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Excessive crank case pressure frustration #1320483
10/14/12 09:58 PM
10/14/12 09:58 PM
Joined: Nov 2004
Posts: 7,647
Houston Texas
PAINT IT BLACK Offline OP
Got a CHIP on my shoulder
PAINT IT BLACK  Offline OP
Got a CHIP on my shoulder

Joined: Nov 2004
Posts: 7,647
Houston Texas
I was using a K&N crank case breather... Nothing internally to baffle oil. Fresh motor build. At idle, everything's ok. Driven in higher RPMs, oil sprays everywhere from that little breather. Huge Mess.

Did. This before and the builder went back through it because of oil loss. Not smoking much, just oil getting sucked up into the pcv valve and fed to the intake.

So here we are again. My thought is to use a baffled breather (and maybe even a catch can at the pcv valve?) or a crank case evac system like this to manage the blow by:

http://chucker54.stores.yahoo.net/morcranevsys.html

I understand the rings aren't yet seated on this new motor, but this is obviously unusual. If a leak down test shows nothing very telling, am I on the right track for managing the oil.. At least temporarily?

The build: 360 stroked to a 408. Eagle crank, H beam rods, forged pistons, aluminum heads, hydraulic roller cam 248/254 duration, 109 separation, roller rockers .600 lift, M1 intake, final compression is 10.5:1 - dyno'd great for the budget at 500hpp/520tq.

Just trying to figure out wtf is going on!!

Re: Excessive crank case pressure frustration [Re: PAINT IT BLACK] #1320484
10/14/12 10:15 PM
10/14/12 10:15 PM

A
Anonymous
Unregistered
Anonymous
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Is the PCV valve working properly?

I've had one stick before, the engine built up crankcase pressure and blew oil out the dipstick tube!

Re: Excessive crank case pressure frustration [Re: PAINT IT BLACK] #1320485
10/14/12 10:18 PM
10/14/12 10:18 PM
Joined: Nov 2005
Posts: 15,118
85086
moparpollack Offline
Lil Herman
moparpollack  Offline
Lil Herman

Joined: Nov 2005
Posts: 15,118
85086
Are there baffles in the valve covers? What type of driving? Drag race? auto cross?


56 Plaza 63 D100 step side 67 Coronet, 68 Roadrunner, 69 Super Bees, 69 Coronet 500 convertible, 70 Roadrunner Post, 79 D150 360, and a severe case of Mopar a,d,d
Re: Excessive crank case pressure frustration [Re: moparpollack] #1320486
10/14/12 10:27 PM
10/14/12 10:27 PM
Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
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RapidRobert Offline
Circle Track
RapidRobert  Offline
Circle Track
R

Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
I would add some baffles to the valve covers or get baffled ones


live every 24 hour block of time like it's your last day on earth
Re: Excessive crank case pressure frustration [Re: RapidRobert] #1320487
10/14/12 11:07 PM
10/14/12 11:07 PM
Joined: Jan 2003
Posts: 32,882
Grand Prairie,Texas
stumpy Offline
I Win
stumpy  Offline
I Win

Joined: Jan 2003
Posts: 32,882
Grand Prairie,Texas
Just to be sure you have a breather in one valve cover and the pcv in the other.

Re: Excessive crank case pressure frustration [Re: RapidRobert] #1320488
10/14/12 11:17 PM
10/14/12 11:17 PM
Joined: Jan 2003
Posts: 74,904
U.S.S.A.
JohnRR Offline
I Win
JohnRR  Offline
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Joined: Jan 2003
Posts: 74,904
U.S.S.A.
Add me to the baffles crowd , without them you are going to have happen exactly what is happening , the factory didn't install them in the valve covers to keep a 50/50 weight bias ...

Re: Excessive crank case pressure frustration [Re: JohnRR] #1320489
10/15/12 12:13 AM
10/15/12 12:13 AM
Joined: Nov 2004
Posts: 7,647
Houston Texas
PAINT IT BLACK Offline OP
Got a CHIP on my shoulder
PAINT IT BLACK  Offline OP
Got a CHIP on my shoulder

Joined: Nov 2004
Posts: 7,647
Houston Texas
The baffles are there. Street car with a strip attitude. Pcv is new, acted this way with the old pcv. Forgot to mention leaking rear main seal. Again, fresh build.

Re: Excessive crank case pressure frustration [Re: PAINT IT BLACK] #1320490
10/15/12 02:37 AM
10/15/12 02:37 AM
Joined: Aug 2003
Posts: 8,716
Baltimore/Denver
64Post Offline
master
64Post  Offline
master

Joined: Aug 2003
Posts: 8,716
Baltimore/Denver
Do you have engine breaking when coasting down in gear?

Re: Excessive crank case pressure frustration [Re: 64Post] #1320491
10/15/12 03:16 AM
10/15/12 03:16 AM
Joined: Aug 2003
Posts: 12,291
Kent, Wa
340SHORTY Offline
Truck Nut
340SHORTY  Offline
Truck Nut

Joined: Aug 2003
Posts: 12,291
Kent, Wa
Excessive crankcase pressure is only cured by installing new rings. Evidently your rings are not broken in yet or they were improperly installed/broken. Anything you do is only a bandaid for a serious internal problem..


I am truckless..
Re: Excessive crank case pressure frustration [Re: PAINT IT BLACK] #1320492
10/15/12 07:49 AM
10/15/12 07:49 AM
Joined: Feb 2005
Posts: 28,312
Cincinnati, Ohio
Challenger 1 Offline
Too Many Posts
Challenger 1  Offline
Too Many Posts

Joined: Feb 2005
Posts: 28,312
Cincinnati, Ohio
Something is not hooked right if you have a proper baffle in the valve cover.
I ran some MT valve covers years ago without baffles and it did this. I bolted a good sized baffle in the valve cover with the PVC valve in it and it fixed my problem.

