Threaded fitting on Koyo radiator

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smagnotta

smagnotta

SuprSal
Apr 5, 2005
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All,

I purchased a Koyo 53mm Radiator, part number [KOYO-R0171]. Long story short, my previous radiator was an aftermarket one in which the stock oil cooler was removed and the 2 oil lines routed to the radiator.

I also just purchased an aftermarket oil cooler and hoses to connect these 2 oil lines. My question is about this new Koyo radiator. Upon inspection, I could see and understand where all the hoses and lines plumb into, except for a large threaded opening at the bottom of the radiator near the drain plug. Is this for oil or tranny lines to connect to for cooling? What is this the input for? Anyone know what the fitting size is? My other radiator does not have this large threaded hole.
 
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suprastanger507mgte

2x88+2x89+1x91+2x92=ME
Apr 5, 2005
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smagnotta said:
All,

I purchased a Koyo 53mm Radiator, part number [KOYO-R0171]. Long story short, my previous radiator was an aftermarket one in which the stock oil cooler was removed and the 2 oil lines routed to the radiator.

I also just purchased an aftermarket oil cooler and hoses to connect these 2 oil lines. My question is about this new Koyo radiator. Upon inspection, I could see and understand where all the hoses and lines plumb into, except for a large threaded opening at the bottom of the radiator near the drain plug. Is this for oil or tranny lines to connect to for cooling? What is this the input for? Anyone know what the fitting size is? My other radiator does not have this large threaded hole.
Click to expand...

You may have bought the wrongKOYO>
You must have picked one up for a 1JZ equipped Supra, and that threaded bung is for the Hydraulic Fan's temperature sender.
You can block it with a similar threaded bolt with some thread tape or return and get one for a 7MGTE equipped car.

Koyos make them for both.
 
smagnotta

smagnotta

SuprSal
Apr 5, 2005
202
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WashPa
suprastanger507mgte said:
You may have bought the wrongKOYO>
You must have picked one up for a 1JZ equipped Supra, and that threaded bung is for the Hydraulic Fan's temperature sender.
You can block it with a similar threaded bolt with some thread tape or return and get one for a 7MGTE equipped car.

Koyos make them for both.
Click to expand...

I checked and the web site said 1JZ, but it is compatible with the 7M with minimal mods. It was the only one listed for the MK3 Supra in most of the Internet listings.

Yes you are correct, it is for the hydro fan on the 1JZ.

And I forgot to ask: does anyone know the size of the fitting by chance? I searched the Net and there is not much info on the specs for any particular model, just basic info. Again, this is the fitting size for the Koyo Aluminum Radiator JZA70 Supra fan hydro bung -- the large threaded bung next to the drain plug. I would like to block it off.
 
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supra90turbo

supra90turbo

shaeff is FTMFW!
Mar 30, 2005
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There is NO koyo radiator for a 7M application. Only 1JZ, and the only difference is that threaded bung on the lower tank. Plug it and go on your merry way.
 
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CarlosPTR210

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Apr 5, 2006
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I install it few weeks, I only install a extra water temp sensor that I have there, but the auxiliary fan will hit the lower screw for support, so you need to modify it, I hit them will a hamer :evil2: , and then use metal pice with holes and that it!:biglaugh:
 
smagnotta

smagnotta

SuprSal
Apr 5, 2005
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WashPa
Thanks for the help guys. Yes, the only thing I've seen on 5 or 6 sites is a Koyo for the 1JZ, not the 7M. I got it off eBay for $320 + $40 shipping, so it was not that bad.
 
smagnotta

smagnotta

SuprSal
Apr 5, 2005
202
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WashPa
Some suggested to try using a spare water temperature sensor. I tried one and it began to thread and then stopped. It's not a fit.

I checked with Champion and Jeff Watson said a 94 Twin Turbo temperature detection switch would work. It's a bit overkill since that costs $65 new.

Couldn't I just get some kind of thread measuring tool and see what I need and then just purchase the threaded plug or bolt at Lowes or Home Depot/similar store?

Or should I go to NAPA with the radiator? <-- might be the way to go
 
smagnotta

smagnotta

SuprSal
Apr 5, 2005
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WashPa
OK guys to finish this thread out, I received an excellent email and picture from Larry_A. The red arrow points to the hole in question. Larry_A used an old cold start injector time switch to plug that hole (gold part in the picture). It's the sensor on the thermostat housing closest to the cam gears. The size is 16mm x 1.25 pitch (see details in the picture). A 5/8" bolt standard size is close but be careful. I went to Lowe's, Home Depot and Auto Zone with no success. They had a 16mm x 2.0 bolt that started to thread and then stopped. With this being aluminum (very lightweight and soft metal), it is not a good idea to force anything. Some have also used an 89+ coolant sensor they had to plug that hole. There's one on the thermostat housing. This is all good if you have these extra parts lying around. If not, you can ask someone on the list for a used one, or try to get a 16mm x 1.25 bolt (approx 1.5 inches long). Another possibility is a temperature switch from a 1994 Twin Turbo Supra. I would go on supraforums.com and ask someone for that one. A final possibility is to get someone to weld that hole shut, but this is aluminum so I am not sure if that is an easy task.

Here's a pic:
fit.jpg


Thanks again to Larry_A. You can visit his website at http://oldschool.supracentral.com. His tagline (avatar) is "Old School".
 
smagnotta

smagnotta

SuprSal
Apr 5, 2005
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Nice pic thanks. My fan shroud is making it tough for this install. Obviously because this rad was made for the 1JZ. Do you use the 7M fan shroud with the Koyo?
 
Mr.PFloyd

Mr.PFloyd

I am the Super Devil
Jun 22, 2005
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smagnotta said:
Nice pic thanks. My fan shroud is making it tough for this install. Obviously because this rad was made for the 1JZ. Do you use the 7M fan shroud with the Koyo?
Click to expand...
well as many may realize due to half of them breaking all the time, with a bigger radiator, a fanshroud isn't really necessary... It's only active at idle anyway.
 
drbowser3

drbowser3

The Doc is in...
Jan 17, 2006
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Tampa,FL
I would reccomend that you NOT use the fan shroud. The Koyo is lacking a few of the mouning points, and also sits higher. I put my KOYO in, when less that a mile, and the fan and shroud had a fight. KOYO lost the battle, shroud broke and stabbed a hole in the radiator opening up 5 tubes.
 
CRE

CRE

7M-GE + MAFT Pro + T = :D
Oct 24, 2005
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Denver, CO
For those who are planning on getting a Koyo. Subaru radiators (I'm not sure if it's all models and years) use a 16mm x 1.5 nylon drain cock. It's a perfect fit and no worries about different metals reacting and they've got a rubber washer built into them. The one I picked up matches the smaller one which came with my Koyo.




EDIT: Okay, got my Koyo in today. Not a terribly difficult task, but tedious. The fan shoud fits just fine is you cut down the lower mounting bumpers as shown:

fit.jpg


I've got plenty of clearance. Also, I'm damned happy with my new rad!!!
 
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