Sam's build thread

[sambb]

Ok because I have engine stuff on my mind I have an oil level checking question. I always used to check the oil level cold. But now I have an oil cooler which with say a meter and a half of lines adds up to some additional capacity. The cooler itself sits more or less level with the sump with possibly half the cooler sitting above the sumps oil level. So I'm thinking that that head of oil above the sumps normal level will naturally try to equalise when the car is rested yeah? ie some of it flowing back and raising the sumps oil level at cold. When the car is started, warmed and the oil thermostat opens and primes up the cooler then the 'operating level' of the sump would actually drop below the measured cold level wouldn't it.
So am I right in thinking that when oil level is measured cold, that that level is actually exaggerated by some of the cooler capacity that has flowed into the sump? Wouldn't the best way to measure oil level after oil cooler fitment be when the car is warm and the oil thermostat has opened and you know all of that system is primed up??

[Sydneykid]

It's not common for the oil to flow back into the engine from the cooler as to do so it has to have access to air to replace the oil. Since the oil pump is not open to atmosphere (its pick up is immersed in oil) the air can't get in (to the cooler) through the oil pump. This leaves the only access (for air) to be via the oil filter, which most engine manufacturers design to not empty back into the sump (anti drain back) as that means zero oil pressure on start up.

The oil flow routing is determined by the oil cooler adaptor, so maybe just confirm the oil flow, it's usually;
pump ----> adaptor -------> cooler -------> oil filter ---------> engine.

Cheers
Gary

[Sydneykid]

But then again I haven't run a catch can before so wouldnt know if thats normal to see a bit of vapour coming out illuminated by headlights. My older cars all just had a crank breather going out under the car and a filter on the rocker cover when that kind of thing was ok and other cars just had stock PCV systems so I've never noticed that before.
I went down and spoke to my mate. We may do the leak down next week. While we chatted we left the car idling for ages and it actually didnt blow anything at all when I gave it a big rev when I went back out to the car so maybe its not stem seals.
He reckons if the comp test shows that the combustion chamber sealing is ok, that it could still be the oil control rings. He also said the turbo could still definitely be a culprit if it was dry sooty looking on the hot side.
I must admit this does all coincide with changing from a VW 504 spec 5W30 to a non VW 504 10W40 oil which does have me thinking that the oil could have a part to play.

With leak down testing we do 2, commonly called wet and dry. Dry test first which tests the ring sealing and the valve seating. If that shows minimal leak down then all is well. If we do get questionable leak down then we do a wet test, which requires pouring enough oil down the spark plug hole to seal the rings. Then we do another leak down test, if the leaking stops them we know it's rings. If the leaking doesn't stop then we know it's valve seating.

Not always, but commonly if a wet leak down test shows the valves not seating then the valve guides are usually stuffed. Being either the cause of the poor seating or the result of uneven seating. It doesn't always go hand in hand, but it's a pretty good indicator.

Plus if the wet leak down test shows it's a valve problem then head off is easier than an engine out.

Cheers
Gary

[Sydneykid]

The reason we run oil at 100 degrees minimum is to boil off any condensation from the oil. So as the engine temp climbs to 100 degrees I fully expect to see water vapour flow out of the catch can, which is easily visible in the headlights. Obviously since this was mixed in with the oil it caries the oily smell with it. Once the engine has reached operating temperature and the water has boiled off then the water vapour trail should diminish to zero. Plus when the engine is below operating temperatures there will be some blow by until the pistons expand, taking the rings with them.

Cheers
Gary

[sambb]

Thanks for that Gary. Can make a plan off that for sure. I'll confirm the oil cooler routing tonight. Yeah I hadn't thought in terms of the oil being hydro locked up past the pump. That's good to know.
I did a dry compression test last night just to check that nothing was glaringly cactus and got 163, 166, 164 and 165psi on 4 cranks which is well within spec and variance between cylinder tolerance. I could have wet comp tested it but since nothing was wrong with the dry test I just put it back together. I'll do dry/wet when I do the leak down soon and for now am going to bung some Nulon euro spec 5W30 back in it and see if anything changes.

[sambb]

Gary my adapter plate (Mocal) goes between the block and the filter. The path the oil takes is from the pump > block mounted OE housing > adapter plate top side > straight to cooler (bypassed if oil cool, all to cooler if oil hot) > back from cooler to other side of adapter plate > into filter > out of filter into engine. The mocal adapter can only go on in one orientation. The only thing you can change is which side of the cooler the pipes go to. Mine pumps to the bottom side of the cooler and comes out the top and then gets filtered.
I think I can get a one step hotter oil T stst for the Mocal plate too (currently 80 degrees think) which should get it up to 100 degrees quicker. It gets up to 80 quick enough but does seem to trail off in getting to 100. I'll call MSCN Sydney about that tomorrow.

[Sydneykid]

Gary my adapter plate (Mocal) goes between the block and the filter. The path the oil takes is from the pump > block mounted OE housing > adapter plate top side > straight to cooler (bypassed if oil cool, all to cooler if oil hot) > back from cooler to other side of adapter plate > into filter > out of filter into engine. The mocal adapter can only go on in one orientation. The only thing you can change is which side of the cooler the pipes go to. Mine pumps to the bottom side of the cooler and comes out the top and then gets filtered.
I think I can get a one step hotter oil T stst for the Mocal plate too (currently 80 degrees think) which should get it up to 100 degrees quicker. It gets up to 80 quick enough but does seem to trail off in getting to 100. I'll call MSCN Sydney about that tomorrow.

That's the normal routing, so should be all good with the oil filter having anti drain back. I wouldn't stress too much over how long it takes to get to 100 degrees, just that it gets there. Plus it doesn't have to stay there, once the humidity is boiled off it doesn't come back until the engine cools down. Over a cold weekend, like the last one at Wakefield, we end up with about half a cup of water in the catch can. Obviously, as we use E85 it's hygroscopic nature attracts a bit more humidity than say Pump98, but water vapour is still a factor.

Cheers
Gary

[metalhead]

Hey Sam, are you going to come up and have a run at Ringwood on Sunday, get some practice in before the state round? It's on the A2 layout...

[sambb]

Hi Andrew. No have kids soccer, ref'ing, family going O/S etc etc. I'll just be turning up mid August for the state round and trying to remember it really - hope we get 5 runs! I could possibly practice and camp but jeez Ringwood isn't the most hospitable place.

[metalhead]

Yeh fair enough. Come August you could come and camp at our place if you wanted?