Piston to valve contact. How bad is this?

[RB30-POWER]

to go blaming the tune at this point in time with a shonky rebuild, valves hitting pistons and what not, would be wrong, imho.

valve hitting pistons may have caused a spark/pre ignition or just a sharp edge/hot spot in the combustion chamber that allows pre-ignition to happen and blow the gasket.

to blow a gasket like that on an na engine, something is wrong, either a really high static compression ratio and low octane fuel or possibly mechanical.

is this engine running kalmaker? should be able to monitor knock, although it may have been disabled, they tend to be rather sensitive and can pick up noise in general, so it may have been fiddled with.

best of luck anyway.

[TK]

Short term detonation won't really show up on the pistons, the spark plug is where you need to look, but even there may not tell the story.
It may be time to go through the whole thing, cc everything & check comp etc.
Blown head gasket can have amny causes, from detonation through to crappy finish on the heads etc - just coz the finish looks ok doesn't mean it's flat, if it's surface ground with too much load on the wheel it can dip quite a lot as it goes past the chambers, leaving low spots right where it's worst to have them.

It's a pity you're so far away, I'd be quite happy to have a look & see if I could figure out what is going on - I've actually built quite a few tough V6's.

[260BC]

Thats a bad deal Steve, hope it can be sorted without too much more financial pain. Good engine builders are hard to find in Brisbane, PM if you want to try the bloke who built my VG30DET.

[Steve]

I just deleted by accident my whole big long rant so now I'll start again and give youse the edited version.

The engine's supposed to go back together tomorrow arvo. I've hung onto the head gaskets so I can go over everything before old mate tries to hide anything... At this point i've lost my sense of humour pretty majorly. If there's one little thing not been done that i've asked to be fixed I'm going to pull the job and go elsewhere. I didn't hit him up for a new set of slugs, but did insist the fly cuts be fixed if that's possible. If it's a hack job when I get there the shit's going to hit the fan.

Yes I do have a Kalmaker running it, and the knock sensor is working and the filter has been adjusted for what is engine noise and what is knock. It's not knocking. We brought the ignition back to 21 deg total advance at WOT and from 70 - 100kPa which is pretty much everywhere with this cam AFR's are between 12.5 to 12.8 across the board and drop back to 13:1 at 70kPa

[lukevl]

Fly cuts will require re-ceramic coating so don't forget to hit him up about that.
Like Bill and TK say- plastecine is the way to go so you can find where the valve goes.
TK- I agree about starting with the car in neutral which is why i hate that Holden made it mandatory!
Stocky- Leave him alone. Its personal choice. I don't pick on the colour of your car- even though I should

[Steve]

Stocky- Leave him alone. Its personal choice. I don't pick on the colour of your car- even though I should

It's OK, he's a part time wanker, on the job. lol

The pistons were coated mainly for the skirts, but the tops get done anyway. I'm with you that they should be re-done but at this point I'll be happy just to see it back together to my satisfaction.

[stockymcstock]

yeah but anyone who modifies one of those cuntarse engines is asking for trouble, they just don't lend themselves to modification at all. if i was you steve i'd whack a 2j in it and sell the engine - may break even?

btw luke you're not at tighe any more i guess? i'm thinkin about getting a custom grind cam for my runabout car - can't hook me up any more? heard you moved out west or something....... i guess it all comes down to mining eventually

[stockymcstock]

also maroon > white











ps my car looks liek shit

[Steve]

Make that Full Time Wanker.
Fuck off out of my internet!

[Sturmovik]

Buick V6s were pulling big numbers before the 2J even existed :p

http://www.youtube.com/watch?v=VneQFkT2WPQ

[crack]

there is a dude on streetcommodores.com who has run numerous 11 sec passes with a standard buick engine, log manifolds, gt3582r (1.06 a/r turbine) and kalmaker tune. if he was to replace his engine with another high km buick i couldn't see him paying much more than a couple of hundred max for it.

therefore, stocky while i can see your point about it not being worth modifying the engine internally, i cannot see why you need to do an engine transplant when they can handle a fair bit of abuse and are very cheap to replace.

[Sturmovik]

http://www.youtube.com/watch?v=CFOrksIsbPw

[BigMuz]

I know they don't seem to line up but valve float does exactly what you have even with heaps of static clearance.

[Steve]

So could valve springs be the problem?

[stockymcstock]

i think youse cunts are all overlooking the fact that buicks suck arse

p.s. not really


p.p.s yeah really