Blowby
06-21-2006, 11:29 PM
#1
Blowby Got some nice blowby at idle. Nice steamy constant puff out of dipstick and oil fill cap at idle. Builds pressure also. Gauge reads 10-12psi in vacuum at idle. Are my ringlands fooked? Stock bottom end btw. If so, time to go forged. 
06-21-2006, 11:32 PM
#2
Apparently, blowby and ls1's are hand in hand... within reason... As long as it's 10-12in hg not psi, you're okay =) Don't wanna "build" pressure... That's about where my TA ran with the turbo on it and the hot cam... always thought that was kinda low, but what the hell did I know, going down the road and letting off and letting the motor slow the car down, it'd spike up to 15, but that was it... SilverSS, runner till she comes apart then forge it. =)
Just hope my bottom end is okay. And yes, I'll drive it till it goes out.
06-21-2006, 11:47 PM
#5
That a boy, I did, lost the top of #2 at like 4 grand and 1/2 throttle getting into boost in 2nd gear. Was able to drive it home even with a crack in the sleeve. Just backfiring out of the right bank, and throwing multiple misfire on #2 cylinder on the laptop the whole way home. Pulled the plug and melted piston liquid all over the threads. DONE. 97K miles on the longblock, it was just time. Just don't beat on it, and make SURE it doesn't EVER see KR, you'll be fine.
Trending Topics
06-22-2006, 12:37 AM
#8
Enigine runs fine (besides the blowby issue) but there is a slight ticking noise from the engine when revved. Anybody experienced with bad ringlands? I'm just thinking the worst case scenario. I've searched but no clue. I'm sure the bottom end has seen enough abuse from me but hey, that's what I bought this car for. Weekend car to rag on. 
06-22-2006, 04:42 AM
#9
I would say you have a cracked ringland. You should not be seeing excessive blowby (nice steamy constant puff) at idle pumping out of the dipstick, and the ticking noise is a good indication. A cracked ringland can eventually cause the piston to slightly **** in the bore, which can cause the block to crack. This happened to the customer of the first CTS-V that we installed an ATI ProCharger in, after he had us crank the boost up higher than what it should of been at on a stock bottom end. We had warned him, but he wanted to risk it... A cracked ringland can also cause the broken off part to be pounded up into the bottom of the cylinder head. This happened on my '99 hugger orange Z28 after the stock bottom end broke a ringland after 126,000 miles. The last several hundred miles were at 15 psi... Bob
06-22-2006, 12:43 PM
#11
TECH Resident
Join Date: Jan 2004
Location: Castro Valley, CA
Posts: 832
Likes: 0
Received 0 Likes
on
0 Posts
Blowby is pressure from the combustion chamber that leaks past the piston/ring/cylinder wall tolerance into the crankcase. Please correct me if I'm wrong...
06-25-2006, 02:26 PM
#13
Launching!
iTrader: (5)
Join Date: Jan 2005
Location: Mustang, OK
Posts: 221
Likes: 0
Received 0 Likes
on
0 Posts
I guess it's the same thing on the lt1? I am getting some blow by, not at idle, but my dipstick pops out when I'm at WOT. Could ANYTHING else cause blow by that doesn't have to do with pulling the motor apart? This block that was built by coast high performance has only like 8 miles on it.
06-25-2006, 04:07 PM
#14
Originally Posted by 97SprChrgd383
I guess it's the same thing on the lt1? I am getting some blow by, not at idle, but my dipstick pops out when I'm at WOT. Could ANYTHING else cause blow by that doesn't have to do with pulling the motor apart? This block that was built by coast high performance has only like 8 miles on it.
Make sure your pcv isn't allowing boost into the crankcase. Also, are you running a breather of any sort?
06-25-2006, 04:49 PM
#15
my car kept seeing knock retard of 4 degrees on the dyno every time it hit 5600 rpm, found that one of the cylinders was registering too much air flow and dropping timeing. my tuner corrected what it was seeing and it stopped pulling timeing, was that the right thing to do? or was something else going on in the tune?
06-25-2006, 06:18 PM
#16
Launching!
iTrader: (5)
Join Date: Jan 2005
Location: Mustang, OK
Posts: 221
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by TS6
Make sure your pcv isn't allowing boost into the crankcase. Also, are you running a breather of any sort?
06-25-2006, 07:04 PM
#17
Launching!
iTrader: (3)
Join Date: Feb 2002
Location: Wilmington, NC
Posts: 281
Likes: 0
Received 0 Likes
on
0 Posts
if you are running an LT1, give Greg Carroll a call at www.blowerworks.net, he has build a PCV valve strictly designed for boosted LT1's it has an integral one way check valve with a very low cracking pressure that allows vacuum from the intake to remove pressure at idle/cruise, but closes as soon as there is pressure/boost in the intake.. no more silly flapper plate style PCV valves that may or may not work. it is a very nice machined buillet peice that fits in the stock PCV location on the intake manifold. cost is around 39 bucks.. but I have one on my turbo vette and one on the blow 95 vette.. neither suffers from pressure in the crabnk case from the PCV.
Chris
Chris
06-25-2006, 07:14 PM
#18
Well I can say the same. Pushed it to the limit's, noticing a bit of blow-puffing out of the filler. All so had flashing SES light while in 6th gear, ok at any other point, would also get a bit of KR on WOT runs. Motor was even running much hotter than before. Good old compression check told me #5 was shot. 65psi vs 150-160 on the rest.
06-26-2006, 03:10 PM
#20
Launching!
iTrader: (5)
Join Date: Jan 2005
Location: Mustang, OK
Posts: 221
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by HUGGER ORANGE SS
Again my friend. Sorry your having trouble with the motor..
I'll help you re build it. ;-)
Clint
I'll help you re build it. ;-)
Clint
See, that's what I'm talking about. That's why I love ls1tech. ONly problem is, there is no one around ME to help with my motor. Where's the Okc love!