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I talking to a guy today at wakie who had a 590rwhp 32 Gtr he had one of the better breather systems ive seen (1" hoses into the catch tank, vented to atmosphere etc) he had a 1.5mm restrictor and was still chronicly filling the catch tank after 5 or so laps...and this catch tank wasnt small either, I didnt ask whether he had the rear drain or not or which oil pump he was using.

But he was wishing he went with the 1.2mm restrictor.

I dont advise plumbing the catch tank back to the inlet...even after the AFM's...on decel our circuit car at superlap (due to the poorly set-up system) sprayed oil out the inlet and shorted out the afm's. This happened on the 1st 'hot lap' into turn 1. If we didn't have our mate and Aussie production car champ. Luke Searle at the wheel the car may have ended up on its roof. The car cut out and had no engine power, power steering, ATTESSA etc

I'm leaning towards just forgetting about the vac setup tbh because of the potential mess if it goes wrong and this is an even worse scenario! Aiming to keep crankcase pressure to atmospheric pressure is a good enough target i think.

I talking to a guy today at wakie who had a 590rwhp 32 Gtr he had one of the better breather systems ive seen (1" hoses into the catch tank, vented to atmosphere etc) he had a 1.5mm restrictor and was still chronicly filling the catch tank after 5 or so laps...and this catch tank wasnt small either, I didnt ask whether he had the rear drain or not or which oil pump he was using.

But he was wishing he went with the 1.2mm restrictor.

I think that's possibly why m speed has the return on the first small oil/air seperator, it allows the 'heavy' oil to return to the sump and the air to swirl up and exit to the next catch can where the air is scrubbed clean and vented.

Dirtgarage has almost an identical setup on his car to m speed, disregarding the additional head oil drain. For people arguing about oil contamination that argument is flawed in a race car as the oil would be changed after every race anyway.

And returning the majority of oil that leaves the engine is obviously a good idea when you have a problem like the 'guy' in your example.

?

all you gods of oil drainage

can i have a drain to each side of the engine?

conected by the cam breathers?

Do you mean straight from the cam breathers to the block or through some kind of pressure vent?

i currently run a rear head drain to passenger side

my catch-can can easily be plumbed back to the driver side??

Can't see why not. Intake and exhaust side seem to work well. On the intake side it needs to be below oil level though and on the exhaust side it doesn't matter as much.

Gary seems to have had lots of success with his way and clearly m speed appear to be happy with theirs where it is.

Only one return would be needed though i think, -10 or larger.

For people arguing about oil contamination that argument is flawed in a race car as the oil would be changed after every race anyway.

Contamination, from what? Condensed water vapour? It boils off with the right oil temperature. Dust? I have a filter on my catch can breather. Ditrty cacth can? I don't think so. So what contamination are they talking about?

BTW I don't change engine oil after every race meeting. I used to many years ago, but then I sent samples to Castrol Technical for testing and they came back with perfect reports after 1, 2 and 3 race meetings. Especailly now that I'm using ethanol which, with its lower vapourisation temperature, doesn't contaminate the oil like petrol does. As per above, water boils off, so if the engine is in good condition, which I confirm with regular leak down tests, there is no need to waste 10 litres of oil 8 times a year.

Cheers

Gary

Contamination, from what? Condensed water vapour? It boils off with the right oil temperature. Dust? I have a filter on my catch can breather. Ditrty cacth can? I don't think so. So what contamination are they talking about?

BTW I don't change engine oil after every race meeting. I used to many years ago, but then I sent samples to Castrol Technical for testing and they came back with perfect reports after 1, 2 and 3 race meetings. Especailly now that I'm using ethanol which, with its lower vapourisation temperature, doesn't contaminate the oil like petrol does. As per above, water boils off, so if the engine is in good condition, which I confirm with regular leak down tests, there is no need to waste 10 litres of oil 8 times a year.

Cheers

Gary

lol....you answered your first question with your second statement.

