Looking for a set of these pistons, 86mm bore, for a 2.1 ZVH turbo conversion.

A set of turbo pistons would be nice, but any C20XE will do - found in Vectras, Astras and Calibras of the early 90's.

I'm no Opel expert, so if anyone is willing to write some information for me, to aid me in my search for the best pistons for the job, I'd be very grateful.

Thanks!

You are right. Any xe pistons will do but early astra GTE and calibra turbo ones are forged items made by Mahle. They are a lot stronger.

You will have to bore your block and increase the size of your rod little ends to fit the XE gudgeon pin. Most machine/engine shops will charge you £100-150 for this work.

My only question is why bother with the cvh head?
Stick to sixteen valves!!

The RST exhaust manifold will bolt straight on with small mods and that only leaves you the induction side to sort out.

Doug.

theres someone on the westfield forum with a set of pistons/rods for sale off an xe...

Ned.

oops i mean blatchat forum:
http://www.blatchat.com/t.asp?Id=48486

[Edited on 1/3/04 by ned]

I'm sticking with the CVH head, mainly because I invested a lot of money in it, getting it properly flowed, with 45mm inlet valves. I also find it very easy to maintain - I only ever need to replace half the number of parts as with a 16V head, and cam timing is a breeze.

Another reason, is that with very tight TÜV regulations, it's practically forbidden to change to engines which were never built into your model from the factory - by keeping the CVH head and rocker cover, it will still look quite standard, and I should be able to blag my way through any roadside checks. I think a shiny Zetec rocker cover would be a bit more noticable, than a dipstick poking up in the wrong place.

I also enjoy the challenge of building something different - here in mainland Europe, I'm one of only a handful of people doing such a conversion (in fact there's only 1 dutch guy currently building a ZVH Turbo, and in Holland there's also one on Webers, a friend of his)

BTW I've heard that all XE pistons are Mahle forged items, up until a certain date, when they changed the heads and pistons to be less noisy. I'm thinking anything before 92 will be the right ones. Be nice to find the LET items, but they are probably rarer than hens teeth.

Thanks for the advice - I'll keep you all posted on how it progresses.

the let ones i'm guessing will be different as the calibra turbo engine was lower compression, unless this was achieved by different rods or head gaskets? the comperssion ratio on an let is more like 8.5:1 than the xe's 10.5:1.

Early engine/pistons are better. You may be referring to the later 'low noise' type head. I'm not exactly sure but know after a certain date they used cast pistons which were weaker.

Hope this Helps...

Ned.

I've been told that the crank and rods are always the same, and the heads are also the same (so called Coscasts or later Opel versions - opinion varies on which is best, but they are all interchangable between Turbo and N/A apparently). So the change must come from the pistons. Found a table where the bore and stroke of the different engines is listed, and they are the same.

Here's some info from Accralite:

Vauxhall Opel 2.0L & 2.5L 16v Turbo
Bore:86.0
Comp:30.05
Pin:21.0
Vauxhall Opel 2.0L 16v
86.0
30.5
21.0
So the turbo ones are marginally shorter - not a bad thing for building a high boosting turbo!

Still, if the guy you put me onto is willing to sell his pistons for a nice price, then I'll be well on the way.

BTW Ned what happened to your set?

Garage did you machine some extra oilways into the pistons? I've heard this is needed to provide adequate lubrication.

[Edited on 2/3/04 by ON-UJAH]

Unfortunately he only had a set of the later pistons - so the search continues.

Are you just looking for pistons or do you need the rods too? I do have a set but was holding onto them for the mo, mail me an offer (offline) if you're interested (they are the early type pistons from an early xe engine).

Ned.

I'm only looking for the pistons.

Okelly dokelly Ned - absotively posilutely sent you a mail-ah-doo-dah already, neighbor.

email replied...

Ned.

So another question for you guys - what rings should I run? I'm thinking the LET rings would be fine, but do they fit OK?

If not, would the ring gaps be too tight for the turbo, if I used XE rings?

Thanks for all your help!