm hopeful that I won't need to consider that option, though. It's definitely the option of last resort.

[mangocrazy]

I think it would get too hot to be reliable. The pipes do fit normally, last time I looked mark had a VX bottom pipe refurbished for sale that would be a solution.

Yes, it's probably marginal at best. I'll check out Mark's listing.

[mangocrazy]

After looking at the problem from all angles, I decided that the only way the pipe would fit was if the bracket was removed and either relocated or a new bracket fabricated and welded to the pipe. So I apprehensively fired up the angle grinder with slitting disc attached and cut through the 5 welds holding the bracket to the pipe, thankfully without doing too much collateral damage to the pipe. Once free of the bracket, the pipe wrapped round the block without fouling anything and could be manoeuvred to a suitable position without any effort. There's enough slack in the flange mounting holes to give quite a range of adjustment, as it happens.

It quickly became apparent that the existing bracket would not be able to be re-purposed and that a new bracket would have to be fabricated and welded on. Time to break out the cardboard and make a CAD template. What was also rather alarming was the degree of corrosion that existed between the pipe and bracket. Being only tack-welded in place, and not sealed off, corrosion can (and does) form between the two skins. At least I'll be able to arrest that particular piece of rot while figuring out a way of making it fit to the multi-purpose bracket.

In other news, the A4 stainless M10 x 1.0 drain plugs arrived and one of them was fitted to the block, using generous amounts of Wurth CU800 anti-seize paste. It's a taper thread and screwed in leaving about 2 mm of the total 10 mm depth proud of the block. I'm cautiously hopeful that it should be a long term solution.

[mangocrazy]

Progress has largely stalled on the engine front, as the inlet manifold is still away at Stanwood's being 'fettled' and I've only just got the lower water rail back from the platers. After removing the original thin steel bracket I gave it to the platers to chemically strip the electroless nickel plating in preparation for welding a different bracket on (fabricated by me). Unfortunately they misunderstood my intentions and re-plated it... The main man there assures me that it won't hurt the welding process, in fact he maintains that EN plating is sometimes done as prep for welding. We shall see...

With time on my hands I've been giving the adjustable camwheels some thought, and am seriously thinking of putting the OE one piece cast camwheels back on. If the engine was to be running uprated cams, big valves et. etc. then adjustable camwheels would certainly be required. I'm not. I will be running standard cams , slightly increased compression ratio and standard valve sizes. And DCOE 45 Webers (36mm choke), of course.

So why do I need adjustable camwheels? As far as I can see I won't need to deviate from standard cam timing and will actually be making life more difficult for myself when it comes to changing belts, as I can no longer use the camwheel marks and associated pointers. What are people's view on this? I can't see much in the way of upside, only downside.

[peteracs]

Hi Graham

I guess it depends how accurate the original wheels are in terms of actual timing. Maybe someone else has measured it?

Peter

[WestonE]

Hi Graham

Precision in cam Timing vs accurate TDC makes a difference and gives you the chance to mark the cam boxes for 100 degrees to 120 degrees and check for valve clash before building with a short belt (VX drive belt). It is not unknown to gain 10BHP on these engines by accurate cam positioning and small known changes.

No Vernier wheels no accuracy.

Eric
PS if TDC is not accurate and well marked you are in a world of trouble.   

[mangocrazy]

OK, I was probably being rather impetuous. On thinking further about it, as long as all pulleys are marked up and reasonable care is taken, replacing a cam belt with vernier camwheels should be no less troublesome than with OE camwheels. I would probably feel happier if all the pulleys could be locked in some way, but that is clearly not an option.

And having spent good money with Stanwoods to build up the top end with vernier camwheels, it would be a waste of time and money (and downright foolish) to revert to OE camwheels. As Eric says, it would probably also throw away valuable bhp before the engine had even run.

[mangocrazy]

I managed to make a small but pleasing amount of progress on the back/bottom water rail saga. I've cut off the original mounting bracket that should bolt up to the multi-purpose bracket by cylinder 4 (but was at least 10mm out with the new water pump fitted), and have been nervously fabricating an alternative bracket to cater for the altered pipe location/trajectory. With the rudimentary shaping tools I have (and the lack of skill) it's not going to be factory perfect but as long as it provides a good degree of support then I'll be happy.

Today I bolted the rail securely to the water pump at one end, fixed my new bracket to its intended location and then clamped the two together as best I could while drilling holes through both to allow me to rivet the two parts together prior to taking the assembly to my tame welders for permanent fixing. Once they've secured the bracket to the rail I think I'll drill the rivets out and get them to finish the job with a couple of spot welds to seal the holes. Then it will be back to the platers and perhaps then I can finally fix the back/bottom rail permanently to the engine.

