oh jeeez - That really isn't good!

[Ian H]

Wow thanks so much for this - a glimmer of hope!
I would never had thought piston crowns would have a cut out like that!
Will pull the heads and take a very good look at the piston heads and valves.
Will let you know what I find

 

[Ian H]

so here it is 'chunky' crown and all - straight out of the manuals kindly provided by this great forum - many thanks peeps!

 

[zagatoes30]

To add it has been known for the bottom end bearings to be damaged as a consequence too. Not every time though.

Alfas tend to do this, when a valve hits the piston flat spots the bottom end bearing which fails soon after if you don't replace. My Alfa specialist always replaced just in case.

I think its safe to say this valve hit the piston, from my 3.2 V6 GT - It now makes a perfect desktop paper weight

 

[conaero]

Yes it is , or no one would have reported bent valves in the past. Only non interference engine I've come across was a modern Fiat Cinquecento.

Correct. The current Fiat 1.2/1.4 as found in the 500 is the only non interference engine I know of.

 

[Ebenezer]

What's an interference/non interference engine?
Eb

 

[philw696]

What's an interference/non interference engine?
Eb

Interference is where valves hit the pistons when it goes wrong and a big bill ahead

 

[Ebenezer]

So most engines are interference and the pistons will hit the valves if the timing goes awry. So what's the advantage of interference engines?
Eb

 

[philw696]

So most engines are interference and the pistons will hit the valves if the timing goes awry. So what's the advantage of interference engines?
Eb

High performance usually with closer tolerances.

 

[Tallman]

So most engines are interference and the pistons will hit the valves if the timing goes awry. So what's the advantage of interference engines?
Eb

Higher compression and more options to shape the chamber for optimum combustion and flow

 

[azapa]

What's an interference/non interference engine?
Eb

as mentioned above, if you imagine a valve fully open, and a piston at top dead center, in a non-interference engine the two won't touch. On the other hand, for example, in most modern engines with "interference" when a cam belt breaks (or chain, or similar) and the valve is stuck fully open, but the pistons are still moving, the impact between the two will break expensive stuff.

 

[Ian H]

Ok so I have started the adventure to remove the cyldinder heads and see what damage may have arisen - bit scary.
I have the cylinder head cover off on one side but have left the plenum in place.
I have removed the 10 cylinder head retaining studs but the cylinder head still seems pretty well scured to the block.
I know it may need a bit of pressure to release the head but just want to make sure I haven't missed anything before applying force?
Also not clear exactly where to apply any force given soft alloy heads all round?
Any guidance greatly received
Many thanks

 

[rs48635]

Correct. The current Fiat 1.2/1.4 as found in the 500 is the only non interference engine I know of.

Think my MX-5 engine is also non interference.

 

[madmanmart]

Ok so I have started the adventure to remove the cyldinder heads and see what damage may have arisen - bit scary.
I have the cylinder head cover off on one side but have left the plenum in place.
I have removed the 10 cylinder head retaining studs but the cylinder head still seems pretty well scured to the block.
I know it may need a bit of pressure to release the head but just want to make sure I haven't missed anything before applying force?
Also not clear exactly where to apply any force given soft alloy heads all round?
Any guidance greatly received
Many thanks

Have you removed the cam shafts?
If I remember you need to remove them and then the buckets before so the cam boxes will come off.
Then the head comes off.

 

[rs48635]

I would think if it was an interference engine there would be quite a bit of noise associated when it failed and certainly not just whirring when you spin it with the starter. Fingers crossed for you!

My Busso V6 snapped a belt.
Before I realised this the starter whirred away quietly. Once the belt is snapped and the piston haven't valves there might be no further metal on metal noise. In my case all 24 valves and several guides were ge-fuckt. Somehow the bottom end survived.
Bad luck with your 3200 and hope you can get the engine repaired.

 

[Wack61]

Correct. The current Fiat 1.2/1.4 as found in the 500 is the only non interference engine I know of.

Mx5 1.8 Is non interference , I'll have to dig mine out of the garage , sun is out

 

[Jhc32gt]

There's a 3200 on copart auctions currently. Ending on Monday.
Engine in it is good and has just had a new cambelt and water pump...

 

[Nibby]

Think my MX-5 engine is also non interference.

Austin Montego, non interference and the easiest car to change the timing belt on as I was even able to do it.

 

[philw696]

Austin Montego, non interference and the easiest car to change the timing belt on as I was even able to do it.

Montego to Maserati respect to you sir.

 

[Ian H]

Ok so I guess the cams and buckets need to come out first before the head comes off.
Proving **** near impossible to get the crazily tight rear cam box hex screws out with zero visibility /clearance while the engine is still in.
Time to walk away for a bit ...

 

[Black Mazerati]

I don't know if this is a factor here. Do these have roller lifters?

Different set up, but I had a guy build a beast of a motor for a boat I had. The only problem was he forgot to check the piston to valve clearance. We get it out and it didn't want to rev past 3,000 RPMS so then he pushed it....bang! Destroyed 4 valves. I insisted on a new block and pistons as the block would have been at it's limit if it was bored again. Then I asked him about the lifters....oh, they will be fine he says. In less than 5 hours every lifter for the 4 valves that here hit came apart. Food for thought.