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Thread: Chasing oil leaks

  1. #1
    Join Date
    Apr 2013
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    143

    Default Chasing oil leaks

    My (BDA/BDR) engine leaks lots of oil - like tablespoons, not drips. Some of it is from the oil tank, and I should be able to track that down and fix that.

    Some of it is in the area of the two vertical hoses at the front left on the engine - the hoses that run from the head to the block. One is rubber, one is braided stainless. Both use crimp hose clamps on both ends. Here's a picture of the top connections for those:

    Name:  Hose connections.jpg
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    I was planning to remove and replace those hoses, but based on how tight the space is and the type of clamps I might pass on this. Thoughts?

    It also might be leaking around the oil pan gasket, so I plan to pull the pan and replace that.

    Lastly, I am considering installing an oil check valve, like this, to keep oil from flowing from the tank back into the engine when at rest:

    https://www.pelicanparts.com/More_In...BoCmMEQAvD_BwE

    It just seems like the oil flows back to the engine and finds places to leak out. This is a high quality part (and priced accordingly), which is used in the Porsche world. Thoughts?

    Also thoughts on other common leak points in BDA/BDR/crossflow engines?
    1997 Caterham, BDA
    1991 Miata, supercharged
    2017 VW GTI

  2. #2
    Join Date
    Feb 2009
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    NYC
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    Ahhhhhh...the Ford Corrosion Protection Program. I know it well....on a 289 V8!

    Are those hoses rated for oil?

    Not sure what these hoses are for - head to block? Are they breathers? ONce purpose is known, then I would consider changing hoses if they have gone oil permeable from age and make them braided stainless outside/oil rated rubber inside with AN end fittings for extra leak protection. That should allow you some level of precision of achieving clearance.

    Definitely make a change in the oil pan gasket.

    Is the oil tank for the dry sump? My concern for using a valve like that is what happens on start up after sitting a while? Is there sufficient lubrication around the engine to avoid critical wear in start up phase as the oil may not be located where it is really needed.
    Mike
    2010 Caterham CSR with Cosworth 2.3 Duratec
    2018 Caterham 420R with 2L Duratec 210hp at Donington UK
    1975 BMW CSL Group 4 (restoration finished - track set up time)
    1977 Holden Torana "A9X" (awaiting restoration)
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    1982 Ferrari 400i (radiator replacement)
    1965 Ford Mustang Fastback "Holman Moody"
    1992 Ford Escort RS Cosworth WRC (dyno time)
    1990 Range Rover 2 door Classic
    and another project car coming....

  3. #3
    Join Date
    Apr 2008
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    San Jose, CA
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    How much oil pressure do you see? I think those are the hoses that run from the front cover to the head. You can try snugging them down, but they may need to be replaced. I don't think you will be able to add AN fittings if I recall correctly.

    Since you mention both a tank and a sump, I assume you have a dry sump system. My concern about that valve would be its restriction - especially since they do not provide any specs on it. I have a similar problem on my dry sump system. Since my sump is behind the engine and relatively low, I store the car with the front end up which keeps the oil in the tank and prevents it from draining into the sump. If it has been a really long time, I sometimes add a small amount to the sump before start up and crank without plugs. I've been considering developing a priming system (theoretically it can be done with a pressure sprayer or commercially available priming pump). If you fix the problem of the oil draining into the sump, your sump leak may not nearly be as bad.

    Oil pan gaskets are always tricky on a kent block. I prefer the rubber saddle seals over the cork ones, but you need to make sure that they meet the flat cork gaskets correctly to get a good seal. I am also a fan of studs on the block to better locate the gasket/sump during assembly.

  4. #4
    Join Date
    Apr 2013
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    Yes - I am dry-sumped. I guess I should have mentioned that, but I assumed that all BDA/R engines are.

    Oil pressure is good. Runs high when cold - per the previous owner's advice I keep the revs low to not go over 80psi when cold. I don't remember exactly where it runs when warm. At idle it's very low - like maybe 10-15 psi, but Quicksilver Race Engines who built the engine told me that that is normal for these engines, and I am running the oil they recommended.

