BDR oil leaks

[BlueBDA]

I am trying to track down the oil leaks in my new to me dry-sumped BDR. Engine was rebuilt by Quicksilver RacEngines 1000 miles ago. I have wiped everything off, driven it, and then let it sit. There's a drip of oil under the tank, some oil around the sump, and the side-mount oil pump is very oily. I did re-torque the sump pan nuts, although I couldn't reach two of them as the starter is in the way and I didn't feel like taking it off yet. It has leaked maybe a few tablespoons in a few days. The previous owner mentioned a valve that I can get that will prevent the oil from running by gravity from the tank back into the sump when the engine is off. Can anyone point me towards one of those? Of course I am going to try to tighten every hose connection (all threaded fittings). Any advice on particular areas to check or methods to find and eliminate the leaks would be greatly appreciated. Also it would be great to connect with any other BDR owners, to be able to share information in the future. Thanks.

 

-Jeff

[Vovchandr]

I am trying to track down the oil leaks in my new to me dry-sumped BDR. Engine was rebuilt by Quicksilver RacEngines 1000 miles ago. I have wiped everything off, driven it, and then let it sit. There's a drip of oil under the tank, some oil around the sump, and the side-mount oil pump is very oily. I did re-torque the sump pan nuts, although I couldn't reach two of them as the starter is in the way and I didn't feel like taking it off yet. It has leaked maybe a few tablespoons in a few days. The previous owner mentioned a valve that I can get that will prevent the oil from running by gravity from the tank back into the sump when the engine is off. Can anyone point me towards one of those? Of course I am going to try to tighten every hose connection (all threaded fittings). Any advice on particular areas to check or methods to find and eliminate the leaks would be greatly appreciated. Also it would be great to connect with any other BDR owners, to be able to share information in the future. Thanks.

 

-Jeff

 

I read advice somewhere in the 7 community and stuck with it while troubleshooting all my fluid leaks (when I started I had coolant/oil/windshield washer/fuel and transmission leaks). With me having an Accusump system, remote filter and an oil cooler it was a LOT of lines to try to nail the leaks from.

 

The advice was to take paper towels and zip tie pieces around connection points. 90% of the time it has worked every time.

 

Now I'm down to leaking from the bell housing and I think the washer bottle loses fluid under hard right turns and spits it on the windshield. Regardless give that a try.

[BlueBDA]

Brilliant! I'll give it a try. Thanks so much.

 

I read advice somewhere in the 7 community and stuck with it while troubleshooting all my fluid leaks (when I started I had coolant/oil/windshield washer/fuel and transmission leaks). With me having an Accusump system, remote filter and an oil cooler it was a LOT of lines to try to nail the leaks from.

 

The advice was to take paper towels and zip tie pieces around connection points. 90% of the time it has worked every time.

 

Now I'm down to leaking from the bell housing and I think the washer bottle loses fluid under hard right turns and spits it on the windshield. Regardless give that a try.

[inchoate]

My car has a BDR in it, but I'm wet sumped so not too much to add.

 

I've been gathering information about BDR motors but they're hen's teeth in the states. I found it very helpful to join the British 7 club, lots of good information over there.

 

If you can speak Japanese the BDR has a serious cult following over there.

[bsimon]

Cars with dry sumps always mark their spot on the garage floor. They are not asserting some kind of dominant behavior or anything, it's purely by design.

 

The oil in the system wants to find it's gravitational level. Oil in the tank migrates through the gears in the pressure section of the pump and finds it's way into the crankcase sump. Since the sump is so shallow, the oil level eventually submerges much of the crank seals. Oil will piss out on the floor over time since crank seals are not designed to be submerged.

 

Any plumbing that is below the level of the oil in the tank constitutes a potential leak as well, although these can usually be sorted out.

 

This is what you need...:jester:

[BlueBDA]

That is the exact pan that is catching my car's drips as I type :-).

 

Isn't there a way to keep the oil in the tank from flowing back through the pump when the engine is off?

