Offical 1FZ head gasket debate (1 Viewer)

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e9999 said:
If you clean up the surface real well, you could then calibrate your pyro against those readings and now have much better numbers. Of course, you'll have to keep the surfaces clean to measure anything accurately later on too.

Actually e9999 for pyro readings you want to measure the BBR (Black Body radiation) NOT any reflections so dirty (black non reflective) is what you want not clean.
 
MH_Stevens said:
Actually e9999 for pyro readings you want to measure the BBR (Black Body radiation) NOT any reflections so dirty (black non reflective) is what you want not clean.

sorry, not quite correct.
 
Is anything useful output from the DIAGNOSTICS terminal under the hood as opposed to the OBDII port? Surely there is a gauge that can be calibrated to run from the stock temp sensor to parrallel the idiot gauge. MORE RELEVANT to this thread is ther not a contact temperature sensor that can be attached to the head at the "weak spot" on #6 or CO sensor that go in the coolant? Has anyone ever used the coolant dyes that detect CO? Are they compatible with Toyota Red?
 
michael there are several options but no silver bullet yet. we lack someone with the time and skills to formulate a solution.

there was a thread a while back about changing the resister in the stock gauge to make it work properly. It got as far as someone (raventai?) graphing the resistance curve of the stock gauge and establishing that the stock gauge is the same original manufacturer as and is very similar to the gauge used in a Miata which has been successfully modded to address the same issue by miata folks. The next step is for someone with electrical skills to take one from an LC apart and start swapping out resisters and calibrating. If someone can get it to work accurately within the modest rotation arc permitted by the factory gauge then I among many will implement such a mod. I am not skilled enough to design it though and best i can do would be to chip in for the costs of someone who did.

The hks unit noted above by turbocruiser taps off the factory temp sensor. It also costs over $200 and looks like a piece of junk imho.

Cheaper and better looking is the greddy bung plus a mechanical gauge in the A-pod mount approach (and a manual switch if you want an aux. fan). I see no major issue with getting a temp reading from the rad hose area. It is all relative after all and you will still see the major fluctuations. You can also calibrate it to the ECU output by hooking up an OBD2 scanner and comparing the pod gauge and scanner readouts.

for you folks with OBD2 you could in theory put in a carputer or an obd2 adapter for your laptop and get all kinds of nice readouts. Us folks with OBD1 aren't so lucky.
 
e9999 said:
sorry, not quite correct.

e9999999999999

I'm all ears if you would like to elaborate
 
powderpig said:
Well it is good to know that you turbo with the Geddy stuff get a good steady reading, with out too much spiking. I would of thought different with the type of flow through the hose. Thanks for the heads up. I usually only take offence when some one challanges me at work (Big smile). These formums are for discussions and for every one to contribute (except John Shotts (big smiles again)). Any how no one person can try everything and their is more than one way to skin a cat. If my dad computer is up I will keep looking in if I can. later robbie


Thanks Robbie, just to clarify, I would never ever ever presume to post a challenge to you ... you have more mechanical experience, expertise, skill and savy than I could ever hope to have. I was only wanting to share the experience I have had here with my aftermarket gauge and more specifically exactly where i installed the gauge. Furthermore, at first I was having a hard time thinking through why my gauge DID NOT spike as I assumed it would. It was Beowulf who explained the thing to me based on how far from that pipe the gauge sensor was mounted and based on that fact how the coolant streams get the chance to mix together. Anyways, I wanted to word my first post really really really well so it was not worded as an argument and I hope it did not read that way but anyways thanks for the follow up. :cheers: :cheers: :cheers:
 
hobbes said:
e-

I dunno. Those things are pretty simple. I'm more worried about the gauge readings.

Correct me if I'm wrong, the temp sensor is fine but the TEMP GUAGE dumbs down the readings. IOW, doesn't the computer get its (accurate) reading from the same sensor? I'd love it if someone could figure out a way to make the OEM gauge useful. I think RT put out a call for a gauge to play with, but I'm not sure if he ever got one.

Actually there are 3 temp sensors on the left side of the engine. one is the 226° switch that turns off the AC compressor, it comes back on at 217°, there are two other sensors one for the ECU and the other for the gage, no interaction between the ECU and gage circuits.

I think the numbness is built in the gage itself not the sensor. As Semlin said the Miata has a similar gage made by the same company and the mod is in the gage. Unfortunately their gage circuit is different enough that their mod will not transfer over directly but hopefully can be a guide for someone to come up with the 80 series mod.

I have not been able get a gage yet, I tried to get the gage from the 95 being parted out but the cluster was already spoken for.

Semlin I think it was Rich and Photoman? that did the sensor curve, the first was in water (up to 212°) the second was done in oil to got the full curve, I have pulled my gage out took pics and made a schematic of the circuit wile I was changing bulbs in the cluster but could not have it out long enough to go any further.
 
hobbes said:
e-

I dunno. Those things are pretty simple. I'm more worried about the gauge readings.

Correct me if I'm wrong, the temp sensor is fine but the TEMP GUAGE dumbs down the readings. IOW, doesn't the computer get its (accurate) reading from the same sensor? I'd love it if someone could figure out a way to make the OEM gauge useful. I think RT put out a call for a gauge to play with, but I'm not sure if he ever got one.

Actually there are 3 temp sensors on the left side of the engine. one is the 226° switch that turns off the AC compressor, it comes back on at 217°, there are two other sensors one for the ECU and the other for the gage, no interaction between the ECU and gage circuits.

I think the numbness is built in the gage itself not the sensor. As Semlin said the Miata has a similar gage made by the same company and the mod is in the gage. Unfortunately their gage circuit is different enough that their mod will not transfer over directly but hopefully can be a guide for someone to come up with the 80 series mod.

