RS 5tu

iTrader: (2)

Why go 2.1 and not say at 2.0 is it just the fact that you can use calibre pistons? what power gain would you get say over a 2.1 instead of 1.8 (i have 1.8 btw) but never bother thinking about 2.1 how much could you do a 2.1 with calibra pistons and modded rods?

Also any one know all the bits you have to do and need to do a 2.1 and rough cost (parts only no labour)

vroooom ptssssh

its not even 2.1 im sure its something like 2048CC

XRT_si

iTrader: (2)

True, C20LET pistons dont ACTUALLY give 2.1. Just everyone says it.

RS 5tu

iTrader: (2)

Yeh i know but is the piston not shorter giving little more stroke (if you know what i mean) making it 2.1? Thats the only thing i can think of

Stavros

Anything over 2050cc is classed at 2.1?

Isnt it over that?

If not, thats retarded.

RS 5tu

iTrader: (2)

as above its 2048cc but if the piston were shorter it could move further down the cylinder giving it 2.1

bonus_boy

but its a 2048cc so its classed as a 2.0...

RS 5tu

iTrader: (2)

it must be 2.1, do you not have to bore it out?

Red16

the reason people dont stay at 2.0 is because the used Zetec engines need a rebore, hence the increase in capacity (whatever it may be)

pa_sjo

I think back to automotive school for you sonny

Stavros

I was gonna say that earlier, but resisted

RS 5tu

iTrader: (2)

Whys that? there are more ways to increase cc than a rebore. Any way it was only a guess as i dont know,How els do they get 2.1? or is what you are saying there is NO 2.1s

pa_sjo

I'm sure someone out there has used 86.5mm pistons to obtain a real 2.1L zetec.. 86mm bore by 88mm stroke is 2.0L, not 2.1L.

And you're right, you can increase displacement by change stroke, as well as bore. Running a shorter compression height piston though is not changing your stroke!!

RS 5tu

iTrader: (2)

So my wording was crap but you get what i mean?

pa_sjo

No, it was just wrong. You said a shorter piston gives you more stroke, which it does not. The crank dictates the stroke, the piston has nothing to do it with it

Stavros

a shorter piston gives you lower compression stu, nowt else

RS 5tu

iTrader: (2)

Well like i said it was only a guess to how you got 2.1
So if i got a 2.0 with calibra piston it would still be 2.0 becouse its actually 2048cc So my question is would it be worth it changing my 1.8 for a 2.0 i would say no...?

pa_sjo

What is your 1800cc engine? Turbo? 8v? 16v?

RS 5tu

iTrader: (2)

1.8 Turbo 8v

pa_sjo

So are you asking about simply changing the bottom end to a 2L one, or going the full 16v?

RS 5tu

iTrader: (2)

Well coz my car is off the road i am doing some changes efi conversion and restoring it and respray, I was after a bit more power but since i already have a 1.8 would i get a good increase and how much and how to get this "2.1" people always rave on about. Staying 8v btw i have got a good spec head.

pa_sjo

Then you'd most likely not get any more power, just get a wider power band..

RS 5tu

iTrader: (2)

No point then for the price i could build a bottom end i could spend the money on something else. (like finishing it )

xrsi

iTrader: (1)

also rod length plays a part as well in the stroke

piston height can be a factor in the overall stroke that can be used within an engine as a shorter length between the rod pin and the crown will enable you to have a slightly larger throw or longer rod compaired to an identical engine with a larger pin to crown length as it would protrude out of the bore if it were the same length. But as said the height of the piston is mainly to do with the CR ratios.

the larger the capacity the more torque and power that can be obtained from the same mods as the increased capacity offers the chance for more air to enter the cylinders and in turn more fuel creating a lsrger bang within the cylinder (i said chance as at full throttle with the engbine approaching the red line the time the valve is open for gets les and less and there is a critical point where the cylinder can no longer obtain enough ai to be full in the time the valve is open, this is normally at the point of peak power)

if you were going to change to a 2ltr for the cost of the calibra pistons and also the work required to fit them to the rods then i would just get some propper pistons for zetec (likes of JE are cheap)

pa_sjo

What? I'll repeat what I said. The crank is the ONLY thing that dictates the STROKE of an engine. Rod length, piston height, completely irrelevant.

SiZT

xrsi

iTrader: (1)

i said the piston height dictates the maximum stroke you can have. Yeah thinking back harder to my uni days im thinking of dispalacement where rod length is included not stroke, its late at night and im knackered!

pa_sjo

The piston comrpession height AND rod length dictate the maximum stroke you can have (well, and the physical space you have inside the crank case )..

It doesn't hurt to stir up the ol' grey matter on this stuff

xrsi

iTrader: (1)

its really bad, i sat through 3 years of lectures and finished 2 years ago and havent had to use anythnig from my degree!

normally i can rememebr alot of the stuff without refering back to some old notes (as long as it wasnt engineering maths - hated that! lol)

yeah making sure you have enough room for the throw inside the crank case is always a good idea! wouldnt be supprised if people havent when designing an engine before now! lol