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93 4d lx, z6,ported, port matched, compression bumped, balanced, manual swap
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Is your vc baffle still in place? Sometimes with a high compression build the vacuum signal is actually too strong at the manifold, keeping the pcv valve closed at idle, or mostly closed, not allowing enough flow to keep pressure low until vacuum drops with part throttle. Having the baffle still in the vc in these cases will cause high crankcase pressures at idle and at high throttle when vacuum signal drops and pcv valve closes.
 

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93 4d lx, z6,ported, port matched, compression bumped, balanced, manual swap
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Most common cause of crankcase pressure, especially with higher compression, is bad valve stem seals, next is valve guides in addition to stem seals.

Pull the intake manifold off, grab a small mirror, and remove the valve cover. SPray carb cleaner at the valves and see if anything makes it into the intake port
Could certainly be an issue, most machine shops will just take a gnurled bit to "refinish" a d guide, it only works for a short time.
Could sticking rings still be an issue even though I still have an expected amount of compression?
yes, especially if ring gaps are a bit too tight or p to w clearance is too high.
Yeah that baffle is still in place. And the difference of air being pushed out of the valve cover hose connection vs the oil cap is huge. Could the baffle really restrict it that much?
Most definitely, even 6 7mm holes drilled in that baffle in the correct places should alleviate the excess pressure that can be caused by a high cr build with too high a vacuum signal at pcv port, causing the pcv valve to shut at idle or cruising loads.
 

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What are you tuned on? What tb are you using? Fitv on the bottom or just coolant ports?
 

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93 4d lx, z6,ported, port matched, compression bumped, balanced, manual swap
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😱😱😱 i meant to take pictures of the modified one I had off today that solved this same issue, stupid time crunches and blazing hot sun reflecting off shiny shyt distracted me.
 

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93 4d lx, z6,ported, port matched, compression bumped, balanced, manual swap
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How could this be with brand new valve stem seals. The shop that I took the head to said the guides were fine.
They ALL say the guides are fine, but they rarely are. they are usually at the very loose end of the specs on hondas by about 200k miles, with hondas large exhaust valve lift and vtec intake lobes there is a lot of lateral force applied to the tip of the valve stem, so the guides tend to taper from top to middle and bottom to middle. For some reason 95% of machine shops don't see this as needing replaced.
 

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93 4d lx, z6,ported, port matched, compression bumped, balanced, manual swap
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Extend the pressure gauge up to the windshield, tuck it under a wiper, tape it to an angle you can see it and go rip it a few times, I bet under load is where it's building pressure, and likely coming from exhaust guides.
 
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