Oil cooler non-return valve?
Discussion
I have a mk1 MR2, to which I fitted a Laminova oil-water cooler, fed by a sandwich plate under the oil filter. Hose and fittings are -10.
The cooler is above the level of the sump.
My problem is that oil pressure is slow to come up on the first start of the day. Subsequent starts, even after several hours parked, oil pressure comes up almost instantly.
No signs of wear in the pump.
My assumption is that the oil in the cooler is slowly draining back into the sump - I assume via the oil filter, although that's supposed to have an anti-drainback valve.
I plan to fit a non-return valve in the inlet line to the cooler - one of these : http://speedflowdirect.com.au/itemdetailspage/2035....
The manufacturer confirms it's
a) Suitable for oil (viton o-ring seal)
b) Rated to well over max pressure it will see.
c) Opens (in the flow direction) at 3 psi.
Is it likely to cause too much pressure drop?
Will it solve the problem?
Am I barking up the wrong tree?
I start reassembling a freshly rebuilt engine for it this weekend, so I need to make a decision in the next few days.
The cooler is above the level of the sump.
My problem is that oil pressure is slow to come up on the first start of the day. Subsequent starts, even after several hours parked, oil pressure comes up almost instantly.
No signs of wear in the pump.
My assumption is that the oil in the cooler is slowly draining back into the sump - I assume via the oil filter, although that's supposed to have an anti-drainback valve.
I plan to fit a non-return valve in the inlet line to the cooler - one of these : http://speedflowdirect.com.au/itemdetailspage/2035....
The manufacturer confirms it's
a) Suitable for oil (viton o-ring seal)
b) Rated to well over max pressure it will see.
c) Opens (in the flow direction) at 3 psi.
Is it likely to cause too much pressure drop?
Will it solve the problem?
Am I barking up the wrong tree?
I start reassembling a freshly rebuilt engine for it this weekend, so I need to make a decision in the next few days.
PaulKemp said:
I had two different solutions for two similar engines I built.
1 was a remote thermostat the diverted oil flow back to the engine after a short pipe run from the takeoff plate and the other was a thermostatic takeoff plate which I thought was a better option.
This means the thermostat will hold oil back in the cooler from cold start, if you still get drain back because you turn off the engine when hot the solution is to idle the engine until the temperature drops below the oil thermostat operating temperature which is usually higher than the water thermostat.
Another option if still having trouble is to fit an pressurised oil reservoir such as accusump.
I was avoiding using a thermostat, since as I understand it, the coolant warms up faster than the oil, so on cold start the oil will warm up faster if it's exposed to coolant.1 was a remote thermostat the diverted oil flow back to the engine after a short pipe run from the takeoff plate and the other was a thermostatic takeoff plate which I thought was a better option.
This means the thermostat will hold oil back in the cooler from cold start, if you still get drain back because you turn off the engine when hot the solution is to idle the engine until the temperature drops below the oil thermostat operating temperature which is usually higher than the water thermostat.
Another option if still having trouble is to fit an pressurised oil reservoir such as accusump.
I could swap the takeoff for a thermostatic one pretty easily.
stevieturbo said:
And does the filter have a drain back valve ?
Most do...but it would be easy to check.
The oil light on my van takes an age to go out sometimes...but it's been like that for over 600k and it's still going.
Just how slow is pressure to build ?
Could you bypass the cooler for a few days to see if it makes any difference ?
Is pickup pipe o-ring etc definitely ok, correct weight of oil ?
The filter packaging said it had a non-return valve, but I haven't checked the filter itself.Most do...but it would be easy to check.
The oil light on my van takes an age to go out sometimes...but it's been like that for over 600k and it's still going.
Just how slow is pressure to build ?
Could you bypass the cooler for a few days to see if it makes any difference ?
Is pickup pipe o-ring etc definitely ok, correct weight of oil ?
When it was started in the morning, it took several seconds for the oil light to go out, and sounded a bit clattery for the first second.
Given that I am refitting a fully rebuilt engine, I want to avoid any issues.
As the oil cooler pickup is a sandwich plate under the oil filter, I may assemble it and run it in without the cooler - I can reconnect it next filter change, after the rings have bedded.
If I started it after an hour or two, iirc it took much less time for the oil light to go out, and no clatter.
I still think a one-way valve would solve the problem, but a proper low restriction flap valve is around $200.
Like the BMW above, the oil filter is on it's side under the exhaust.
In the short term I will run without the cooler for the engine break-in; I may fit a kill switch so I can crank the engine without starting it. If the oil line relocation I plan doesn't solve the problem, it may require a better one-way valve.
Like the BMW above, the oil filter is on it's side under the exhaust.
In the short term I will run without the cooler for the engine break-in; I may fit a kill switch so I can crank the engine without starting it. If the oil line relocation I plan doesn't solve the problem, it may require a better one-way valve.
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