Contamination, from what? Condensed water vapour? It boils off with the right oil temperature. Dust? I have a filter on my catch can breather. Ditrty cacth can? I don't think so. So what contamination are they talking about?

BTW I don't change engine oil after every race meeting. I used to many years ago, but then I sent samples to Castrol Technical for testing and they came back with perfect reports after 1, 2 and 3 race meetings. Especailly now that I'm using ethanol which, with its lower vapourisation temperature, doesn't contaminate the oil like petrol does. As per above, water boils off, so if the engine is in good condition, which I confirm with regular leak down tests, there is no need to waste 10 litres of oil 8 times a year.

Cheers

Gary

Blow-by as you pointed out can break down oil prematurely. We get all four of our 2000hp @ 800rpm 16 cylinder engines oil tested by Castrol too. They are a very good bunch, Infact Castrol were the ONLY company that would guarantee there oil to not leave unwanted buildup through the system. It's good that you get your oil tested it can show up more than just the oils lifespan. Saves lots of money, especially when you need 200litres for each engine when due for a change..

Edited by GT-RZ
Contamination, from what? Condensed water vapour? It boils off with the right oil temperature. Dust? I have a filter on my catch can breather. Ditrty cacth can? I don't think so. So what contamination are they talking about?

I'm sure you've smelled blow by before. Are you telling me depending on the state of the motor or quality of the build/tune that there isn't unburnt fuel vapor and carbon in blow by?

I'm sure you've smelled blow by before. Are you telling me depending on the state of the motor or quality of the build/tune that there isn't unburnt fuel vapor and carbon in blow by?

I think he is trying to say his engines have minimal blow-by hence less contamination and now that he is on ethanol he has even less to worry about.

So really not much of that applies to the majority of us who are not on ethanol.

In reality all engines have blow-by and in a street application where people do not change there oil as often contamination is something to be aware off. Don't think many of us get our oil tested either, id rather just do regular oil changes eh?

Gotcha, and yeah, I think most people on here just do regular oil changes with out getting the oil sent off. I've done it a couple times after I put a stroker motor in my jeep, but only because it was a fresh motor and I wanted to gauge it's health.

I think you missed the point guys, he was talking about race engines, not daily driver road engines. I don't know about others but my race engines are in good condition, they don't have blow, well not for for very long anyway. I fix it, I sure as hell don't keep on changing the oil because of contamination from blow by. The competition is too hot to survive with a down on power engine.

Cheer

Gary

I think you missed the point guys, he was talking about race engines, not daily driver road engines. I don't know about others but my race engines are in good condition, they don't have blow, well not for for very long anyway. I fix it, I sure as hell don't keep on changing the oil because of contamination from blow by. The competition is too hot to survive with a down on power engine.

Cheer

Gary

My original statement said in race application an oil drain from a catch can would have little ill effect due to contamination especially since the oil is changed more frequently. I may have said after each race, I'm not here to nit pick - more frequently than street application is a better phrase.

I said race engines THEY did not. If you read back they were talking about general ill effects of having the oil drain back. not just from RACE ENGINES.!! Hence my statement:

"For people arguing about oil contamination that argument is flawed in a race car as the oil would be changed after every race anyway".

So i'm unclear what your original post was about? you run methanol and have zero blow-by (apparently) in your engines...

Edited by GT-RZ
My original statement said in race application an oil drain from a catch can would have little ill effect due to contamination especially since the oil is changed more frequently. I may have said after each race, I'm not here to nit pick - more frequently than street application is a better phrase.

I said race engines THEY did not. If you read back they were talking about general ill effects of having the oil drain back. not just from RACE ENGINES.!! Hence my statement:

"For people arguing about oil contamination that argument is flawed in a race car as the oil would be changed after every race anyway".

So i'm unclear what your original post was about? you run methanol and have zero blow-by (apparently) in your engines...

It's not that complicated;

I only use Castrol oils and lubricants (mentioned in any of my previous posts whenever lubricants are discussed)

I'm talking about the race cars, mine and others that I look after, not road cars.

