Other Stuff > Misc / Open
DOT4 to DOT 5 Silicon
Lobo:
Thanks for the tips Nige / Ted - the rubber fuel pipe with slit worked perfectly, and with a mod to your jam jar using a 2L plastic milk bottle with interference fit on the hose. It consequently sits happily anywhere and at any angle - I bled all 4 corners in about 30 mins via the conventional method.
The car all buttoned up until next time - rewiring he mid year + likely engine out / new gaskets as a bit too oily tbh.
McCabe-Thiele (Ted):
Good outcome - fwiw my jam jar has now been upgraded to a see through thick plastic bottle (ex-PLJ) I think it was.
You mention - a bit too oily - what type of crankcase breathing system does it have if any?
When BL introduced the positive crank case breather system to the old A series engines it was a wonder cure - likewise on the old Opel 1900 cam in head engines.
Just thought I would put it out there for consideration.
K2-K6:
Good to get it all completed Simon. Those little tube make quite a difference in that it seals virtually perfectly and such a simple device too. They make even complex system very easy to bleed even new ABS etc.
Did you mean negative crankcase pressure Ted ? I thought they all pulled slight vacuum on the cases to avoid pressure trying to push oil out of any seals etc. It may have come from Buick V8 when they bought that as originally it was arranged this way, V8 being quite a windy arrangement in terms of case volumes vs piston volume and movement. I've a injected one now that has dipstick sealed which if removed you can hear the idle air valve compensate for the increased flow pulled through the cases.
We test them with a rubber glove on the oil filler to see if it inflates or sucks in assessing if working correctly. In bad cases the valley gasket is pushed upwards under the inlet manifold if they've not been looked after well, that because of pressure building up to much.
VW has many sealing faces with barrels, heads, pushrod tubes etc all individual components to seal too.
Lobo:
Thanks Ted, a bit of lateral thinking that - never considered that.
Nige… somehow I’d have though exploding gases loaded up a crankcase pressure if anything vs dropping it below ambient - a bit confused here!
Ted - a breather next to the oil filler vents to the air filter, which is basically an oil bath used to trap particles. The upper 1/2 of the engine is ‘acceptably’ clean.
Below the air-flow baffling (ie ducted tin-ware over the cylinder heads) it’s a different matter - the lower engine is fairly damp with congealed oil. I’m guessing years of weeps as Nigel alludes to with chaotic air flow all making one horrible mess… (the lower engine is a bit wetter than the pic suggests)
K2-K6:
--- Quote from: Lobo on January 25, 2023, 10:59:18 AM ---Thanks Ted, a bit of lateral thinking that - never considered that.
Nige… somehow I’d have though exploding gases loaded up a crankcase pressure if anything vs dropping it below ambient - a bit confused here!
--- End quote ---
Yes, i wasn't clear there. The cases venting into inlet tract on engine side of throttle plate (carburettor or injection) pulls constant vacuum on crankcase void to keep it "empty" in effect. But as noted, if that supply is too great it or shifting, it can affect idle rpm hence the dipstick has a seal at the top to prevent it sucking in through there.
One of the checks is to pull the dipstick on this, revs should go up, then by pulled back down to target as ecu modulates the air bypass route to adjust.
It fails if pipes/flame traps etc are not maintained and flow impaired.
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version