Na-t. Who's done it and what ya get

No no not at all.
You just missing the point here. At what point exactly are you calling your increased cylinder pressures? What, at cranking, idling flat out, Overrun?

It wouldnt matter if the engine was at 20:1 CR AND boosted!
Torque produced is just a function of the pressure on top of the piston at 90degree crankpin/conrod angle yer?

Lets saya NA 3000cc V6 at 6000rpm produces "x" torque. Thats because there is a given amount of cylinder pressure produced in each cylinder. Lest just say 1000psi

A 3000 v6 at 6000rpm boosted to 25psi but producing the same "X" horsies has exactly the same maximum cylinder pressures doesnt it!!!!!!! boosted or not!!!! because the torque is the same!!!!!!

Think about it!!!!!!
If they were higher, the engine would be producing MORE power no?

If cylinder pressures are less (for same config.) the engine produces less.

So an NA engine tuned up and on the same boost will only produce minor torque increases for the same rpm. Run it on corn juice and things may be different but still, not by any stratospheric amount.

What your being smokescreened about is the cranking pressures. What 150psi v's 250 psi (just sayin). And that actually matters when your talking, what lets just say 10 times that in combustion pressures??

Cmon mate!! Do you see where Im at now? Boosting an NA is simply a matter of controlling combustion. If you control the combustion well enough, you make more power (volumetric efficiency)

The ONLY reason HD gaskets, like MLS or even worse solids, is to allow dickbrains who cant tune, a bit more latitude to grenade their engines and not replace a HG.

A headgasket blowing is (in a silly way), like mother-natures way of telling you something is wrong. Pain! if it hurts, its wrong.
If even a cheap generic HG blow repeatedly, then its the mechanical mother natures way of telling you something is WRONG!!!!!
NOT that the gasket is cheap! its just a cheap gasket will not cope with the pain!! It will cope perfectly well with cylinder pressures of the stratospheric levels!
Detonation will even eventually ruin a solid copper gasket with an o-ringed block. But by then, "IF" the piston crowns havent collapsed or the big end bearings havent had all their white metal removed, or an exhaust valve hasnt burnt!!!!!!!

E

 

cylinder pressure at boost obviously has to be at a certain rpm to reach that calculated pressure ?..in my case 4500rpm (max torque)

then why does the above calculator say it increases.?

you cant agree that the more comp you have and the boost you run ...the more cylinder pressure you have?


.

 

Why dont you have a read of the title of the page mentioned.
That may just clarify things.
Let me know what you think.
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The calculator doesn't consider ignition though. If you slap it together with a stock TT ECU the pressure will be higher because timing will be the same, temps higher and propagation quicker, but people generally drop a bit of timing and/or add fuel which reduces peak pressure again.

Other things are changing as well though, combustion chamber is a different shape so propagation speed/direction probably changes a bit. Higher C/R means faster pumping so the engine will hit peak efficiency of the cams and plenum/heads etc. earlier meaning more power at lower revs so peak pressure experienced across the map is probably higher for the same peak jiggawatts.

So.. everybody's wrong? I demand thorough scientific testing! At someone else's expense though.

 

You might need to read the page title AS WELL lol
Additionally its a far les specific issue in discussion here that is the subject of interweb fallacy!
Your becoming too specific Fists!
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yes cranking cylinder pressure

 

and you're too general

Comparing unlike engines I would agree it's a long draw to judge cylinder pressure just on CR but the VGs are designed I would be surprised if the NA pistons didn't create higher moments of stress even making the same power down at the crank.

That link did point out something I should have thought of that makes me feel a little better about the compression tests I do up here in Canberra though.

 

well thats got a little of topic :rofl:
my 2 cents after looking into the head gasket im going to stay original for engine protection . think of it as a fuse for the engine
i would rather a head gasket go before a piston starts melting

 

Of course. That stating the obvious. if you dont have increased cylinder pressure at the combustion event, the engine doesnt make any more power!!!!

However the original point I made was the foolish notion that and higher CR engine with a blowjob SUDDENLY needs extra tough bolts and special gaskets due to "increased" cylinder pressure.
BlackBeast mentioned this early on. Its not his fault. its a widely accepted myth!!! Most likely perpetrated by some of those armchair experts that seem to inhabit Performance Forums
So I questioned it. I knew exactly what the response was going to be, but then that would have taken the fun out of it and nobody would have learned anything!!!!!

There is often a valid reason for me being an asshole and creating such debate!! Sometimes people go away and enlighten themselves!

Mission accomplished!

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not disagreeing with any of that

keep increasing "cylinder pressure at the combustion event" (making more power) and something has to give .

stock gaskets and head bolts will have their limit .

why are there stronger head studs and increased sized studs available and metal gaskets ?
just for marketing and shit tuners ?

 

For the vast majority of us, probably yes.

 

Up

After all that I get a probably ?

The majority of us aren't running higher comp and 30psi .
there is a difference between a once off power run and constantly pushing this power .

I'll run my L19's and metal gaskets .. everyone else can stay stock gaskets and bolts .

Spoken to and know enough engine builders ,tuners that run these for this reason .

Cheers

 

1000nm at 4500rpm

 

And very good for you man!
Fit whatever bolts you think will help.

However, this has little to do with the original claim you made where stronger headbolts and funky gaskets were a pre-requisit to cope with increased "cylinder pressures" when boosting an NA.
And I asked why.

Thats OK tho man, its one of those many myths that easily gains traction over time via interwebs, if its not stopped short.

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Well for a boosted Na with moderate boost I'll agree .
All good .