Page 3 of 3 FirstFirst 123
Results 41 to 51 of 51

Thread: PCV and oil leaks

Forum to discuss Austin Healey Sports Cars

  1. #41
    Jedi Knight DerekJ's Avatar
    Join Date
    Nov 2004
    Location
    Cotswolds, UK
    Posts
    1,480
    Thanks Thanks Given 
    0
    Thanks Thanks Received 
    4
    Thanked in
    4 Posts

    Re: PCV and oil leaks

    TOC you nailed it!

  2. #42
    Jedi Hopeful
    Join Date
    May 2017
    Location
    Gloucestershire England
    Posts
    123
    Thanks Thanks Given 
    0
    Thanks Thanks Received 
    2
    Thanked in
    2 Posts

    Re: PCV and oil leaks

    Steve,
    Sorry, I've probably missed something. Where's the PCV located on the image above? I can't see it.

    Is that 5" or 0.5" under hard acceleration? I think 5" may be a bit on the high side. If it is 5" I would say the valve isn't reaching the "sonic flow" condition because the valve orifice is a bit on the large side. It would be interesting to try a smaller valve rather than a larger one.

    I'm proposing to use a manometer instead of a gauge because all of the gauges I've seen here measure 0 - 30" Hg. I don't expect cheap gauges to be accurate enough to measure 1" Hg reliably. Anyway why spend 30 bucks when I can make a manometer out of a bit of plastic tubing!

    On another point, I'm not claiming this is rocket science. When you search the web you find MANY technical papers on this subject by University's, Ford, Caterpillar, Toyota, etc. and you start to wonder why so much money has been spent on it. From my reading of the few I have downloaded, drawing a vacuum on the crankcase will affect oil distribution and engine performance. I guess the manufacturer's are trying to avoid warranty claims by funding this research!
    Most papers I've seen agree that the depression isn't arbitrary. They're trying to avoid sucking oil/air/dirt through engine seals or cavitation/slip in the pump.

    To conclude, I agree, apart from the fact that it interests old retired engineers with little else to do (Me!) most of us are probably trying this to prevent oil leaks. After all it's cheaper than pulling the engine out. As you get older you have to work smarter, that engine is heavy!

    AJ
    ps I wouldn't dream of leave my Porsche idling with the oil cap off. Why would you do this?

  3. #43
    Jedi Warrior Drone Dog's Avatar
    Join Date
    Jun 2017
    Location
    Seaford, DE
    Posts
    572
    Thanks Thanks Given 
    2
    Thanks Thanks Received 
    10
    Thanked in
    9 Posts

    Re: PCV and oil leaks

    steve
    are you thinking you will not need an oil catch can in the line?

    once it cools down, i will have to test my set up on the road and see if my reading changes.

    only other thing i did was put a small mark on my valve. just a quick check to see if it moved while driving.

  4. #44
    Jedi Warrior Drone Dog's Avatar
    Join Date
    Jun 2017
    Location
    Seaford, DE
    Posts
    572
    Thanks Thanks Given 
    2
    Thanks Thanks Received 
    10
    Thanked in
    9 Posts

    Re: PCV and oil leaks

    AJ
    if you look close i think Steve has his filter and air valve hooked to his side pipe, which is in front of his Valve cover T. his valve cover T has his connection for his gauge on the laft side and his PCV valve on the right side which goes to his manifold.

  5. #45
    Yoda steveg's Avatar
    Join Date
    Sep 2007
    Location
    Altadena, CA
    Posts
    3,659
    Thanks Thanks Given 
    86
    Thanks Thanks Received 
    135
    Thanked in
    115 Posts

    Re: PCV and oil leaks

    AJ - apologies for the unclear photo; my PCV valve is per the pic in Post #5 above. Yes, it's 0.5" under hard acceleration.

    DD - later today, I'll be working on making an orofice to match the flow on the brass valve. My valve is fairly stiff, so I wouldn't be worrying about it shifting while driving.
    Steve Gerow
    Altadena, CA, USA
    Maker of most complete Big Healey rear disc kit
    Check out my galleries:
    http://www.pbase.com/stevegerow


  6. #46
    Jedi Hopeful
    Join Date
    May 2017
    Location
    Gloucestershire England
    Posts
    123
    Thanks Thanks Given 
    0
    Thanks Thanks Received 
    2
    Thanked in
    2 Posts

    Re: PCV and oil leaks

    Congratulations Steve, I think you've cracked it.

