Big end bearing failure! Study for Engineering Degree

[99GTB]

Mine went at about 170ks, I had only just done an oil change went down the road to test the new turbos I had just spent all day swapping over and was thrashing it before it was probably fully warmed.

New oil + not warm + thrash = big end fail

oops..

[pedro]

no failures as yet

brumby done 320ks and is still going strong i believe{sold it a few years back}

95 wrx 251ks still on original engine

98 type r 130ks just purchased and fingers crossed but sounds all g

guess ive been lucky so far.

perhaps the more you maintain your wheels the luckier you get.who knows?

[chrisjunkie]

 SAS said:

Also reasons as to why you ran a bearing would be much appreciated

New owner, oil and cambelt changed did about 800kms then BANG. Luckily it was just outside home. Bought a new shortblock used old heads and single turbo conversion ;D

I take it down to the oil in the car being really old when I got it and then a change in type of oil...

Murphy's Law applies "New owner = car trouble"

[Andrew NR]

'92 Legacy GT done 239,000km and not done a BEB or had a rebuild.

[aim]

The only engine damage I've done is warped some heads after a blown radiator hose going up a hill.... in a '74 MG BGT. yeeeah No bearings on a subbi though. None out of the 5 our family's owned

[Ryan]

 SAS said:

Also reasons as to why you ran a bearing would be much appreciated

Too much rev limiter didn't help lol

[gazzy2000]

The 97 STI i owned.... i brought it off a farmer WITH a blown BEB 104,xxxKMs

He said that they only had 91 on the farm and the insurance company did a fuel and oil analysis and didnt pay him out because:

1) it had crap oil and/or hadnt been serviced in yonks

2) the fuel was 91 octane

Thats the story he gave me.

[R.D]

this Topic is making me scared.

If this happens, is it pretty much new engine, or can it be fixed, $$$?

Mine done 150kms, still good.

[Guest boostcut]

if you dont do any work yourself, i.e pull motor out and strip to shortblock.. expect to pay around 3-6k.

[B4 2000]

 R.D said:

this Topic is making me scared.

If this happens, is it pretty much new engine, or can it be fixed, $$$?

Mine done 150kms, still good.

nothing scary, take care of your car and your car will take care of ya and yeah sh!t happens sometimes. EASY

[wrx_lou]

Dtech would of done mine for around 1500. It went while he was tuning it though so he was able to stop it before it did too much damage. would of gotten away with just new rings and bearings.

[T.Rev]

Needs a qualifier of how many track days b4 it blew.

[Joker]

I've done a handful

[RSB]

Not Yet.

Had the Car 2 Years now. It's NZ New and was purchased from auction with 93kms on the clock and FSH. Now on 144kms, bigger primary, more boost and yet to have an issue.

Touch wood.

Oil+filter changes roughly around the 5-8k mark - whenever it starts to obviously discolour. I also run a flush every second change.

[cpt kernow]

 gazzy2000 said:

The 97 STI i owned.... i brought it off a farmer WITH a blown BEB 104,xxxKMs

He said that they only had 91 on the farm and the insurance company did a fuel and oil analysis and didnt pay him out because:

1) it had crap oil and/or hadnt been serviced in yonks

2) the fuel was 91 octane

Thats the story he gave me.

Did all the red paint chip off the manifold during removal or when the conrod wanted out the block?

I've done two in my "84 vauxhal (read holden) astra 1.3 both due to high revs. Dropped a replacement engine in the blew the second within weeks and got a warranty.

It was also the only car I had stolen. Was dumped 100m from my house. I guess the theives weren't too impressed with the dakka dakka dakka dakka dakka sound from the engine bay

[Guest keltik]

Not yet. 95octane fuel, no boost yet, 155,000kms. Change oil every 10,000ish kms. Thrash the living **** out of it and have done a few track days.

