35 replies to this topic

[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.

not advised if you have a Kat.

 

Pipe can be braised in down stream of cat

[Icey]

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...

 

That's an oxymoron. You have a worn-out engine but are worried about performance?

[Ethel]

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. 

 

One of the best things about forums is how they make you think about things you'd just accepted.

 

Look at where the CCV hose connects in relation to the throttle and you obviously have a point. Though it will be hiding behind carb's piston and have the throttle disc opening towards it, both factors that are likely to do more for the depression than the flow. 

 

I wonder if it's more like the part throttle leaning devices you also find on some hif's. If it is then the restriction in the oil filler cap will be important in limiting the maximum air ingress and keeping the crankcase pressure more constant. The consequence being the breather will mostly respond to the amount of blow by.

 

We need somebody suffering from mild boredom with a flow bench and a manometer. 

[Inno]

 

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...

 

That's an oxymoron. You have a worn-out engine but are worried about performance?

 

What I was referring is that worn out engine can produce as much smoke through the breather to completely downgrade any possibility to drive if it is connected to the intake system.....so to get back minimum chance to drive the car at all (not performance) people use to disconnect it from air intake system and just redirect it below the car and like that you could get extra 10 or even 20.000 km of daily drive before overhaul ........as I said, I just mentioned that as an example what can be extreme situation.....I am sure guys older than 40 can remember cars smoking more beneath the engine than from exhaust - that was coming from the breather just connected below the car (on worn-out engines)... even when you were buying a car back then you would always disconnect the breather to see how much it smokes and that would be direct indicator for piston rings status and engine compression....

[BaronVonchesto]

don't forget that venting the crankcase fumes to atmosphere pollutes the air. Please don't. Emissions controls systems exist for a reason.

[Retroman]

mmm... Catalytic converters,  they don't work until they are up to temp, when the engine produces much less polutants anyway,

 

and they increase fuel consumption...There are getting to be so many heavy metals from cats at the road sides they can almost be harvested

 

EGR...can cause more poor running issues than most things...Great or grate ?

 

mmmm DPF...just moves the pollution somewhere else using tech that creates pollution in being created, maintained and disposed of [some parts may be recycled]

 

I'm not impressed with any emission control system, all heavy metals / plastic / rubber pipes, wires and gubbins...created how ? using what ? and recyclable ? Making it more complicated does not make it cleaner overall, it just creates more gubbins to produce, go wrong and dispose of, which cannot be more envirionmentally freindly...only reduce the measured emmisions at that point at the time measured, and tick the box.

 

Who's to say the unburnt engine fumes are more or less toxic than tailpipe emmissions ? or the total impact of the life cycle of the 'control system' ?

 

I think the tailpipe is moved to somewhere else and made bigger...its just that we can't see it or measure it, but the actual vehicle tailpipe ticks the box, which keeps all the bods happy as they have jumped through the loop....albeit without taking the impact of the whole vehicle impact into account.

 

There is no over-arching EIA [envirionmental impact assesment] for the entire life of a vehicle, including production, use, maintainance and disposal. Then there are all the components / systems they are made up from. If they all had an EIA we could make informed comparisons. We would probably all be walking if that was all taken into account.

 

An A series engine in good order vented into a catch tank - water and a few drops of mayo / oil....

 

I am sure if the full life EIA was accounted for we are all doing a great job keeping our old Minis going when compared directly and fully to the more modern machinery...most of which will be dead in ten years or less, usually due to keeping up with the Joneses or some electrical issue.

 

Sorry for the rant...but its like saying nuclear power doesn't produce Co2....just building the plant produces how much ?

[unburntfuelinthemorning]

Don't forget the vast amounts of energy used to recycle "end-of-life" vehicles too.

 

If it was truly about the environment we'd be encouraged to make do and mend and to stop buying new stuff we didn't need but of course it's about political point scoring, vested interests and the debt driven economy which needs to keep growing for us to just stand still.

 

I think there are genuine concerns about exhaust pollution in areas of concentrated vehicle usage but it does seem to then become a way to make more money (London low emission zone) and sell us more stuff (new "clean" cars). 

 

I remember when you used to smell petrol engined cars on choke a lot but that's virtually gone now only to be replaced with fumes from fairly new diesels.  So much for newer vehicles being clean.

 

When I was at college in the early nineties we received a handout warning us about the dangers of benzine in the recently introduced unleaded fuel and how catalytic convertors did nothing about this so to be careful running engines in workshops.

