sierra td piston damage

[rodney]

hello people just wanted some opinions really ,

i havbe a k reg sierra 1.8 td , when i bought it it were sluggish and tappy , along with a smoke trail where ever i went ,
i ajusted the pump timing and got it runnin better , but still sounded cammy and left black smoke when under load and on idle ,i thought smoke may have been due to lack of air due to moody cam hence the smoke , anyways i bought a 2000 escort van td , 90k etc , ran well , thought id swap cams and lifters , locked it off with pins and spun it by hand when done etc ,
but it didnt like running and ran worseeven after a few ajustments! , so today i pulled the head off thinking ill put the td escort head on etc,

this is what i found!!............




wernt expecting that! although i had a feeling that something would show once i lifted the head ,

the valve marks are on all 4 and i can tell if they are fresh or old , i half tempted to rub the lips from the valves down thats on the pistons from contact , they are very sharp , the heads got cracks as you can see but i got the new head to go on ,

you guys reckon ill get away with them pistons? , i don't want to have to fit my spare bottom end too if i don't have too , so thought it ask some opinions

[Deleted]

Dayum, i think Sierra TD Pistons are hard to get, not sure if Escort ones work?

[sowen]

I'd do as you say and de-burr the pistons, I think it's highly unlikely they would fail because of hitting the valves. Only thing I can think of is how deep is the damage, as it's overlapping the combustion depression in the piston face?

[rodney]

danny they look identical to the escort pistons in my 2000 td van , I'm thinking to tidy the pistons and fit the new head , i only want to swap bottom ends if i really have too lol ,

the bores and edges of the pistons seem ok,.

[dodgerover]

Do they do different thickness head gaskets for those like for the peugeot/ ford 2.3D if so go for the thickest one in case someone has skimmed the block

[usedabused]

I had exactly the same issue in my 98 escort estate only deeper and fitted a set listed for a P100 worked very well afterwords.

[rodney]

i bought a standard gasket for a td escort van today for when i put it back together , the car ran poor when i bought it so this may have already happened prior to me buying it , just cant be 100% , so ill prob clean pistons up and fit the escort head complete on the sierra and see how it goes,.

[bortaf]

TBH i don't think i've had a ford TD without whitness makrs from valve conntact, usually down to a snapped belt in the past, usually a snapped belt means a snapped cam from the impact rather than cracked pistons but if it happens on cranking, idle or when out of gear you just get the whitness marks.
They do need the right head gasket (3 differant sizes on the ford 1.8), there will be a tab that sticks out between the head and block with holes or notches in it, you need to match the marks or thickness as if too thin a gasket is used they can contact at high revs, they run very close safest bet it to use the thickest available.
Get a feeler gauge on the cam/follower as if the valves have impacted they can shorten and that opens the the gap and they will need reshimming/replacing

[retrowrongun]

Over revving the motor is probably the cause of that
It's funny cos cosworth yb motors are exactly same too mate
After 7k the valves tend to clip pistons

And those pistons will go again no worries

[rodney]

sweet i thought so but being my own motor i wanted some opinions lol , ill put a thread on the car once its running , i need to find the time this week to do it as its gonna be my daily for a bit

[retrowrongun]

Ill get some pics up of some of my yb pistons lol
And you may be suprised as they really do clip when over revved
Never had any probs with reusing them tho as long as rings, ringlands and sides of pistons are good

[chairchild]

another vote for "clean 'em up"

Derv pistons are tough things

[rodney]

well i put it together today , fired it up and seem to run ok , then i made i rookie mistake and retightened the head just to be sure and snapped a bolt pmsl , so i gotta pull the head again , and later td escorts have thicker head bolts that sierra td's so gotta make sure i get the thin bolts,

was having a bad day from the start and thought it got better till i broke it pmsl,.

[chairchild]

I've had bad days, but that one sounds pretty crappy! lol

[retrowrongun]

Ouch but if makes you feel better have personally done the same before now
I always run car about for 100 mes or so and let it all go through a few heat cycles first before retourquing bolts now

Either way bad luck fella at least you should now be able to whip it all off again blindfolded and hopefully stud should come out freely being freshly put in

Fingers crossed mate

[bortaf]

Yeah you really need to fit new bolts bowt £15 on egay (bought some last month for the TD going in me cortina)

[rodney]

yeah proper gay , on the upside ive ordered new gasket and bolts , soon as they arrive ill get on it and hope the broken bolt comes out ok lol,.

[retrowrongun]

With the luck you have had so far can see you having to get a mig out and weld a nut onto the broken stud to remove it lol


There I've said it now hahaha , phew that feels better

[rodney]

you f*$ker lol , bolt broke high up so I'm hoping theres enougth to grip,.

[dodgerover]

Once the pressure is off them they usually come out ok....They really aren't expensive for a new set of stretch bolts everytime