Jump to content
SAU Community

Recommended Posts

As I'll be doing an external oil cooler, I'm replacing my stock RB25 oil cooler with an RB20 oil filter housing. My RB25 left passage is currently plugged.  Is it best to keep it plugged or too remove and replace with bypass valve? I have a bypass valve on hand ready to install but I've never seen any concrete info on which is best. Most discussions seem to have a split vote.

My concern is that without bypass valve, will oil pressure be higher on occassions it should not or does it only bypass due to a clogged filter? 

 

Thanks

IMG_20220414_182523.jpg

Edited by TurboTapin

With an external oil cooler I would imagine that you want a bypass both for filter pressure and the oil cooler. In the RB26 the factory housing has a relief valve on it for either scenario. I'm pretty sure that the block itself does not have the relief valve.

On 4/14/2022 at 7:45 PM, joshuaho96 said:

With an external oil cooler I would imagine that you want a bypass both for filter pressure and the oil cooler. In the RB26 the factory housing has a relief valve on it for either scenario. I'm pretty sure that the block itself does not have the relief valve.

Yea I think bypass is the way to go as well but I want to get other peoples thoughts before I drill out the plug. 

After taking the night to think about it, I could see a lot more positives then negatives to removing the plug and fitting in a bypass valve.

I center punched, drilled and taped the plug M8x1.25. Used a plate and a bolt as a puller and it came right out. After lots of cleaning with a magnet, shopvac with a small vacuum hose and brake cleaner; I gently hammered in the new bypass plug using an appropriately sized socket. 

image.jpeg

image.jpeg

image.jpeg

image.jpeg

image.jpeg

  • Like 1

Your calls but I think the filter bypass valve is there for two reasons .

Firstly some careless or clueless never change oil and filters . 

Secondly really cold climates may make it hard for oil to flow through the filter .

When I was playing with L20B fours back in the late 80s I had that bypass removed and plugged , I was using a remote filter as well . Note that L20Bs use a larger Z115 style filter std .

I don't think oil filters magically clog up , if you are prepared to change your oil and filter at reasonably regular intervals you should never have a problem that a filter bypass could solve .   

  • Like 1
On 4/15/2022 at 6:44 PM, discopotato03 said:

Your calls but I think the filter bypass valve is there for two reasons .

Firstly some careless or clueless never change oil and filters . 

Secondly really cold climates may make it hard for oil to flow through the filter .

When I was playing with L20B fours back in the late 80s I had that bypass removed and plugged , I was using a remote filter as well . Note that L20Bs use a larger Z115 style filter std .

I don't think oil filters magically clog up , if you are prepared to change your oil and filter at reasonably regular intervals you should never have a problem that a filter bypass could solve .   

Agreed! You seem to have made two great points to keeping it yet removed it? In your opinion, what are the positives to removing it? 

Edited by TurboTapin
On 4/15/2022 at 6:28 AM, TurboTapin said:

After taking the night to think about it, I could see a lot more positives then negatives to removing the plug and fitting in a bypass valve.

I center punched, drilled and taped the plug M8x1.25. Used a plate and a bolt as a puller and it came right out. After lots of cleaning with a magnet, shopvac with a small vacuum hose and brake cleaner; I gently hammered in the new bypass plug using an appropriately sized socket. 

Pretty sure this is the correct thing to do if you know that there will be no downstream relief valve. Looking at the RB20 housing I don't see anything like the relief valves in the RB26 housing.

On 4/15/2022 at 8:40 PM, joshuaho96 said:

Pretty sure this is the correct thing to do if you know that there will be no downstream relief valve. Looking at the RB20 housing I don't see anything like the relief valves in the RB26 housing.

Agreed. The RB20 housing does not have a bypass/relief valve. That's why RB20's have the bypass valve in the block. Cheers. 

Amm this is why you buy a nice greddy oil filter re-locator, they have the bypass built in at the filter re-locator. Also thermostat for the oil cooler.  Much easier than messing with the block.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • If the tyres were fitted when new, I wouldn't expect much over 5 years of use. Especially if the car lives outside full time.  If the tyres had been stored under ideal conditions and are being purchased new, I'd fit a set of already 5 year old tyres if I only expected to get 1 to 2 years of use out of them.  I've purchased many a set of new (but quite old) tyres from St George Tyres when I just needed some decent rear tyres to drift on.  Here is a pretty crazy example, can't say I've ever bought 11 year old tyres from them before though lol.  https://www.stgeorgetyres.com.au/momo-tyres-245-45-17-outrun-m3-official-product-by-momo-italy.html
    • Also, a tip for young players  Check the dates on new tyres before they fit them, I always ask this question at the tyre shop, as they have tried to put "new" tyres on one of my cars a few years ago, but the build date was about 3 years old
    • Yeah - 4 or 5 years is the limit for decent tyres. Pedestrian grade tyres with 400 TW ratings start out hard and don't start to suffer until they are somewhat older again. But the stickier decent stuff? Nup. My current ADO9s are < 2 yrs old, 17000km in, only have about the minimum 2mm of tread depth left, and they are.....not what they used to be. They are clearly much harder now than when new. Whether that is heat cycles (unlikely, for a road tyre), different compound between top and bottom of tread, or actually aging out (in less than 2 years!!!) is not really able to be discerned. But I'd credit actual aging as being at least part of the cause. I've got an old pair of ~50% worn AD08Rs in the shed that I really need to get rid of. They started feeling waaaay too hard to put back on the car after a couple of years sitting there.
    • Personally I wouldn't put tyres over 4 or 5 years old on any of my own cars. Once they go hard the grip characteristics completely change. As per most things it only matters in an accident and that's when you most want them to do their job!
    • I'm replacing the front tyres on the E39 tomorrow because one of them has a few gouges out of it. There is so much tread still on them but they're also 9 years old and the rubber is super hard.  This falls within the guidelines of 10 years old that I've read which surprises me given their condition.  I'm curious about whether you guys care about tyre age or just judge the tyre based on condition? How old would you consider too old?
×
×
  • Create New...