1967 S3 FHC rebuild

[ill_will]

Some of you may have followed an engine rebuild thread I've posted to tracking progress getting a 1700cc motor built up over the last 2 (actually maybe closer to 4) years. (Here viewtopic.php?f=39&t=49709)

The chassis body and gearbox had been sitting in a garage an hours drive from me since 2009 but recently, having the engine more or less back together, I got it trailered and its now it's only five minutes cycle away. Hopefully I can make some progress now, and thought I'd start a thread to track it in case anyone is interested.

The rolling chassis was put together in around 2009 by me with a lot of enthusiasm but a tight budget and without much knowledge and/or skill and there were a few jobs that I knew needed doing. My records of the specifics are a mess having gone through several house moves since. The known unknowns:

- One of the trunnion threads was worn although bushes were new.
- One of the outer drive shafts was worn at the interface to the outer bearing,
- Quaife ATB unit needed fitting in the diff
- The front inner poly bushes were missing inner washers.
- Steering rack was a little notchy.

I started pulling off the bits but fairly quickly realised I might as well completely disassemble it, so now have just the chassis, with brake lines and handbrake cable left in, and the bare body attached to it. The dash is still there but resting loosely as is the heater ducting.

[ill_will]

Predictably stripping it down has revealed a ton of other jobs which need doing.

The rack was not good - the pinion had some bad pitting as did one of the inner track rods.

I got a better donor Triumph Herald steering rack and had Kiley Clinton rebuild it. They have the roll dies available to shorten and thread the track rod inners without using a cutting die (there is not enough material to cut as the nominal diameter of the rods is smaller than the major thread diameter.) It was expensive but the service was good and the rack feels like new.

Stripping down the front uprights (vertical links) showed that one was fine but the other one was a bit worn at the top. I managed to source a couple of Stanparts replacement so have replaced them both. One of the (new, non Stanpart) trunnions I had was a bit tight on the new upright but TTR have Stanparts ones and that was a good fit.

Over the past few years I've collected a few other parts, and have some tubular wishbones for the front too, and TTR stub axles. The tyres will be wider and stickier than the original design so this seems prudent.

[alanr]

Be aware that genuine Stanparts that were made in the UK no longer exist.
Lots of parts with Stanpart inscribed on them are now actually made in either India or the Far East.

Alan.

[ill_will]

Thanks for the heads up Alan, I didn't know that.

[ill_will]

Over the last few days I've designed a few bits of tooling to help with the build (mostly mandrels for pressing in bearings to the rear hubs and diff, which I'll make on the mill) and tried an experiment which might be of interest.

I wanted a flywheel locking tool to install the clutch so drew one up in Autodesk Fusion (which is a CAD / CAM package I use) again intending to make it on the mill. The tooth meshing was a bit tricky to measure so I printed one off on the 3D printer at work to do a test fit.

The material is called FormLabs Grey V4 resin and they claim a UTS of 65MPa (for comparison, the lowest grade structural mild steel is maybe 5 times that, from memory, so it isn't cheese.) From snapping bits in my hands it appears the fracture toughness is quite poor, however. I thought it would be interesting to try using it to torque the flywheel bolts up (to the DB spec, I think it's 50 or 55 ftlb but dont have the number in front of me.

Anyway, it worked absolutely fine, and there was no significant damage to the tool evident afterwards.

So a low effort, quick option for certain types of minimal usage tooling. That said the loading for this example is quite favourable so for many cases the material will likely be unsuitable.

I'm thinking about trying a more ambitious test next, making a slide hammer plate to pull the diff output shafts out. Need to figure out whether the resin will cope with heating up the diff casing before doing this, however. It will be interesting to see if the hammer impulses shatter it.