 

I've also seen how statistical data was manipulated to show how the reduction of lead usage in petrol corresponded to decreasing lead levels found in people's bloodstream whereas in actual fact bloodstream lead levels had been reducing throughout most of the 20th century even when lead in petrol was increasing and this can be attributed to the replacement of lead pipes for drinking water supply!

[croc7]

Hmm interesting. Thanks everyone.

Have you decided what to do croc7?

Probably install the CCV system and see how I like it although I’m not crazy about the additional clutter in the engine compartment. But if it promotes better crankcase venting......

Edited by croc7, 19 April 2019 - 12:02 AM.

[Ricewind]

I did the "Evacusump as per vizard.." thing on my old 1380cc Mini engine Berkeley. It worked very well, I used a couple of "remote servo's" non-return valves that I found in the scrapyard. I will do the same again on my latest Berkeley project. 

 

The main reason I did this was that the better the vacuum you can pull in the bottom of the engine, the less "windage" you get. Windage is the air movement under the pistons. The air movement creates a surprising amount of resistance and therefor if you can reduce the air density it will help with the efficiency.  At low engine speeds you get little to no venturi effect from the exhaust and as the throttle will most likely be partially closed the inlet manifold will have more of a vacuum and so closes the non-return valve (closest to the exhaust). The fumes going into your manifold should be negligible and anyway you are on partial throttle at this stage.

 

However when going at full throttle, with a good flowing air filer, the inlet manifold pressure is close to atmospheric and of little use in reducing windage etc. This is when (providing you have a good free flowing exhaust system) the venturi effect takes over. At this stage a good vacuum can be achieved (providing your engine is not worn out) and the non-return valve near the exhaust opens and the one nearest the manifold closes (providing you have put it in the correct way round unlike my first attempt where fuel air mixture pulled directly from the manifold nearly created a cherry bomb ram jet). 

 

Harmful fumes from the bottom of the engine are only evacuated through the exhaust when running fast and efficiently, although the two catch cans (only one shown in the diagram) should remove the majority of these fumes, I shall make a larger knock out pot to reduce them even further. I shall also get a vacuum gauge or an old sphygmomanometer for the dashboard connected to the crankcase where the vacuum reading will indicate the state of wear in the engine.

[ansmania]

I’m thinking of plumbing 3 pipes (clutch breather, rocker cover and timing breather) into this system. Would this be alright? Would the exhaust/intake manifold suck up oil?

Also, how good are our breathers at catching oil? I’m dreading pulling oil laden fuming into the exhaust causing white smoke.

I’m thinking of using the Provent 100 air oil separator to oil before introducing the air into the exhaust/intake manifold.
https://www.mann-hum...rovent-100-300/

[nicklouse]

I’m thinking of plumbing 3 pipes (clutch breather, rocker cover and timing breather) into this system. Would this be alright? Would the exhaust/intake manifold suck up oil?

Also, how good are our breathers at catching oil? I’m dreading pulling oil laden fuming into the exhaust causing white smoke.

I’m thinking of using the Provent 100 air oil separator to oil before introducing the air into the exhaust/intake manifold.
https://www.mann-hum...rovent-100-300/

If kept original they work very well. They are designed to drop the oil out of suspension. Adding that item is not needed.

[Ethel]

I  wouldn't connect the rocker cover. It would likely just draw fresh air straight through from the oil cap and reduce the flow of blow by fumes that the other 2 will hoover up.

 

There'd be some oil mist thrown up by the rockers too.

[danc]

I have a Provent 200 and it's fed from the clutch breather and fuel pump blanking plate location. I use a standard pinhole vented cap on the (unvented) rocker cover to let a bit of fresh air in.

The 100 is probably a bit easier to fit as the 200 is a big beast!

[Spider]

I have said a bit in this thread already, but to say some more,,,,

 

The Factory CCV System was one item I feel they got very right, it's a brilliant system and for 99% of road cars, I feel it's the best system to use.

 

 

Also, how good are our breathers at catching oil? I’m dreading pulling oil laden fuming into the exhaust causing white smoke.

 

The factory items in good condition are very good. There's perhaps a bit more to them that meets the eye and the system as a whole has many 'finer' points which I think maybe over looked.

 

The Inlet (at the bottom) of the factory Oil Separator is around 4 times the flow rate of it's Outlet, so the fumes entering the separator are doing so at a fairly low flow speed than those leaving the Outlet and it is this which is one key item that makes the system work so well. Another key item is the CCV Port as I mentioned previously.
 

[ansmania]

Thanks for the replies. I don’t have a canister anymore; IIRC, they didn’t quite capture fantastically. Besides, any oil in the intake will definitely reduce octane.