Tag: cylinder head

Guesstimates about compression ratio 3 + oxidation stuff

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Before taking the cylinder head for oxidation removal, I tried (my best) to measure the head volume.

Better get some proper measuring equipment. My trusty 10cc syringe wasnt that accurate, but I got a result that was definetly over 36cc’s. I’m going to use 37cc’s until I get better tools. Next time I’ll use windscreen washer fluid or some cheap alcohol, because surface tension.

My syringe actually stopped at 38cc’s 🙂

Then measured both the deck height and stock 4A-GZE piston compression height. Deck height is 191mm and stock piston compression height 30.5mm.

Valve guides are oxided as well. Or rusted. While getting degreased for the high-tech coatings, some of the alkaline washing liquid leaked inside and made a mess.

Compression calculations:

Seems that the stock pistons are level with the deck when at TDC. Stock 4A-GZE pistons have 30.5mm compression height and Wisecos have 30.68mm. Therefore Wisecos will poke 0.18mm above deck level.

  • Bore: 81.5mm
  • Stroke: 77mm
  • HG thickness: 1mm
  • HG bore: 82mm
  • Deck clearance: -0.18mm
  • Piston volume: 5.9cc
  • Combustion chamber: 37cc

With these values the CR is 12.3:1

  • 1mm headgasket – 12.3:1 CR
  • 1.2mm headgasket – 12:1 CR
  • 1.4mm headgasket – 11.7:1 CR
  • 1.6mm headgasket – 11.4:1 CR
  • 1.8mm headgasket – 11.1:1 CR
  • 2mm headgasket – 10.8:1 CR

Well, the numbers are the same as before… and squish clearance sucks when head gasket is thicker than 1mm.

Wiseco, you suck.

Aluminium oxide inside oil passages

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That white, powdery stuff there is aluminium oxide. And it’s baaaaad.

While being washed for those technical coatings, something happened and insides of the cylinderheads got exposed to washing agent. Aluminium reacted with washing agent and end result was aluminium oxide.

Aluminium oxide is that same stuff that is glued to paper to make sandpaper. Wonder what it would do inside my engine if left there…?

Nah, I’m taking it back to the coating company 🙂

Valve keeper, retainer and spring trick

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I saw this trick somewhere, probably on the internet.

IMG_20170314_211355

Pick a suitably sized socket, 17mm was perfect for me. Then, insert a strong magnet into it (or two)

IMG_20170314_211414

Put the socket (with magnet inside) against the retainer…

IMG_20170314_211424

…and hit it with something hammerlike, preferrably soft mallet. The hit will compress the spring, loosening the valve keepers which will stick to the magnets which would otherwise disappear after short flight inside the garage.

IMG_20170314_212131

4age valve spring free length should be 41.09mm. If shorter, throw them into bin. Mine were longer for some reason…

Next, I’ll have to find a similar way to get everything back together 🙂