I have not been able get a gage yet, I tried to get the gage from the 95 being parted out but the cluster was already spoken for.


semlin said:
michael there are several options but no silver bullet yet. we lack someone with the time and skills to formulate a solution.

there was a thread a while back about changing the resister in the stock gauge to make it work properly. It got as far as someone (raventai?) graphing the resistance curve of the stock gauge and establishing that the stock gauge is the same original manufacturer as and is very similar to the gauge used in a Miata which has been successfully modded to address the same issue by miata folks. The next step is for someone with electrical skills to take one from an LC apart and start swapping out resisters and calibrating. If someone can get it to work accurately within the modest rotation arc permitted by the factory gauge then I among many will implement such a mod. I am not skilled enough to design it though and best i can do would be to chip in for the costs of someone who did.

Semlin I can find the time and although not "professional grade" have enough skills for small circuits like this where I cannot get lost, the part missing is the parts to work with. No need to chip in used parts wont be overly expensive just hard to find.

I think it was Rich and Photoman? that did the sensor curve, the first was in water (up to 212°) the second was done in oil to got the full curve, I have pulled my gage out took pics and made a schematic of the circuit wile I was changing bulbs in the cluster but could not have it out long enough to go any further.


After reading about the Miata mod the arc of the gage is not a problem, you actually get to choose the range, you can have a wide range with would not show detail but would nto pep out hot or cold. Or if you are only interested in a particular set of temperatures then you can set it up for that and get finer gradation.
 
I'm going to get a scientific gauge from my microbrewery. No electrical sensors, the type where you just bolt or weld a metal wire to the spot to be measure and run to a big ass 4" dial in the cab. What's the best place to put the sensor?
 
MH_Stevens said:
I'm going to get a scientific gauge from my microbrewery. No electrical sensors, the type where you just bolt or weld a metal wire to the spot to be measure and run to a big ass 4" dial in the cab. What's the best place to put the sensor?


no electrical sensor but it's a metal wire? what could that possibly be? A hollow tube with a gas? Or you're counting on making a thermocouple with the wire and engine metal? Most temperature sensors (thermocouples, RTDs, Thermistors) work on electrical principles.

btw, keep in mind that if you have a post 95 you can get all these numbers and many more out of the OBDII with a laptop or PDA. That for sure is the route I'm taking!
 
RavenTai said:
Actually there are 3 temp sensors on the left side of the engine. one is the 226° switch that turns off the AC compressor, it comes back on at 217°, there are two other sensors one for the ECU and the other for the gage, no interaction between the ECU and gage circuits.

I think the numbness is built in the gage itself not the sensor. As Semlin said the Miata has a similar gage made by the same company and the mod is in the gage. Unfortunately their gage circuit is different enough that their mod will not transfer over directly but hopefully can be a guide for someone to come up with the 80 series mod.

I have not been able get a gage yet, I tried to get the gage from the 95 being parted out but the cluster was already spoken for.




Semlin I can find the time and although not "professional grade" have enough skills for small circuits like this where I cannot get lost, the part missing is the parts to work with. No need to chip in used parts wont be overly expensive just hard to find.

I think it was Rich and Photoman? that did the sensor curve, the first was in water (up to 212°) the second was done in oil to got the full curve, I have pulled my gage out took pics and made a schematic of the circuit wile I was changing bulbs in the cluster but could not have it out long enough to go any further.


After reading about the Miata mod the arc of the gage is not a problem, you actually get to choose the range, you can have a wide range with would not show detail but would nto pep out hot or cold. Or if you are only interested in a particular set of temperatures then you can set it up for that and get finer gradation.


Raven,

In terms of choosing a range for the gauge to respond within how about creating a seperate circuit altogether wired in parralell to the gauge with a switch so that the flick of the switch would determine the range of the gauge? This would allow you to see when the engine gets warm on those bitter cold days and when it is almost overheating on those deathly hot days. Would this work?

Snow
 
HG failure rate is about 15% here per the poll....
 
snowcruiser said:
Raven,

In terms of choosing a range for the gauge to respond within how about creating a seperate circuit altogether wired in parralell to the gauge with a switch so that the flick of the switch would determine the range of the gauge? This would allow you to see when the engine gets warm on those bitter cold days and when it is almost overheating on those deathly hot days. Would this work?

Snow

Maybe, right now I am assuming we will be able to get ranges similar to this,

http://www.gravitydesign.net/saturn/miata/94-97MTGLP.cfm

Personally I would rather have the tighter range, pegged on C it has not warmed up yet , and have a low max, once it get above a certain temp all I need to know is it needs to be shut down. But if you spend quite a bit of time in cold weather I could see where you might want the wider range,

Having a switch to switch ranges might be neat but I would not recommend it, more parts to install more parts to fail, more confusion about what the gage is saying etc.

But we are getting ahead of ourselves, nobody is yet working on this mod.
 
e9999 said:
btw, keep in mind that if you have a post 95 you can get all these numbers and many more out of the OBDII with a laptop or PDA. That for sure is the route I'm taking!

What SOFTWARE/CABEL CONNECTION are you going with? Seems your right about this being the way. I'll follow.
 
RavenTai said:
But we are getting ahead of ourselves, nobody is yet working on this mod.

I wouldn't say NOBODY...

A friend loaned me his laptop with the OBDII + Toyota software from www.obd2.com (ease diagnostics) and I'm experimenting with how accurate the temp sensor is (handheld pyro vs. OBD II readout).

With at least that data point we'll know how accurate the temp SENDER is. From there I can map the voltages over time and compare with the OBD II temp reading over time to establish the relationship. Then tear into the gauge and see what needs to be done...

Of course it's slow going with a 1 year-old and a full-time-plus job so don't hold yer breath! But there is SOME progress being made...

:cheers:
 

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