304 ignition timing advance.

[EYY]

Ran it for 20 minutes and didn't have an issue. Well, not until the first skid, but that's another story....

C'mon, don't leave us hanging!

 

[Not_An_Abba_Fan]

Crack in number 2 bore and a piece broken off the piston. But it did drive off the pad and made top 50, but couldn't compete in the finals as it was dead.

 

[tim_pato]

Ouch! Would a crack and pressure and/or sonic test have shown a weak spot? Or was it piston failure?

 

[EYY]

Sorry to hear mate! How far was it bored out? .060?

 

[Not_An_Abba_Fan]

It was at .060". Have a .040" block here now that we are going to rebuild. Everything apart from the pistons and rings is salvageable. Which we have to replace anyway with this block.

I would say a weak spot since it was at 0.60".

 

[tim_pato]

Would a crack,sonic or pressure test have shown it? I hear them mentioned all the time, is that the sort of thing they are trying to prevent with these tests?

 

[Not_An_Abba_Fan]

Yep, pretty much. It may have shown it in this case, but maybe not.

 

[mr j-man]

Mate id be wipping that manifold off and pouring some oil onto those lifters..
The last thing u wana hear is a clunk and a dead cylinder.

I soaked mine in a container for a day or two....its a must for flat tappet cams, well id do anything possible to eliminate any form of failure

 

[tim_pato]

Wouldnt soaking them in oil effectively pump them up? Because the spec sheet says not to?

 

[Not_An_Abba_Fan]

It does pump them up, but you also get instant oil pressure by prefilling the lifters. The 304/8/55 has fairly good valve to piston clearance, so the couple of thou extra push on a fully pumped up lifter won't matter. The first few revolutions will settle them.