BRAMMER

iTrader: (23)

2wd in a 200 block - would they be fine or not?

Advantages and disadvantages please

RS SHAUN

iTrader: (24)

This is what I'm thinking about, do I use a set of mint 2wd pistons with pockets done, or buy 4wd ones with the offset pin?
Don't won't piston slap!
Cheers shaun

rsmark86

iTrader: (3)

as above will piston slap when cold... but otherwise cant see there being a problem

BRAMMER

iTrader: (23)

What causes piston slap with 2wd pistons in a 200 block and not in a 205 block? i thought they were both identical bore at std size?

v man

its the position of the gudgeon pin that causes the slap

4x4 pistons ahve an off set pin so the piston gets pushed up the bore in a better way

but if you by new pistons then they all ahve the off set pin now anyway

BRAMMER

iTrader: (23)

But why in one block but not another? i never suffered from it at all in my original 2wd motor

rsmark86

iTrader: (3)

well if they dont at the mo then my guess is it wont change mate... might have already had the off set pins in the past

tabetha

ALL YB PISTONS 2WD AND 4WD HAVE OFFSET WRIST PIN, the difference is 4wd have more offset, it's not detrimental in any way other than annoying some people, if it doesn't go away when warm then you have a little wear, but will still go for miles, mine had piston slap when hot, but still managed 200,973 miles before it was taken apart, compression was fine, as was mpg, and emissions, it did 40+ mpg without especially trying, emissions were 0.97% CO, 137PPM, with 190,000+ on it.
The oil rings went like overnight almost, and started drinking oil at 1L every 10-15miles, hardly smoked at all though.
The 2wd degree of offset hasn't been used for years, I'd be seriously amazed if it was still used, the reason for the offset is the thrust of the piston as it is pushed down the bore it tries to rock, the offset is to counter this.
4wd yb were reworked in several ways, one way was more offset to the wrist pin, hence less noise.
tabetha

cossie891

iTrader: (1)

How do I tell if I have 4wd pistons or 2wd?

tabetha

Have the correct tools to measure the offset of the wrist pin.
If they are under 10 years old I would be amazed if they had the original 2wd pin offset.
There has been significant material changes over the years, so any cossie engine built now benefits from this, and would likely have a tighter bore clearance, I run 1+1/2 thou bore clearance for example, the pistons contain massive steel straps inside the casting so they don't expand as much as before, this is one way in which the materials have got better.
I know my engine is new but there is NO noise from cold, not even half a tap from a tappet, these have done 80,000+ miles, but I cleaned them out, they are INA, made in germany(they have factories everywhere) but they are nothing special inside just bog std same as all the others I've cleaned out over the years.
tabetha

BRAMMER

iTrader: (23)

I would imagine numbers

cossie891

iTrader: (1)

Do you know what the numbers are dude the ones in my new 205 engine has a semi circle in the skirt and the ones in my old 205 didnt have them any ideas whats what