Offset race rods on WBX?

[fastback]

yeah that's one of a few theories. cracked cylinder hydrolock

[buildabiggerboxer]

Hey Fasty, what a blow . now my training in the VW engine warranty dept comes in handy, here's what likely happened.
have a look at the liner remains, i recon a circlip came out, went for a ride for a bit, so it will have scored the liner heavily with the pin working its way over and also pushing it into the liner wall, the rod will be bent and the shells show the wear pattern of the now cocked piston and rod, it carried on running like this , then the circlip slowly worked right downwards low on the skirt, splitting the liner at the bottom until the circlip came free and into the sump, probably breaking the pin boss and lower piston skirt at about this time, but the motor was now wounded but running still, the crack travels up the liner for a bit, then you make boost on another run and the crack now zoomes right up to the top and boom! shatters the liner/ piston and all you can see besides.
look for the escaped circlip/bits of, it will testify to its freedom bid far more than its opposite member.
sorry to see the mess its made, i did a few worse than that one time, one was a turbo backfire that slammed the exhaust valves into the pistons at 7500 rpm, Do Let me know what you find mate. BBB.

[buildabiggerboxer]

Fasty, me again, another thing i noticed with the blow up, it blew like an air cooled, just looked like the usual oil fire smoke, whenever i blew a wasser, its like the Titanic, with more steam than a foggy day can manage, didnt see too much like that going on? low on coolant maybe???

[fastback]

the wristpins looks like the have not touched the cylinders as i asume it would have been "grinding" marks on them
they look a bit hammered though.
also a possibillity is that i have done a bad job spacing the cylinders.
as i looked at the other cylinders and they have some wear on the lower part.
actually on the fragile cylinder skirt. so maybe the skirt has cracked. ?
i used 6mm spacers under the cylinders and 5.5" rods. so the pistons are a bit lower in the cylinders.

[syncrogreg]

Sorry to see such a mess fastback. What brand cylinder and piston were you running? It almost looks like the piston just broke up?

[buildabiggerboxer]

My 98's are thinner than yours at the bottom, those look plenty strong enough, i still recon a circlip did it, i can see the lower ring stopping point, and the wear is on the thrust side of the liner, quite bad from just the lower piston skirt, the mark in the top of the photo is down lower than the other for some reason. have you found the clips yet?. they hide up the oil pick up tube often..
many folk delete the screen, but i lost an expensive oil pump and a damaged engine one time, so i use a screen always, even for d/s.
if the circlips look undamaged, we can look else where for the cause.

[fastback]

the cylinders are genuine VW stock wbx bored to 96 .
actually a piston/cyl set from gowesty with the je pistons.
the engine stopped pretty fast IIRC. the oil pump had oil only inside it, not the light brown mix that was in the valve covers.
BBB how low does your 98 pistons go beyond the skirts in the Okrasa engine ? i asume it's a stock setup?
i have found one complete clip and one part of the other.

[buildabiggerboxer]

Hi ya fasty, i also used a 5.5 rod with cut piston bowls, the long rod would help .100" with bottom protrusion, i dont know the protrusion measurement off hand, as its all assembled and running, but they are a fairly short piston, i would guess we have about the same figure for it on both our motors.
the broken circlip is the smoking gun, a magnet should find the remainder, the will be scuffed and blue in parts, but its almost proved it i recon, how could the clip otherwise get broken?

[fastback]

the clip coming loose is one of the theories,
but i also think the
clip could be hammered and broken by all the flying piston/cyl parts.
what are a better solution for the clip? double clips?
here's some of the burr

IMG_20121021_132203_crop (Medium).jpg

[fastback]

the piston skirt protrudes 16mm below the cylinder skirt. (mockup on another case)

IMG_20121021_150238.jpg

[syncrogreg]

Sounds like you are thinking what I am thinking fastback. That the piston is coming out of the liner too far and cocking over and eventually shattered. I am very interested by your build. What I don't undertand is if you lengthened the cylinder height with 6mm spacers, how did you lengthen the water jacket? The way you were pulling away from that porsche on the straights was very impressive. I hope you get the old girl back on the track soon.

[fastback]

hi greg
I made a 6mm spacer that i cut out and glued to the head(in a press) with a glue that they are glueing bodyparts on Volvo's
it's a 130 degree C max rating, had no problem with the glue , but will swap to high temp Silicone that comes in the gasket kit in V 2.0

Have just started on new case now to get the V 2.0 of the engine
The engine has been great fun this season, so i'm eager to build it up.
i will do a few mods' 84x98mm , a tad less cam and a bigger turbo.
and with some custom sylinders and pistons.

IMG_20120413_193451 (Small).jpg

IMG_20120415_171059 (Small).jpg

[fastback]

hmm spiro lock's or Tefon buttons.... ???

[buildabiggerboxer]

Fasty, Draw backs? Teflon buttons are quite heavy, especialy 24mm, Jake may have some T4 ones, spira locks can come out and may be a too high fiddle factor for wassers, not for me, i have considered buttons as there is no way they can out, they would need a hole in them for extractor tool. but i still favour a proper circlip, i put them, "definetly not in the groove" then push them in with a socket so that i hear that " click" ,
out they come again if no click, i go again untill i 'hear' it seat in the groove. i use modified pins as a reamer tool to debur the pin holes on the bench.
Liking the spacer mate, i made mine to fit in the gasket channel with dirko either side.
I just blew my T25 DG tow bus, H/C in header tank, 350,000 HARD miles on her, just had rubber gaskets 10 years ago, all original inside, amazing engines, just doing a quick 2.1 upgrade for her now, hope it does the same milage tho,
Good luck with the new build, onwards we go, Chin up mate..

[fastback]

The DG are Donkey's

i don't see how teflon button could fit properly on this style of pistons??