Thought I would start a new thread continuing on from the Top feed under Plenum fuel system. For those of you who have been following here is the out come of taken things for granted. I used my spare Lower Plenum and never thought to replace the Idler Pulley Stud Bolt. This is the end result Valves kissing the piston.
You MAY be able to get that bolt out using an "Ezi-out"(providing you can drill an accurate hole into the broken end piece)but I would be amazed if those "kiss" marks haven't bent your Valve Stems(or cracked your Pistons). When all else fails, there is always suicide, but don't be too hasty just yet(Miracles do happen, occasionally). Good Luck!:zlove:
Time to get serious Time to get serious, Engine out and forged gear and some modified heads are in order - I think I have pushed the stock motor with its old parts beyond it's limits. we would of got 320kw + out of it with more boost & a good alternator to keep the volts up to the 460L/hr welbro.
Wow! All that horsepower you were going to get must have been too much for the stud! Then again, I wonder if the marks on the rear cover & the rear of the pulley had anything to do with the stud failing? FYI: The striations on the stud indicate the failure was not a single load impact & also indicate the direction of load.
Wow So you worked all that out from a couple of photo's, you are the best. Shit I spent years doing a mech engineering degree, and nearly 30years on the job. Anyway I wasn't saying the power output broke the stud, it is just time to complete the forged motor the block has been on the engine stand for over 12 months. thanks anyway. .
having had this happen myself (i was extremely lucky and the cams sprung to closed position and never hit a piston) I can vouch for the nightmare of getting it out, I tried easy outs but they failed. In the end I drilled it out all the way up to a size suitable to retap and used a HT bolt instead of a stud there.
The only time I have seen this happen is when the tensioner has been incorrectly set and is close to closed. Under acceleration, the gaps closes up and puts enormous strain on the idler studs eventually causing them to break off.
