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And there's also a filter on the breather nipple on the hot side of the valve cover?
Only on the hot side. Cold side has the PCV system.
Just got a chance to use my computer. Leaving vermont soon. Will stop at a harware store and pick up some bolts to 'lock down' and tee off the cold side pcv system so it's essentially disconnected.
Edit: left the hot side open, no filter. Put filter on pcv and blocked off IM. Time to see if that helped!
Pcv seemed to be leaking at low air volume.
Originally Posted by sonofthehill
Sounds like you're having fun with your car.
I mean... it is running... and it did make it 250 miles.... and doing a few mountain passes at night with the top down and just the stars up above was pretty awesome soooooo....
Last edited by ridethecliche; 09-02-2018 at 03:15 PM.
there's no reasons this mild turbo setup needs more than just stock breathing plumbing.
I mean, the plumbing was stock!
My workaround didn't work at all. I had to go back to the way things were because I started getting oil shooting out the driver side and smoking everything up when it tried to ignite the manifold...
I did this on the passenger side and left the driver side open.
It actually idled okay... I think this PCV is an aftermarket part, but I examined it and it seemed to still work okay. I think I might have bought it in a pinch and then forgotten to order an oem one.
I ordered the GTX part that psyber suggested so lets see what that does. I do have 2 catch cans I bought off the forum a while ago so I can work on getting things together for that, but I agree that I need to figure out why this is happening since it shouldn't even be remotely necessary where I'm at right now. It wasn't ever an issue with the stock motor in the past and that was running more boost. I'll try the GTX part and if that doesn't help, I can work it up further. Otherwise I can chalk it up to this being a shitty part.
I'm going to look up sixshooter's writeup for the catch cans. I remember reading it somewhere and I want to reference it before I start working on things. I
no the GTX one is WASTE OF MONEY. WHEN WILL YOU NOOBS LEARN?! It leaks in boost like every other pcv out there. god dont you guys read ever post here since 2006?
All one ever needs is a .50c check valve in front of the pcv to ensure no boost gets through it. the end.
I actually had read that... but figured it was worth getting that over the stock if I was buying an OEM one anyway. I'm pretty sure that mine is aftermarket and I meant to replace it with an oem one before but totally forgot once I had things running.
That goes to the IM. It's where the Pcv would normally connect .
It also didn't work. Oil spat out from the driver side and tried to set the engine bay on fire so I went back to stock and drove home gingerly. I would have wired the wastegate open if it caused any more issues.
I have two catch cans that I'm planning on running. The passenger side I might run back to the intake with the pcv and check valve kind of like how brain has it, but with a catch can there as well so schmoo isn't going back into the IM. Or just listen to sixshooter and run it VTA. The driver side is going to be VTA with the catch can for sure. Only thing is I bought them on here and the don't have a dipstick so I'll have to keep tabs on them.
I'm just surprised that this happened out of the blue after I lowered boost... Guessing it points to a pcv issue.
Figured it would be useful to have a baseline after fixing timing. Cylinder 2 is still has the lowest compression hot, but also has the worst leakdown due to what appears to be exhaust valves. Guessing that explains the lower compression as well?
In any event, looks like the heads going to come off over the winter for a refresh.
Are you guys looking at the hot or cold compression because the hot compression isn't great... Especially for a just built motor.
I didnt do the compression test wet since the leakdown already kinda showed me where the air was going. That makes sense right? Also kinda ran out of time to do it wet last night. Can check it next time I drive it. Only takes like 15 minutes to do. Of note: I haven't noticed any smoking on decel or otherwise.
Also put in the gtx pcv. Waiting for the check valve to show up in the mail now. Hoping to start messing with EBC now.
My hot dry numbers are right at 150 on all 4. Hot and wet numbers are ~180 across. Probably ring wear and not worth pulling the head.
OTOH, my leakdown numbers are right at 20 across. That freaked me out until a couple of engine builders (who build drag engines) told me leakdown tests are notoriously inaccurate, and if I am making at least 100HP from a N/A Miata engine, things are sealing well enough, as 20% would cause a very measurable loss of power. Said my dyno tells the tale and looks fine. Too bad about the rings, but run her til she tires completely out if I want to.
Sure. Now that I have hot dry numbers, I can redo hot wet for the hell of it to close the loop.
I guess it can show what's playing a bigger role for the leakdown.
Do folks ever do wet leakdowns? I guess that might be a bit useless in my case since cold compression is fine and it's pretty hard to do a leakdown hot since it requires undoing some exhaust stuff...
The high leakdown numbers for the exhaust valves aren't concerning enough to warrant taking things apart in the winter?
Also, 100 wheel sounds a bit low from an NA 1.8, especially 99 and up with a megasquirt.
09-02-2018, 01:58 PM
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