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Old 09-01-2015, 07:25 PM   #41
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The only time I've had a dipstick pop out was when I cracked a piston in 1/2, FWIW. Hard to imagine any other situation that would cause it short of hooking the turbo outlet to the valve cover.
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Old 09-01-2015, 07:26 PM   #42
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<p>
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Originally Posted by deezums View Post
Why does your valve cover leak? Mine doesn't, and I don't even think I have RTV on it any longer. Did it get chewed up, or do you have astronomical crankcase pressure blowing it out?
</p><p>Just little bits in places. Last time it was around the CAS. Before it was the little place next to the cams.</p><p>Its never a lot, just enough to annoy me.</p>
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Old 09-01-2015, 07:27 PM   #43
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<p>
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The only time I've had a dipstick pop out was when I cracked a piston in 1/2, FWIW. Hard to imagine any other situation that would cause it short of hooking the turbo outlet to the valve cover.
</p><p>Old pcv valve and old rings, popped my dipstick all the time.</p>
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Old 09-01-2015, 07:31 PM   #44
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If your crank pressure ever gets anywhere near boost pressure the PCV valve will open, and you will eject a dipstick.

It happens a lot, and it's usually not a split piston especially if you still have some sort of PCV.

If you don't have PCV and it does pop, ****'s fucked.
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Old 09-01-2015, 07:38 PM   #45
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Quote:
Originally Posted by deezums View Post
If your crank pressure ever gets anywhere near boost pressure the PCV valve will open, and you will eject a dipstick.

It happens a lot, and it's usually not a split piston especially if you still have some sort of PCV.

If you don't have PCV and it does pop, ****'s fucked.
I would agree with the "If you don't have PCV and it does pop, ****'s fucked"

And if you have PCV and it pops the dipstick, your PCV setup is bad too. Because the PCV should be non-existent from a functional standpoint while in boost. It's only operational in vacuum by design.
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Old 09-01-2015, 07:41 PM   #46
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<p><strong>WHICH IS WHY WE ARE HAVING THIS DISCUSSION ABOUT CHECK VALVES AND PCV VALVES. BECAUSE WE ALL AGREE THAT AIR SHOULD NOT MOVE FROM THE INTAKE MANIFOLD INTO THE CRANKCASE. SO EITHER A CHECK VALVE OR BETTER YET A FUNCTIONING PCV VALVE</strong></p>
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Old 09-01-2015, 07:41 PM   #47
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Yes, and you should try and fix the problem by figuring out what causes a functioning check valve to open when it shouldn't. If the valve is not defective, something else is happening to open it.

I suspect most people open a PCV valve with old tired rings and lots of blowby on high boost. If you enlarge the exhaust cover port and never allow boost pressure to be near crank pressure (any time! Between shifts, on launches, whatever.) you probably find your **** works all the time now.

I am talking to pat, yuuus!
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Old 09-01-2015, 08:02 PM   #48
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Quote:
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Yes, and you should try and fix the problem by figuring out what causes a functioning check valve to open when it shouldn't. If the valve is not defective, something else is happening to open it.

I suspect most people open a PCV valve with old tired rings and lots of blowby on high boost. If you enlarge the exhaust cover port and never allow boost pressure to be near crank pressure (any time! Between shifts, on launches, whatever.) you probably find your **** works all the time now.

I am talking to pat, yuuus!
It's known that the stock PCV valves suck for boost, I read that here years ago, I think Scott did a write up on it but it could have been someone else. People put the GTX PCV valve, or gutted the stock PCV and put an inline check valve that can handle the boost. I think the gutted PCV valve + check valve is best, as there were people who had a PCV valve fail and it spit the guts of the PCV into the cylinder head....
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Old 09-01-2015, 08:36 PM   #49
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I don't see how that is possible, the other side of the PCV is a sealed container, the larger spring and plunger wouldn't ever make it past the valve cover and the baby spring would have a hard time of it. Were these miata people having the PCV fail, or some other car? If you were super paranoid, you could put some copper brillo pad in the baffling to make sure it would never happen.

See this m.net post for pictures, also shows the exhaust side baffle port thing and some of the holes I propose every turbo miata enlarge at the earliest convenience. The dude is right on when he says there are multiple strategies, so look at them all, and then look again before you do anything.

MX-5 Miata Forum - View Single Post - FNG in need of a little help!

Top is 1.6, I don't see how it could eat anything. The other miata, yeah, without brillo it could happen.
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Old 09-01-2015, 08:41 PM   #50
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<p><img src="https://cimg4.ibsrv.net/gimg/www.miataturbo.net-vbulletin/958x504/80-oqgdr04_99281c886d8f892f12fb79791914ef102968ede4.j pg" title="" /><br /><br />&nbsp;</p><p>With that picture how does the pressure ever get into the baffles with that bit welded shut?</p>
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Old 09-01-2015, 08:41 PM   #51
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It was miata BP motor, dunno what year or any of that.

I'll try to go buy a boost gauge and measure my crankcase pressure sometime. I'm curious what my setup would show, since the PCV is gone and it's just a breather hose on the other side.
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Old 09-01-2015, 08:46 PM   #52
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Quote:
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With that picture how does the pressure ever get into the baffles with that bit welded shut?
See the two green arrows? There's a plate with a vent/oil drain that covers it.



I'm not sure why they recommend welding that last bit shut, that's how the last bit of PCV baffle oil drains if I'm not mistaken.

This is a 1.6 cover, 1.8 are similar.

Pat, even without running PCV you'd obviously benefit opening up ports to relieve any crank pressure you find.
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Old 09-01-2015, 08:47 PM   #53
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<p>Because oil can pool there under hard cornering. I remember that now.</p><p>Didn't know about the center entrance there.</p>
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Old 09-01-2015, 08:53 PM   #54
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Welding that oil's only exit shut doesn't seem like a solution, though? I thought the fix for oil pooling was to open the ports up. If oil collects on that plate covering the baffle, it most certainly will pour out the PCV port the next corner you take. If the proposed green holes are drilled flush with the plate, maybe?

Air exiting the port will want to suck oil with it if the restriction is too small. It will do the same with brillo, so don't use too much. You want larger ports so air can still exit while not drawing more of the draining oil up with it.
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Old 09-01-2015, 10:22 PM   #55
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<p>New PCV valve fail. Video of me blowing is uploading.</p><p>TPS screws are the perfect size for mounting the bracket</p><p>Pics and vids incoming.</p><p>&nbsp;</p>
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Old 09-01-2015, 11:19 PM   #56
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Quote:
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<p>New PCV valve fail. Video of me blowing is uploading.</p><p>TPS screws are the perfect size for mounting the bracket</p><p>Pics and vids incoming.</p><p>&nbsp;</p>

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Old 09-01-2015, 11:33 PM   #57
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<p>I ******* hate my internet. It has been failing lately.</p><p>
</p><p>TPS screws</p><p></p>
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Old 09-01-2015, 11:41 PM   #58
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Deffo do not want. I never checked mine against my finger like that, mine may well be leaking a bit.

I wonder... if mine leaks I might try setting the valve face down on a hotplate then push the plunger into the plastic with a pin, try and melt the plastic valve seat to shape. Whatever leaking happens is probably just due to the mold lines on the plastic, it is a flat face plunger right?
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Old 09-01-2015, 11:46 PM   #59
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Quote:
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Deffo do not want. I never checked mine against my finger like that, mine may well be leaking a bit.

I wonder... if mine leaks I might try setting the valve face down on a hotplate then push the plunger into the plastic with a pin, try and melt the plastic valve seat to shape. Whatever leaking happens is probably just due to the mold lines on the plastic, it is a flat face plunger right?
But wait, just the fact that there is evidence of some leakage doesn't mean it's no good. He blew on that thing for some period of time, and the total space involved was virtually none, so my guess is that an entire crankcase volume would see next to nothing from a boost event lasting the time it takes to go through a few gears, no?
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Old 09-01-2015, 11:52 PM   #60
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Quote:
Originally Posted by good2go View Post
But wait, just the fact that there is evidence of some leakage doesn't mean it's no good. He blew on that thing for some period of time, and the total space involved was virtually none, so my guess is that an entire crankcase volume would see next to nothing from a boost event lasting the time it takes to go through a few gears, no?
Who knows? How much boost? Maybe it leaks worse when you apply 20 PSI instead of 0.2?

The easy simple proven way to fix this problem is install a check valve that's actually designed to see pressure levels that we turbo miata folks see.
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