Oil in Weber Carbs

[Mike J]

Has anyone else experienced this. Don't use the Stag for long journeys generally . Had to drive about 40 miles today and it was dumping oil when stopped. Got home and the Weber (Stag Weber) was full of engine oil. All around the air filter and sprayed across the engine bay. See photos. Also noted the feed to manifold copper pipe was loose.

[DZP]

Hi Mike,
I cannot see if you have the Stag Weber Active Breather System (ABS) installed, but if you have the copper pipe at the base of the carb, then I suspect you have.
Your carb is sucking oil straight from the cam cover into the air intake, this should not be happening of course.
First thing is to check the engine oil level. Did you top-up recently?
If the engine oil level is OK and you have the ABS installed, then more likely than not, your ABS PCV (Positive Crankcase Ventilation) valve has failed.
The PCV valve is what stops high inlet manifold pressure from sucking oil straight out of cam cover and burning it in the engine, as it should only open during lower inlet manifold vacuum pressures.
Whilst you debug the issue, I would remove the breather pipe feeding into the bottom of the air filter and direct it to drop any oil away from the engine avoiding any hot spots.
You can test the PCV valve by squashing the pipe from the inlet manifold to the PCV valve whilst idling.
At idle, inlet manifold pressure is high and hence the PCV valve should be closed, when you squash the pipe you should here a click as the PVC valve opens.
Regards,
Den

[KOY 23]

Welcome to the world of aftermarket fuel systems. The Strombergs are very good at handling engine breathing on a worn engine. You don’t know that your engine is worn until you ditch them, been there, had the pain and expense to cure a problem I never knew I had. As I see it you have 3 options:
1) Add catch tanks, PCV valves etc, which may or may not work depending on severity. Cost £100+
2) Rebuild engine. Cost £5k+
3) Refit Strombergs. Watch Church House Classics video, if they need reconditioning. Cost depends on what needs doing but low £100’s

[Mike J]

Thanks to both of you. Engine was rebuilt about 10k miles ago . So am hoping should be OK. Will check valves tomorrow but refit Stroms seem a good idea. Don.t think the Stag Weber conversion has been thought through properly. I have had numerous replacements and "upgrades" at a cost, over the time I have had the Weber fitted. Will let you know how things progress. Thank you again.

[SaskStag]

My car also went through the same pain. I have receipts for a professional engine rebuild about 5000km earlier to my installation of the kit. Granted, it was an earlier set up to thise available now and I had to design my own breathing system and incorporate a pcv valve. It worked better, and I fixed every oil leak, but eventually oil was blasting out of every seam, covering the engine bay. I replaced the Weber with refurbished Strommies and all the leaks instantly disappeared.

[Wheelz]

Mike J, I can see that you have the cam cover pipe connected to the air filter, so oil must be coming out of your cam cover, which should not normally happen. I found that cleaning out a partially blocked gauze in the cam cover cured mine. If the gauze has never been removed and cleaned it could be caked with carbonized oil after 50 years of use.

The Weber is no different to a Holley or even Fuel Injection in regards to the breathing. If the cam cover is blowing oil out you could use a simple catch can or the stagweber breather kit.

You have to wonder if oil is coming out of the cam cover, where does it go when you are running the Stroms. I suggest it would be sucked into the carbs and burnt in the engine?

[Mike J]

Gauze in cam cover was cleaned approx 1 k miles ago. There is also a whistling noise from the Weber. so think put the stroms back on . Have lost faith in the Weber conversion.