Disassembly of a 69 Z/28 DZ Three Oh Blew Engine

[SuperNovaSS]

The counterweights have a few nicks but nothing catastrophic. The seller actually expected no damage to the block or crank. We came up with 2 prices. One price was higher and came with a unwind clause if there was damage and the other was as is. I am a gambler and went with the as is. The internals could have been much worse in my opinion. Thanks for all the replies guys. I am going to do another post soon about media blasting.


Jason

[Day2_69Z]

. The seller actually expected no damage to the block or crank.

Jason[/quote]

Jason, I'm sorry but I can't stop laughing at the sellers expectations especially as I look at the pan ..... he must of been the one that didn't change the oil or have the timing set nor the valves set not even to say why
in the hell would you rpm a high revving motor Without Screw in studs ,or let alone pinning them.....Who ever blew it up EARNED that Pleasure of hearing how mechanical catastrophic pleasure sounds..... [img]<<GRAEMLIN_URL>>/crazy.gif[/img]

This had to been locked up and I bet overheated, I wonder how tight the rod bolts were when you untorqued them for removal....
still laughing but now at myself knowing the former owner of my Z/28 blew it up &quot;way better&quot; than yours.
The motor was already heavily worked on the drag strip, street and road racing.....sleeved in 4 cylinders, line bored twice, maybe 3 times before and only decked 4-5 thousaths.....roller cam with gear drive on a street n strip car, not a good idea.
Needless to say, anything that can happen to an engine blowing up happened to this lil 302...It Grenaded !
with only the top end and externals salvaged....... funny but not that funny when it happens to your own stuff.....

Tom

[Dave Rifkin]

Is that crankshaft salvageable; looks pretty beat up.

[SuperNovaSS]

Believe it or not, the engine did spin free after it blew up. I did not try to spin it when I bought it.

As far as the crank goes, the jury is still out. It depends if it is cracked. The mag powder doesn't lie.

Jason

[earntaz]

Absolutely crack check! And don't believe the theory of stand it on a rag and tap with a hammer to get a good &quot;ring&quot; ... UGH!!!

[427TJ]

R.I.P. Rest In Pieces.

[BJCHEV396]

Good stuff Jason.Very informative and interesting!

[SuperNovaSS]

Hey guys,


I thought I would just give an update for those following this thread.

The block came back from the machine shop with the only cracks being in the 2 cylinders I showed in the pictures. It is fixable and is being sent to Australia along with the oil pan which will be installed in a real Z/28 with a very close VIN.

The intake went to Australia to be installed on yet another Z.

The heads had no damage other than the one bent valve and have gone to the South where they will bring another Z/28 a little closer to correctness.

The crank was found to have no cracks so it was sent to Engine Warehouse in Sacramento, CA to be checked, welded, and turned. It came back a few days ago and looks awesome. It cleaned up at 10/10.



Jason

[scuncio]

Cool, glad you could save it. Why did you weld the crank?

[SuperNovaSS]

The journal got a bit beat up by the rod: