GUYS, BRILLIANT BRAINSTORM THANKS TO A MENTAL NUDGE FROM SILWORM:

We have a problem with rear apexx seals going bad. We need to monitor the rear rotor more:

Why not tap the hole and install a temp sensor in that location?

 

That is definitely one of the reasons I favor the tap idea. But, if I were you and I didn't have another reason to tap this location, I'd pick another one. I believe that, on the 3rd gen at least, there is already a temp sensor on the rear housing under the oil pressure sender. There are two temp senders, one in the neck and one in the rear housing.

I don't know how the stock setup uses the two of them for certain. I've never confirmed this, but I believe I was once told that the sensor in the neck is the one used for the guage and the one in the rear housing is used as the temp input for the ECU.

 

Opposite, the one in the neck is for the ECU, the one in the housing is the guage sender.

PaulC

 

My set up is not in a 7, but I taped into the upper water outlet (above the t-stat) and routed the hose from the heater to this location. My reasoning being that the water would always be circulating through the radiator as it exits the hotest part of the motor (combustion side of water jacket). I figured I could get better flow through this area to keep temps down.

Down side, it takes longer to warm up - but for race car its not a problem.

 

Hmmm... why run a t-stat at all if you're going to do that? I'm not being facetious.

The stock configuration routes the heater core outlet back to the lower radiator thus allowing the pump to constantly circulate. One of the reasons that I don't want to loop (in addition to simplification) is that I think that there would be a beneficial increased static pressure in the engine generated by the pump when the t-stat is closed which would help reduce localized boiling.

Just a thought.

 

My vote is drill-tap-pipe plug. It will never blow off while your on the track. If you don't know much about tap sizes or reading tap charts thats ok because I've noticed a lot of hardware stores sell "kits" that have the drill bit and tap in one package. Id stay away from caps or anything like that.

 

1/2"NPT is the winner.&nbsp This will work at least on the top fitting - can't confirm for the side one.


-Ted

 

I don't run a thermostat - not really. My thermo has the edges drilled with 6 , 3/16" holes to allow water to flow even when it is closed.

Seems to work well, even in a much smaller engine compartment with a limited radiator size.

 

Just to add a bit more to the caution regarding the hose cap- on a 280ZX I had, I replaced a hose cap 4 times in 10 years.. The package I bought it had two in it, and I'd keep the other one in a convenient location because I knew I'd need it sooner or later.

 

Could you use the coolant nipple as a turbo coolant line?

 

dp

 

The majority of the streetish engines I have had around for a long time all have had that mod at one point or another.
Die Grinder off the steel portion.. then pipe tap the steel/cast remains and then go to Home Depot and buy IIRC (It is late) 1/4" pipe tap for the upper rear pass side that was for throttle body heat.. and 1/2" for the heater core feed portion.
Then a swirl of thread teflon tape and snug into the holes some pipe plugs.
Done.. No leaks no drips no hose clamps.. no pieces of heater hose with Lug bolts in them.. or whatever things people will find to stick in there..

The nice part?
If you want to go back to a heater etc.. you unscrew the plug and put in a pipe.

Not that I would ever want to put street stuff BACK INTO a car... eek.. that is sacrilegious.. I mean I have heard of this.. "Restore" thing.. but have not seen it yet.

 

how do yuo prevent the chips/metal from going into the coolant if you drill and tap while teh engine is isntalled in the car?

 

i know people dont like it, but what about some JB weld, then put a nipple over it? I would think JB weld would block the hole quite well. Because if you try to tap it on the car, you will most diffenetly get shavings in the coolant.

 

It is a trick.. but it is easily done.

Lightly oil or grease a dowel rod that you buy from the local hobby store.
Then lightly tap it into the hole so it is firm.. almost snug.. but you can still pull it back out.

Using your Air grinder, or Dremel.. cut off JUST the metal portion... It requires a gentle touch so you cut off OLNY the metal and not through the dowel.
Then when you have cut all the way around.. The grease/oil prevents and tiny particles from getting into the water system.

Then with the rest of the water system closed off put a hose into the opening of the water filler with it turned on lightly..
This will cause a small jet of water to come OUT of the hole you now have.
Then take your Tap and carefully start threading it into the hole till you are deep enough to put the plug in properly.
When you back it out it will allow any thread particles to jet out the flutes in the tap. (As it does when threading it in)

DO the same on the larger heater hole but use a larger dowel. (After plugging off the small hole)

It works nicely.. And yes when you start tapping you WILL get wet. It sprays out a bit when you first start cause of the tightness of the tap.
Dont get all carried away and have such high water pressure that it blows the tap out of your hand. Just enough so you are keeping a flow that is coming up out high enough to prevent the particles from dropping into the coolant passages.

OH yes.. go back and forth A LOT with the tap to keep making your cuts smooth and the particles small. The water will keep the tap cool and lubricate it as well... of course not as well as tapping fluid.. /shrug

Thats how I have done it... your mileage will vary with the skill and ingenuity level of the applicant..

 

thats seems alittle to risky for me to try, but are there any doubts on JB weld and a nipped over it?

 

Ehhh.. if you dont feel comfortable with a mod.. DONT DO IT... It is really simple.. If you have thoughts that is may not go well.. thats a good reason NOT to do it.

JB weld? Ehh.. not something I have much experience with.. I imagine it could work.... But I think I used it on a goKart in Jr High.. and it didnt work too well IIRC... but I dont really remember what I used it for at this point.. it was a LONG time ago. Prolly.. well.. more than 20 years ago.

I would try it by "welding" a cap of sorts over the larger heater pipe.. that way if it doesnt work you can fairly easily chip it off afterwards.

 

spin have u actually done that procedure to the water pump housing? Cause i would think the metal shaving would be heavier and easily fall

 

i mean rear iron not water pump housing

 

Yep.. Just make sure that you have decent water pressure etc. so it is jetting out etc. while using the tap. AND make sure not to get all heavy handed and do all the cutting at once. Cut a 1/4 turn at most.. then back off.. then 1/4 then back off etc..

As I said.. if you have reservations.. DONT DO IT.

/shrug

Didnt have any problems when I did it on the old assembled motors.. but again.. I was overly careful and made sure things were right before starting to cut thread.

I know that some on the forum (SHift Mad Quick Yo!) may think that since they read it they can do it... and get out a air chisel to do a port.... OR they can do a 20B swap for 5K out the door.. turn Key! And make 1K hp to boot!

Then again there are many that cant.

Most are in the middle in one way or the other.. from very little wrench exp.. and good motivation.. to Much too much grease under the nails.. and not as much motivation..... but years of Exp.

Then there are the shift mad quicks.. and the Rick Engmans.. I think we are all in the middle.. one way or the other.

If you feel confident.. give it a whirl. Worst case scenario.. you do something like break off the tap in the iron housing.. and Now you have a good reason to port your motor! Oh yeah.. I guess if you were heavy handed with the tap.. and brute forced the thing.. you could crack the iron. But again... that goes to the exp thing..

If you are comfortable.. go fer it. If not.. buy a 5 buck hose and run it to the waterpump.