126 Progress log - 126 1.1 8v FIRE with a Van Aaken turbo kit

[Tom126]

A few days later, a few more bits taken off the block and inspected/cleaned/stored.

The block as it stands (waiting bolts to mount it to the engine stand):

The collected parts:

If the part isn't in one of these two pictures it's in the tub of degreaser, which is slowly eating all the aluminium parts... I should really take those out.

Looking at the bores, all surfaces look like this:

Which look quite good, original(?) hone marks all still there with no visible damage. When the pistons are out there will be a quick multi point measurement of the bores to see if they are as good as I need.

The head is being replaced with a reconditioned one - I'm not equipped to deal with the head work and testing.

Next step is to get the block on to the stand, get the crank out and take a look at the bearing surfaces and measure up for rings and bearings. Probably paint a few bits too.

Away from the engine, I need to set up the instrumentation in the car. I have an AFR, RPM and boost gauge to install, thinking about where the radio would normally go (no chance of hearing that anyway). The issue is routing the wiring. In my haste to insulate and carpet, I didn't leave a flap along the nearside footwell to allow for any further wire runs to be added. Tempted to penetrate above the bell housing of the gearbox (there's a ~150 mm square panel that can be removed/modified) and run the wires along the centre console...

Also need to work out the oil feed to the turbo - the feed line I was supplied looks to be oil tight but it's been around the block. It also doesn't seem to have a restrictor in. If anyone knows, what thread size is the filtered take off from the oil pump housing? I did search here and google it up but no luck. What size restrictor would you fit in line between the pump and the turbo? I have seen 0.9 mm being a very common size. This is a T15.

Cheers!

 

[Tom126]

For what it's worth on the restrictor, Garrett reckon 40 thou orifice will do unless exceptional circumstances, which I don't think I'm in here...

Turbo System Optimization

Turbo System Optimization covers the auxiliary systems and how to properly calculate, install, identify problems, as well as tips for how to correct

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[Tom126]

A little further on, checked the main bearings which are in tolerance, on the loose end. Nice an even throughout. I'll keep them in.

I had spent a bit of time measuring all the constituent parts of the compression ratio calculation, did a rudimentary combustion chamber measure with some acrylic and a syringe. The head had been skimmed and the chambers came out even at 20.9 ccm.

The combustion chambers were also cleaned up and polished/sharp edges knocked off.

Knowing everything I was able to plug the numbers in to a calculator

(https://goodcalculators.com/compression-ratio-calculator/)

I simulated taking off 2.4 mm using the piston to deck clearance. I then took off 2.4 mm

This is about half of final depth of cut, I was taking off about 0.8 mm a pass. The 2.4 mm takes off all shaping and makes it a completely flat piston. This was not an ideal setup and took a bit of dialling in, but I don't have tall jaws and I really didn't want to take the pins out of the piston/conrod assembly.

I saw somewhere that VA suggested 'a couple of mm' when asked how much they take off a piston for their high boost kit. As this head is skimmed and that I wanted to reduce the CR quite a bit, that seems about right.

Next job is to get the new rings in, bolt the bottom end back together, sort out the turbo drain in the (new) sump and work out how to fit the intercooler in there...