Originally Posted by 1fast62
ok Im stumped here. i just finished my 454 full solid roller alum heads had it running about 4 hours on it and the timing chain broke! :/ .. really weird i know, i have been doing research trying to figure out what the heck happened. this will sound crazy but my block number says its a gen 5 (91-95) ok everything on the motor matches a gen 5 however the front of the motor is drilled for a gen 6 timing cover. if you look at summits parts they give you a application for each part. the timing chain set i have was for a gen 5 i did not relize it was drilled for a gen 6 until last part of assembly when my timing cover was different. and they say the timing set is different for a gen 6. i cannot see how when comparing them but im wondering if thats what caused it to break. i was running a cam button with a very exspensive timing that broke in half when the timing chain decided to break. Do any of you guys have exp. with theses newer blocks. please share whatever you can. the motor ran awesome and had unbelievable power no signs anything was wrong until bang. no more chain.
Could be a manufacturing defect. It could be something fell down between the gear and chain (small nut, bolt, screw, whatever) and that could snap it- after all, in a case like that something
has got to give, and the chain is the weakest link.
I would carefully inspect the chain and gears under magnification for any signs of the cause, but unless you're a skilled inspector you may never know the exact cause.
Did the assembly go normally, the chain wasn't excessively tight or loose on installation?
You started to say an expensive "timing something
" broke- was it the timing cover? If the end play was set incorrectly and the timing cover broke because of that, and a piece of the broken cover fell between the gear and chain... or the cam walked out far enough that the chain tried to ride up over the gear... that could account for it.
In other words, the cover broke first, causing the chain to break, not the chain breaking broke the timing cover.