schpenxel

Did you clean that third piston from the left or was it cleaner than the rest already when you pulled the head off?

neverstop

I always keep can of torco in my trunk too. cheap insurance.

if it were me I'd drop that piston out for sure. it can get way worse if there is something broken and you try and beat on it and it grenades

aAZz

Piston #4 is the one that had the valve issue and thats the one that looks the cleanest. I haven't clean any of the pistons

I normally drive around with a 5 gallon jug of race gas but like i said i dropped the ball this weekend. Whats strange to me is i drove it almost 100 miles home as i was in Marana, AZ to north phx and car drove great aside from slight misfire. If it was something way worse I would think it would of grenaded on the way home.

stevieturbo

Really it all needs to come apart. Ringlands can be cracked, broken, whatever and you'll not see it from above.

As for the valve, is that video with valve closed, spring fitted etc etc ? If the melted part of the plug doesnt end up down the side of the piston, it can sometimes end up under the valve damaging it and the seat before it exits the engine. Assuming it didnt just melt into oblivion lol

slow ride

You could rig up a plate and leak down the cylinder if you are crafty.

stevieturbo

And it would still be a gamble.

They need inspected properly, or dont bother at all and hope.

The_Nigel

The valve got hit most likely due to the plug tip breaking and it was caught between the valve and the seat.

If you have a good head put it on with a used headgasket and torque them halfway and do a leak test to see if you're getting any crankcase blowby.

ajrothm

Odds are, it broke the middle ringland on the piston. It also likely closed up the ring gaps (cooked the rings and they lost tension).

Every time I have ever melted a strap on the plug, it was accompanied with either melted pistons and/or torched rings.

Time for the rebuild/upgrade.


At a minimum, knock that one piston out and take a look at it. If its broke, hustle up another stock piston/ring pack and throw in it. Call it good for cheap.

schpenxel

And you have melted a few

ajrothm

Yeah....I know...

And don't even know why...thats the worst part.

stevieturbo

Well plugs do not melt from good tuning and setup.

Therein lies a clue.

I was at an event recently.....a guy with a truly stunning car had spent a fortune over the winter months. Totally new engine, turbo setup etc etc etc An easy 40-50k spent ( 4cyl car )

It blew up literally on its first outing, before it even finished its first lap. Melted pistons, melted plugs.
An engine making only moderate power, on race fuel etc

There is no way in hell that engine should even have been stressed.

But to look at the build, it's blatantly obvious why it failed. So many flaws and poor implementation it just shouts that those involved should never have been with a car at that level. They were clearly in over their heads. How some of the places involved are still in business is a mystery !

But that is the tuning world. Money doesnt always prevent problems.

Knowledge does. That usually comes fro experience.

You'll only see melted plug tips from too lean and/or detonation. It really is that simple for 99% of cases.

aAZz

Quick update for any of those that care. Decided to try my luck and slap on a set of 317's that I had laying around. Finished putting the car back together last night and drove it to a car meet that's about 50 miles round trip. Car runs fine no misfires at all. Drove it to work this morning and everything looks good. Debating on just ordering at least some 80# injectors and doing a flex fuel kit so when I do beat on it I can do it on E54.

russ472

Awesome! sounds like you lucked out

aAZz

Definitely did. Still really want to find out exactly what caused it as I would like to prevent it. Not sure if i got a bad batch of gas, the change in elevation from phx to tucson or if one of my injectors wasn't functioning properly.

Unreal

If anything tucson would be safer than phoenix.

aAZz

That's what I figured. I normally fill up at QT which I've seen in Phx is one of the most consistent gasoline stations but that night we filled up on the way there at Circle K so leaning towards bad batch of gas or injectors.