[Mk2] [Generic] Differences Between N/A and Turbo Oil Filters

[JeffD]

Ever wondered what the difference is between an N/A and Turbo Oil filter? Me too! Only one way to find out for sure so I bought myself a new hacksaw tonight....



Looks like they both contain pressure release valves then :-)



You can just about make out the spring in the pressure release valve here:



Closer look at the filter element:



On first appearances it looks like they are identical apart from capacity. Only thing I'm wondering now is whether the spring is rated the same. There is a different no stamped on the bottom of the valve....

[BenF]

LoL - I like your style

Interesting that the NA filter also has the pressure release valve - that is news.

Where is the pressure relief valve fitted? I thought it was at the base, but from your pictures I'm not so sure ...

FWIW - I've used the turbo filters also on the MK1 NA as well as the Roadster Turbo - with a larger filter element, there should be theoretically a better flow across it with less oil pressure drop, especially if you're driving hard.

[JeffD]

Its at the top at the opposite end to the inlet. TBH the main purpose of the exercide was to confirm that the N/A filter had the pressure release valve in. Although syaing that Toyota say all their filters do :-)

BTW That red stuff is non-standard - its blood from when the hacksaw slipped - ouch!! LOL!

[BenF]

Ah, so that explains the 'dome' on the top of the filter.

Hmm, its a good reason for getting Toyota filters rather than pattern parts.

Have to say though that pattern filters are getting ridiculously cheap - £1.20 for a Mk1 filter which is the same as for a Mk2 NA. I got a few for the trackday car as they're changed regularly - and I'm not so worried about using pattern parts on that car, as it is 'in keeping' with the rest of its character IYSWIM

I did see the red on the filter... ouch Always seems to happen when you're working on a car....

[JeffD]

Know what you mean about pattern parts being cheap but I can certainly vouch for how well made these things are! I thought I would whip through them with a hacksaw but it took quite a while - wont go into too much detail in case your having a late supper but it was as the hacksaw slipping which caused the blood loss :-(

Anyway, there not too expensive:
http://www.flashmetal.com/index.asp?fun ... T&catid=40

[paul port]

Here's some pictures I took Years ago of an American NA filter (90915-YZZA2)



The spring that keeps the assembly pressed into the base:


The Pressure relief valve


The Anti-Drain-Back valve in the base


A Sectional view of the filter material (Odd Design, must maximise area or something)




Again, I believe the Turbo filter (90915-YZZA1) is basically the same thing but LONGER.


Question regarding your photos... I can't see the filter material end caps that seal the top and bottom pleats - where are they?

Paul

[Monkey]

Hmmmm, glad this has been posted.

I recently ordered some oil + filter from guy at opie.

When I was about to do the oil change I checked the new one against the one I already have and it is shorter. Can this still be fitted or have I been sent the wrong one?

I have done a search to try and find out why one is shorter, but have had no luck.

Thanks

[JeffD]

3SGTE Turbo filter is 90mm in length.
N/A Filter is 70mm in length.

Personally? I wouldnt anything else other than a genuine filter - especially after taking one apart the quality is even better than I expected.

Some people use Turbo (longer) filters on an N/A but IMO I wouldnt deviate from the manufacturers recomendations - if they were interchangable why would Toyota go to the bother of making 2 different types? mmmm....

Certainly wouldnt put the shorter one on a Turbo.

[Monkey]

Nice one Jeff!!

That is pretty much what I thought anyway, it's just nice to hear it from someone else.

Down to mr t on Monday I think.

As for opie sending the short one............

[JeffD]

I do genuine MR T Oil Filters (and even 1/2 ones LOL!) on my shop here :-)

http://www.flashmetal.com/index.asp?fun ... T&catid=40

[JeffD]

BTW I've just notioced I didnt actyally answer Paul's question about the photos. Everything that was inside the filter is shown in the photo (but cut in half). Theres's a rubber seal around the bottom of the filter element but only round the threaded entry. No seal at the top either but saying that there is a strip of rubbery glue at each end which acts as a seal (I believe). See below.



Heres a closer pic of the pressure release valve closed:



An if you apply quite a bit of pressure (lot more than you would imagine!) it opens:

[paul port]

umm that is very odd indeed...
I must presume the filter pleats are sealed just below the ends (that Look very open!)?

Otherwise.... think.... oil is input through the middle section, it flows outwards - what is stopping it oozing out the top of the pleat?

In my photo, you can see the card top and bottom end caps.

paul

[JeffD]

I'm sure someone will correct me if I'm wrong but I think...

Oil is drawn up the outsides of the filter and then passes through the wings of the filter into the central chamber then out.



If the filter becomes blocked and oil can not pass from outside to inner chamber the pressure will force the by-pass valve down



so oil now flows right to top of filter through the now open valve then straight down the middle :-)



And that my dear friends is what makes a genuine filter better than an aftermarket one LOL!

[JohnnyC]

And that my dear friends is what makes a genuine filter better than an aftermarket one LOL!

Now you need to saw in half a Toyota fuel filter to see if it has a similar bypass valve

[JeffD]

If you provide it I'll do the sawing ;-')

[BenF]

Jeff, nice diagram - but I can confirm oil comes out of the centre of the nozzle, so the flow is 'backwards' to your diagram.

Makes quite an impressive jet if you forget to refit an oil filter

Also - as for the NA vs Turbo filter - I suspect Toyota spec a shorter filter for the NA, purely on grounds of cost.

I can't think of any technical reason as to why a long filter should cause a problem (subject to space etc) where a short filter would have been previously ..

[paul port]

It still does not answer the question - why in your photo are the pleat ends not sealed?

Take your last series of photos...
If oil could enter the end of the pleat (in the direction of the arrow), it would completely bypass having to flow through the filter material to reach the centre.

[paul port]

I think the diagram is correct, oil goes in on the outer and out through the centre - reason being the drain back valve....

In the USA filter, the drain back valve is basically a rubber skirt that seals against the 'holes' around the edge of the filter base. In order to open that seal, oil would have to be pushed in through those holes

paul

[JeffD]

Hi Ben/Paul

Ben: My diagram shows the oil coming out the central hole?! Also, know what your saying about cost but it would be cheaper if they only produced one type of filter rather than 2.


Paul: Bottom diagram is showing flow when a filter has become blocked - hence it should bypass the filter material, go straight to top of filter then vak down through the bypass valve which has now been forced open by the increased pressure of oil not being able to 'escape' through the filter material.

Regards Jeff

[BenF]

Jeff, sorry - to be clear - oil enters the filter from the centre.

You can test for yourself by removing the filter and turning the engine over on the starter for a few seconds