forger pistons opinion

[xandyx]

hi there!

i bought a few months ago another G shell, and now i'm going to pick up an enginenext week.

there's a fella selling a set of forged pistons for a bargain.

just wonder if they are suitable for daily driving. what are the advantages and disadvantages of using them?

i think they are wiseco's, don't know about the bore, just know they are bigger that standard.

cheers
André

[Jezza-7]

I use to use mine as a daily and i never had a problem. I actually thing it helped driving as yo dont need to put your foot down as much,

[GR40]

I doubt there is any disadvantage to them...

[Yoof]

Forged piston by it's nature takes more heat energy to expand, so there's more blowby on cold start and possibly slightly lumpier running from cold. After a few seconds they're fine- you can tell the differance between a 1341cc start up and a 1272cc.

[xandyx]

thanks for your reply's!

i've been searching the web, and they talk about oil comsumption and that the piston rings don't last longer as standard. did you notice something similar?

my plans so far, are to use a spare charger that i have, with rs2 mod, 65mm toothed, and a ppp chip (will order).

don't you think it's worth going forged? as i sayd, will be my daily car, and once in a while i drive a bit of boost here and there!

[hayesey]

well it'll cost you about £1000, what do you want from the car?  people dont tend to buy those pistons purely because they are forged, it's more about the increased bore giving more power. 

[randombadger69]

I just did a 76mm overbore.

Machining cost

Bore block to pistons £100
Face block £30
Lighten and face flywheel £45
Balance crank F/W and clutch £72.50
 
Plus vat

£297

Rods and pistons were £900

rings for pistons are £125 for wossner if replacements are needed.

From VW. Core plugs, main journal bolts, breather pod, flywheel bolts, oil pump and chain were £255 inc vat. (Add a main crank bolt to that list).

And an elring block repair kit is 80 Euro's off Bar-tek. (Some off the end plate gaskets are now obsolete from vw as was the water pipe gasket).

KS main and big ends were £60 off RS engine supplies. Thrust washers were about £7.

Should give you a realistic price guide for re-building a block.

The main advantage i can see other than increased bore and strength is the forged pistons shoud dissipate the heat away from the crown of the piston more efficiently. Thus helping reduce cylinder temperature, increasing charge density slightly.

[hayesey]

why did you buy rods? do you just mean standard ones?

[AlexG40]

What CC does a 76mm overbore equate to?

[randombadger69]

because they were shiny

They are considerably lighter though.

1306.5 iirc.

[AlexG40]

Out of interest, any reason for not going bigger?

[xandyx]

i will get the pistons really cheap, like 150euros (125£) they only rode for 300miles. the guy then build a 1.6 golf block with a t28 turbo.

allready talk to a guy to order new rings. i can get the block bored for 100euros (85£) and get the flywheel lightened and balanced for under 50£

my only doubt is reliability for daily use. i just want to reach about 150, 160hp, don't know if worths spending that amount of money.

maybe i can reach that power safelly with cast, what do you think?

i remember reading that there's someone near to 200hp using cast pistons. i know it's a big risk..

thanks for your reply's!!!

[AlexG40]

You can piss 170 plus with stock internals, I'm pretty sure Hayesey is running stock insides at 190bhp.

If you need a good home for those pistons let me know...

[hayesey]

yeah I have standard cast pistons and have 194bhp.  It's perfectly safe, all about getting the fuelling right and being careful to have a rich mixture at high loads to keep it safe.  With larger bore it would make more power but I didnt have the budget for it all.

[Justin14100]

Standard internals are amazingly strong, if you were going forged it'd only make sense to go to 77mm for the extra power it would produce. Otherwise the standard bottom end is strong enough.