Cast or forged?
Turbo Mini Forums

Now up until the last few days i was set on some forged pistons but now doubt has come into my head as to whether they're actually needed.

Obviously compression ratio is an advantage of the forged pistons as you dont have to enlarge the head chamber as much.

I will be under crown cooling and this engine is going to be perfectly set up on some form of mappable ignition.

So is the extra ?200+ (since the cast prices have now dropped nicely at MED) really worth me spending or should i use the money else where?

Bear in mind this car is being built for dragging/track days so will get some serious abuse and i want to build this as a serious contender over the following years.

(one of the main reasons is ive used some of the piston money to buy a new multipoint cage :cool:)

Edited by iain on 9th Mar, 2005.

thinking about the above iain

one top turbo guru stated.

do not run to the forged piston shop every time you want to build a high performance turbo motor.

also your going to fit under crown cooling!

this helps things some what

this is open for debate iain........................................

but if you are going to drag the motor then the added expence would be worth it....... sort of peice of mind

and bear the expence

my oppinion

Edited by BENROSS on 9th Mar, 2005.

Yeah but what sort of piece of mind would forged ones give over cast? I.e. what sort of margin?

Also the forged will be lighter, yes?

Just trying to see if the ?200 extra is worth it really. At the moment its a no as i want to build a spare short engine anyway so once i start racing i dont have to stop

I can buy 2pairs of cast for every one set of forged is my theory....

Its going to be interesting to hear different opinions.

Dave runs cast omegas with no probs.

Phil.

WWW.TURBO-MINI.COM

Dave who Phil?

coxon

and i know you run forged jon.

2 top quality cars and both running different pistons. This is what is confusing me really.

What sort of chamber size do you need to run with the 11cc cast omegas in +20 form for 8ish - 1? roughly i mean. Are we talking high 20's?

TE he!!

Both wrong!!

custom , jobbies for jon .... only the best will do.

Everyone knows that instructions only have to be read if the thing doesn't work....

Learn something new every day!

20 thou a bit low ... squish and all that

Everyone knows that instructions only have to be read if the thing doesn't work....

yes but i have no idea what squish is so it doesnt affect me.....lol

With all the reliability aids you have on the car ( under crown cooling, mapped ignition and i take it a decent intercooler) I personally cant justify spending an extra ?200+ on the pistons, quality cast pistons have proven very reliable in a turboed a'series, even with regular drag/track days.

-MINI CLUBMAN 1380 TURBO-

I run minispares 'mega' cast pistons... These are visually identical to the AE 'turbo' piston - ie VERY strong, although a tad heavy, but that doesn't matter when your shifting at 6300RPM anyway!

Forged are generally only needed when you want that extra CC's in the piston bowl - the cast's just aren't available that large!

I've never 'broken' a AE turbo piston, or a minispares MEGA piston - but did have the ringlands separate off a cast omega. That was probably due to a fuelling problem however...

Stick to cast if you can get the CR you want with them. ?200 goes better in other places - like mapped ignition!

thats my thinking. just wanted to justify it!

15cc forged with undercrown cooling.

Can anyone explain this undercrown cooling,I know its from a zetec motor.Do the jets screw in to the small end ???

Metro turbo weekend driver,Mini turbo in the making again!

Legend has it forged pistons stay together if you do hole one, where cast break up. I always ran silly compression ratios on my Morris Minors and never holed a piston (and that used to detonate quite a bit from time to time). Also, the forged metal has a harder crystal structure which is more prone to surface abrasion. Ring lands wear faster? (I would have thought). Although I've seen a set of 180000 mile forged pistons and they looked OK.

I'm running cast, just because I'm pretty sure I won't hole one.

Bugger off, I'm getting there.

this was a "rover sport" 15cc forged piston

Edited by minimark on 11th Mar, 2005.

Everyone knows that instructions only have to be read if the thing doesn't work....

that "was" a std piston though wasnt it mark? think i sent you a fresh one?

Dangerous - Do a search for Zetec on this site!

Not totally sure who pioneered the Zetec oil jet, but i reckon he's a really popular guy who everyone loves, and will have loads of folks offering to buy him beers and give him drives at Avon Park 05.

Edited by turbodave16v on 9th Mar, 2005.

Guess that can be arranged....

my zetec oil jets where fitted by the man himself, although I bought him half a pint last year, he aint getting any more!

Team Racing

Next time my motor is out if any one want to fit oil jets for me I will buy the 2 full pints of regular lager( not that expensive strong type )

http://www.rabdunn.co.uk/

allan:

you mean the strong type which comes in brown cans called Special Brew

did you Know you can run 50PSI OF BOOST with no detonation! with that stuff

lol