Jump to content
SAU Community

Recommended Posts

Currently have my head off and am comsidering removing oil cooler and fitting a rb30 threat adaptor to fit filter strait to block and running no cooler at all, its only a street car, am just trieng to do whats needed while am at this stage, also can i plug the hoses that run down to the cooler? Iv also read about people blocking the big coolant line barbs at front and rear of block to, what do you guys reckon?

Cheers, chris

Link to comment
https://www.sau.com.au/forums/topic/410470-rb-25-is-an-oil-cooler-needed/
Share on other sites

The water to oil heat exchanger can be a reliability issue. If the coolant has not been well looked after in the car over the years, then corrosion will eat the heat exchanger and if it opens up you get oil+water, which is seldom good. On that basis it may be worth considering getting rid of it.

For a street car, you probably do not need an oil cooler at all, even the oil-water one. Older RB engines did not have the oil-water units. They are not actually intended to cool the oil. They are intended to warm it up faster. The faster an engine comes to operating temperature, the faster it can comply with emissions limits. That's pretty much the sole reason they got added. They do help cool the oil a bit, but seeing as they just add that heat to the coolant, it's not exactly gaining you a lot, as the radiator could probably cool the engine the same amount without any heat coming from the oil.

If you do remove it, don't block the water hoses. Join them together.

If you do remove it, don't block the water hoses. Join them together.

Reason being? Just curious as to why you'd need to join them?

I looked into this a while back, an RB20 runs a similar type cooling setup under the plenum but with no oil cooler obviously. Blocking the ports for the oil cooler would in fact mimic an RB20 cooling route setup under the plenum.

Hence why i'm curious as to why you said join them together.

Dead legs with coolant in them are bad. Old nasty coolant sludge trap anyone?

Point taken.

So, join them up or weld them up then. Same obviously goes if your deleting the heater obviously.

While semi on the subject of coolant. Coolant filters, yay or nay?

That's a tough one. They have their place. A well maintained cooling system won't need one. I suspect the only time you want to put a filter in is if you have had an event that has put crap into the cooling system and would like to pull it out. Run it for a while, check it frequently, take it out when it stops pulling stuff out. If you have one in there all the time and don't check it regularly, it may just turn out to be the cause of a failure rather than the prevention.

How long?

Are you running E85?

Find someone with a RB20DET and ask them, I do however my old RB20DET's oil taking ages to warm up when compared to the RB25DET. Would leave my house, drive to the gym and the oil temp would be still lower than the water temp.

Find someone with a RB20DET and ask them, I do however my old RB20DET's oil taking ages to warm up when compared to the RB25DET. Would leave my house, drive to the gym and the oil temp would be still lower than the water temp.

Johnny, did you have an oil cooler? If you did, did you have a inline thermostat?

Yeah I used B&M core and the Permacool inline thermostat and Permacool relocator.

Took ages to warm up man, mind you there was like over 3m of hose used as well (I know you hate homo relocators lol)

I have yet to install an oil cooler to my previous R33 and my current one.

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

    • Nope. The seal is in the drive. A new cable would just fill up and continue to convey oil to the speedo head. To check if this is what is happening, take the cluster out, dismantle the speedo and have a look. You probably don't even have to dismantle it. If there is oil coming up the cable, the drive into the speedo will be grossly greasy. I had to manually (and delicately) clean the gunk out of my speedo.
    • Thanks for the quick response mate, and I agree Nismo 555s, Z32 and high flow 2871 in OP6 housing (run by PowerFC) would all be "period correct" and should be a simple, reliable and reasonably quick track car.
    • It is normal for a speedo to read 0-10% high (unfortunately), intended by manufacturers and ADRs (although not in this case) to ensure your speedo does not read low if your tyres are worn. Speaking of which, what size tyres do you have on the rear, and what does they tyre placard say you should have? you can use this https://tiresize.com/calculator/ to determine what % difference that is causing Personally, when I buy tyres for a car I buy a size that will bring the speedo back to being more accurate; it if it reads 5% high I buy tyres that are 5% larger diameter. If you had an electronic speed sender like R33 onwards, the other option is to add a speedo adjuster but that won't work in R32. Finally, you  might be able to find a different sized gear for the speedo sender but that will be limited to what already exists (and I don't know what sizes do)
    • OK...so dumb question to check....do the hi beams actually come on when the push the stalk to engage them (keeping in mind your headlight switch must be at ON as well)
    • Nah it factory manual not sure about ratio but it looks like there’s been some work at the rear 
×
×
  • Create New...