16 replies to this topic

[Artful Dodger]

Hi there,

I want to run airoquip hoses for my oil system, and am using dash 8 unions, so obviously i will need to run adapters in the main oil feed and into the filter housing (basically where the metal oil feed pipe goes from and to)

does anyone know what thread they are or what adapters i will need?

it is an A series block i dont know if they used slightly different threads in the later blocks.

[benpopham]

Hey
I used -6 bits and bobs on mine, and this is what I found in my project file about them..

hoses for oil lines - torques.co.uk
2 x -6AN to 5/8ths -18 UNF Male Male Adapter for oil filter and block
1 x 90 Deg -6AN Female Tubed Hose End 809106 for out of block to hose
1 x Straight -6AN Female Hose End 800106 for out of oil filter to hose
-6 Pro-Lite Hose - 8.74mm ID

This was from one of the swiftune filter housings, but Im sure they are the same.

Ben

[Artful Dodger]

Exellent thanks. So the adapters I will need are -8 to 5/16ths UNF.

You sure? Looking At the one in the filter housing it looks
Like a taper thread? And the one in the block
Looks bigger than 5/16ths

[benpopham]

Yep, thats correct. Iv got 2x 5/8UNF to -6 adapters, one into the block and the other into the filter housing. But like I said, my filter housing is the Swiftune one, so may be a different thread.

http://www.carbonwee...ens_mini14.html
http://www.carbonwee...ens_mini11.html

[Artful Dodger]

Ok thanks! Only issues that there could be is that your engine is the later type and the thread may have changed, but I doubt that, and that the filter head thread may be different, but the worst that could happen is than I have to send them back!

Anyone else have an idea?

[samsfern]

I know the threads are different in the spi filter housing. Can i ask why you didnt just buy the braided oil transfer pipe kit?

[Artful Dodger]

I got an oil cooler with some airoquip ends and hoses cheap (40 quid!) at a show, so I'm binning the cooler
And using the lines. I was going to use airoquip anyway. Because race car:P

[dklawson]

I am curious how you have (2) 5/8-18 fittings in use. I know that one goes in the block where the banjo bolt is normally. However, the one in the filter head should be NPT, probably 3/8 NPT.

The -6 hose probably corresponds well to the size of the original external oil pipe size. However, the smaller the hose, the greater the pressure drop in that hose. If you can use a larger hose, then select one as long as it looks "normal". For example, a -8 hose will not look too much larger than the -6 but it will have a lot more internal area and therefore a lower pressure drop.

[Artful Dodger]

I am curious how you have (2) 5/8-18 fittings in use. I know that one goes in the block where the banjo bolt is normally. However, the one in the filter head should be NPT, probably 3/8 NPT.

The -6 hose probably corresponds well to the size of the original external oil pipe size. However, the smaller the hose, the greater the pressure drop in that hose. If you can use a larger hose, then select one as long as it looks "normal". For example, a -8 hose will not look too much larger than the -6 but it will have a lot more internal area and therefore a lower pressure drop.

he has a swiftune filter head, i thought they would have a different thread! thanks.

so would you say -8 is too big? it was run on a mini before but i dont know the history. its only running an oil cooler so there isnt a huge amount of pipe

[Artful Dodger]

another question!

is UNF the same as BSP??

neither demontweeks or raceparts UK list UNF - JIC adapters..

demontweeks do the JIC to NPT though 8)

Edited by Artful Dodger, 16 December 2012 - 04:44 PM.

[Artful Dodger]

looking on the minispares website its says that

Pre 1992 engines have 5/8" block union and 1/4" npt thread for the filter head.

12A engines from 1992 on have 11/16"UNF block and 11/16 filter head

now i dont know i i can just use these because i doubt that they go from that to a JIC -8. but it gives me what i want to know. BUT, where on earth can i find a JIC to UNF adapter?!?

[dklawson]

Don't let the JIC designation confuse you. It is the industrial equivalent of "AN" which most automotive racing hoses use. JIC will couple with AN but they tell you not to because the thread fit classes are different. That's important on multi-thousand PSI hoses but not so important on engine oil pressure hoses that are relatively low pressure and seldom see pressures higher than 100 PSI.

The "dash" number in a JIC/AN designation specifies the size (through hole) first, including the conical compression features. The actual mounting threads can be anything (BSPP (G), BSPT ®, SAE, UNF, NPT... and probably more). You will not find these at a hardware store but will find them at race supply houses. Do not lock yourself into buying the fittings from an exclusively Mini parts business. There are a lot of different fittings out there in the racing market.

You asked if UNF was the same as BSP. It is not. BSP is a pipe thread and UNF is a straight machine thread. 5/8-18 (UNF) is a straight machine thread slightly smaller than 3/8 NPT. In a pinch you can have a 3/8NPT thread re-cut to be 5/8-UNF. You can get away with this on "low pressure" car systems because 5/8-UNF is a straight thread that requires a sealing washer and does not seal on the threads.

Is -8 hose too big? No. To minimize pressure drops you should use the largest hose possible but at some point larger hose will start to look ridiculous AND the flow will be much more restricted by the hole through the fitting. Consider what you found in your research that the filter head is tapped 1/4 NPT, not 3/8 as I mentioned earlier. The hole through a 1/4 NPT fitting is not 1/4" but probably closer to 3/8" or 10mm (that's just the way pipe sizes run). As such, there is not a real benefit in using a hose much larger than 10mm inside diameter.

I am sure this is as clear as mud. You can use either the -8 or -6 size fittings. If you have not bought these yet I would buy -8 just to minimize the pressure drop. Be advised though that if you are making the hoses yourself from bulk material... cutting the braided hose and installing the end fittings can be a real pain. I don't enjoy working with the stuff and consider it an area where I might have a pro do it for me next time.

[Artful Dodger]

thanks for your help, it has been invaluable.

i have already got -8 fittings and pipes made up, so no issues there

i will phone around tomorrow to see if anyone stocks JIC - UNF fittings.. someone must do, i have seen people run jic fittings with a single adapter:P

[dklawson]

I normally direct people to MiniSpares for parts but you may also have success at Minisport.

Go to either site and search for "cooler". You will find many items that may be of interest. Note first that both MiniSpares and Minisport sell 1/2" inside diameter hose for the coil cooler systems. The common material will just be reinforced rubber. Race shops will have similar material with the stainless overbraid. Both vendors appear to offer straight fittings to go between this size hose and the 5/8" block threads. However, a straight fitting will not have the low profile of a smoothly bent elbow or banjo fitting.

Both offer a 5/8" to BSP adapter for the block and a corresponding BSP sweeping tube elbow that should fit the 1/2" oil hose. Those would give you a nice low profile connection to the block and that only leaves the 1/4 NPT to JIC/AN fitting for the filter head and the mating fitting to go into the other end of the hose.

[Artful Dodger]

Ok thanks. The only issue I have now is that I do already have piping and unions. All earls unions and are -8 JIC.

I can find the NPT to JIC adapters easily but not the UNF to JIC..


I don't think I would get it through a mini store because they don't do JIC adapters, and I can get a discount from
Demon tweaks and race parts UK:)