I'm getting close Splinter. It'll be the third one though.
splinter67,
Nov 23, 3:15pm
Keep buying lotto tickets just dont get one for this week Ive already got the winning ticket
msigg,
Nov 23, 3:29pm
I agree with intrade.
newtec1,
Nov 23, 3:33pm
Exactely,more like the sound of the pistons hitting the side of the bore when they out of sequence,nothing to do with the B/E.
floscey,
Nov 23, 4:05pm
i thought the pinking , was the sound of the two flame fronts hitting each other , and would have more damage effect on the ring lands of the top ring .
chebry,
Nov 23, 4:08pm
I was making bearings before you were hatched youve never scraped and fitted a bearing in your life.
mechnificent,
Nov 23, 4:25pm
Yup, that's pretty much it. And bouncing off the combustion surfaces. it's all caused by the flame, nothing mechanical about it.
mechnificent,
Nov 23, 4:25pm
And yes I have actually. old triumphs for one.
chebry,
Nov 23, 4:34pm
Exactly different completely from bigend knock
intrade,
Nov 23, 4:44pm
the question was "quote "Do big end bearings give
any warning , or can they just fail! "quote end. and the knocking is the bigwarning that your engine is getting rooted and that includes bigends as the fuel ignites before the piston got to the top whacking it backwards .its like taking ahammer and hitting the piston just before it reaches the top instead of after it reachedtop dead center. The knock is the warning signof the possibile soon destroyed bigends as it gets worse and worse the more playyour bigends have the more it will hit the pistons befor it gets to the top .
intrade,
Nov 23, 4:49pm
once you hear the bigends knock then its to late to repair it cheap thats a engine rebuild as there is probably half a shell missing already . http://www.youtube.com/watch!v=kN3nCDkmJDw
now diesel is a different story as that is a self-ignition engine it operates on detonations lol just keep in mind that is only for petrol engines Diesel is a whole different story as to why bigendsget nuked there.
splinter67,
Nov 23, 5:17pm
Intrade if your engine is knocking its F%$#d its not a warning sign it too late already
intrade,
Nov 23, 5:23pm
the youtube clip of the bmw engine yes , but thats not the pinking from to low octane fuel and or wrong timing for the fuel . pinking , that is your warning sign to not use low octane fuel whatch the video if you dont understand it.
Gor blimey seen enough pistons with holes melted in em from detonation. As to big end bearings in older low compression engines one used to hear a **rumble** -I.E. 186-holdens triumph 2500's Back in the low compression basic mettalurgy non nitride crankshafts. Nowadys MOST modern high compression engines the classic symptom of **big end bearing noise** Is the rattle in mid engine Rev range off load. The noise is the pistons hitting the cyl head due to the increased big end clearance. So yeah 40posts later. Sheesh. Incedentaly simplest check is crank a non-firing engine and time how long it takes for the oil pressure warning light to go out. AND quickly turn the ignition back on and time how long it takes for the light to come back on. Incedentaly the engine in post number one Could be a 1HDT ToyotaDIESEL common for big end bearing failure. So all this *pinking* .mmm well!
intrade,
Nov 23, 5:43pm
as i said complete different story if it was a diesel. when you hear the noise on a diesel do not start it again as it gets wors mutch faster then on petrol there is no retarding of timing and knock senders its just the big bang coming soon on diesel.
snoopy221,
Nov 23, 5:47pm
1HDT Toyota diesels actually don't really make noise they just have mega low oil pressure.
net_oz,
Nov 23, 7:16pm
Had a '74 mazda B1600 that had a hur of a knock for months. Finally pulled it apart and found that the big end shells were about 3 inches wide and very thin. Mind you the timing chain was rooted too and knocking against the timing cover that much that it put a hole in it. All the oil lines were half full alloy of filings. Damn thing never went the same after we done it up.
chebry,
Nov 23, 7:28pm
All engines fire prior to Top dead centre Ive never seen anything timed to run firing after tdc your explanation as usual lacks credibility a big end knock under load signals the bearings are already shot shut it off or expect big problems.
strobo,
Nov 23, 11:44pm
Exactly ! poor combustion less down force and any thing to do with the big ends is incidental.
zephyrheaven,
Nov 24, 7:18am
Seen em with good oil pressure & still run em - usually starts at #5
paul861,
Nov 24, 8:06am
so its not the fuel , rather the timing of the engine(to suit whichever fuel) which possibly could encourage big end failure
busybeaver2,
Nov 24, 11:57am
My Telstar has suddenly developed this tap/knock eminating from the motor after a good year or so with no problems at all , garge mechanic said it probably a big end bearing and the motor is basically shot unless I'm going to pay bout the same as the cars' worth to fix it . Should I get a 2nd opinion to see if it's something else ( more cheaply remedied ) ! Or go ahead and seek a replacement
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