    How will you size the orifice to match the valve flow, trial and error? When I did my MG I used a short length of steel rod with a 1.7mm hole drilled through it and I rammed it into the pipe before the PCV

    I tried fitting a catch tank between my breather T and air filter and it pressurised the rocker box and the gasket leaked. See image attached. I think the sintered metal filter in the head is too fine and there wasn't enough suction to draw the gases through from the crankcase. It may work better attached to the inlet manifold.

    If you could summarise what you did when you finish I think we can draw a thick line under this post and PCV valves.

    If I order one of those valves from NAPA tomorrow, do you think I might get by next spring!!
    Thanks guys.
    AJs-l1600.jpg

  7. #47
    Yoda steveg's Avatar
    Join Date
    Sep 2007
    Location
    Altadena, CA
    Posts
    3,659
    Thanks Thanks Given 
    86
    Thanks Thanks Received 
    135
    Thanked in
    115 Posts

    Re: PCV and oil leaks

    AJ - I've never felt the need for a catch tank. My engine has <7000 miles since the rebuild. Very little oil seen in the PCV valve after running. Will keep checking.

    Am using a 1/2" electrical panel hole plug. For the jet, 7/64" hole resulted in almost no vacuum. Settled on 3/32" hogged out slightly to give: 1.5" Hg idle or downhill; 1" cruise; 0.5" hard acceleration.

    screenshot.1877.jpg screenshot.1876.jpg

    I'm going to trim the edges and enclose it in the 5/8" hose from the side pipe to the rear air cleaner.

    DD - what did you use to plug the left side of the T?
    Steve Gerow
    Altadena, CA, USA
    Maker of most complete Big Healey rear disc kit
    Check out my galleries:
    http://www.pbase.com/stevegerow


  8. #48
    Jedi Warrior Drone Dog's Avatar
    Join Date
    Jun 2017
    Location
    Seaford, DE
    Posts
    572
    Thanks Thanks Given 
    2
    Thanks Thanks Received 
    10
    Thanked in
    9 Posts

    Re: PCV and oil leaks

    steve
    i got rubber stoppers from Lowes. they were in one of the drawers in the bolt aisle.

  9. #49
    Yoda steveg's Avatar
    Join Date
    Sep 2007
    Location
    Altadena, CA
    Posts
    3,659
    Thanks Thanks Given 
    86
    Thanks Thanks Received 
    135
    Thanked in
    115 Posts

    Re: PCV and oil leaks

    Semi-final install. Orifice inside 5/8" hose (blue tape). Gonna run the vac gauge for a few drives for QA.

    screenshot.1878.jpg
    Steve Gerow
    Altadena, CA, USA
    Maker of most complete Big Healey rear disc kit
    Check out my galleries:
    http://www.pbase.com/stevegerow


  10. The Following User Says Thank You to steveg For This Useful Post:

    John Turney  (08-20-2019)

  11. #50
    Jedi Warrior Drone Dog's Avatar
    Join Date
    Jun 2017
    Location
    Seaford, DE
    Posts
    572
    Thanks Thanks Given 
    2
    Thanks Thanks Received 
    10
    Thanked in
    9 Posts

    Re: PCV and oil leaks

    Steve
    much cleaner set up.
    you were asking about the plug i used. you could just put a rubber cap over your fitting to seal that side off. then it would be easy to hookup the gauge anytime.
    fullsizeoutput_2d4.jpg
    fullsizeoutput_2d4.jpg
    same idea as here just up on top.

  12. #51
    Yoda steveg's Avatar
    Join Date
    Sep 2007
    Location
    Altadena, CA
    Posts
    3,659
    Thanks Thanks Given 
    86
    Thanks Thanks Received 
    135
    Thanked in
    115 Posts

    Re: PCV and oil leaks

    Quote Originally Posted by Drone Dog View Post
    Steve
    much cleaner set up.
    you were asking about the plug i used. you could just put a rubber cap over your fitting to seal that side off. then it would be easy to hookup the gauge anytime.
    same idea as here just up on top.
    Good idea about the cap. I need to replace my lo-rent plastic barb with a cool brass barb like yours.
    Steve Gerow
    Altadena, CA, USA
    Maker of most complete Big Healey rear disc kit
    Check out my galleries:
    http://www.pbase.com/stevegerow


Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •