Throttle body heater pipes

[dan 0]

Cheers,

 

Thats another little weekend project for me then :)

[Andy Brookes 0]

have been thinking about binning my headlamp washers, now I have a use for that 7 litre washer tank and the high flow pump (may be a bit noisy though!)

 

Question on the PCV bypass, how's it done and what benefits do you see? I have had a read up on PCV's and it seems that they help to stop sludge build up as well as helping to burn of the crankcase gases. I have also read that a sticky PCV will cause idling problems, maybe a cause of VR idling problems that a few suffer with, including me.

[PhatVR6 0]

Ditching the PCV means you haven't got hot smelly horrible oily air going into your engine. meaning the intake keeps cleaner and cooler.

 

downside being, you crank case is now relying on venting to atmosphere, rather than having the air drawn out by the induction vacuum (hence PCV, positive crankcase ventilation).

 

so, whilst your engine breathes cleaner, you may not, and you may experience oily smells in the car which is rather unpleaseant. so long as all your sels are ok you shouldn't have this happening.

 

and of course, it's not good for the environment, hence why they are pumped back into the engine (along with the fuel fumes fromt he carbon cannister) to be burned off.

 

you'll also get a bit of oil dribbling out of the filter, but it'll hit the manifold and burn off. if you find this unnacceptable, pipe it to a catch tank.

[Andy Brookes 0]

Thanks for the explaination Phat. I think I will keep the PCV stuff, but will do the throttle body mod.

 

Hoping for good weather tonight to fit my Milltek sports cat and full system, along with a turn2 CAI kit, The C is going to sing after that lot!

[Kevin Bacon 5]

That's why so much oil gets in the engine because it's sucked out as you say.

 

You'll find if you vent a pipe into a catchtank, the amount of oil in the pot after a week is nothing like what normally goes in the engine. Schricked people have the added joy of oil accumulating in the long, flat plenum where the flap lives.

 

If you remove positive crank venting from the VR, what implications does that have? Will the gases escape quickly enough from the engine to avoid excessive crank pressure?

[Andy Brookes 0]

An explaination of the PCV taken from http://www.misterfixit.com/pcvvalve.htm

 

 

PCV - what does it stand for? Positive Crankcase Ventilation. Let's pick that apart a word at a time and see just what this little piece of hardware does. Let's start with the word Crankcase. The crankcase of an internal combustion engine is that portion of the engine that contains the crankshaft (no duh), the connecting rods, the under side of the pistons. It is also connected via passages in the casting of the engine block to the upper engine, the valve train, the camshaft and the timing gears and chain. The most critical part of the above components regarding the PCV is the pistons. Fuel and air enter the combustion chamber on the top side of the piston where the fuel burns and forces the piston down. That motion is converted into rotary motion of the crankshaft via the connecting rods and the crankshaft. That is what drives your car.

 

I mentioned that the combustion takes place in the combustion chamber. Ideally all the combustion gases which are in the combustion chamber stay there until they are exhausted via the tail pipe, however as engines get older (and even in brand new engines) some of the combustion gasses get past the sealing hardware on the pistons, the piston rings. As the engines age, the clearances between the rings and the cylinder walls increases and more of the combustion gasses escape into the crankcase. These combustion gasses contain acids and other harmful by-products of combustion which used to escape from the crankcase via a breather tube which exited into the environment. All that garbage going into the atmosphere makes smog and other breathing problems in our environment. In addition, the moisture in those gasses also caused sludge to build up in the engine, so the PCV system also helps reduce the sludge build up. So the engineers decided to capture all that stuff from the crankcase and ventilate it in a way that it becomes less harmful. Notice I said less harmful, not pristine. Notice also that we have covered the second word, Ventilation.

 

What's so positive about Positive Crankcase Ventilation?

 

It is called positive since there is a positive force that removes the combustion vapors from the crankcase. That force is vacuum - just like the vacuum that sucks the dirt out of your rugs and furniture only this vacuum is derived from the engine, not from a Hoover. Vacuum derived from the engine is a rather sensitive resource, that is you don't want to steal any vacuum from the intake manifold when the engine is idling. However, when the engine is running at highway speed the engine can afford to allow a "vacuum leak" to occur via the PCV Valve. It is a metered flow of air, controlled by a needle valve inside the PCV Valve. When the engine is at idle and vacuum is high the force of the vacuum overcomes the force of a spring inside the PCV Valve and it is closed down to allow a flow of about three cubic feet per minute. When the throttle is opened and the intake manifold vacuum is reduced (closer to atmospheric) then the spring in the PCV Valve forces the valve to open allowing up to six cubic feet per minute of flow to occur.

 

So, what goes wrong? First, the spring can become weak or break and the valve will not open at all. This results in no removal of engine vapors and a build up of pressure in the crankcase. The air will actually flow backwards into the air cleaner. One symptom of this is oil in the air filter housing at the entrance of the PCV tube. This can also occur if the Blow-By is too high. Second, the valve can get gummy and stick in the open position allowing too much flow at idle conditions. This results in a rough idle or a stalling condition.

[PhatVR6 0]

means sh1t all for a vr6, there is no valve.

 

they work fine on VR6's, you just may see a bit of steamy air coming out of the breather filter.

 

I've ran one on this very engine I now hav in my corrado for a good 2 years with a breathe riflter on, never had any bother with it, never had any oil getting in my intake boot and foulding up the throttle body either.

[Andy Brookes 0]

opps!

[GarageQueen 0]

wooo, 50bhp for £3500, no thanks.

 

That's ok, I don't sell them. I should start if the going rate is £3500.

 

Turning my attention to the subject of this thread :

 

If bypassing the throttle body heater had the effect of reducing the intake temperature by 10'C, say from 20'C to 10'C, you'd see a peak output gain of about 7.5bhp. With airflow of around 132g/s on Wide Open Throttle at peak power it won't have anywhere near that effect but hey this the internet, why let facts get in the way? Let's try it with 1'C drop, from 20'C to 19'C. Result : a rather disappointing 0.65bhp gain.

 

Bosch Motronic M2.9 is calibrated with the aid of an intake manifold temperature model to compensate for the warm intake manifold heating the Air Intake Temperature Sensor during long periods at idle.

[PhatVR6 0]

A gain is a gain......so you think that pumping 100C water through it or not is only going to make a 1C difference?

 

work it out math boy.... :roll: