Lets play the guessing game!

[fubar andy]

After seeing Campbellju's post that he's putting his engine back in, I finally looked at mine this evening.

Currently I think I'm looking at a head gasket failure and the catch tank filled with water and oil after the engine made a PPPFFFTTTT sound at around 4500 rpm at low load *4th gear*
(Although the original builder said, I've had massive detonation and the pistons have destroyed themselves - although looking down the bores, pistons looks ok, but I can't tell until I crack it open)

Would it be reasonable to say the piston 1 has been the one that let go?

Bearing in mind that the engine has been untouched for over a year now, do the rest of the plugs look acceptable, or is there anything I might have missed?

PISTON 1



PISTON 2,3,4

 

[campbellju]

#1 spark has an oil issue, the others aren't perfect but #2 and #4 could get cleaned off the next time you got the car under load with higher temperatures.

Oil doesn't necessarily mean it's a HG, if you're oil ring fails on the piston then it would have the same affect. My first standard engine failed in this way and my catch tank didn't fill with oil.

 

[PobodY]

I'd say something similar, and would probably give the other three a rub with a wire brush, re-gap, then put them back in (if you weren't tearing it down). - It could be that the crap on the other plugs is from sucking something through when the failure occurred.

Diagnosing from spark plugs is a bit of a black art, so it really only tells you the state of the engine shortly before it was shut off... but it does look like yours was upset.

 

[fubar andy]

Without question its upset but when it popped the catch tank filled with water and oil (with vapour) since then it's evaporated.

It certainly won't run and I won't bother trying to fire it up.

I'm very keen to crack open the engine but I'll have to wait till my man cave is ready.

Would the oil rings fail so quickly with less than 500 miles of running in time?

 

[campbellju]

when it popped the catch tank filled with water and oil (with vapour) since then it's evaporated.

Would the oil rings fail so quickly with less than 500 miles of running in time?

Not unless there was a catastrophic failure..... which there was. As the water got into the oil, even if only the HG failed, it would be worth stripping the bottom end down to check for any other issues. Otherwise you might go through the hassle of changing the HG and find something different fails in another 500 miles.

First step is still to take your head off and check the source of the failure.

 

[The Doc]

Plugs 2 3 4 look to have alloy deposits on them, 1 looks oil and moisture covered, i think detonation and ring or ringland failure on cylinder 1 as det sometimes manifests itself on the side of the piston first.

 

[fubar andy]

it would be worth stripping the bottom end down to check for any other issues. Otherwise you might go through the hassle of changing the HG and find something different fails in another 500 miles.

Without question that's what I'm going to do, I don't want to risk anything and I want to make sure that everything is spot on before I even think about rebuilding it!

Plugs 2 3 4 look to have alloy deposits on them, 1 looks oil and moisture covered, i think detonation and ring or ringland failure on cylinder 1 as det sometimes manifests itself on the side of the piston first.

Yeah I did see that on the plugs and it did make me wonder whether it was partials?