I was also able to convince myself that there is working clearance between the adjustable camwheels and the yellow plastic cam guard. I'd got it into my head that the camwheels would foul the guard, which is one of the reasons I was thinking of reverting to OE camwheels. They don't foul the guard and they are staying.

[peteracs]

Hi Graham

Not too shabby a job, I would definitely get the rivets out and have it welded up as they will undoubtably leak eventually as they are.

Peter

[mangocrazy]

Hi Graham

Not too shabby a job, I would definitely get the rivets out and have it welded up as they will undoubtably leak eventually as they are.

Peter

Yes, that was my thinkig as well. If it can go wrong, it will. I took the pipe to my local welders and they did a very nice job of putting a seam around most of the 3 edges of the bracket. The back of the bracket will be left open as to try and weld that would cause a lot of heat distortion and would throw the mounting points out. I've now drilled the rivets out so will head back to the welders on Monday morning to get those holes spot welded. After that time for a final trial fitment before getting the unit re-plated (for the third time...)

[frankxhv773t]

A small point, I'd say filling the rivet holes would be "plug" welding. Spot welding joins sheet metal without any holes. It's a lovely neat job though  so no need to apologise for your fabrication skills.

[peteracs]

Hi Graham

As a belt and braces you could pressure test for any leaks before fitting?

Peter

[mangocrazy]

A small point, I'd say filling the rivet holes would be "plug" welding. Spot welding joins sheet metal without any holes. It's a lovely neat job though  so no need to apologise for your fabrication skills.

You're right. My welding terminology was a bit off there. Spot welding is normally robotised, as far as I know and is commonly used in car assembly lines. Now it's been welded it certainly feels nice and solid.

[mangocrazy]

Hi Graham

As a belt and braces you could pressure test for any leaks before fitting?

Peter

If I could think of a way of doing that, I would. But with all the various take-offs along the rail it wouldn't be easy. I'll probably just settle for filling that section of the pipe with water and ensuring no leaks.

[frankxhv773t]

Spot welding doesn't have to be robotised. Before production lines were automated cars were spot welded with hand held units. You are supposed to be able to build a spot welder out of an old microwave oven, something that has fascinated me for some time.

[mangocrazy]

The whole process of welding fascinates me, and has done since I was a teenager (a long time ago!). I've got a cheap SMAW (stick) welding set that I practice with, but anything that requires a good finish or requires strength I hand over to the professionals. Which is basically everything... I'm told that stick welding is the best to start on, as if you can master that then other forms of welding will come easier. But I haven't progressed beyond making ugly blobs on test metal yet...

[frankxhv773t]

I haven't done stick welding but suspect that is most difficult. I did gas welding in a metalwork evening class and loved it. I found being able to watch the colour of the heated metal gave very fine control as did feeding welding rod in to the weld pool by hand. The down side is having to invest in and store the kit. Likewise traditional MIG welding which requires keeping a hulking great gas bottle cluttering up the garage. I recently got a little gasless MIG which is much more convenient. The downside is that being cheap it doesn't have fine control down to gentle settings for thin metal which made it useless for trying to weld up a hole in a top water rail. The current is set with two rocker switches allowing four pre-set amperages whereas the old traditional MIG has a high / low range switch then a rotating knob allowing fine control and very low power when needed.

[Nigel]

Being a reasonably competent stick welder, I also bought a gasless MIG
thinking it would be easy to learn, and struggled. I don't know if
it's me or the machine.
I wish I knew someone with the equipment to have a go at proper MIG and TIG.

[mangocrazy]

I've made friends with a couple of brothers who run a family welding business (their father started it), and it amazes me the way they just know exacrtly what settings to use for what type and thickness of material. They weld everything from tiny stainless pieces used in surgery to ship's propellers that take up half the unit. Most of the stuff they do is TIG, but there is also a fair biit of MIG work. But they are using welding sets that cost upwards of £2000, so that also plays a part.

I did buy myself a MIG set a while back (a middle of the range Clarke gas set), but haven't got round to getting the Argon mix gas bottle for it (hobby bottles are a waste of time in my opinion). Now that lockdown is easing I must get that sorted and start practising with it.

Proper gas welding with filler rods requires use of oxy-acetylene kit, which is a bit like inviting an unexploded bomb into your shed/garage. I'd love to have a go, but no way would I consider storing the bottles in any domestic premises.