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Turbo Mini Forums

hi, i dont want to run sky hight boost, but is it worth removing the 'beaks' from the chambers on my head?

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why would you remove the beaks? the beaks are good

i read that avonbar remove them,,,,, stop hotspots? wouldnt it lower cr as well?

http://www.turbominis.co.uk/forums/index.php?p=vt&tid=175

Found this a while ago, may be of some help.

AL

Lol, I just looked on the 'show us yours' section and mentioned that.

Benross did mine for me, quality job, and quick turn around.

Even if your not planning to run stupid amounts of boost IMHO its still worth lowering the CR from standard, if your running anything over 10psi. But there are many different views people have on this.

Do you know what CR your running now?

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1/4mile in 13.2sec @ 111 terminal on 15psi

no, guess its standard as the head has had a small skim, but have the leyland metro dished pistons.
only plan to run at 4psi or whatever standard is, hopefully will work nice with the 286 and t2
the man at the rolling rd will be able to tell what boost if any i can crank it up to

It'll work shite with a 286, as it has FAR too much overlap for use with a turbo.

The little beak you've got on your head there is not worth 0,5cc. Keep it, get the proper pistons.

How big are the chambers at the moment?

Edited by Vegard on 23rd Nov, 2006.

I agree with Tom, bin the 286, it'll be awful to drive. MG metro of Avonbar PH2 is what you want.

Standard psi is 7 for mettro turbo.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

hi, sorry to drag this post up again....

jst have a few questions tho, if anyone can help

regarding the pic of mt head chamber, my dad has access to the machining facilites via work and mates, was wondering if you keep the beak, where do you take metal from? is it both the beak side, leaving the general shape of the beak, the side where the sparkplug comes through or both? also, isnt it a good idea to remove the beak? wouldnt this give hotspots, leading to holes melting in the pistons on a turbocharged engine? any info apreciated, thanks

Keep the beak ...... Won't give hot spots, will improve combustion dynamics and if your going to reduce it do it evenly so that the remaining beak is similar in form to the original, just smaller.

Plenty of metal to remove to lower CR before the beak pops up the list.

Every day is a school day ...........

How fast and how expensive ...... the same question...

this has been cover many times

IMO remove the beak

Alot of peeps will disagree!

Edited by Rob H on 12th Dec, 2006.

what sort of cc is that head rob?

"Turbo's make torque, and torque makes fun"

"did you know you can toast potato waffles?"

Rob pm sent

Simply machine the standard Turbo pistons, you can achieve 8.5:1 CR with a standard 21.4cc chamber head the standard pistons are tough old boots even when machined 'correctly'

Keep the beak.

Haven´t changed my mind, keep the beak. Cut it back if you wish but don´t remove it completely. I´ll take a photo of my cuurent head and upload it later this week.

Am i right in thinking the beak is there to produce swirl and get a more efficient burn? If this is the case, surely it's not so much of an issue on a turbo engine as you (should) have at least 7psi of boost to force it through with. Although in saying that, you can run 7psi on 9.4 CR pretty confortably if it's set up right.

Save your money, ditch the cam and stick an mg one in. Spend the money on an intercooler setup instead.

The beak gives you alot of squish area, pushing mixture towards the plug for a faster burn yes?

I kept it, its there fore a reason and so long as you dont leave a sharp edge on it then i cant see it would get much hotter than the rest of the head (exhaust valve must get hotter!)



(Thats for 8.5:1 with stock turbo piston's)

Edited by slater on 12th Dec, 2006.

26cc

the beak doesn't only push the mixture toward the plug it mainly create a swirl that force the burned gas to go away and not stay in the comb chamber, then a faster and more efficient burn is made, burned gas making a wall to flame front, then your unburnt gases need more time to "see" the flame then the combustion is longer and you have passed the peak crank angle efficiency, so you have less cr but more knock index ,less power and need more ign advance :/

Heavy

Edited by turbodave16v on 13th Dec, 2006.

Deal or No Deal??