 

Cars with dry sumps always mark their spot on the garage floor. They are not asserting some kind of dominant behavior or anything, it's purely by design.

 

The oil in the system wants to find it's gravitational level. Oil in the tank migrates through the gears in the pressure section of the pump and finds it's way into the crankcase sump. Since the sump is so shallow, the oil level eventually submerges much of the crank seals. Oil will piss out on the floor over time since crank seals are not designed to be submerged.

 

Any plumbing that is below the level of the oil in the tank constitutes a potential leak as well, although these can usually be sorted out.

 

This is what you need...:jester:

http://www.usa7s.net/vb/attachment.php?attachmentid=14689&stc=1

[bsimon]

That is the exact pan that is catching my car's drips as I type :-).

 

Isn't there a way to keep the oil in the tank from flowing back through the pump when the engine is off?

 

I've heard of people installing check valves to stop the back flow. I'm not a big fan of check valves. Personally, I feel the oil supply to the pump should be as unrestricted as possible. Extra parts create extra problems.

The use of check valves in dry sump systems will also create great debate in auto forums...YMMV

[BlueBDA]

Wouldn't the check valve have to stop flow in the same direction as the flow when the engine is running, i.e. tank outlet to pump inlet? Doesn't make sense to me...

 

I've heard of people installing check valves to stop the back flow. I'm not a big fan of check valves. Personally, I feel the oil supply to the pump should be as unrestricted as possible. Extra parts create extra problems.

The use of check valves in dry sump systems will also create great debate in auto forums...YMMV

[bsimon]

Wouldn't the check valve have to stop flow in the same direction as the flow when the engine is running, i.e. tank outlet to pump inlet? Doesn't make sense to me...

 

They use the check valve as what I would consider a MacGyvered residual pressure valve. The spring is relied upon to keep the valve closed against gravitational pressure. When the engine starts the higher operating pressure opens the valve fully (or so you hope). You can see why I'm not a big fan.

[BlueBDA]

Thinking through it I figured that is what they are doing. I might try it anyway, but there has to be a more elegant way to solve that problem.

 

They use the check valve as what I would consider a MacGyvered residual pressure valve. The spring is relied upon to keep the valve closed against gravitational pressure. When the engine starts the higher operating pressure opens the valve fully (or so you hope). You can see why I'm not a big fan.

[papak]

It seems that you guys are approaching this from a purely "BDR" perspective. How does Porsche manage this? Many more seams and seals in an air-cooled motor and most Porsche owners are pretty compulsive about the purity of their garage floor. The same for Ferrari as well. Maybe call the guys at Quicksilver and ask them. I ran an Accusump on a track car for a number of years and used a manual ball valve to shut off the accusump prior to shutdown. It never leaked and I never had to question whether an electrically activated valve was functioning correctly. While it's not exactly the same application, perhaps this approach might work. More positive control than a spring loaded check valve. On the other hand, there are a number of truly essential check-valve controlled functions in aircraft that are very reliable. Maybe check Aircraft Spruce.

Edited October 26, 2018 by papak

[Minnis]

It’s funny, I’m doing the same exact thing today- tracing oil leaks on the left side of my dry sump bdr. I had repaired one already- the oil return sleeve was improperly ‘glued’ and ill fitting to the head. JB weld to the rescue. I see my catch can might be the culprit of some of the other mess, but some fresh oil on the accessory gears.

[Minnis]

In the two pictures attached, are the oil return valve in the front left if you are facing forward (above the headers). The one picture shows red glue that didn’t hold. The other, the sleeve that no longer fits to the head that I could pull right out. So far the JB weld has solved the issue.

[BlueBDA]

Reviving this thread to add that I have discovered what valve that people use in Porsche 911s:

 

https://www.rothsport.com/Products/Engine/Oil-Inlet-Check-Valves/Oil-Inlet-Check-Valves.htm

 

Not cheap at $300, so hopefully that implies reliability.