35 replies to this topic

[croc7]

I’m currently venting both breather hoses on an A+ 1360 to the atmosphere and am considering re-routing them to vent into the HIF44 for perhaps better breathing. What will that nasty stuff do to the nice clean air/fuel mixture going into engine?

[Spider]

If there is 'normal' amounts of 'nasty stuff' then you won't notice it, but you may need to make a small mixture adjustment.

 

Usually when this is done, a vented filler cap is also fitted.

 

If there's a lot of 'nasty stuff' then that lowers the Octane of the mixture, however, I would say, that would be the least of your worries.

[unburntfuelinthemorning]

Would fitting a minature fan of some sort to blow fresh air into the crankcase and push the 'nasty stuff' out work and save the engine having to eat it's own fumes?

[nicklouse]

Would fitting a minature fan of some sort to blow fresh air into the crankcase and push the 'nasty stuff' out work and save the engine having to eat it's own fumes?

nope.

[unburntfuelinthemorning]

Why not?

[nicklouse]

as that is not how it is designed to work.

 

the oil vapor is drawn out of the engine at a lower pressure it then enters the oil separator where the canister volume change and the wire wool cause the oil to drop out of suspension and return to the engine. so you get less contaminates in the air the engine burns. pressurizing the crank case will stop this working and increase the resistance to the crank moving.

[mini13]

and also cause oil leaks.

[unburntfuelinthemorning]

Yes of course, blowing air in, daft idea, scrap that.  

 

Would it not be better though to use something like a vacuum pump to create the depression to suck the air through the crankcase and vent it to atmosphere rather than sending it down the inlet with the air/fuel mixture and so adding something other than clean air and fresh petrol to the mixture entering the cylinders?  (In an ideal hypothetical world with a favourable wind.)

[Icey]

Yes of course, blowing air in, daft idea, scrap that.  

 

Would it not be better though to use something like a vacuum pump to create the depression to suck the air through the crankcase and vent it to atmosphere rather than sending it down the inlet with the air/fuel mixture and so adding something other than clean air and fresh petrol to the mixture entering the cylinders?  (In an ideal hypothetical world with a favourable wind.)

 

A vacuum pump, like the bloody great lump sat in the front of the car?

 

You're over thinking this. The amount of air drawn through the engine is regulated by the filler cap. There isn't a lot of air moving about in there.

 

Yes, it will introduce some contaminants into the intake but not enough to worry about if the engine is healthy. If you're that worried about it, install a catch-can.

[Retroman]

Evacusump as per Vizard...

 

Pipe braised into exhaust...the 'vacuum' then sucks any fume and vapour into the exhaust

 

Benifit is its supposed to stop oil going up the bores, thus not diluting the mixture

 

Tried it and it does no harm but would need trying on a RR or dyno to see any bonus pounds or horses.

[Ethel]

... it only sucks when there's manifold vacuum.

 

I.e. the throttle is near to closed and the cylinders aren't filling anything like enough for contamination to cause problems, like detonation.

 

These are the same fumes that were in the cylinders during preceding cycles, you're just giving the engine an extra go at sticking them down your exhaust pipe.

[nicklouse]

Evacusump as per Vizard...

 

Pipe braised into exhaust...the 'vacuum' then sucks any fume and vapour into the exhaust

 

Benifit is its supposed to stop oil going up the bores, thus not diluting the mixture

 

Tried it and it does no harm but would need trying on a RR or dyno to see any bonus pounds or horses.

not advised if you have a Kat.

[Spider]

Most Crankcase Breather Systems are set up as a flow through system. They don't just lower the pressure in the Crankcase (relative to the atmosphere), but also have 'air' movement through the Crankcase. This is so that the system not only removes combustion gases that's by-passed the rings, but also moisture that reacts badly with most oils.

 

... it only sucks when there's manifold vacuum.

 

I.e. the throttle is near to closed and the cylinders aren't filling anything like enough for contamination to cause problems, like detonation.

 

These are the same fumes that were in the cylinders during preceding cycles, you're just giving the engine an extra go at sticking them down your exhaust pipe.

 

In the case of the PCV Set up, yes, however, the HIF44 is fitted with a CCV Port (Closed Crankcase Ventilation) and this doesn't work from Manifold Vacuum but from Flow Rate (as in CFM) through the Carb at any given moment.

 

Comparing this to the PCV Set up, they are IMO, chalk and cheese.

 

The PCV does work from Manifold Vacuum and that is where I see it's much less effective. Most blow-by occurs when the engine is making more power, and that's when the throttle is wider open, it's also when the Manifold Vacuum is reduced.

 

The CCV Sysetm works on Flow Rate through the Carb. The high the Air Flow through the Carb, the more flow through the Crankcase (from this port). As mentioned, most blow-by occurs when the engine is making more power and that,s when the throttle will be open more and so the air flow rate through the Carb is higher. 

[unburntfuelinthemorning]

Hmm interesting.  Thanks everyone.

 

Have you decided what to do croc7?

[Inno]

Check this to get idea:

 

 

 

or this:

 

 

Although MED video doesn't cover all possible breathing engine exits....

 

Many other staff on line but it looks like that non system that connects breathers back to the inlet actually contributes performance but rather emission regulations and ecology standards (air and road pollution)...

 

If the engine is good connecting the breather to the inlet may not disturb road performance, if too much smoke comes out (worn up engine) then it drastically reduces performance when connected to inlet......many years ago it was a practice with all cars to just disconnect it from the air filter once engine becomes worn out and directed it down the road to avoid ventilation contamination....and you had cloud of smoke around the car....guess nobody does it these days even with old cars...