crankcase pressure
crankcase pressure Ok. At WOT my dipstick pops out and shoots a little oil on the valve cover. I have a breather on the pass. side valve cover and a cap on the driver side valve cover. Should I take the breather off and use a cap b/c I have a pcv valve? Or(and I read this), should I put the cap on the pass side and the breather on the driver side? Or do I need a vacuum pump. I got lots of boost and new engine.
sounds like the rings have not seated yet did you use chrome rings if the rings have not seated and you are running boost you may be blowing boost into crankcase chrome rings usually take well over 500 miles to seat in and sometimes more
If you haven't disabled the PCV system you are definitely getting oil in the intake. For that I'd recommend at least a catch can. You probably need a check valve in the PCV and passenger valve cover-to-TB hose as well to keep some of the boost out of the crankcase. Mightymouse has a good setup on his LS1 turbo where he's blocking off the TB inlets and routing the PCV through a catch can and into the turbo inlet to create some vacuum in the crankcase. There's also krankvent and Moroso and Mr. Gasket crankcase evacuation systems for sale that might lower the pressure. All of these are cheaper and simpler than a vacuum pump, which is also an option. I'd also search "pcv oil catch" and read up.
https://ls1tech.com/forums/showthrea...=pcv+oil+catch
https://ls1tech.com/forums/showthrea...=pcv+oil+catch
Last edited by bone324; Jun 14, 2006 at 05:28 AM.
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I wonder if you can put a little vent filter on the front of the intake where it vents out, instead of having the PCV run into the Drivers side and putting the oil and vapors in there..
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chrome rings take a longer time to seal,take the turbo off or keep it at minimum boost and drive it around at high rev to make them seal better,keep an eye on the oil
3 30min drives at say 1st 55 2nd 65 3rd 75to100% of rev range at high speed
3 30min drives at say 1st 55 2nd 65 3rd 75to100% of rev range at high speed
dude i really believe that you are getting blowby from the rings not seating yet and having boost on top of that........if you have the pcv system hooked up that will be creating vaccumm in the crankcase but if it is still building pressure then you have blowby again my 434 did the same thing for 3 weeks of steady running and then one day it just stopped but i had prolly 1000 miles on it by then.........who built the motor? did you use chrome rings.......did you get a good crosshatch in the cylinder walls? ......if you used chrome rings did put a rough crosshatch which is needed for chrome rings........did you clean the cylinder walls with solvent after honing which is a big no-no....answer these questions and i may be able to help you better....also what was your piston to wall clearance...ok ijust seen the post where you used chrome rings so lets go from there they will take forever to seat with boost also what kind of hone job did you do when planning to use chrome rings instead of honing the final hone with lube just use water you want a rough hone with chrome rings to help them seat..........if you used solvent to clean the cylinder walls after honing that could also be a problem only use soap and water solvents for the most part seal up the hone grooves and dont let the rings seat
also in the future skip the chrome rings just use regular iron rings they seat well and work just as well the only place to really use chrome rings would be an application where you wouldnt be using an air filter they are more forgiving with junk inside the cylinders
actually, coast high performance built the block. I take what I said earlier back. They are nodulary moly top, clevite rings. I'm pretty sure these guys know what they are doing? It's a fully forged block. Pistons, rods, crankshaft, etc...Coasthigh.com
Last edited by 97SprChrgd383; Jun 14, 2006 at 02:29 PM.
yeah everybody knows what they are doing......but lets take a look at most machine shops there is really only about 2 people that work in that shop who know what they are doing or really care and those are the owners and the manager.....but who do you think does the machine work usually the high school drop out that works there for 9 bucks an hour...**** does happen and obviously there is a problem if you have blowby do this then do a CLT and compression test on the motor see what percentage of leakdown you have and what the compression differences are from cylinder to cylinder and that will tell you alot about your problem....make sure when you do the clt the piston is at true TDC and both valves are closed or you will just turn the motor with the air pressure.....if you have low compression or wide differences in compression add a little oil to the cylinder and do it again if the compression comes up most likley the rings are not sealing
When I said I'm pretty sure these guys know what they are doing, I meant that like "I HOPE these guys know what they are doing". I am absorbing your info like a sponge good man, so don't get all bent out of shape on me here. I did ask for the info. I appreciate the info given and I am going to do these things that you have mentioned. I'm sure it's just what you said, that the rings haven't seated. Sounds like the most possible cause of the dip stick popping out. Has anyone else delt with coast high?
sorry man i just get aggravated when someone asks a question and then it doesnt sound like they want to hear the answer....i would turn off the boost and run it nwithout it for a while....when i was a kid my dad owned a machine shop and i grew up building motors since age 12 and trannies and i have seen some of the people that work in these shops...........
See, that's the beauty of ls1tech and other car forums. There are people on here that actually know what's going on(for the most part) with the cars and can help you solve pretty much any problem yourself without taking it to those people. What if I just drive it with out running at WOT for a little while. That should do it right?
I'm sure Predator is right, it sounds like he has alot of experience in this area. But running the normal PCV setup on an LT1 with that much boost is going to create a good deal of crankcase pressure that the PCV system can't optimally handle. Even if the engine is broken-in properly you're likely to have some excess pressure. I'm only boosting 8-9 psi and have a constant crankcase pressure code as well as some oil coming from my breather. I'm going to have to add vaccuum at some point and like I said, there are numerous ways to do this.
I'm looking for the cheap way to do it other than running a vacuum pump. I think having to lines going from the valve covers and t'd off to the intake before the inlet of the supercharger is a good idea.