No PCV system

[Thowdfella]

My car is a 122s 1966 and I have been reading about the PCV system. It says that this was fitted to b18b and B18d engines in 1966 but eliminated on the B20 however my car hasn't got one. Should it have?

[Ron Kwas]

Tf;

I don't know where you've been reading, but any place that states PCV sys was "eliminated on the B20" is incorrect...PCV was changed for B20, the most notable difference is direction of flow, but always present (with market, and carb or injection variations).

I suggest you read here: https://www.sw-em.com/pcv_diagrams_and_notes.htm

Cheers

[Thowdfella]

Thanks for your reply Ron and an interesting article. However on the B18 POV diagrams, it shows the two variants of oil filler caps and mine is no 43 i.e. Without the outlet tube on it and the ventilation box again is no 4 - without a tube connection on. So no PCV connections anywhere. Why do they show oil fires with and without connection pipe? Does this mean some engines have PCV no some don't?

[Ron Kwas]

TF;

No 4. the Oil-Trap, will always have a fitting (beyond the block tube, 22mm for B18 or 27mm for B20 Ref: https://www.sw-em.com/Service_Bulletin_1966_P-21_12.jpg )...departing upward OR downward, but if there is an Oil-Trap fitted (opposed to the formed pipe shown in first pic under OCV) then there is PCV (or OCV!). I suggest you have another look at your Oil-Trap and report what you find.

..."oil fires"...??

Good Hunting!

Edit: Added info and link

[Thowdfella]

Sorry Ron the "oil Fires" is google deciding what it thinks I want to say.
Should have read - Why do they show oil filler caps with and without the PCV tube unless some engines don't have PCV?
My oil trap - no 4 - has a tube going straight into the engine and a breather tube going down and under the starter motor
The oil filler cap has wire gauze inside it

[c1800]

Tf;

I don't know where you've been reading, but any place that states PCV sys was "eliminated on the B20" is incorrect...PCV was changed for B20, the most notable difference is direction of flow, but always present (with market, and carb or injection variations).

I suggest you read here: https://www.sw-em.com/pcv_diagrams_and_notes.htm

Cheers

I think the reference is that the PCV VALVE was eliminated on the B20, yes?

[Thowdfella]

Story Ron, you have lost me now. I am trying to find out if I should have PCV on my 1966 122s. On your last reference, my car fits the second example of OCV, but that suggests it was only fitted until 1964. So how come my 1966 model is fitted that way?

[c1800]

Story Ron, you have lost me now. I am trying to find out if I should have PCV on my 1966 122s. On your last reference, my car fits the second example of OCV, but that suggests it was only fitted until 1964. So how come my 1966 model is fitted that way?

You may have a previously replaced engine to an earlier model. Or someone previously modified the PCV system to an earlier one.

[Derek UK]

You appear to have the second type basic system i.e. an open flow system but with a mesh in the side ear as a flame trap. The mesh can get clogged up by sticky oil fumes if you have ring blow-by so that is worth washing out. The two later systems, B18 one way and B20 reversed way, attempt to keep a slight negative internal vacuum and also try to make the engine burn those fumes making for less emissions than if it was just vented to the atmosphere under the car.
If you have a servo, the early types get their vacuum from an outlet on the front of the alloy inlet manifold. The later ones have to get it by either tapping into the a fitting on top of the manifold or via T piece in the hose that goes across the engine from the PCV on the side ear to the restricted nipple in the centre of the inlet manifold, alloy or iron. The restriction in the manifold is important, use the more open one which outwardly looks the same, and the engine reads it as a big air leak. No way of tuning the carbs properly with this "leak".
Bottom line is you either have proper full flow closed system done by the book or you leave it open and let the fumes out.

[Ron Kwas]

Tf;

I think C1800 and Derek have covered it well...the important thing is to understand what is being done, and that there are a number of factory variations and implementations...then you can make the decision as to which configuration to install, or not...and if you are not the first owner, its easy to realize that some changes or creativity (correct and less than correct!) may be in place from before your ownership...

Cheers