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R33GTS25T oil filter mounting face diameter ?

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Hi all , if anyone has access to an S2 RB25T engine could you please measure the diameter of the base where the oil filter seals against .

The standard Z145a seal diameter is supposed to be 63mm OD , if that base is 70mm or larger we could use a Z68 filter which is basically same thing but 20mm longer .

Thanks in advance and cheers from Adrian .

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Haven't measured it, I did years ago and managed to squeeze a Z115 in which is even bigger than the Z68. It has a seal diameter of 70mm.

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Just measured the two blocks I have in the parts dept. One block would only have enough face to be 66mm the other is 65mm. The RB30 block I fitted the Z115 to, must have had a larger face area. So no to Z68.

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On 3/7/2021 at 6:56 PM, discopotato03 said:

if anyone has access to an S2 RB25T engine

series 1 block was 66mm, series 2   65mm

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Hi and thanks for your time .

What I was actually asking about was the face where the filter seals against on the aluminium housing with the water oil heat exchanger on it . This is a 96 GTS25T by the way .

I removed my standard Ryco Z145a filter today and the diameter of the filter mount is around 71.5-72mm . I had a Ryco Z68 here so I tried it and it works fine . Its basically same thing as Z145a but its around 20mm longer and its seal diameter is about 70mm . Z145a is 63mm . I cleaned everything up and got a small mirror on telescopic handle to see behind it . I can confirm that no part of the seal is exposed so there is no way it can blow out and leak . I went for a drive and confirmed no leaks .

I've looked further and there is another filter - Ryco Z37 , that is same as the Z68 but 143mm long rather than 120 . Z145a is 100 long , or high if you like . Z37 was standard I believe on 70s/80s Cressida's and HiAce so easy to get and not as expensive as filters on some late piles of garbage .

If you want even larger I can't see why you couldn't fit one of those inexpensive filter "sandwich" plates , to space it further out and use a good ole Z115 like all the old Nissan/ Datsun L Series engines used . These are also 140 odd mm long but larger seam diameter like 94mm vs 82mm . Same 70mm seal OD . These won't go directly in the std filter location because the filter body and rim is too big in diameter . The Z145a and Z68 only just clear the webs near the water oil heat exchanger . The filter sandwich plates are advertised as around 28-30 odd mm deep so may get out past obstructions for a 94/95 mm OD filter ie Z115 . Please don't ever substitute a cheaper Z9 for a Z115 . They have a lowish pressure bypass valve in them , which you don't need as RB25DETs have them on the engine side of the filter . Z9 was for early Fords , nuff said ...

All these filters I've mentioned (except Z9) have the same features as Z145a , ie no bypass valve/have anti drain back valve/no anti siphon valve .

I am not a fan of todays cars thimble sized oil filters , I reckon more capacity is better within sensible limits .

Lastly and a little OT , for anyone interested my Mitsy Evo 6 wears a Ryco Z79a because its larger than the now std piddly oil filter and clears the oil coolers banjo bolts . Z79a is standard for Mazda 323s back in the carby days so again available and not as expensive as the current trend of thimble sized oil filters .

Take care and cheers from DP03 .


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