jclayc

iTrader: (8)

Oh god, not another catch can routing question, you're thinking... mine's only sort of that.

I've got a Scoggin Dickey built NA 416ci LS3 shortblock (11.7:1 compression) fit into my 05 CTS-V using Mamo 235 heads, FAST 102 intake, LS2 TB. Oil runs 35psi at hot idle & 85+ at WOT. I'm getting a lot of oil in my intake but not in my catch can - I've tried two cans, routed according to the maker's specs: one Elite Engineering and a Mighty Mouse PCV one.

• Elite: hose from the intake behind TB to one side of the can, hose from the valley cover to the other side of the can with the passenger valve cover hose run to the intake elbow.
• MM PCV side run to the intake, other side to the pass valve cover, valley cover to the intake elbow, as per his instructions. Regular oil cap and the driver's valve cover outlet is capped in both situations.

That tells me case pressure is high and blowing oil past my rings and/or valve seals. How do you suggest I alleviate that pressure, other than a vacuum pump? Go with much bigger lines? That plus T in my driver's valve cover to the hoses?

Thanks in advance.

KCS

iTrader: (20)

Is there sealant on the rocker bolts?

jclayc

iTrader: (8)

Used blue Loctite but not sealant. I'll do some searching but do you recommend copper RTV, teflon paste or aircraft sealant?...

[reading more] first, I'll check with Mamo to see if his work opens up the intake rocker bolt hole into the intake runner before I start taking them out and sealing. Then, it seems ARP thread sealer or Permatex thread sealant with Teflon is the way people go.

jclayc

iTrader: (8)

Man, Mamo is fast on his support - like a minute after I mailed him, he let me know yes, the intake rocker bolt hole is in the intake runner and he "normally uses teflon style sealer on the intake bolts... ARP makes a high temp version"

I would have chased catch can routing forever if you hadn't turned me on to this angle, KCS - thank you!

KCS

iTrader: (20)

No problem, happens a lot actually. Hopefully that's the fix.

Trucker82

I dont understand about the intake rocker? Is it a blind bolt hole that leads into the intake runners and intake pressure is bleading out into the case or valve assembly?

I just installed a vibrant performance closed loop catch can and they suggest that the valve cover line to the can not be elivated above the engine in order to catch the most fumes. Also that the can itself be mounted at or slightly below the valve cover. Thats my 2 cents.

KCS

iTrader: (20)

Usually when LS heads are ported, the rocker bolt hole is exposed in the intake port. During idle and part throttle, where there is high manifold vacuum, the oil can be sucked into the intake ports through the rocker bolt hole. It's kind of a dead giveaway when there is oil in the intake ports but not in the manifold runners.

Trucker82

Ahh! Thanks KCS!

jclayc

iTrader: (8)

Well, I took the intake rocker bolts loose and they already had sealant on them. Nonetheless, I cleaned them up, re-applied Permatex 59235 High Temperature Thread Sealant and torqued them down.

I ran the engine up to temp and idled for like 15-20 minutes. Pulled the intake... a good amount of oil was pooled in the back corner again w/ just a dribble in the catch can. I can look in the intake ports and see oil pooled on top of the valves.

The heads were new from Mamo (w/ new valve guides) and the short block was new & was assembled by Scoggin Dickey so I assume the rings are clocked correctly & cylinders are round. I've only got like 600 miles on it. My only remaining ideas:

I have a Schumann oil pump that puts out very high oil pressure (like 70 psi cold idle/35 warm and gets around 80 warm at speed). Perhaps that's too high of oil pressure and it's just blowing oil by the rings.

Perhaps because of the above, I need an aggressive breather setup (not just a closed catch can).

Cylinder compression/leak down test to see if - despite everything being new - I've got a ring or valve problem.

Jimbo1367

I'd try a air compressor oil seperator in line AFTER the CC. See if this helps. Maybe the rings will seat better with time. Don't baby it.