I'm seeing a few threads about crankcase pressure with strokers and didn't want to muddy up their threads. I just upgraded from a 377 to a 418 LS3 about two months ago, maybe about 1200 miles on the new motor, I'm concerned that the PCV and/or crankcase pressure is not ideal since we only re-used my old Norris Motorsports catch can and are using the OEM PCV fittings. How do I know whether I have a concern?

 

Blowing out your dipstick or rear main seal would be a good indicator. If you wanted to measure, I'm sure you could tap into the valley cover or something and install a 2-3bar MAP sensor.

 

I definitely want to be proactive. How would I know if I blew out the rear main seal, unexplained oil loss? Slipping clutch?

 

Seeing excessive oil in a properly set-up catch can setup is a good indicator that you’ve got a blow-by problem.
If you pop a rear main seal out, you’ll know it from the smoke show in the rear view mirrors and oil trail following you. Clutch will likely slip, yes.

 

I've used a regular hand vacuum gage with the plug stuck in in place of the dipstick, just to get a ballpark reading.
You should not be seeing much if any positive pressure. FWIW,, it takes 2x1" (-12) hoses to properly vent a 406 Sprint motor..
Of course its a dry sump..

 

I'd say that's a good idea with the vacuum gauge in the oil dipstick tube. But unless you have a gauge in car you can see when engine is under load, WOT, & revved out.. on a dyno could be a good time to check. One other indicator, besides the dip stick & rear main, would be checking your throttle body? If you see oil blown on the out side of throttle plate. From the clean air PCV port. It's making some pressure. I'm pretty sure this is a norm thing anyway. Lol.

 

If it makes you feel better I'm at 1200 miles on my TSP 454 running the same sort of PCV setup and don't appear to have any pressurization issues based upon dipstick not popping, relatively minimal catch can oil, and simple vacuum plug on the driver's side rear PCV port not blowing out. That said being the setup peaks around 6300 the limiter is at 6800 so I'm not spinning that high either compared to some of the big cube NA setups. But I was initially concerned about pressurization too.

 

stock bottom end LS2, heads/cam/intake my tuner wanted me to add a breather cap, I did.

 

Just FYI, I had crankcase pressurization yet never had the dipstick push out. I was pushing oil past the valve cover gasket, oil pan gasket and out of the oil filler.
I ultimately solved that by venting both valve covers with 2 -10 lines and a Mighty Mouse draft can

 

Did 10AN lines of each valve cover to a breather on the 427 and no issues here. I'll probably run two breather cans one under each of the hood stops on this 99 Camaro build.

 

I had the car on the lift today at a different shop than the one who overhauled the motor, and there is now oil on the bottom of the bellhousing and tranny, it doesn't seem to be coming from the top end. My normal maintenance/speed shop said the dipstick tube is oriented in this way to avoid the headers and they didn't see a way to improve it to reduce the force (10-20lbs) to make it more like stock (1-2lbs). However, it's much worse than it was before it went into the overhaul shop, but perhaps they bent it for better clearance. I'd be surprised if excess crank pressure would blowout a dipstick that requires 10-20lbs of force to remove by hand. I don't have an adapter for my vacuum gauge large enough to fit over the dipstick tube.

I checked my catch can today, and it was full to about the bottom of the filter in the lid. By weight, it was about 7oz of oil. The last time I emptied it was a few days after I took delivery of the car, odometer was 199356 on the receipt, about the first week in May, and the odometer is currently 200796. So that's about 1500 miles. I'm not seeing any smoke shows and the clutch isn't slipping, but I'm not beating on it either. I'm rarely taking the RPMs above 3-4K in daily driving.

If this is crankcase pressure, what is the simplest bolt-on fix that doesn't involve welding on larger bosses, etc.? Won't a breather cap cause other side effects?

I texted the shop owner who overhauled the motor, waiting for their feedback.

 

if your not beating on it that's alot of oil. i would have a leak down test done and see what it is. I was having crankcase pressure issues also but i didn;t have alot of oil in my catch can. I just installed a vacuum pump system on my car. works good and no more pressure issues for me. car even seems to run better and throttle is more responsive also. I would check the health of your engine first.

 

I agree with Boback, thats too much oil for windage. Thats more like a ring seal issue. Start the car and take the oil cap off and see if you have air (blowby) coming out

 

Sounds like you have an issue with the engine itself, unfortunately. Could be poorly prepped cylinders, oil rings upside down, etc. Breathers and vacuum pumps may just be a band aid.

 

The shop owner texted me back yesterday afternoon said he's not in this weekend but will contact me Monday morning to schedule me to come in. Should I be driving it any differently given this concern?

