Gravity Fed Alex Staidle Professional Moderator Location: Δx = ħ/2Δp Join Date: 08/21/2009 Age: Settling Down Posts: 1,719 Rally Car: Various Heaps |
also! my dipstick blows right out of the tube... alot. i have it zip tied down right now... any suggestions?
First Rally: 2010 First RallyX: 2004 (a bunch) Driver (0), Co-Driver (7) Organizer (3), Volunteer (3) Cars Built (2.5), Engines Blown (2) Cages Built (0) # of rotations (3.5) Last Updated, Apr 9, 2023 |
Aaron Luptak Aaron Luptak Super Moderator Location: SLC Join Date: 02/15/2008 Age: Midlife Crisis Posts: 776 Rally Car: Civic... |
determine whether all your combustion pressure is leaking past the rings or the valves (or both)? ![]() ![]() http://www.utahrallygroup.com |
NoCoast Grant Hughes Senior Moderator Location: Whitefish, MT Join Date: 01/11/2006 Age: Midlife Crisis Posts: 6,818 Rally Car: BMW |
Valve stem seals.
Super common problem. Do a leak down and compression test. Or buy some bigger zip ties. Are you getting a ton of blow by out of the crankcase breathers? One at PCV valve on top rearward of valve cover, other comes off some annoying place down underneath the intake manifold. I welded a -8 or 10 fitting on my valve cover and pushed a nice big piece onto the block one and ran it to a nice big oil catch thingy. It still blew lotsa air but the tank never had much oil in it. Grant Hughes Edited 2 time(s). Last edit at 03/11/2013 05:15PM by NoCoast. |
john vanlandingham John Vanlandingham Junior Moderator Location: Ford Asylum, Sleezattle, WA Join Date: 12/20/2005 Age: Fossilized Posts: 14,152 Rally Car: Saab 96 V4 |
Yep. Do a leak-down..
Many of these buggers have sat and when these sit there can be rust in the bores, that rust is abrasive...listen in the oil filler hole while pressure is up... You better not hear some roaring wind sound.. John Vanlandingham Sleezattle, WA, USA Vive le Prole-le-ralliat www.rallyrace.net/jvab CALL +1 206 431-9696 Remember! Pacific Standard Time is 3 hours behind Eastern Standard Time. |
Gravity Fed Alex Staidle Professional Moderator Location: Δx = ħ/2Δp Join Date: 08/21/2009 Age: Settling Down Posts: 1,719 Rally Car: Various Heaps |
yea i have oil film around the filler cap, pcv, etc. ill check compression and whatnot. hopefully it will just be valve stem seals.
First Rally: 2010 First RallyX: 2004 (a bunch) Driver (0), Co-Driver (7) Organizer (3), Volunteer (3) Cars Built (2.5), Engines Blown (2) Cages Built (0) # of rotations (3.5) Last Updated, Apr 9, 2023 |
john vanlandingham John Vanlandingham Junior Moderator Location: Ford Asylum, Sleezattle, WA Join Date: 12/20/2005 Age: Fossilized Posts: 14,152 Rally Car: Saab 96 V4 |
Compression is best when looking for dead holes. LEAK DOWN is for pinpoint where the problem is, not IF, but what . Intake valve? Exhaust valve? Rings? Leak down is the hot ticket. John Vanlandingham Sleezattle, WA, USA Vive le Prole-le-ralliat www.rallyrace.net/jvab CALL +1 206 431-9696 Remember! Pacific Standard Time is 3 hours behind Eastern Standard Time. |
Gravity Fed Alex Staidle Professional Moderator Location: Δx = ħ/2Δp Join Date: 08/21/2009 Age: Settling Down Posts: 1,719 Rally Car: Various Heaps |
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john vanlandingham John Vanlandingham Junior Moderator Location: Ford Asylum, Sleezattle, WA Join Date: 12/20/2005 Age: Fossilized Posts: 14,152 Rally Car: Saab 96 V4 |
listen in tailpipe---exhaust valve listen in intake----intake valve listen in oil filler------rings.. some of the cheesiod tester reduce shop line pressure. I lurv full line pressure; lets ya hear easier. John Vanlandingham Sleezattle, WA, USA Vive le Prole-le-ralliat www.rallyrace.net/jvab CALL +1 206 431-9696 Remember! Pacific Standard Time is 3 hours behind Eastern Standard Time. |
NoCoast Grant Hughes Senior Moderator Location: Whitefish, MT Join Date: 01/11/2006 Age: Midlife Crisis Posts: 6,818 Rally Car: BMW |
