bassboy

As you may have seen from my other thread, I will be carrying out a 1.8 zetec turbo conversion as a gap fill in my car...I have been looking into decompression plates and came across a few people who have used VAG 1.8t pistons as they are forged and meant to be good for some serious HP, which in my engine they should be fine as im only looking for 180hp or there abouts

Does anyone know what compression ratio you end up with roughly? And doing it this way, can we do away with a de-compression plate?

Im basically building the engine for as cheap as I can and can get the pistons for free so it will only cost me the machining work and boring the block out slightly

Thank you for any help

slammedorion

Not any help to your question...

But for what Vag lumps cost is not worth trying to fit a 1.8t in with box?
Be different and they've been fitted to most stuff, cheap enough to get get reasonable power out of them...

studabear

bassboy

Thing is, I have the 1.8 zetec for free, im also building a 1.8 20vT mk1 golf which I have the pistons out of for free...this is to be a cheap build hence using whatever I can put together on a very low budget...

The real engine is where the money will be going lol

I know its been done a few times, but no one seems to be coming forward with compression ratios etc

Turbo Zetec

iTrader: (1)

yes, they fit with bushed silvertop rods, use 20mm pin pistons rather than the 19mm tapered rod ones if possible as it'll be much stronger. I can't remember the CR though. don't try to use the american zetec rods, or blacktop or the pistons will stick out of the top.

bassboy

Great information right there! Thank you for that, I didnt realise it had to be silvertop rods! I just seen a set of zetec rods which are apparently off a silvertop engine machined for a 21mm pin for C20LET pistons...do you think these would work?

Im just looking for the cheapest way to get 180-200hp which will be fine for me for now...either de-compression plate or the 1.8T pistons route

slammedorion

Tbh if your only after 200bhp
Just use some arp bolts and a decomp plate
Your wasting time and effort tbh if you wanna put the money into another engine why bother...
Standard engine will cope fine

bassboy

Yeah ive decided to ditch the 1.8t piston idea and go for a decomp plate or a 2mm thick head gasket

Had a friend run around 300hp on the thick head gasket and it lasted fine until he done a top speed run lol

Does anyone know if the ARP bolts differ from steel rods to the original con rods? I have a set in the garage but need to check their part number and what rods they fit

jonny s2

iTrader: (12)

vag pistons have been machined to fit zetecs before. either way you will see 250 hp

bassboy

Yep I know its definitely been done, but what pistons and rods were used? Blacktop? Silevrtop? Which 1.8t pistons were used? What CR is the end result? Its all pretty sketchy in the details so I will just end up either using a thick headgasket or using a decomp plate

jonny s2

iTrader: (12)

1.8 silvertop 8-2-1 compression i beleive on machined zetec rods
a 2mm decomp plate would allow 250hp or so

bassboy

Yeah thats pretty much what was said above about the Silvertop rods...hence no point in me going down that route...so far I have spent around £100 and have got

1.8 Zetec engine complete
Exhaust manifold adaptor from zetec to CVH
RST Exhaust manifold
ERST exhaust - not paid for yet
New ERST T3 turbo - 2wd Saph turbine, 360 thrust bearing, .48 exhaust housing, -31 actuator
Jenvey inlet manifold with Esc Cosworth TB - already had
2 litre flywheel and clutch new
Universal intercooler
MTX75 gearbox and conversion kit

Cant remember what else....next big things I need to buy are decomp plate or thick headgasket, Megasquirt MS2, injectors and god knows what else lol

Thank you for confirming the silvertop rods and letting me know what the CR etc is..great help!