First, let's go over what is currently happening in your engine without a catch can installed. All internal combustion engines that run off gasoline are 4 stroke engines. This means that the piston has to go up and down a total of 4 times to complete a cycle. The piston first goes down with the intake valves open creating a vacuum. This draws in the cool dense air for combustion. At the same time, fuel is injected into the cylinder. The intake valves close and then the piston rises up towards the top of the cylinder. This compression creates an immense build-up of pressure in the cylinder. The only things containing this high pressure are the cylinder itself, the piston and the piston rings that seat against the walls of the cylinder. The intake and exhaust valves are obviously closed as well. The pressure is so high that a very small amount of the air escapes around the piston and piston rings into the crankcase. This is called "blow-by". The amount of blow-by increases as the engine RPMs rise. Also, an engine with more cylinders will have more blow-by. Obviously not all of the air escapes or else combustion wouldn't take place. A diagram of the 4-stroke cycle can be seen below. Only the first 2 steps are relevant in regards to the catch can.
Inside the crankcase, you have the crank which is turning in the oil pan which is full of oil. This keeps it properly lubricated. The positive crankcase ventilation (PCV) is necessary to ensure there isn't a build up of pressure in the crankcase. This would cause the crankcase to possibly crack under the pressure and create a huge mess of oil on the street. So the PCV system removes the pressure from the crankcase and reverts it back through the intake tract via crank case vents. This pressure isn't made up of 100% air. It will also contain a very small amount of oil as well since there is so much in the oil pan at a high temperature. This air and oil mixture is then entered somewhere after the intake system, passes through the intercooler (if you car is turbo or supercharged) and then re-enters the combustion chamber (cylinder) through your intake valves to be re-burned. The oil will actually coat everything on its way back to the combustion chamber. It will develop in the intercooler, boost hoses, intake manifold and intake valves. Just on the other side of these valves is where the combustion is taking place where the temperatures are extremely high. This is what actually causes the oil to solidify on the valves. With the oil passing through the intercooler, it can actually coat the cooling fins which will hinder the intercooler's ability to cool the air therefore lowering the efficiency.
The caking on intake valves is only a problem with direct injection engines. For all other engines that use port injection, the gas is introduced before the combustion chamber which means it flows over the intake valves and enter the combustion chamber premixed with the air. This action of the fuel flowing over the intake valves actually cleans the valves from any oil that make already be on there. The oil never has the chance to cake on the valves in port injection engines.
Having oil caked onto your intake valves can cause the following symptoms:
- Knocking
- Pre-ignition
- Loss in power
- Loss in fuel economy
An oil catch can does just that. It catches or prevents the oil from re-entering the intake tract. A catch can is placed right after the PCV and before the intercooler. This means that a more pure (sometimes 100% pure) air mixture will go through the intercooler and intake valves. A more pure air mixture entering the intake valves means no caking and none of the symptoms listed above. Oil catch cans are highly beneficial in race applications and if you track your car. However, for my purposes, it was more of a preventative measure as I wanted the extra gunk to be collected and eventually emptied out instead of having it recirculate.
I decided to buy a 42 Draft Design catch can. Reason for this was because a forum member I had met, Chris, had purchased this catch can from Greg, who owns and runs Carformance and who is also the Australian distributor for 42 Draft Design products. Chris, who has a Golf R himself, said he would be the guinea pig and was trying to get a mounting bracket set up which could be used and sold with the catch can together, thus eliminating any need for custom work. After collaborating with Greg for a few months, the new mount was ready and I had told Greg that I would like to be one of the first to purchase it once the bracket was complete. After some initial delays, a few weeks later I had received the catch can.
Prior to receiving the oil catch can, I had also ordered a cold air intake. Basically, a cold air intake is a system used to bring down the temperature of the air going into a car for the purpose of increasing the power of an internal-combustion engine. For a turbo car like the Golf R, it's an inexpensive way to increase performance. All cold air intakes operate on the principal of increasing the amount of oxygen available for combustion with fuel. Since cooler air has more density for a given volume, cold air intakes generally work by providing cooler air from outside the hot engine bay. Better designed intakes use heat shields to isolate the air filter from the rest of the engine compartment, providing cooler air from the front or side of the engine bay. VW Racing had just released their new cold air intake system for the MK6 Golf GTI's and Golf R's and I decided to purchase it. I contacted Ian from Rennenhaus as he is the official distributor for VW Racing parts, and within a few weeks I had the intake ready to install.
I decided to buy a 42 Draft Design catch can. Reason for this was because a forum member I had met, Chris, had purchased this catch can from Greg, who owns and runs Carformance and who is also the Australian distributor for 42 Draft Design products. Chris, who has a Golf R himself, said he would be the guinea pig and was trying to get a mounting bracket set up which could be used and sold with the catch can together, thus eliminating any need for custom work. After collaborating with Greg for a few months, the new mount was ready and I had told Greg that I would like to be one of the first to purchase it once the bracket was complete. After some initial delays, a few weeks later I had received the catch can.
