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-   -   crankcase breather again.... (https://www.volvoforums.org.uk/showthread.php?t=265614)

jamie Mar 26th, 2017 22:27

crankcase breather again....
 
1 Attachment(s)
Hi Everyone
I have studied what others have said and just want to be certain I have the right set up.
Here is a photo of my set up at present.

I have a B20 block
FI head
Twin SUs and the Servo
At present the servo pipe connects to the inlet manifold
The pipe from the oil filler is just to the open air
Nothing is attached to the flame guard, which I see on Ron Kwas SWEM diagram should be connected to the inlet filter. I am using K&N so they do not have the little pipe to connect into.
Suggestions, solutions please
The oil filler cap was full of what looked like soaked oily paper but may have just be 50 years of oily rubbish. I will wash it out with petrol tomorrow. I will also flush out and wash the flame guard tomorrow.
Jamie
PS I hope photo loads as this is my first attempt

jamie Mar 26th, 2017 22:33

1 Attachment(s)
PPS I was going to add one of those mini filters on the oil filler cap and get rid of the pipe.

I attach photo of the flame guard sitting all alone with no pipe leading from it....what should be happening there?

Thank you

Jamie

swedishandgerman Mar 27th, 2017 10:25

That's all been disconnected basically to give open air breathing, which is good enough. It just means that the fumes from inside the chamber are freely exiting to the atmosphere and into the cabin of the car. Depends on whether that bothers you or not!

The gauze inside the cap needs to be regularly cleaned out and whetted with oil - that's to act as a dust trap. Ideally, the flame trap end needs to be cleaned out too and piped away under the car in order to stop the smeech getting into the cabin too much. It will breath absolutely fine like that, but susceptible to more dust getting into the chamber, so regular oil changes are advised.

I see you're a Westcountry boy, so I expect you know what a smeech is!

If you do want to go down the route of closed crank case breathing, both ends need to be connected as per Ron Kwas's diagrams because in really basic terms, the fumes enter the manifold either through the manifold take off OR the into the inside of the air cleaner. One route or the other depending on the amount of draw in the manifold (IE basically engine speed or engine load). In other words, if one way is connected and the other isn't, the fumes go to open air anyway! You'd need to get a pipe connector onto one of those pancake filters.

If you put one of those small filters onto the top of the oil filler or the oil trap, it restricts flow.

jamie Mar 27th, 2017 13:30

I would rather not have the smeech smell in the cabin, although I have the grommet set from Simon to fit first. So maybe all I have to do is put a discharge tube from the flame guard to the level of the sump and then the smell will blow under the car......perhaps.
Jamie
PS Like a lot of Somerseters, I don't originate from here, I'm from Zoorray (Surrey!)

Derek UK Mar 27th, 2017 13:56

As said, the engine is currently set up as an open system. This is basically how the B18 was run. The B20 changed to a closed system for emissions sake and the air/gases flow was reversed. That system has to be set up properly to work efficiently. Mixing up the pipes etc will either change it to open or pressurised. The later is bad and will cause oil blow by at the seals. Your engines looks to be using the early alloy inlet manifold with the vacuum take off to the servo coming out the front. This manifold often has no other positions for pipework although there is a boss in the top middle that may be tapped for a fitting. This gives other options for your side connection. There is also a better cast iron one piece manifold you can use, not the one with the butterflies in, which does have extra positions for pipe fittings.
In your case to keep things simple you can change the oil filler cap to the early flat top type and get rid of the hose to nowhere. This cap flows both ways as needed. The current side ear could be changed to an earlier type with the fixed metal pipe going downwards or a hose could be fitted to the fluted stub that is there now. Not so neat but confess that my B18 has one fitted. Came with the car I offer as an excuse.
If there is little or no ring blow by the crank case pressure is self regulating, more so in an open system. With pistons going 2 up/2 down the pressure should balance but there will be a sort of flutter pulse at the oil fill hole and the side vent. If you hold your hand over the hole you should not feel either continuous suction or pressure trying to force your hand away. The jury may be out on the use of a mini filter on the side vent as it is now. I don't think the restriction will be much different to that with the mesh one in the oil filler cap. It's certainly neater than a scruffy hose and will keep dirt out of the engine. Checking/cleaning after 1k miles, say, would give you an idea how it was working. If really clogged up inside there are probably other engine problems to address I'd think.

gothamus Mar 27th, 2017 15:55

anywhere
 
I have a b20 as well but no servo. Right now I am breathing to the fresh air with little filters on the flame trap and the breathing oil filler cap. I Suspected oily fumes gunking up my front throttle flap recently. so it wouldn't close all the way (idling at 2500 rpm) I took the hose from the filler cap off the manifold. I don't notice any difference in performance. I just have 2 smoke stacks under the hood. I haven't noticed additional stink or fumes in the cabin.

I have thought of guiding it away from the engine compartment. A second exhaust pipe? (not actually!) I don't know where I would guide it to make it less likely to go in the cabin. A whiff of smoke coming from the engine compartment or under one of the doors? Maybe guide it through to the wheel well. I feel like it will just leave a tide of smoke in the hose going back and forth and less fresh air.

jamie Mar 27th, 2017 22:18

Any photos of ...2 smoke stacks under the hood....or.....my B18 has one fitted, would be most useful.
Derek, could I rotate the "ear" 180 degrees so that the external pipe is facing down instead of up and even connect a short piece of pipe which wouldn't need a bend in it to drain out??
Will change as you suggest and update and add a photo.
Thanks for your help
Jamie

Derek UK Mar 27th, 2017 23:51

No you can't reverse the side ear, but as I said. you can loop a hose downwards if you wish. If you haven't checked Ron's page on the similar thread, there was no need to start this one, check it out.

http://www.sw-em.com/pcv_diagrams_and_notes.htm

jamie Mar 28th, 2017 00:17

I did read it three times and I am sorry it was not found to be altogether clear to my mind, hence bothering you all on the forum. Ron's link is good, but when you put together different parts it becomes unclear. Thank you all for your patience and for your help

charlski Mar 30th, 2017 23:10

Jumping in on this I have a similar situation, b20 with a weber on, to vent to atmosphere I presume I connect oil filler cap to carb air filter, then canister on side if block straight to atmosphere ?? This way I presume its sucking clean sir in through the filter and venting straight out of side canister to atmosphere ??


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