Quench after head and block skim

[scoobydo123]

Hi all ka24de engine so not popular in the UK. I am having to have the block decked and also head skim as going MLS gasket. The pistons are deep dished 7.5 CR at standard deck and head thickness. Got various options avaialble for the new HG thickness as going cometic. How do I go about selecting best gasket thickness for best quench. Head has been skimmed multiple times before (blame previous owner). Block had been decked before but very poorly leaving a finish that looked like a file. Assume this was done when the forged pistons and rods were installed as I think the new pistons wrist pin was offset by design. Want to try and get it right this time :-)

Edited by scoobydo123 on Sunday 5th October 21:27

[Sardonicus]

Little point chasing quench with dished pistons

[scoobydo123]

I was thinking that but AI sent me round in a circle. Tks

[Luther Blissett]

Quench still matters, even with deep dish pistons. What determines the distance is how much crank flex or rod stretch the engine undergoes at max revs. As a rule of thumb you want a max clearance of around 1mm for a performance engine.

[Sardonicus]

Luther Blissett said:

Quench still matters, even with deep dish pistons. What determines the distance is how much crank flex or rod stretch the engine undergoes at max revs. As a rule of thumb you want a max clearance of around 1mm for a performance engine.

Hardly worth the bother though with dished pistons

[Luther Blissett]

Why? the benefits of tight quench remain. There's still a quench pad on a head for a reason.

[Sardonicus]

Even tight quench into an open piston bowl no real world benefits IMO

[Luther Blissett]

If the bowl if offset so it doesn't extend to the quench pad it should do something beneficial.

[Sardonicus]

Think we with have to agree to disagree on this one as I wouldn't be running bowled pistons if I was chasing quench benefits

[scoobydo123]

Hi thanks these pistons are total bowl style so thanks for confirming not much point in concern. Just aboit to start another question that is delaying me moving onwards.

[AER]

What do people mean by "quench"? Do they mean squish?

Quench is waht you definitely don't want to do once you've lit the fire.

Squish is what gives you increased charge mixing at TDC. You'll need <1.0mm for it to do anything useful, even more so if your squish areas are very small, which is normal for today's 4-valve combustion chambers.

[Sardonicus]

My apologies on all my comments I was referring to squish not sure how "Quench" got in my comments misread but Ive left previous comments up or this wont make sense as I haven't either

Edited by Sardonicus on Friday 28th November 13:45