    There is definitely no room for AN fittings on the two vertical hoses - the connections are I think cast into the block and head, and in very tight spaces. One hose is braided stainless, and the other is black rubber. I am guessing, but not sure, that Quicksilver would have replaced these during the rebuild 4 years and under 2k miles ago. Trying to tighten the clamps is an interesting idea. I need to get into that area this weekend and see if there's even room to get a tool in there with the engine in the car. I suspect not but we'll see. I have wondered if I really do need to pull the engine to really get at all the potential leak points.

    When you refer to rubber saddle seals do you mean to use those (whatever they are?) in addition to the cork gasket? Also - should I use any RTV silicone or other gasket adhesive in addition? Torque spec on the pan nuts is very low - it's very tempting to tighten them a bit more, but I know I shouldn't.

    I've even thought about installing a manual petcock in the oil feed line, so I can just shut it off when the car sits for a while. I think I could manage this, putting a sign that says "Turn On Oil" or something like that on the steering column whenever I shut it off. But I realize how risky this is.
    1997 Caterham, BDA
    1991 Miata, supercharged
    2017 VW GTI

  5. #5
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    Apr 2013
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    FYI this picture shows the two hoses to which I referred:

    Name:  Cosworth_BDA_1600cc_Engine___Race_Car_Parts_for_sale_at_Raced___Rallied___rally_cars_for_sale__r.jpg
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    1997 Caterham, BDA
    1991 Miata, supercharged
    2017 VW GTI

  6. #6
    Join Date
    Feb 2012
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    Roswell GA
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    Torque values on oil pan bolts are low due to their small dia. and oil pans are generally thinner gauge metal. I'm not familiar with dry-sumps as far as construction.
    Life happens while you're making other plans
    1995 Caterham Crossflow RHD
    1990 Miata
    2007 GMC Sierra WT
    2013 Mini (Her's)
    2014 Outback
    JOHN DEERE D130

  7. #7
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    Apr 2013
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    One more thought: From people's experience, should I just pull the engine to get all all the potential leak points?
    1997 Caterham, BDA
    1991 Miata, supercharged
    2017 VW GTI

  8. #8
    Join Date
    Dec 2014
    Location
    Los Angeles
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    The next time the head is off, consider TIG welding on a pair of bungs to accommodate AN fittings. Absent this possibility, when you replace the hoses, be sure to use sleeved hose clamps to avoid damage to the hose material. Try to arrange the orientation of the screws to allow you to use an 8mm socket for tightening. It’s less likely to slip in the process.

  9. #9
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    I forgot to ask - do you have an aluminum dry-sump pan or a steel one?

    Here are the saddle seals I was referring to: https://www.pegasusautoracing.com/pr...sp?RecID=10906 (Rear in this case and there is a note about the aluminum vs. steel pans).

    If is leaking from the rear main - removal is definitely required. Doing an on pan underneath the car isn't fun but can be done. It all depends on how much access you have. You may be able to loosen the motor mounts and move the engine to get to those hoses. without completely removing the motor.

    I like to use a very small amount of "the right stuff" by permatex where the flat gaskets meet the saddle gaskets. I used loctite aviation No 3 to secure the cork gaskets in place. Some people say good things about Cometic gaskets, but I've never used them.

    80 PSI is high, but not awful. Your oil pump likely has a pressure release valve you can try adjusting.


    I once saw a 65 mustang with an industrial ball valve pumbed into his sump tank. He had a big note over his ignition key that said "Did you open the sump valve?!?!" Even then, I'd be worried about the restriction of the valve.

  10. #10
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    Roswell GA
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    Quote Originally Posted by BlueBDA View Post
    One more thought: From people's experience, should I just pull the engine to get all all the potential leak points?
    It would more effort to start with, but you have full access to all the areas you need to address and cuts out second guessing.
    Life happens while you're making other plans
    1995 Caterham Crossflow RHD
    1990 Miata
    2007 GMC Sierra WT
    2013 Mini (Her's)
    2014 Outback
    JOHN DEERE D130

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