No leaky then probably valve stem seals. Pretty sure that's how I detected mine, though it might have just been compression check since I had one of those easy at hand and all holes checked out good and held compression. Grant Hughes |
john vanlandingham John Vanlandingham Junior Moderator Location: Ford Asylum, Sleezattle, WA Join Date: 12/20/2005 Age: Fossilized Posts: 14,152 Rally Car: Saab 96 V4 |
Honeychile, leaky stem seals don't blow dipsticks out. They suck erl in on decel John Vanlandingham Sleezattle, WA, USA Vive le Prole-le-ralliat www.rallyrace.net/jvab CALL +1 206 431-9696 Remember! Pacific Standard Time is 3 hours behind Eastern Standard Time. |
RDR Jay Anderson Mega Moderator Location: Chicago, Il Join Date: 01/30/2013 Age: Settling Down Posts: 29 Rally Car: 1983 Toyota Celica |
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NoCoast Grant Hughes Senior Moderator Location: Whitefish, MT Join Date: 01/11/2006 Age: Midlife Crisis Posts: 6,818 Rally Car: BMW |
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MarkHille Mark Hille Mega Moderator Location: The hills of CT Join Date: 10/04/2011 Age: Midlife Crisis Posts: 135 Rally Car: I have two crap boxes |
Like what jay said, if your pcv is broken it will put all of your boost pressure straight into your crankcase and blow your dip stick. That being said, a properly functioning pcv valve only relieves crankcase pressure when you let off the throttle so if you have long full throttle periods the only way pressure is being released is through the small breather on your cam cover…or out your dipstick. People say high boost (>20psi) will tend to blow the dipstick no matter what your doing because of increased blow by. The solution seems to be a catch can like Grants. Here is a good resource. The added benefit to a catch can is that oil/oil mist is no longer being pushed/pulled into your intake which also helps raise the detonation prevention level so win win.
Only down side is it isn’t as environmentally friendly so you would be killing all of our great grandchildren…or possibly failing emissions in California. I have also read that the vacuum through the pcv valve helps prevent “engine sludge†by sucking out harmful vapors found in the crankcase but I am of the party that says “I don’t believe you and who cares anyway…use good oil and change it often. Problem solved.†|
john vanlandingham John Vanlandingham Junior Moderator Location: Ford Asylum, Sleezattle, WA Join Date: 12/20/2005 Age: Fossilized Posts: 14,152 Rally Car: Saab 96 V4 |
Mark the only "boost pressure" getting into the crankcase is getting in past the rings..
And cars without turbos also need crankcase ventilation.. You are confusing issues- symptoms- results. If "boost pressure" got into the crankcase...boost is what 12-20-30 psi? Even normal aspirated motors make 150-200 psi on the starter motor, without spark/boom.. They make shit-tons of Pee Esse Eyes when running... See what I's saying? John Vanlandingham Sleezattle, WA, USA Vive le Prole-le-ralliat www.rallyrace.net/jvab CALL +1 206 431-9696 Remember! Pacific Standard Time is 3 hours behind Eastern Standard Time. |
NoCoast Grant Hughes Senior Moderator Location: Whitefish, MT Join Date: 01/11/2006 Age: Midlife Crisis Posts: 6,818 Rally Car: BMW |
Here's another good read.
http://www.burtonpower.com/tuning-guides/tuning-guide-pages/engine-breather-system.html Wait, so boost doesn't push past leaking valve stem seals when you are say, pressurizing the intake manifold to 1.5 bar? I'm having trouble grasping that one... Enough to blow out the dipstick, valve cover gasket, etc? If it were my car and I was about to pull the trans anyhow to fix a clutch and do a T5 swap, I'd go ahead and pull the valve cover, get a AN fitting welded onto the top instead of the cheesy little oil seperator thing, and setup a decent breather system anyhow. Regardless of what else you are doing, that is probably a good idea. Grant Hughes |