42 Draft Design oil catch cans. I opted for left one with the billet top and black wrinkle finish on the can.
Prior to receiving the oil catch can, I had also ordered a cold air intake. Basically, a cold air intake is a system used to bring down the temperature of the air going into a car for the purpose of increasing the power of an internal-combustion engine. For a turbo car like the Golf R, it's an inexpensive way to increase performance. All cold air intakes operate on the principal of increasing the amount of oxygen available for combustion with fuel. Since cooler air has more density for a given volume, cold air intakes generally work by providing cooler air from outside the hot engine bay. Better designed intakes use heat shields to isolate the air filter from the rest of the engine compartment, providing cooler air from the front or side of the engine bay. VW Racing had just released their new cold air intake system for the MK6 Golf GTI's and Golf R's and I decided to purchase it. I contacted Ian from Rennenhaus as he is the official distributor for VW Racing parts, and within a few weeks I had the intake ready to install.
VW Racing cold air intake offering for the MK5 GTI, MK6 GTI and MK6 Golf R.
I contacted Chris to see if we could do a DIY with catch can seeing as how he was the one who fabricated the mount, he'd have a better idea on how to install it. I also asked if we could install the intake at the same time and he was fine with it. So I arrived at 9:30am in the morning at his place and we got stuck in. We started with the intake. Ripping off the OEM engine cover was a right pain in the ass, but luckily we didn't break anything.
Engine cover off. Intake and catch can ready to be installed.
After a few hours, we ended up installing the intake. Not as straight forward as we thought it would be and after a test drive, not as loud inside the cabin compared to when I had my Forge TWINtake on my Jetta. However, the "whoosh" sound is more apparent under load. There were some custom modifications we had to do to make it fit the Golf R. The intake itself is simple plug and play. However it seems like that this intake caters for both the K03 and K04 turbos. Those with a K03 turbo (i.e Golf GTI) should be fine but with K04 turbo, the diverter valve (DV) is at the front (compared to down towards the bottom of the car on a GTI) and the pipe from the DV runs up the side and into a bung on the hose as seen in the picture below. You have to create a hole on the silicone pipe to accomodate for the DV bung. To be honest, VW Racing's method to cut a hole on that silicone pipe is a piece of shit really. They give you a "cutter", which is just a small hollow cylinder and what they want you to do is to line that cylinder inside the silicone tube, put a block of wood inside the tube tube so that the cylinder presses up against the pipe from the inside, place it on a flat surface and smash it using a rubber mallet. Pretty ghetto for an intake which cost as much as it did.
VW Racing instructions on how to fit the DV bung to the silicone pipe. Pretty pathetic to be honest.
Problem with this method you do not know if the cutter is in the right place because essentially what you're doing is taking an estimate and an educated guess as to where the bung "should" go. You'd be basically hitting with the mallet and hoping for the best. Not only that, the block of wood needs to sit on the bit of the pipe which bends. Plus, really, for the DIY'er, who has a small block of wood like that lying around? It really is a bullshit design. So instead, Chris took the disconnected DV tube and then loose fitted the silicone pipe onto the turbo, then got the DV tube and placed it where it would be optimal, traced around the circumference of the DV tubee against the silicone pipe, used a drill and a wood bit to drill into the pipe, cleaned the edges with a small stanley knife and attached the bung applied with some Loctite to make sure it stays in place. Apart from that, no real issues in fitting the intake. If you have a GTI, it should be just a case of taking the engine cover and old intake off and putting this one on. For the Golf R, GTI Pirelli or the GTI Edition 35, you would need to create that hole in the silicone pipe.
A much more accurate way of cutting the hole for the DV bung in the silicone pipe : A drill with wood bit and a Stanley knife to clean around the edges. Perfect!
Intake installed. Notice how the DV tube lines up nice and straight connecting to the silicone pipe.
Would have been near impossible with the method VW Racing provided.
Would have been near impossible with the method VW Racing provided.
I had also bought two 1 metre long silicone hoses for the oil catch can as theoretically, it should last indefinitely and not have the excess oil eat away at the pipe. However, when Chris was cutting bits off the hose pipe and trying work out how to feed the pipes to the catch can, the problem we ran into was that the actual silicone hose itself wasn't flexible enough and when we ran both hoses together under the air duct of the intake, it came dangerously close to hitting the radiator fan. Since the hoses weren't as flexible, it was hard to place it somewhere which wouldn't make it a problem and away from any moving objects in the engine bay. In the end, we gave up trying to come up with a solution because there really wasn't one. But I still needed a way to drive and get home, so Chris offered to give me his hoses he had on his Golf R, which were just normal heater hoses you can get from Super Cheap Auto. And because the hoses I bought were of no use anymore (not to me anyway), I said he could hang onto them so he could experiment with them for whatever. Heater hoses are cost effective, but they aren't really designed for oil and if unattended for a a few years, it can corrode and eat away at the hose and you will end up having crap all over your engine bay. It should last at least a year for my application and for now it will do the job fine. Eventually, I will be going to Enzed real soon to buy proper 19mm hydraulic hoses, which should theoretically last forever.
Oil catch can installed. Notice the route of the right heater hose to the oil catch can.
This is not the most optimal place to route a heater hose to the catch can but it will work as a temporary measure.
This is not the most optimal place to route a heater hose to the catch can but it will work as a temporary measure.
Ideally, I would like to have both pipes running in the same direction as the hose on the left and keep them together with a zip tie.
All in all, it was a successful day out and massive thanks to Chris for helping me with the DIY. If it wasn't for him, I wouldn't have been able to get through installing this as quick as we did and I would also be stuck with those silicone hoses.
If you would like to purchase these items as well as many other mods which may be available for your Golf GTI or Golf R, please visit :
Rennenhaus
http://www.rennenhaus.com.au
Carformance
http://www.carformance.com.au
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