The only way to test them would be to build yourself a flow rig.
They rarely go wrong to the point they would cause issues like that, it would have completely failed and you would have no oil going back to the dry sump tank - or you would be suffering from oil surge.
Wet sump versions of these engines run and do not suffer with enough excess crankcase to cause issues.
What makes you say it is excessive? Is the engine blowing out oil?
At idle there is quite a bit of pressure coming out of the PCV breather location.
Catch can fills 50-75% every 20 min session.
In this picture of a Hayabusa dry sump system it shows a -12 feed from the can and a -12 return to the tank. My car has a -12 feed and a -10 return to the tank. Makes me also wonder if the pump is incapable of pumping enough oil back with the smaller return.
Has this a problem that has just started or been there as long as you have owned the car?
AN12 or even AN16 feed on later cars with an AN10 return is standard on all Radical's so no concern there.
I assume you are setting the oil level correctly and not over filling it? Ensuring that you run it up and pick up the revs before checking the oil level?
How is your breather piped up? On a standard Radical set up the engine breather goes to the dry sump tank and then a breather from the top of the dry sump tank to your catch can.
Have you tried a leak down test? How many hours are on the engine?
Has this a problem that has just started or been there as long as you have owned the car? It has been happening since I bought the car 5 years ago.
AN12 or even AN16 feed on later cars with an AN10 return is standard on all Radical's so no concern there.
I assume you are setting the oil level correctly and not over filling it? Ensuring that you run it up and pick up the revs before checking the oil level? Correct, the oil needs to be 6" from the bottom of the tank to not spew out, approx 2L of oil. Anything more than that and the puking occurs.
How is your breather piped up? On a standard Radical set up the engine breather goes to the dry sump tank and then a breather from the top of the dry sump tank to your catch can. I have a gen 1 oil tank, the breather originally was setup like this picture below. I cap'd the one going to the catch can and added a line from the top of the tank going to the catch can. This helped big time, but the catch can still filling up about 50% each session.
Have you tried a leak down test? How many hours are on the engine? I did not continue on with a leak down test since the compression numbers were so good. The engine has approximately 41 hours and is a 1340.
@rlm-dan have you, or anyone reading this, ever known anybody to need an additional engine breather port added to the valve cover going to the oil tank?
Sounds like you are there with the plumbing, although that oil level sounds low to me? Is there a later tank that you could fit that is larger? Any pictures of the pipework on the top of your oil tank?
Do you have a bore scope? Worth taking a look in case it is something like a cracked barrel.
If it is not plumbing then there could be chance of an internal engine problem. I honestly do not think that the scavenge pump is the problem, do you monitor oil pressure? If the pump was not returning the oil to the tank, to the point that the engine is over full and blowing it out, then I think the engine would empty the oil tank and you would be suffering oil pressure problems - well before the engine was blowing it out!
We have only ever run additional breathers on the cam cover for forced induction engines and even that isn't really needed. Again I don't think this would solve the problem and if it did you are just masking an issue elsewhere.
The scavenge pump sounds normal to me, they sound like that. Give it a go taking it apart if you fancy, ensure you do not loose any of the drive keyways and pay close attention to the fitment of the middle separator plate, this can go in both ways but one way will cause scavenge problems. You will see wear on the body, this is 'normal' biggest thing to look for is excessive wear and also if the shaft located into the body has excess movement but none of this will cause the problems you are seeing.
Okay, leak down showed 5% leak down on 3 cylinders and 7% on the 4th.
Scope showed nothing unusual with my eyes. I did video one "suspect" spot in cylinder 2 that my virgin eyes didn't know what they were looking at. Seeing as how it's at the top of the cylinder and appears to be beyond the stroke of the piston rings it's probably no big deal.
Apparently the video doesn't want to play on the site, it's an Avi file and I needed to install VLC to see it. So I added a screenshot below here.
Are those markings on the wall between the bores or at the front/rear of the cylinder?
In the first picture I wouldn't be too concern, although is hard to see with the lighting but that second one doesn't look great.
On a side note it looks like the engine still has titanium valves fitted? If that is the case I would highly recommend replacing them for reliability. If you did this you could time removing the cylinder head with having a good check of the bores and the head gasket.
@rlm-dan Those markings are on the exhaust side of the engine, not inbetween cylinders. It has been mentioned to be that it might be a ring end gap that made them.
The video link attched to this post may or may not work on android cell phones, works on laptops/desktop. Might work on Iphones??
