fiestaturbo.com

[Percy!]

Ok I plan to fit a t3 to my 2.0 and run it at around 200bhp and have been told I have 3 ways of gettin lower compression, can you please tell me the advantages, disadvantages and prices of each:

1, Use a decomp gasket

2, skim the pistons

3 New pistons

Thanks

[Max M4X WW]

From reading previous posts in the past, I think Calibra Turbo pistons is the ideal solution?

[heeman10]

Piston skimming is nasty

[Project]

Can't (safely) skim the 2.0L pistons.

Decomp plate - cheap, and if you put all the breathers and oil return(s) onto the sump instead of the block then you can use a standard 2.0L block, so if you do hole a piston you just need to swap in a standard block.

Forged low-comp pistons are a lot tougher but can still go pop if you don't pay the $ to have the car properly set-up.

/Munk

[Percy!]

I don't think I can get away with Calibra Turbo pistons, isn't as a slight re-bore needed?. My engine is a series one 2.0 zetec which means it is basically a re-bored 1.8 so thats not a good plan.

I won't get the pistons skimmed, doesn't sound good.

So looks like a decomp plate it is, but what kind of power would a standard block be pushed 2 with this kind of setup? Should take 200bhp but how much further could it go?

I suppose new pistons is the way forward for really high power but I don't plan to go much past 200bhp.

So whats all this about compressions ratios? is there a basic guide anywhere?

Also anybody know where I can get a decomp plate from?

Thanks for the help so far.

[saqmaster]

I don't think I can get away with Calibra Turbo pistons, isn't as a slight re-bore needed?. My engine is a series one 2.0 zetec which means it is basically a re-bored 1.8 so thats not a good plan.

I won't get the pistons skimmed, doesn't sound good.

So looks like a decomp plate it is, but what kind of power would a standard block be pushed 2 with this kind of setup? Should take 200bhp but how much further could it go?

I suppose new pistons is the way forward for really high power but I don't plan to go much past 200bhp.

So whats all this about compressions ratios? is there a basic guide anywhere?

Also anybody know where I can get a decomp plate from?
Thanks for the help so far.

Series 1 Zetec? Do you mean the Pre 97 Zetec E engine (silver top)? Either way, you wont have a problem with the Calibra Turbo pistons (86mm bore). You will need a re-bore, and unless your engine has done 200k or has been damaged in the past, you shouldnt have a problem. Decomp plates and skimming pistons is nasty. The Opel pistons on a standard zetec head will give you around 7.5:1 CR..

If you're converting from N/A to Turbo, you have a lot more things to worry about than just dropping your CR

[Percy!]

I know I have more to worry about, just trying to get my head around this bit, I may have found a solution:

http://www.mountune.com/acatalog/Z984129.html

Whats the difference between the Fully skirted and slipper?

But they are deigned for the 2.0 zetec so its a swap rather than rebores etc

Still confused about compression ratios, what does it all mean? Trying to understand what I am actually doing to my car!

[heeman10]

The compression ratio tells by what magnitude the original mixture volume in the combustion chamber is compressed. If you have a high compression ratio, your squashing the starting volume to a very small volume, which will give big power and big heat, stresses etc. Any use?

[Percy!]

Thats makes more sense now, thanks.

So are the above pistons any good? and as above anybody know the difference?

[heeman10]

Well you've got a choice of two haven't you - maybe get two of each? I'd speak to an experienced tuner to get their opinion.

Basically, the slipper piston does away with the skirt and the bottom. This will give two "benefits"; weight loss and friction reduction. Though there are no weights listed with them, I doubt it's going to lose much more than 10% of the piston's weight, and as far as friction is concerned - I don't think you're planning on building a highly-tuned, frequently-rebuilt engine (you're after around 200bhp right?), and so I personally don't think the reduction in friction is particularly important.

The skirted piston will weigh that little bit more, but because the skirts are in contact with the bores, you might get more even, light wear on the bores because the piston won't have the room to "rock" inside on the up and down strokes. Who makes those pistons by the way?

[Percy!]

JE racing pistons including pins and rings

For 2.0 l zetec engine standard bore (84.99mm) no need to over bore.

1.27mm inverted dome to give a compression ration of 8.8 -1 (on 48cc standard UK head)

Compression distance 29.74mm

Fully balanced as a matched set

Not bothered about price of the 2 as its only a slight difference,

So basically the fully skirted is the safe option for what I am trying to do.

Thanks for your help

[saqmaster]

JE racing pistons including pins and rings

For 2.0 l zetec engine standard bore (84.99mm) no need to over bore.

1.27mm inverted dome to give a compression ration of 8.8 -1 (on 48cc standard UK head)

Compression distance 29.74mm

Fully balanced as a matched set

Not bothered about price of the 2 as its only a slight difference,

So basically the fully skirted is the safe option for what I am trying to do.

Thanks for your help

That's not a low enough compression ratio, and i've seen these pistons on eBay.. And you will _want_ to get oversize pistons as your engine most likely will _definately_ require a bore and hone.. Measure your bores before you order pistons