Z421 or Z89A oil filter

[Thevak]

I am wondering if the Z89A at $16 is a suitable option for a Z421 at 50 for the Alfa 33? I change the oil and filter every 5000km.

[310]

use z89a its ok
I was genuine alfa filters from 156 busso engines same as z421

[Sportscar Nut]

Think Z89A is the Ryco filter quoted for the boxer engines. I use Techno filters on the Sud as are identical to the original OEM filter and usually get from the Spare Place in Adelaide but a lot of Alfa parts dealers stock. The Ryco's are bigger in size so capture more oil.

[colcol]

The Ryco Z89A is a common oil filter, and i have purchased them from K-Mart, and have worked fine, they have more filtering capacity than a small Genuine, UFI or Technofilter, but most likely take longer to pressure up from start, i have found the Ryco's are made in China and the Genuine filters made in Italy.
They fit a lot of Alfa Romeo motors and some Range Rovers, you can sometimes get them cheaper if you buy 6 or more, Colin.

[Steve S]

Id buy a UFI, about $22 and a close match to the original. Z89A may fit and work but they are not equivalent to OE

[colcol]

Looked up the Ryco website, the 2 oil filters are slightly different, the Z89A is a lot cheaper than the Z421, but i couldn't find out why,
        Seam Diameter, Overall Height, Seal Outside Diameter, Thread.
Z89A       94,0mm           99,0mm           70,0mm                3/4-16-UNF-2B
Z421       95,0mm           98,0mm           72,0mm                3/4-16-UNF-2B

If anyone could shed any light on these 2 Filters, please do, Colin.

[Thevak]

I did notice that the internals were different with the Z421 more complicated in construction. It may be it has a bypass feature or the like.

[colcol]

I have come across the Z421 at Repco, when i ask for a filter for a Alfa 33, when i can't remember Z89A, and it is usually about 3 times the price of a Z89A, and they can't explain why its better, so i get the Z89A, which i have used for years without a problem, even used them back in the 80's when they were Z84 and made down in Footscray in Melbourne, Colin.

[Garibaldi]

Hi Col, which oil filter do I need for my Arna?

[colcol]

I always use a Ryco Z84, as it is the correct filter for that period in the 80's, the Ryco Z89A came out as a replacement for the Ryco Z84, luckily i still have a few old Z84's that i have squirrelled away over the years.
When i take it to shows and Alfa Romeo events, i remove the Ryco and put in a Genuine Alfa Romeo old school filter with the Alfa Romeo logo, without the Fiat-Lancia-Alfa Romeo, that was produced in the late 80's following the Fiat takeover.
I also only use Shell, Agip, IP and Mobil oils as recomended by Alfa Romeo, who had no tieups, sorry 'technical partnerships' with oil companies.
I only play period correct cassettes on the stereo by Duran Duran, Haircut 100 and Spandue Ballet.
As my [lack of] fashion sense hasn't move forward in 30 years, i wear the same clothes as i always do, Colin.

[Steve S]

Looked up the Ryco website, the 2 oil filters are slightly different, the Z89A is a lot cheaper than the Z421, but i couldn't find out why,
        Seam Diameter, Overall Height, Seal Outside Diameter, Thread.
Z89A       94,0mm           99,0mm           70,0mm                3/4-16-UNF-2B
Z421       95,0mm           98,0mm           72,0mm                3/4-16-UNF-2B

If anyone could shed any light on these 2 Filters, please do, Colin.

I know UFI, Mann etc use a 22psi bypass valve. The Z89A is much lower, maybe 8-9psi, they are made for Falcons.

[colcol]

Steve, it is interesting that you say that the Z89A is made for Falcons, for the common 6 cylinder Falcon up to BA, they used Z9, i know cause i have Z9's on my parts washer filter, as Z9's are big and cheap, they use the same thread 3/4 U.N.F., Colin.