Turbo Copper Washers

[proline]

I'm in the process of swapping out my OEM turbos for GT2859s

There are a bunch of M12 & M14 & M18 copper washers for the oil and water lines.

Can anyone tell me the correct/OEM thickness for these?

The washers I have removed are 1mm thick and I assume that is more or less the same before they were originally tightened i.e. the crush is negligible.

The replacements I have are 1.3mm thick.

Not sure if the loss of bolt thread contact is an issue or not, especially for the banjo bolts that attach directly to the turbos.

I'm tempted to anneal the original washers but for some reason that doesn't feel right.

I'm probably over thinking but would value anyone's thoughts.

Would also like to understand why Nissan used two washers connected together for the Turbo oil inlet.

 

Thanks

Lee

[Duncan]

First up, Nissan didn't use 2 washers on the oil inlet which is the clue that it has all been apart previously and you may not be looking at factory washers anyway.

To work out if your 1.3mm washers are OK (I guess so), measure 2 washers + the banjo and subtract the length of the banjo bolt under the head to the end of the thread. As long the answer (ie, how far the bolt will go into the housing) is at least the same as the diameter of the bolt you are all good, probably even a little less is OK as these are hollow bolts anyway.

[joshuaho96]

On 6/1/2022 at 8:39 AM, proline said:

I'm in the process of swapping out my OEM turbos for GT2859s

There are a bunch of M12 & M14 & M18 copper washers for the oil and water lines.

Can anyone tell me the correct/OEM thickness for these?

The washers I have removed are 1mm thick and I assume that is more or less the same before they were originally tightened i.e. the crush is negligible.

The replacements I have are 1.3mm thick.

Not sure if the loss of bolt thread contact is an issue or not, especially for the banjo bolts that attach directly to the turbos.

I'm tempted to anneal the original washers but for some reason that doesn't feel right.

I'm probably over thinking but would value anyone's thoughts.

Would also like to understand why Nissan used two washers connected together for the Turbo oil inlet.

 

Thanks

Lee

https://nissan.epc-data.com/skyline/bnr34/3957-rb26dett/engine/144/15188A/

Looking at the diagrams I don't see double washers. That sounds like an oil leak waiting to happen. The only exception is certain cases where there is a lock washer (split ring) and a flat washer.

[Ben C34]

There is no way .3mm matters for a bolt unless that bolt is very small, like m2 or less.

[proline]

So the two connected washers I'm talking about are labelled 15192F in the 3rd diagram on the page linked to in the response above. The OEM part number is 1518913C00. The two washers sit either side of a banjo but are connected by a strip of copper. As I said above this is for the oil inlet banjo bolt attached directly to the turbo (i.e the where a HKS 0.8mm restrictor bolt would go if needed) not the water/oil tube adapter that bolts to the turbo.

I've measured the amount of thread that will go into the housing and it is 5mm with the 1mm thick OEM washers and only 4.4mm with the new washers. The banjo bolt is M12 - hence my concern.

I've attached a photo to help explain the above showing the OEM washer and the thread depth with the new washers.

Love this forum. As someone who has zero access to GTR expertise and no mechanical background I find the posts here invaluable - thanks.

Lee

[GTSBoy]

That's for convenience of assembly of something which can suck balls to do if you've got to juggle all the parts in a location with poor accessibility.

[Chopstick Tuner]

The thickness difference you mention is negligible. As was said above, the connecting part is for ease of installation rather than needing to hold the inside washer in place while trying to line it up. New pipes with already attached banjo bolts sometimes have a plastic retainer that you rip off once you get the threads started. 

 

They're not that specific, just make sure they're thick enough to actually be crushed and not too thick that it reduces the thread engagement - both unlikely. So just get your diameters right and tighten it up. 

Oh and copper washers should not be doubled up. 

[Chopstick Tuner]

On 02/06/2022 at 9:40 AM, proline said:

So the two connected washers I'm talking about are labelled 15192F in the 3rd diagram on the page linked to in the response above. The OEM part number is 1518913C00. The two washers sit either side of a banjo but are connected by a strip of copper. As I said above this is for the oil inlet banjo bolt attached directly to the turbo (i.e the where a HKS 0.8mm restrictor bolt would go if needed) not the water/oil tube adapter that bolts to the turbo.

I've measured the amount of thread that will go into the housing and it is 5mm with the 1mm thick OEM washers and only 4.4mm with the new washers. The banjo bolt is M12 - hence my concern.

I've attached a photo to help explain the above showing the OEM washer and the thread depth with the new washers.

Love this forum. As someone who has zero access to GTR expertise and no mechanical background I find the posts here invaluable - thanks.

Lee

Just to add, that does not look like the correct banjo bolt. Not a washer issue, that bolt looks too short

[proline]

Thanks for all the replies - very useful.

That's definitely the correct banjo bolt. I've attached a picture of mine and the bolt indicated from the parts page linked to above.

It seems to me to have very little thread engagement but I assume Nissan know what they are doing and it hasn't leaked in the 22 years I have owned the car 🙂

A reduction of 0.6mm (2 x washers x 0.3mm) may not be significant for most bolts but I'm concerned that it is a relatively large amount for a bolt with such little thread engagement.

I'm leaning towards trying to source some 1mm thick washers or annealing the originals but would really appreciate any other comments.

 

[joshuaho96]

On 6/2/2022 at 5:59 AM, proline said:

Thanks for all the replies - very useful.

That's definitely the correct banjo bolt. I've attached a picture of mine and the bolt indicated from the parts page linked to above.

It seems to me to have very little thread engagement but I assume Nissan know what they are doing and it hasn't leaked in the 22 years I have owned the car 🙂

A reduction of 0.6mm (2 x washers x 0.3mm) may not be significant for most bolts but I'm concerned that it is a relatively large amount for a bolt with such little thread engagement.

I'm leaning towards trying to source some 1mm thick washers or annealing the originals but would really appreciate any other comments.

 

Have you considered buying the OEM part? Seems to be pretty cheap.

[proline]

"Seems to be pretty cheap."

Not where I'm based it's not especially when postage is thrown in. The M12 x 18 x 1mm spec washers are pretty rare here - they all tend to be 1.5mm or rubbish quality. Its seems though that that spec is used by some of the motorcycle manufacturers as OEM equipment and I have found a supplier so it looks like that's how I will proceed.