I've been reading that too much oil can cause this also, but how much is too much? Because I was having difficulty with removing/inserting the dipstick, I bought a new tube (12551577) and a new dipstick (12551581). The new dipstick is the same length and the hash also matches. My old dipstick has the current oil level about a 1/2" above the hash with the engine sitting for a few hours. I've not topped it off since I got the car back, So far it's had two oil changes, break-in and 500mi, I'm using a new f-body oil pan with the PF48 style filter, new crank scraper and old baffle,;the old motor used the original pan with the original filter & just the baffle. I'm just wondering if it's something simple like the new parts cause the oil to drain much slower and perhaps the last oil change ended up with more than 6qts.

I just have a very simple catch can setup. Lid port goes to the OEM valley cover nipple, and the side port goes to the intake manifold. Only using fuel lines between the nipples.

 

From my understanding:
Pretty much every engine, especially a performance engine will have air coming out of the breather area.

You want to look for "excessive" air - do a paper flutter test. Cheapest most easiest test you can do. If the paper moves up more than an inch or so in "pulses" - you've got something you really need to look in to.
If the paper just kind of "floats" above the breather hole - this is normal. Every engine has some level of blow-by, no matter how small.

 

Mine doesn't but the only thing you're really going to fell with your hand is a problem, the pulses or puffs of air you mentioned

 

With the engine idling at home, I took off the oil fill cap and set a thin piece of paper on the oil fill neck, and it barely moved, it certainly wasn't bouncing an inch; I have videos but Photobucket is giving me grief uploading them. I was outdoors and there was a slight breeze, but when the breeze died down, it sometimes looked like the paper would slightly get sucked to the opening.

A few takeaways from my visit:
* Pulled the #2 TR6 spark plug, it looks completely normal,electrode is a gray color. Based upon this a leakdown test wasn't performed, but I'm not against having it tested elsewhere.
* The oil is still clear on the dipstick about a 1000 miles after the last oil change, which is about 1500 miles on the new engine
* I've got an oil weep somewhere, added some dye
* Without me prompting, he did ask if I ever added more oil to the engine (no), and then he commented about the level on the dipstick looking high. I reminded him that we transferred the oil baffle from the old oil pan and installed the new oil scraper.
* We talked about replacing the dipstick tube with an aftermarket version, but he preferred OEM for accurate level readings.
* He thought the PCV tubing was too small (3/8") and/or the catch can was too small. He also wanted to equalize the pressure on the driver side instead of capping off that rear nipple. He thought -12 tubing was overkill but thought -10 would be fine.
* He said using a breather to vent to atmosphere is the equivalent of a leak and was not recommended, and the side effect of the oil film was undesirable.
* I inferred he wanted to run two cans, one per valve cover? I could have misinterpreted this.
* I'm using the desensitized misfire tables I inherited from the prior motor calibration, and although I've not scanned for misfires since I took the car home, I'm not getting any flashing SES's
* He said if the rings were installed upside down, the problem would not have waited this long to be exhibited, the symptoms would have shown up immediately after the engine was first ran. He said even if the oil ring had rotated a bit, it shouldn't matter.
* I'm not seeing any smoke out the tail pipes at idle, nor through the rear window or mirrors while driving

 

You could have burned off any oil from a leakdown test on the drive home
I would too
I'd vent both VC's with -10 (-12 if boosted)
A vented catch can (one with a breather) would not be equivalent to a leak unless you left the intake side vacuum ports open. There's be no un-metered air so I dnot know how that would be a leak
1 Can is fine
Be careful with that

Unless you have some new type of pistons and rings, they are supposed to rotate, the cylinder wall cross hatch induces that

 

I returned the misfire tables to stock and drove around for awhile, the misfire current and misfire history PIDs always returned zero, which I found odd based upon what I had seen over the years with an aftermarket cam. The other Misfire PIDs were returning non-zero values though.

Are we sure I have the current hoses routed correctly?

* Driver side valve cover rear nipple capped
* Passenger side valve cover front nipple attached to throttle body
* Front of intake manifold connects to the side port of the catch can
* Front valley cover nipple connects to the top port of the catch can

Right now I'm looking into the following solutions. Is the goal to use -10 fittings on the dirty side(s) and something smaller (which size?) on the clean side(s)? It would be nice to have a solution which is easy to see the level without having to disassemble the catch can. With the can being mounted on the cylinder head, I would imagine it's not easy to see the level without a dipstick, even with a sight hole. For the designs with a check valve inside the catch can, what are the side effects if that valve fails?

MightyMouse Draft (based upon initial email communications with them). They are recommending a 'fitting top conversion' for track days with >15min sessions. Not sure if this will cause residue, definitely don't want residue.
Elite Engineering E2 + clean side oil separator
RX Performance
Saikou Michi dual catch can

I like the dipstick feature on these designs, but they are only 6oz capacity
https://www.racetronix.biz/search/se...words=dipstick
http://www.radiumauto.com/Blog/Post/Catch-Cans-101-102