Is this a tensioner failure ?
 

Hey guys,

I debuted my RS replica on the track this last weekend, and lap two came off a corner to a suddenly really 'doughy' engine. No power, and a really flat sound. Oil pressure was fine. It also emmitted a couple of backfires. I pulled off the track and stopped the engine. Checked fuel pressure and spark - all OK. The car runs a full MSD ignition with programmable computer. The engine then wouldn't restart. I didn't hear any bad noises from the engine, but then I was wearing a helmet.

My engine is a 1980 3 litre with original tensioners, 96K miles. This sounds like a tensioner failure to me, and cam timing moved way off optimum. Any experts on here to concur before I pull it down ?

Is it a given that valves have hit pistons if it was a tensioner failure ?

Thanks all,

Craig H.

Tough to say, until you take the covers off. If the timing jumped, you will have bent valves, not much you can do about it, as the flat six is an interference engine and if you are off slightly, it will be enough to hammer the valves.

You did not install any "crash collars" that limit travel to the piston, so they don't sink in completely and allow the chain to jump?

Good Luck,

George

can you still turn the engine over by hand?
do you hear any scraping or clunking noises?

there's more to injection then having fuel pressure and spark
ignition timing could be off electronically
injectors frequency and duration ditto
could be bad fuel that clogged up a couple of injectors
vacuum problem that's causing bad fuel metering
maybe your throttle valve or linkage is stuck, sticking or semi disconnected....
etc etc

dunno how good your helmet muffles
but valves hitting a piston i would think is still audible, and in most cases will cause so much carnage that you wouldn't call it "missing power feels like a flatspot"