VF SS oil change

[losh1971]

Perhaps the frequency of the oil change is relative to the oil specification changing and more of a focus on synthetic than the earlier years with mineral oils

I reckon you're probably right. Although it all comes from a crude base.

 

[greenacc]

would be interesting to see a clear filter on a running engine, to see if a bigger filter actually uses more of the element or if the shortest path is primarily used, if oil pressure is at say 80psi then if the filter is 80psi within and the outlet is the lower pressure so it flows there easiest it will only filter thru enough of the element to meet the demand, i cant see oil being continually pushed down to the bottom to then be filtered and back up when the top layer will be flowing thru the easiest, oil is uncompressible so like a lifter it may only fill up enough to flow thru and continue on its journey

The difference is the big filter has more surface area of filter in reserve. So when the first section blocks up the flow will move to next unblocked area. My question is how often did filters large and small get blocked within the service interval? If the small ones don't get blocked then I guess you don't need a big one.

 

[bjf66]

suppose you should start comparing the micron size of filters Vs viscosity of the oils used through the years this may answer a few questions
However from a physical prospective here we are placing similar oils into the BBC/SBC which has a filter of 2x the surface area
doesn't figure
I need to get into the engineering mode of the VF/V8 and start to check some of the ATF and engine oil temp (need to check if it has one) while driving and see what they get up to over summer

 

[greenacc]

I reckon you're probably right. Although it all comes from a crude base.

I bet you liked Brockys Mobil 1 add that claims anything with a crude base always contains impurities.
That was a funny add. Almost everything comes from a crude base. Crude oil, gas or whatever. Where else would the base oil come from? You can't make oil out of thin air.

 

[Immortality]

would be interesting to see a clear filter on a running engine, to see if a bigger filter actually uses more of the element or if the shortest path is primarily used, if oil pressure is at say 80psi then if the filter is 80psi within and the outlet is the lower pressure so it flows there easiest it will only filter thru enough of the element to meet the demand, i cant see oil being continually pushed down to the bottom to then be filtered and back up when the top layer will be flowing thru the easiest, oil is uncompressible so like a lifter it may only fill up enough to flow thru and continue on its journey

Yes, you would need to measure pre/post filter oil pressure to see how much pressure is dropped across the filter. The problem is, the filter needs to do the most work when the engine/oil is cold. Generally speaking there is a bypass valve in the system somewhere so that if the oil pressure drop is to great the oil will bypass the filter. As I understand it, this happens when the oil is cold and most resistant to pass through a filter media and potentially at high revs.

There was a bit of info about this on the old AV8 forum, some of the engine builders would modify the oil pumps on the V8's and block the filter bypass forcing all the oil through the filter and some would modify the oil pressure relief (for the engine) to after the filter (IIRC). When doing these mods it was advised to always warm the oil before getting into it as you would see huge pressures inside the filter on cold starts.

edit: added in red.

 

[Immortality]

****, isn't it a fascinating subject?

 

[bjf66]

Here another question but this time on the Trans 6L80E
Although I havent had the 6L80E pan off, I'm assuming its similar to the 5L40E pan, having just replaced the pan in last few days

Therefore plan is to upgrade trans sump to deepened alloy pan to get another 1.5 litre of trans fluid in there
How would you hold the magnets into the alloy pan, working on the bases it's not magnetic
Would I have to epoxy magnets against inside
Im assumning there is plenty of room now in pan and could use a few more magnets to help tidy up inside if there was a fair amount of shavings floating around

Just thinking ahead

 

[losh1971]

Liquid steel or in this case maybe liquid ali, like Devcon.

 

[Immortality]

What does the inside of the pan look like? The trans pan I put on the 4L60e had posts inside (not sure why),I had to grind them down a bit to get clearance for the filter but in theory you could slip a round magnet over one of them. I think my sump plug also had a magnet fitted in it.

Like this one.

 

[losh1971]

If you have a sump plug now, see if it can be drilled out and a magnet glued in with liquid steel. My diff builder does this with BW diffs by drilling the drain bolt and fitting a magnet. He does it mainly to the cone LSD ones as they tend to have a fair bit of metal go through them after a rebuild.