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RB30 Head Gasket thickness for more boost

VL_Turbo
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Piggaz
Piggaz

What’s the limit of boost at 9.0:1? Very curious to know.

FiXtUrE
FiXtUrE

From my understanding you can achieve about 5 - 10 psi with 9:1 - 9:5:1 comp safely before it goes pop.. before you think this wack boost levels, you have to consider the turbo, dump back exhaust, fmi

FiXtUrE
FiXtUrE

Regardless to fuel it’s the boost/comp pressure that will determine if it gos pop or not.

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The Bogan Grand Master

The Bogan

Posted
Posted

I was told running a mineral diesel engine oil for a hundred km or so is better than engine flush in petrol engines.

Not flogging the car, just cruising around for a while.

The detergents in the diesel engine oil slowly breaks down the crud, avoiding big deposits from coming lose and blocking small oil galleries/restrictors.

More so for old dirty/cruddy high milage/ poorly serviced engines though.

IMO, a well serviced engine running quality oil, that is serviced regularly shouldn't really need a flush though.

Opinions may vary 

VL_Turbo Contributor

VL_Turbo

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Posted (edited)

Update.... car is alive!! After 4 flushes of oil no more contamination. Car is up and running and all is good. Thanks everyone for your help. 
 

driving normal is good no problems, but when I press the accelerator ( every 1 out of 10)  I hear like a bang noise ( similar to an intercooler pipe popping off noise), I then notice oil from the drivers side block but if you drive normally it doesn't happen.... Any idea what that noise could be and where it's coming from? )only on boost) 5psi. 
you can see on the pic the I let manifold gasket is wet from oil. Also noticed oil in the spark plug holes, but only happens in boost, drive normally I don't have the oil leak issue. What can make a "intercooler like popping off noise" and then leak oil on drivers side (only on boost) - see attached pic. 
thanks heaps 

B43F2F48-4958-485F-904F-A634F515945A.jpeg

Edited by VL_Turbo
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VL_Turbo Contributor

VL_Turbo

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Thanks to everyone on this forum for your help. I'm stoked. Car is getting tuned on will inform with the results. 

very unusual thing happening, wondering where that loud noise is coming from the drivers side, oil should not be on the intake manifold gasket as per the pic above 

VL_Turbo Contributor

VL_Turbo

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Ho All, 
Have a small issue with my VLT.

maybe someone could help. driving normal is good no problems, but when I press the accelerator ( every 1 out of 10)  I hear like a bang noise ( similar to an intercooler pipe popping off noise), I then notice oil from the drivers side block but if you drive normally it doesn't happen.... Any idea what that noise could be and where it's coming from? )only on boost) 5psi. 
you can see on the pic the inlet manifold gasket is wet from oil. Also noticed oil in the spark plug holes, but only happens on boost, drive normally I don't have the oil leak issue. What can make a "intercooler like popping off noise" and then leak oil on drivers side(only on boost) - see attached pic. 
thanks 

D5F4D3F0-BEF7-41CB-8C57-4DF6FF2ACDA3.jpeg

GTSBoy Grand Master

GTSBoy

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Well, the oil is fresh and shiny. Wipe everything up, put a go-pro under the bonnet and go for a drive. Look for the squirties. Failing that, tape some rags over places where they won't catch fire and go for a boosty drive. Look for tell tales on the rags. It has to be coming from a clean, filtered source with some pressure (most likely, anyway).

As to the other noise, probably the exhaust manifold or turbo gasket is stuffed. They fart loudly.

VL_Turbo Contributor

VL_Turbo

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Update, tightening the rocker cover bolts and went a bit too tight and cracked the rocker cover near the bolt next to spark plug 4. 
can I JB weld it or put some sealant and put it back on or do I need a new rocker cover? Any help would be appreciated 🤦🏽

GTSBoy Grand Master

GTSBoy

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30 minutes ago, Murray_Calavera said:

Where does your PCV valve live and what does the P stand for?

Hmm. That might be a bit misleading. The P for positive doesn't really mean positive static pressure. It just means that the the crankcase is positively (as in, definitely) ventilated. The driving force for said ventilation is suction from the inlet manifold. The engine is ideally under slight negative pressure when the PCV is open, but will indeed likely be slightly positive when the engine is at idle and the PCV is likely closed.

Nevertheless, Murray's point is valid. You can't properly operate the engine with a crack in the cover. If it breathes at all, it will cause some problems. And it will let oil out.

Murray_Calavera Mentor

Murray_Calavera

Posted
Posted

Yeah, I didn't really think about my example for more then a few seconds before typing it out lol. 

It was meant to be a visual aid, probably should have gone with something like, "picture all the skyline's at the track that empty 2L of oil into their catch can after each session". 

Murray_Calavera Mentor

Murray_Calavera

Posted
Posted
16 hours ago, VL_Turbo said:

Installed the catch can today, Hopefully that should de pressurise the crank a bit. I've read on the internet some people do use JB weld. 
cannot find a spare rocker cover locally in south easter suburbs 😭

Get it welded up by a decent welder. Check it for straightness after it's done.

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Dwayne Jake Newbie

Dwayne Jake

Posted
Posted (edited)
On 02/04/2023 at 3:46 PM, Murray_Calavera said:

Get it welded up by a decent welder. Check it for straightness after it's done.

Yeah mate, better safe than sorry. A reliable TIG welder should do the trick 👍

Edited by Duncan
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MBS206 Grand Master

MBS206

Posted
Posted

Did you put a new rocker cover gasket on?

Did you check the PCV is installed in the correct direction, AND is functioning?

 

Just a theory, but where you showed oil coming from, could easily be from the rocket cover.

The bang you're hearing from boosting, COULD be from a stuffed PCV, pressurising the motor with boost, and the bang being it blowing pressure out between the cam cover, and sending oil with it.

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