[ericbushby]

Hi Ill-will
I just think that is a complicated way of locking the flywheel and is making unnecessary work. I just used a Mole wrench clamped on the flywheel rim against what ever it came up to. A bolt through a hole or something else, I cannot remember what. It worked for me.
Eric in Burnley
1967 S3SE DHC

[512BB]

I would be interested in something like that in metal Will, if you could arrange. Quite sure there would be other punters too. If that is not possible, could you make me one in plastic and I will look into the metal variety. Let me know the cost please.

Leslie

[JonB]

If you could post the STL file somewhere (Thingiverse?) I'd be most grateful. I can print one for Leslie, too.

[ill_will]

Thanks for the comments. It seems a few people are interested in the tool.

Here is the STL file (3D part geometry, for anyone not familiar.)

Tooth clamp v4.pdf

(25.47 KiB) Downloaded 32 times

Note I have changed the extension to .pdf as .STL is not permitted, so you will need to change the extension back after downloading. Please let me know if you have issues opening it.

This gives you a few options:

- Find someone with a 3D printer and print it out. Perhaps try a nylon like material which should be much tougher than the resin I used which is quite brittle.

- Upload it to one of the 3d printing hubs where you will get an instant quote and "click to order" type service, to print in one of several materials to one of several tolerances.

For anyone who hasn't tried this kind of manufacturing before, it is very easy to use and worth trying (even if you don't end up actually ordering.) The first Google hit I got was http://www.3dpeople.uk (no affiliation, never used them or even been on their site but hopefully they do what I searched for!) If someone does this would you mind sharing the quote amount please?

- Similar type site but where they make it from a metal of your choice, or find someone to make it on a mill. For a one off with no economies of scale, particularly in the west this will be way more expensive as someone has to program the part and then pay for the machine time to make it. This is also a hard part to make (properly) as cutting the tooth profile is awkward and really needs a broaching machine (I think? Not my area of expertise.) For a rough tool you might be better off milling it except for the teeth and hacking them out with a band saw and grinder tbh.

Leslie - apologies that I'm not planning to make this in metal so won't be programming it, but hopefully the printed version that JonB has kindly offered will be useful.

Hope this is useful/interesting!

[prezoom]

I have a box full of that style made from aluminium for almost every type/style of engine/flywheel I have ever worked on. An almost 70 plus year endeavor to make flywheel removal/installation easier. Aluminium works just fine as the same design was used on VW flywheels, which needed 208 ft lbs. No fancy tools to make them, just a hacksaw and a drill. Not fancy, just practical.

[alanr]

As Eric said earlier...This is how to make an easy job complicated!
A steel tyre lever wedged between the block and the starter ring gear has always worked for me. No fancy tool ever needed!

Alan.

[ill_will]

Each to their own. If I was stuck by the road with nothing else I would get creative with the tools. But having spent over a decade working with some ex F1 mechanics if possible the right tool for the job is preferable as things are less likely to get damaged. And in this case it only took ten minutes to measure, ten minutes to model it up and then press print.

[ill_will]

Prezoom - that's a serious torque wrench! Old beetle?

[ericbushby]

Thanks Alan, I thought I was on my own then.
Ill-Will,
I still think it was unnecessary to make that special tool for the job in hand. However when you explain that it is a simple task for you then it now seems reasonable. I an impressed with the result.
Just to expand a little, I have made many special tools for awkward jobs. I have a drawer in the garage for one off adaptors, modified, bent or shortened spanners or anything which may never be used again, but at least I will know where to find it if there is a next time.
Good work.
Eric in Burnley
1967 S3SE DHC

[JonB]

As Eric said earlier...This is how to make an easy job complicated!
A steel tyre lever wedged between the block and the starter ring gear has always worked for me. No fancy tool ever needed!

Alan.

I wouldn’t bother with it myself, but having a 3D printer confers an obligation to use it. So I’ll run a copy off in ABS and we will see how it goes. Of use also might be a similar tool to lock the camshafts together. Which reminds me - locking the flywheel would be very useful during a rebuild after setting TDC, to ensure it stayed at TDC. Doubt a tyre lever would help much there, Alan.