Hi All, to wrap this one up, here’s an interesting post that might help future decisions on which spin-on oil filter kits to go for.
Originally I had obtained a certain product (whom wouldn’t talk to me after I mentioned aircraft, but weirdly looks like some of their stuff looks to be supplied with my engine) and I decided to “flow the galleries” more and actually widen them out a bit. As the casting felt pretty heavy, I lightened it up by taking off some of the casting along the beefy body and took a little more weight out by making the cooling fins run full length of the casting. All-in-all, I managed to shave off around 7.5oz and got it down to around 17 oz.
Shortly after I looked at the EMPI product again and contacted EMPI as I was unsure what the casing was just behind the spin-on filter itself. I assumed it was probably some sort of by-pass valve if the pressure across the filter got too high. Obviously this would be a far more worthwhile feature if my assumption was correct as it would help in preventing blowing the filter sealing ring out and dumping all the oil. So I contacted EMPI for more details.
Yes, I was correct, it is a Bypass valve. The spring inside is set to bypass the filter when oil pressure in the supply line reaches 95 psi and dumps the oil directly into the pump-return line.
So here’s the findings between the two:
EMPI:
Pros: by-pass valve (a must for our application)
Better quality casting
Offset of spin-on oil filter sits 5/8 inch further back from prop boss (see photo of two brands)
Much lighter casting (weighed without pump or filter) at 16.4 oz’s.
Cons: slightly smaller oil galleries with some obvious restrictions on 90 deg bends
Cannot bore out galleries
Casting flashing which restricted flow on supply gallery
Other, “well-known” brand
Pros: easy to bore out gallery size
More easily to flow bends
Cons: no safety by-pass valve
Heavy at 25 oz
Poor quality casting despite generally excellent reputation for high-end VW aftermarket parts
Clearly the EMPI product is the one to go for, lighter, better quality (despite being made in China, which to be fair, probably both were). I removed the by-pass valve and spring and removed any casting flashings and removed any sharp bends by flowing the galleries where they abruptly changed direction. Flushed system out to remove swarf from my die-grinder.
Hope this helps in choosing which spin-on kit to go for?
Extra info, pump size on the EMPI product is huge, with 32mm gears, whereas other brand, was 26mm gears (same size as Standard Sonex Aerovee size pump). I may try fitting the 26mm geared bypass pump first and see how that goes?