H6 owners should be disqualified from posting

[gazzy2000]

 cpt kernow']

[quote name='gazzy2000 said:

The 97 STI i owned.... i brought it off a farmer WITH a blown BEB 104,xxxKMs

He said that they only had 91 on the farm and the insurance company did a fuel and oil analysis and didnt pay him out because:

1) it had crap oil and/or hadnt been serviced in yonks

2) the fuel was 91 octane

Thats the story he gave me.

/quote]

Did all the red paint chip off the manifold during removal or when the conrod wanted out the block?

I've done two in my "84 vauxhal (read holden) astra 1.3 both due to high revs. Dropped a replacement engine in the blew the second within weeks and got a warranty.

It was also the only car I had stolen. Was dumped 100m from my house. I guess the theives weren't too impressed with the dakka dakka dakka dakka dakka sound from the engine bay

I am not sure, i doubt it. It smashed that alluminium water pipe that runs over that area, but didnt hit the manifold.

I was under the impression that the chips of paint were the normal chips that come off the red STI manifolds.

[stixgtb]

Standard 98 BH5 legacy with exhaust - 101k

BEB failure on piston number 3 possibly due to AFM failure some 6 months prior.

(this might be due to after market air filter attached? maybe the filter oil killed the AFM?)

Regular service however one on the 10k mark (it took a year to drive 10k)

Car hardly driven any long distance, lots of short cold driving. Hardly hit secondary boost.

[ReubenH]

115,000 for me. Not quite on 100K, baaw. Blew a few weeks after i did the first oil change while in my ownership. the old oil was thick and black. very black.

Twin churbro as well.

[Guest]

There are many reasons why this happens. Starting with fuel, too low an octane rating resulting in detonation, the pressure wave effect when the flame front starts from a point other than the spark plug, In bad cases, the plug sparks, ignites the mixture, a hot spot will also cause pre ignition, the fronts collide and the shockwaves colliding creates the detonating effect. This is at its worst when the rod is hasnt begun its decent on the downward (power) stroke, or is at tdc. The driving force down coupled with the rotating force of the opposing cylinder is what bends/breaks rods and hammers bearings.

Too thin oil is another big culprit, not cushioning having enough viscosity and allowing the sides to touch and wear prematurely. This is the same as old oil, that is contaminated with combustion by products and has degraded, or no oil at all due to a poorly baffled sump and loss of pressure. Then you have design aspects including rod length, rod ratio relative to the size of the main bearing journals. Bearing failures became more frequent when subaru upped the rev limits to 7800-8250 rpm, as each increase multplies the force on the rod journal. The tensile load is therefore increased. Then you have stretched rod bolts, worn bearings, out of round clearance problems and a big end that can move around.

[EJ20T]

have owned 6 turbo subarus, not one big end, 169k, 240k, 190k, 118k, 96k, 224k. b4 is coming up to 97 now, with all the pinking it does its the one ive been most worried about

[mattapo]

unknowen service history, suspect very bad.

Was thrashing the tits off it and had been thrashed from cold

170 odd k's

[QRAF]

my 93 pre face lift legacy when at around 189,000kms wingers said it was due to having a pod filter and bov as i heard it dried out the oil. :D

my 98 ver5 is still going strong at 227,000kms but i haven't driven it in a month now.

[driftrex]

 QRAF said:

my 93 pre face lift legacy when at around 189,000kms wingers said it was due to having a pod filter and bov as i heard it dried out the oil. :D

my 98 ver5 is still going strong at 227,000kms but i haven't driven it in a month now.

didnt your v5 do a big end before you got it, or rebuilt for another reason?

[QRAF]

 driftrex']

[quote name='QRAF said:

my 93 pre face lift legacy when at around 189,000kms wingers said it was due to having a pod filter and bov as i heard it dried out the oil. :D

my 98 ver5 is still going strong at 227,000kms but i haven't driven it in a month now.

/quote]

didnt your v5 do a big end before you got it, or rebuilt for another reason?

tensioner blew twice so other reason