My race engines don't have blowby, as I would expect all race engines don't.

I have always recycled the oil from the catch can, generally via the dip stick tube (refer to previous posts in this thread).

My catch can system is filtered.

Even when I used petrol (ie; Pump 98 or Efl LMS or Elf Turbo Max) I didn't change the oil every race meeting, haven't for many years.

After up to 3 race meetings the oil showed no meaningful contamination (ie; as tested by Castrol Technical), that's carbon, petrol, water, coolant, bearing material, piston alloy or dust/dirt.

The highest contaminent was petrol, and even that was mild, usually due to cold start and run enrichment rather than blow by (ie; it wouldn't be unburnt petrol if it was caused by blow by).

Now I use ethanol, so the "every 4th race meeting oil change" is even more stretched, I reckon I will get a whole race season (ie; 8 meetings) before I need to change the oil. Obviously I will confirm this with further oil testing. There is usually 4 to 6 weeks between race meetings, so plenty of time to have the 4 or 5 cars oil samples checked ie; not a full sump of oil, around 100 to 200 mls is plenty, if it's OK leave it in, if not change it. Obviously oil testing shows up all sorts of other issues, like bearing wear, piston skirt damage, excessively rich mixtures in engines and other wearing components in gearboxes and diffs when you test their oil.

Did that help?

Cheers

Gary

What is the benefit of recycling your blow by back into the sump? Please tell me it's something more meaningful than not having to fill up the oil as often. Also, what kind of filtration system would you run that filters the fuel vapor from the oil vapor and only returns the oil back into the sump? And yes, I know this is all a moot point since your engines have zero blow by, I'm just saying for the average street/strip car out there that does.

What is the benefit of recycling your blow by back into the sump? Please tell me it's something more meaningful than not having to fill up the oil as often. Also, what kind of filtration system would you run that filters the fuel vapor from the oil vapor and only returns the oil back into the sump? And yes, I know this is all a moot point since your engines have zero blow by, I'm just saying for the average street/strip car out there that does.

The point is this...Gary's a tightass...recycles his catch tank filth...and doesn't buy the cheap insurance an oil change after each meeting buys you.

When and where do you race Gary ? You seem to enter events and never turn up. Id like to view your results on Natsoft to see what all your expertise nets you on the track. You also in the past told people on here including me you work for certain race teams and when we approach them at meetings they say they have never heard of you.

Gary is the god of all things in motoring and seems to be an expert on every facet of motorsport. He is never wrong.

Someone PM'd me today and made a very fitting statement..." funny how sydneykid always has a way of changing answer to mend things he has said, helpful in a self promotional fashion. "

I came into this thread to just throw a few ideas around...getting some good discussion going and thinking outside the square. Everyone blindly following anything Sydneykid writes is not always the way to go. He has some good idea's but not everything he suggests is the right thing to do.

Edited by DiRTgarage

The only benefit i can see is if your breathing excess amounts of oil then you can return it without worrying about coming up with no oil in the sump, but i think if that is happening you have other issues to look at. unless your in a 24hour race.

If you look at m speeds setup (very similar to dirtgarage) due to the position of the 'drain' from the oil/air separator i believe it would primarily be acting as a crankcase vent with the possibility to allow heavy oil (if any) that has been separated a way back down. Anything that makes it to the next can is very light and would not want to be recycled and is dumped.

They have another drain specifically for oil that plumbs in to the bottom of the sump though from the head.

Bearing in mind i can guarantee they will be changing there oil after every race and do not worry about any kind of premature breakdown of oil. They clearly know a thing or two since they are tsukuba champions.

In saying that keep an eye out for the prostock r34 that looks very serious!!! even moved the engine back a fair way in to the firewall and have custom made all the cradles/crossmembers:

post-41232-1247478919.jpg

post-41232-1247478965.jpg

post-41232-1247479012.jpg

My source is unable to confirm but i'm lead to believe they change their oil after every race too!

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