Either that or your motor is junk.

Rings should and will seat within minutes of the motor running. Sorry to hear about the rear main...

Re: Excessive crank case pressure frustration [Re: 340SHORTY] #1320493
10/15/12 09:55 AM
10/15/12 09:55 AM
Joined: Mar 2010
Posts: 1,880
Out in Left Field, NY
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bobs66440 Offline
top fuel
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top fuel
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Joined: Mar 2010
Posts: 1,880
Out in Left Field, NY
Quote:

Excessive crankcase pressure is only cured by installing new rings. Evidently your rings are not broken in yet or they were improperly installed/broken. Anything you do is only a bandaid for a serious internal problem..


Mine is a fresh rebuild and zero oil usage and no perceptable crankcase pressure. I would do a compression/leak down test.

Re: Excessive crank case pressure frustration [Re: PAINT IT BLACK] #1320494
10/15/12 10:11 AM
10/15/12 10:11 AM
Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
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RapidRobert Offline
Circle Track
RapidRobert  Offline
Circle Track
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Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
Here's a very interesting short read on ring breakin issues. "breakin secrets" at www.mototuneusa.com


live every 24 hour block of time like it's your last day on earth
Re: Excessive crank case pressure frustration [Re: RapidRobert] #1320495
10/15/12 10:36 AM
10/15/12 10:36 AM
Joined: Jan 2003
Posts: 25,200
Upper Midwest
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MoparforLife Offline
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Joined: Jan 2003
Posts: 25,200
Upper Midwest
Remember to that you need a vent on each valve cover. Not just one.

Re: Excessive crank case pressure frustration [Re: MoparforLife] #1320496
10/15/12 11:03 AM
10/15/12 11:03 AM
Joined: Nov 2004
Posts: 7,647
Houston Texas
PAINT IT BLACK Offline OP
Got a CHIP on my shoulder
PAINT IT BLACK  Offline OP
Got a CHIP on my shoulder

Joined: Nov 2004
Posts: 7,647
Houston Texas
I have baffles on both. I guess the leak down will tell the story.... This motor has been. 2 builds, both failures.

Re: Excessive crank case pressure frustration [Re: PAINT IT BLACK] #1320497
10/15/12 04:51 PM
10/15/12 04:51 PM
Joined: Aug 2003
Posts: 12,291
Kent, Wa
340SHORTY Offline
Truck Nut
340SHORTY  Offline
Truck Nut

Joined: Aug 2003
Posts: 12,291
Kent, Wa
Id be looking for a different machinist/builder for the 3rd go around..


I am truckless..
Re: Excessive crank case pressure frustration [Re: 340SHORTY] #1320498
10/15/12 07:36 PM
10/15/12 07:36 PM
Joined: Nov 2004
Posts: 7,647
Houston Texas
PAINT IT BLACK Offline OP
Got a CHIP on my shoulder
PAINT IT BLACK  Offline OP
Got a CHIP on my shoulder

Joined: Nov 2004
Posts: 7,647
Houston Texas
These guys turn out a lot of motors and are very reasonable to deal with. We'll figure it out & ill probably get my Bee's big block done for the hassle.

Re: Excessive crank case pressure frustration [Re: PAINT IT BLACK] #1320499
10/15/12 08:56 PM
10/15/12 08:56 PM
Joined: Jun 2008
Posts: 3,913
usa
L
lewtot184 Offline
master
lewtot184  Offline
master
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Joined: Jun 2008
Posts: 3,913
usa
doing a leak down test is the easiest and probably the most informative course of action.

Re: Excessive crank case pressure frustration [Re: lewtot184] #1320500
10/16/12 12:11 AM
10/16/12 12:11 AM
Joined: Jan 2003
Posts: 6,480
USA
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Molloy Offline
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Molloy  Offline
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Posts: 6,480
USA
I had that problem on my 496. It was the higher Rs that slung oil. It wasn't the rings because it did great on a leak down test. I thought it was the longer throws of the crank. Anyway, a pan evac system pretty much eliminated the problem.

Re: Excessive crank case pressure frustration [Re: Molloy] #1320501
10/16/12 05:31 AM
10/16/12 05:31 AM
Joined: Nov 2004
Posts: 7,647
Houston Texas
PAINT IT BLACK Offline OP
Got a CHIP on my shoulder
PAINT IT BLACK  Offline OP
Got a CHIP on my shoulder

Joined: Nov 2004
Posts: 7,647
Houston Texas
That's the thing. The last time this happened, before we tore it down again, it was only the high revs that did it and the leak down / compression was fine. I'm not using a windage tray, and I think that might help? But if the leak down is fine this time around, I'm going to explore other ways of getting this under control. I bought only the best parts (for what it is), and I trust my builder.

Re: Excessive crank case pressure frustration [Re: PAINT IT BLACK] #1320502
10/16/12 01:41 PM
10/16/12 01:41 PM
Joined: Aug 2003
Posts: 8,716
Baltimore/Denver
64Post Offline
master
64Post  Offline
master

Joined: Aug 2003
Posts: 8,716
Baltimore/Denver
I’ll ask again, if you take the car up to 4-5k rpm and let it coast down in gear do you get poor/good/very good engine breaking? Does your exhaust show any blue under engine breaking?

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