Saturday, 10 March 2018

Better Seam Than Heard

It's taken a while but we finally finished the seam welding the other day.

What a truly miserable task, compounded yet further by the huge number of body panels MrT saw fit  to use to build such a small car. You know it's going to be shitty work when you have a respirator mask, ear-defenders, goggles, cap, hood up and your welding gauntlets on. There's nothing skillful or thought involving about it you just need to have clear vision of how much better off the shell will be when it's done and belligerently move from one seem to the next until there's none left.

The rule of thumb is you only need to do everything between the suspension turrets but we also did the foremost bulkhead too.

First job is to get a knot-wheel on the angle grinder and get all the easy access stuff off. minutes and minutes of that special kind of drone that only an angle grinder can make as you get peppered with high velocity spikey bits of metal and gross semi-melted seam sealer

Then get your blowtorch and soften up all the stuff in the nooks and crannys at either end of the seam as you pick it out with a screwdriver/paint scraper. Smokey but it just feels like a woefully slow and inefficient way to to do it after the knot-wheel.

Another wire brushing, this time with the smaller, softer one in the hand-drill. this gets deeper into the seam than the knot wheel and also gets the paint off really well. Cup brushes and end brushes also come in really handy for the tough spots. By now it should be looking pretty good. Any last little bits can be finished off by hand with the screwdriver and the scraper.

Finally a wipe with a old microfiber and some clutch cleaner.

We're not going to fully seam weld the whole thing, just the suspension turrets and pick-ups. Everything else will be 25mm 'stitch' welded. That is to say a 25mm runs of weld, spaced by 25mm of unwelded seam.

It looks a lot smarter if you take the time to mark it out. I used the width of a steel ruler and a Sharpie. Make nice big marks as they get sooted over as you weld your way towards them. This is where you realize that the last 20 minutes of misery 'cleaning' the seam was only marginally more productive than punching your self in the face. In fairness the interior seems weren't too bad but the exterior one were loaded with sealer really deep into the seam so trying to lay nice clean weld beads is near impossible.

Crappy welds produce lots of spatter so inside the wheel arches was the worst. It's massively frustrating because your welds are so contaminated and you're just getting huge globs of spatter raining down on you and getting under your clothes.

Another brush with the drill before the primer and then onto the next one.

We also fully welded the joins in the sills and the roof. The only kind of accident that really worries me is broadsiding a tree. I fully appreciate that if that happens at speed your in big trouble but if these seams fail the whole car will split open. Luckily they cleaned up really well and they were some of the best runs I laid down.

In other news. I've stripped the engine down and sent it off for a pro measure up. It could use a re-bore but it's going to have to do without. A set of 0.5mm oversize pistons are north of £400. What it will be getting is:

Head skim: 10 thou
Deck skim: 4 though
Performance big end shells
Performance main shells
Thrust washers
Bronze exhaust valve guides. The originals were worn out

I also plan to do a my own very mild porting job on the head. Just to remove the casting flash and tidy up any misalignment between the casting and the factory machining of the head. Maybe a bit of a polish.

We will also be getting all the stock internals lightened and balanced as well as the cam-pulleys, fly wheel and clutch cover. So we should have one of the sweetest running stock-trim 4ages out there. The total cost of all the engine work so far is £830.

We're toying with the idea of a thinner head gasket and maybe some mild/fast road cams so if anybody has any advise in that regard it would be gratefully received. The stock injectors and ECU need to be able to cope though as we don't have the budget to upgrade them. If we can get to 150-160BHP that would be a massive win.

And we picked up a sweet AE86 tubular manifold on Ebay for peanuts. Made by BTB exhausts these things usually go for mega bucks but we picked it up for £50 as they were clearing old stock!

The plan is route the exhaust over the gearbox and into the boot (the battery will be in the frunk) to give us as much ground clearance as possible . As you can see with some relatively minor surgery this little beauty is absolutely perfect.