2Ltr CU piston issue

[dazwatson]

Hi,

Below are pictures taken after head removal due to fuel evaporating back into my dellorto's & suspecting a valve issue, its happening on cylinder No 4, what we have found is damage to the top of the piston & inside the head BUT no valve damage.

It certainly looks like I will be replacing the pistons but my first question is:

Can you just get pistons & rings as the bores are unmarked too, I've seen plenty of barrel kits but unfortunately funds are running low due to the carb conversion?

Next question, the inlet valve on the troubled cylinder is running bone dry, what's causing this?
TOP OF PISTON

INSIDE HEAD

LEFT HAND VALVE ON No 4 BONE DRY

[Bessie the camper]

I think you got a broken valve that course that your need to replace pistons barrels rings, heads and valves repaired plus when your doing all this I'd replaced oil pump and oil cooler and you might as well change push rod tubes.

And get loads of tea bags in I'm on my way to help

[HarryMann]

1) did you take compressions on all 4 cylinders first;
2) have you inspected the spark plugs closely or had any trouble with them;
3) what do you mean by a dry valve?
4) exactly what do you mean by evaporating back up...
Would like a few more symptons when it happened.

[bigherb]

It could have at some time ingested a accelerator pump jet from the 34PDSIT carbs, it never seamed to cause then much problem though.
What do you mean by fuel evaporating back?

[HarryMann]

Yup BH, good thought...
I was thinking an earth electrode off a plug, due to detonation or wrong plug heat range.
Question is...

Did any get down the side of the piston lands and what were the compressions before it came apart ?

[benlawlor85]

I have the same problems with my pistons



I was told the reason you can only get barrel and piston sets was coz they all need to be finely balanced.
Cheapest places seem to be VW heritage at £270 or AA performance at $228 but postage is loads from them

If you have just spent a wedge on new carbs i would just get the new pistons. no point on skimping now.

But I have had some people say replace them now. other say that if the lands are ok dont worry.
Slightly confused tbh.
But new ones wudnt hurt....
Ben

[nutbox]

Hi there,
I don't know if you know but there is a set of pistons and barrels for sale on eBay from vw heritage,one of the barrels is damaged ,they are asking £100 for them.
Hope this helps dazz

[benlawlor85]

1600cc pistons tho by the looks of it.

[nutbox]

Sorry my fault lol,I didn't take note because I knew they was selling some for 2.0cu not so long ago.
Scrub that post then.
Cheers dazz

[sarran1955]

Hello,

These are good for the price

http://en.serial-kombi.com/volkswagen-t ... 36761.html" onclick="window.open(this.href);return false;

AA products.. used them many times.. chinese pistons and barrels.. old style piston rings..

You will need a 'shim type' piston ring compressor..

Cordialement,

[benlawlor85]

A shim type? ive only ever used one of the winedy ones before.
is this the type you mean?
http://www.vwheritage.com/vw_spares_Too ... try_GB.htm" onclick="window.open(this.href);return false;

[sarran1955]

Hello,

Here is one..

http://www.ebay.co.uk/itm/Sealey-Piston ... 56422a2ed5" onclick="window.open(this.href);return false;

Very useful.. because you have very little room between the piston cylinder and head studs.. use a 1/4 drive ratchet instead of the square key shown..

Cordialement,

[benlawlor85]

Cheers. Ill get one ordered.
Removed some valves last night as i managed to borrow a compressor. one wouldnt come out easliy as the area where THE collet goes there was some damage. Think i will file this down with some wet n dry this evey and try again. I dont want to force it as it would obv damage the guide.

[HarryMann]

Think a fine stone might be a better bet than wet & dry.. wash any carborundum out of the guide thoroughly asap.