Signs your winter project just snowballed...

[Blown353]

Well, today was going to be the last drive of my Chevelle before I pulled it apart for my usual big winter changes.

The last time I drove the car was 2 weeks ago to an end of season cruise-in, and everything was fine. So today after lunch I go start it and back out of the garage. I'm really easy on my cars when cold so until the coolant & oil is up to temp I hardly give it any throttle and shift before 2500 rpm.

I'm about 1 mile down the road from the house in 3rd gear at 2200 rpm when the engine starts missing; the mirrors are shaking and the exhaust is popping-- I figure it's a bad plug wire or bad plug as it feels like 7 cylinders and there is certainly raw fuel being dumped into the exhaust to cause the popping. I turn around and head home.

I get home and while it's idling I start disconnecting injector wires; disconnecting cylinder #6 doesn't change the RPM but the raw fuel smell from the exhaust goes away. Bingo!

So I pull the plug wire and check it; the meter says it's OK. Then I pull the plug and see something I never expected to see... I saw lots of $$$ signs.

Something has obviously impacted the plug, folded the ground strap over, and left sharp dings in the ground strap. The engine hasn't ingested any foreign material, so that leaves internal bits. The dings are far too sharp for aluminum to have created, so I'm pretty certain based on how sharp the dings are I'm thinking the upper ring and ring land of the piston came apart.





Then again, I kind of figured something was up; over the course of this year my oil consumption kept slowly increasing and most of the plugs started to show signs of oil in the cylinders. I guess 5 years of 15 psi of boost & abuse on JE lightweight pistons is about all they'll take. When I added the Procharger I opened the ring gaps up but left my original pistons in place; I guess it's time to step up to actual blower pistons.

All the other plugs were OK.

It's probably a good thing it decided to let go at a low RPM, low speed cruise; had it let go at 6600 rpm under 15 psi of boost things may have been really ugly.

In a way this event is a blessing; because if the rings & pistons had scattered next year it would have taken out the turbine wheels on these brand new PT-61/76RS turbos that are my winter project...



More updates after I tear it down. I'm hoping the head, valves, and valve seats are OK, and the block can live with a .010" bore (I'm .020" over right now.) Either that or now is the time to step up to a Dart Little M, I was already pushing my luck with a stock 010 block and 15 psi of boost.

Time to dig a little deeper in the piggy bank for more parts.