Offroad-Express

It's the 3 litre diesel 1KZ motor.
Just trying to do a wee job without dropping my top hose off yet.
Does anyone know the inside diameter of the top hose (or the diameter of the top hose radiator connection, which is the same thing)?
I've bought a VDO water temp gauge and may set it into the top hose with an adapter that has the threaded hole to suit the temp gauge sender (or will the adapter make the top hose too stiff, and cause problems with the motor movement?).
I can't see under the manifold area very well, but there 'may' be a plugged hole already in the head, about 1/2 way back.
There is a threaded hole already in use at the passengers side front of the head, but there does seem to be another similar one back a bit from that.
Is that OK to put the sender in there? That's assuming I can actually get to it easily.
Thanks for any info.
I would prefer to keep the original gauge working too, so don't really want to just bung my new sender in the original (at the front) hole (I know, I'm just being difficult).

On my 185 surf which should be much the same, I drilled and tapped into the outlet on the top of the motor. As there's a blank there waiting to go.ill get a picture and upload later

Alistair

Thanks Alistair.

Can you use the same port I did?

viewtopic.php?f=46&t=42494&p=438221&hilit=Auberins#p434843

Thanks stu_71,
That's what I 'thought' I could see lurking back there on my head.
I thought it was a bung, and had hoped it would lead into the water jacket.
I notice that the alloy connector that attaches to the head (for the top hose to connect to) has a sort of moulding that looks a bit like an unformed attachment point.
This is the connector where in any other motor you would look for a thermostat normally!
There is a hole with thick walls with no thread, and the hole is blind.
I may be able to drill that through, and tap a thread (1/8" NPT) into it.
That would make life a bit easier if I can borrow a tap from some friendly local.
VDO gauge is yet to arrive.
I may mount it in a pod on top of the dash by the window pillar, or biff the dodgy clock and fit the gauge in there.
Cheers.

Dang!
Or words similar to that.
I can see that wee bung back there along the head, about 1/2 way back under the intake manifold, but mine has a welch plug in it (I only had to use a mirror, and torch, and stand on my head to see it).
So, no threads, and it's in a sod of a place to get into with a tap unless I drop the manifold (too much drama doing that).
I do have an M14 tap set, and that looks like being OK to thread into that wee housing which attaches the top hose to the CH.
Then get an M14 to 1/8" NPT adapter and I should be all sweet.
Whipped over the hill to Havelock today and no signs of heating issues, but it was only really a light test to see if I had done a reasonable job of the viscous hub rebuild.
No drama, so all good. Standard Toyota temp gauge never moved, but then, they never do move much anyway.

Sounds like you've got a plan...I think I tapped mine to m16 by memory.was a few years ago tho.

Thanks skidmark,
Yep, that's the wee spot that I thought could be drilled and tapped.
It seems to be way off centre though so I'm wondering if it is possible to drill through too far and get into the sidewall of that housing (and weaken it)?
Drill a hole through of course just big enough diameter to let the sender unit tip protrude through into the water.
I only have the 14mm tap, and at a 'quick look' it seems to offer enough bite to cut a good thread depth with.
I'll get the vernier out tomorrow and have a decent measure up.
Your housing seems to have been made 'fatter' than mine where you cut the thread.
My housing already has a hole formed down into it at that spot, but it's a dead-end hole. There are little 'walls' around the hole in mine, whereas your sender unit seems to sit higher up than mine will.
Did you have an already formed hole in yours or did you have to drill it all out yourself?
I figure cut the thread down into the already formed hole until I reach the bottom (about 15mm or so depth), then when thread is cut I'll drill the small hole through the bottom of the hole, into the water flow.

I just ran the big tap into it that fitted the adapter, the just drilled the hole In the bottom through. Sender sticks up a bit, but reads fine. By memory didn't even drain the water

Well, all sorted.
Tapped out that blind hole to M14 x 1.5, then drilled the bottom of the hole through into the waterway.
Did the final part of the drilling with a well greased drill bit to allow the metal swarf to stick to the drill and not fall into the waterway.
Kept the radiator cap on and so lost only about 1/4 teaspoon of coolant.
Then bunged in a brass adaptor that allowed the 1/8"NPT sender unit to screw in.
All good, and works well.