The power of detonations...?

[Barbapapa]

They had issues with badly machined sleeve bores, so the engine has dropped the sleeves 3 times already, even if the block was heated a fair bit and left overnight to cool slowly with the sleeves under a fair bit of pressure the second time. So I guess that sleeve drop happened at the "same" time, i.e. when the engine was loaded in the higher gears they sunk again. I did not do any machine work on this engine so I really have no idea exactly how they did it, I just was told it was a botch job the first time, and they tried rectifying it after. But the block had sunken liners when they brought it to me now..

I was thinking of contamination from sleeve issues causing an octane drop and then detonation but I have no experience with E85.
The fact that the rods weren't bent amidst all of this is interesting, and the lack of melted pistons, a bunch of 'sharp' detonations near TDC could fit.

[SWR]

I was thinking of contamination from sleeve issues causing an octane drop and then detonation but I have no experience with E85.
The fact that the rods weren't bent amidst all of this is interesting, and the lack of melted pistons, a bunch of 'sharp' detonations near TDC could fit.

I agree, but what stumps me is the fact that the pistons look almost like new wear / damage-wise.. I would expect that kind of force needed to crack a cast iron bottom end completely decimate the ring lands and wrist pins... Then again, CI is brittle when subjected to a punch, so maybe some tool steel lower mains are in order.. popping a piston is cheaper than grenading the block.

[Cubic_Cleveland]

SR20? How much power is it making? Those blocks aren't real strong!

Is it stock stroke? Solid or hydraulic? I'm with you in thinking its not purely detonation, I would have thought there would be more collateral damage.

[SWR]

SR20? How much power is it making? Those blocks aren't real strong!

Is it stock stroke? Solid or hydraulic? I'm with you in thinking its not purely detonation, I would have thought there would be more collateral damage.

Yup, SR20. 586 hp to the hubs when at 25-some psi.. can't ask a Garrett GT3076R for much more. Stock stroke, aftermarket rods, pistons, valve springs and cams.

[Cubic_Cleveland]

That's decent power for a stock block! What kind of sleeves are in it? Do the water jackets have any fill in them?

I have only done one SR of that kind of power, but it had inter locking sleeves and an owner supplied epoxy fill, seemed to hold up ok. Maybe he needs one of these http://www.bulletcylinderheads.com.au/p ... title=SR20

[SWR]

That's decent power for a stock block! What kind of sleeves are in it? Do the water jackets have any fill in them?

I have only done one SR of that kind of power, but it had inter locking sleeves and an owner supplied epoxy fill, seemed to hold up ok. Maybe he needs one of these http://www.bulletcylinderheads.com.au/p ... title=SR20

They said it's Darton sleeves. Don't think there's any filler in it, it stood up well until the bottom end gave in..

[Cubic_Cleveland]

What story do the con rod bearing tell? If it was detonating big time they should show it too.

[grant6395]

MSD rev limiter dropping sparks causing detonation?

come on...

[nitro2]

The melted plugs suggest pre-ignition. It could have advanced into severe detonation so quickly the machinery broke before it had a chance to melt.

True, the other grenaded engine took out a piston and a cylinder wall in about a millisecond. Heard no knock then, and on the engine here they said they heard nothing either, it just started vibrating badly. No wonder preignition is known as the "silent killer"...

Detonation and pre-ignition can coexist, sometimes detonation for a cycle or two then pre-ignition for a cycle or two then back and forth, sometimes pre-ignition and detonation happen on the same cycle.

Sometimes detonation starts, then pre-ignition/detonation coexist, then it turns into full on pre-ignition, all in the matter of a dozen or two cycles which is only a fraction of a second. Pre-ignition won't melt anything if the engine comes apart first

You could get 3500 + psi of peak pressure from full on pre-ignition on 20 lbs. boost. Peak peak pressure is at TDC or slightly BTDC, but high pressure from full on pre-ignition extends from many degrees BTDC to many degrees ATDC so the piston sees the high load for quite awhile (in degrees), in comparison to detonation or normal combustion.

[raynorshine]

What story do the con rod bearing tell? If it was detonating big time they should show it too.

agree!
-detonation should should up in con rod bearings, piston ring lands being pinched, piston skirts collapsing, main caps moving etc...

[Dave Koehler]

While an equal amount of carnage can happen to a NA engine I am beginning to think that those of us that venture to the dark side with power adders should find a way to acquire Clint's products. Everything discussed here can be traced, logged and flogged.

http://www.tfxengine.com/software.html

Clint,
You need to put your website in your signature. I can never remember what the name of it is when I want to show it to someone.

[BrazilianZ28Camaro]

I agree, but what stumps me is the fact that the pistons look almost like new wear / damage-wise.. I would expect that kind of force needed to crack a cast iron bottom end completely decimate the ring lands and wrist pins... Then again, CI is brittle when subjected to a punch, so maybe some tool steel lower mains are in order.. popping a piston is cheaper than grenading the block.

Looks like the block was being way more stressed than the pistons and reached it limit sooner.

Cracks also can be caused by cyclical fatigue loads or vibration.

[justahoby]

I agree, but what stumps me is the fact that the pistons look almost like new wear / damage-wise.. I would expect that kind of force needed to crack a cast iron bottom end completely decimate the ring lands and wrist pins... Then again, CI is brittle when subjected to a punch, so maybe some tool steel lower mains are in order.. popping a piston is cheaper than grenading the block.

Looks like the block was being way more stressed than the pistons and reached it limit sooner.

Cracks also can be caused by cyclical fatigue loads or vibration.

More along the lines I was thinking. Or detonation did not occur till one hot pure ignition point, or excess fuel load (lack of ignition) hence the path of least resistance from liquid build up was the split in the block.

[MadBill]

How do the rod bearings look, especially the uppers?

[SWR]

Bill, they look almost disturbingly ok... ok, there's some marks on them, but not even close to the carnage I would expect after punching out the bottom end of the block... I'll take a photo after.