I was referring to the pressure needed for the hydraulic tensioners possibly being too low at idle, not that there is bleed back, and also referring to a possible reason there are sprung loaded guides, could those springs be critical to idle tension, and so what if the springs go "soft".
That the oil pressure release valve is at an assumed 6 bar, then the pump must be able to sustain it, without bleeding back. When the pump rotor is picking up from the sump, ~ atmospheric, the outlet is discharging into the gallery; to the filter, at up to 6 bar. The intake chamber and the output chamber are positioned such that there is no direct path between the low pressure side and high. I'm just playing devils advocate to get to the truth; particularly as I need to buy the bits before I break into the system:
So yes agreed the possiblilty of bleed back is small by design with the tightly meching pump rotor, but this could still give you a false pressure reading when your setting up your electric pump, and better to over engineer the system with check valves on the supply of both pumps so you can be sure your pressure isn't bleeding back through either pump when they are running, just come down to belt n braces.
this is one time exercise so it has to work! So I need challenges like this. "Proof is in the elimination of all other factors". So picking the wrong issue, is in itself a success as it eliminates it from the equation. Still doesn't confirm the truth or otherwise, so it may well be a check valve is needed. And thanks, now I know where to find them. Pumps in series 10 + 45 psi = 55 psi. In parallel; as these will be, 45 psi? [/QUOTE]
no problem glad the link is of help and yes I totally understand the pumps are in parallel.
Nice one. Don't however see how it can exceed the supply pressure from the pumps, crank or electric? and the pressure from the tensioner should ensure that surely? Only allowing top - up pressure. [/QUOTE]
Same principle as the pumps, series pressure build up in the reservior of the tensioner with the new check valve behind it. The result would be over tensioning of the chains if the bleed off value was not changed.
Sorry I'm not as articulate at explaining as you are but I'm trying.
It's all fine to me. Is the Timing chain supposed to be lubricated by the tensioner through a valve at the back of the Nylon face, at the end of the tensioner piston? A picture I have shows a hole at the centre of the Nylon face? Is the tensioner bleed hole not a pressure valve spraying the chain with excess tensioner pressure, resulting in optimum pressure at all times; assuming the engine isn't starved of oil? There is so much that is unclear, but it's the most sensible place to do it!
I need an old "oil filter and oil cooler sump" for a template. I have abandoned the idea of tampering with the tensioner system, but want to make up a Two Port/Void Manifold, to sandwich between the block outlet boss for the oil feed to and from and the oil filter/oil cooler unit. I intend to pick up oil from behind the trivet/grid in the sump, through the sump wall to the a supplementary oil pump. But I want the manifold to look professional, possibly using a small manufacturing company to machine it. But, other than taking mine off and leaving the car standing naked while it is done, a scrap one would fit the bill.
If the oil pressure is low and these bleed holes are actually valves, they may not open to lubricate the chain. Pure hypothesis, as I just don't have the information to hand.
There is a little more involved with the manifold, but I will leave that out of this at the same time. I'm viewing this as a permanent solution for my car and naturally, those who want to keep their cars for a while yet may consider it a worthwhile exercise.
My PC keeps playing up. God knows how many times it has crashed when trying to post, so I'll get this off, more in hope than anything else.
Port "A" of the manifold will carry the filtered, cooled oil away from the Oil filter/Oil cooler unit, into the galleries - straight through.
Port "B" of the manifold will take the oil from the engine oil pump and then to the input to the Oil filter/Oil cooler. Before it enters, mounted on or within the manifold superstructure will be a tapping point for an adjustable SSPS. It will then go to a "Check Valve fitted before the oil enters the second "B" void.
A second tapping into "Void B", will bring oil from the externally mounted "Electric Oil Pump", which also enters from behind a check valve.
Involved in the control of the pump is the Solid State Pressure Switch; SSPS, which has an adjustable pressure for both set and re-set. Also a timer to allow the pump to continue to run for the period where the oil pressure from the engine oil pump has built up, simply because it has no bleed off and thus opens the check valve, only for the pressure to drop again. This would cause the electric pump to start/stop, so the delay will counter this.
The feed to the electric pump from the sump will be kept as low as possible; below oil level, if at all possible to ensure the pump is always "Wet". It may then be possible, by using high grade flexible hoses to remotely mount the pump in a more accessible place.
Comments please; what am I missing? It should work, but I'd be interested to know why it would not?
Once again trying to get this off before the PC crashes again.
Why should I want to do this? If the mountain won't come to Mohamed, Mohamed must go to the mountain! "Physician Heal thyself". Never thought I could ever use those quotes - ever.