Glenn has done tons of research on this and we are both about to the point of have custom machining done.

Autometer guages have a sending unit that is 1/8" NPT.
An LS1 motor has ports machined in, but are 12x1.5 metric.

Sure there are adaptors, but the wall is so thin the adaptors twist off with MINIMAL torque. And by that, not enough to crush a seal enough to prevent a leak.

Why don't they make a 12x1.5 sender?????

The stock sender ohms out WAY different ... almost 1K ohms lower than the AM.

What gauge is that?

Autometer temperature guages

SW has the same NPT 1/8 thread. They sell adapter kits, but should, as noted sell the real deal.

Steve

Autometer has a adapter that fits in place of the plugs in the head and block. It looks like the 1/2" one that comes with the gauge, except it is metric. I removed the plug in the block and put the adapter and sending unit in just as if it were a sbc. {except it was metric}

Monday I'll go to my friends shop and get the part # for you.

...two words....

MECHANICAL GUAGES!

I know Randy ...

Mike, the wall is SOOOO thin, that any torque at all will snap the things off.
If not going on, they will definitely coming off.

Autometer needs to supply a 12x1.5 sender ....

I think we are talking about two different adapters. The one I used is a part #2268 and it is a 1/8" to M16-1.5. It fits in the large ports of the block {there is one behind the alt, and one at the rear of the block} I am seeing now that you want to use the small port in the cooler adapter above the oil filter. The 2268 fits in the head plugs, if you are going for water temp. It is the same size as the plugs, with a 1/8" hole tapped in it.

how does that solve the problem of putting NPT parts in METRIC holes that are very close in size?


and just for an FYI - i said "F" it, and pulled the water pump, drilled a hole just to the left of the T/B on the round part of the water pump that faces up. tapped it 1/8" NPT and put a temp sender there. i figured that was the bast place to look @ water temp as thats where the water leaves the pump to go to the radiator so it would be the hottest water.

....OK.....one "word"....

LT1



....but seriously, it sounds as if the DO make an adaptor, but it is weak in your experience....How tight are you tightening the thing????? Are you using any sealers, teflon tape, etc?

I can't imaging tightening things so tight the fitting would break.... .....my first Autometer guages were plastic tubing and cheap little compression fittings.....never leaked....just melted the tubing in the Datsun!

They would snap before a crush washer was deformed ...

1.....would....or HAVE?

2. Don't know much about electric guages.....ALWAYS use mechanical.....except for the P.O.S. electric gas guage I put in...but to my knowledge the way they are put into the block, head, etc. shouldn't be different....I have never had a guage sender with a crush washer.....are you sure you are using the proper application?

...don't know....just a thought...

OK....got off my lazy butt and looked at one....

Looks strong enough to me.....have you contacted Autometer about them? May be defective.....can't imagine needing enough torque to snap it!

a M12x1.5 male metric adapter w/ a 1/8" NPT female has a .030" wall thickness. how tight do you think it needs to torqued till it fails?

....that answers THAT question.....

.....how can you judge a part that you haven't tried???? Reading a parts specs on a website, or catalog is no way to come to that conclusion......Autometer is a VERY GOOD company in my experience.....have had ZERO problems in two race cars (tons more if you count the ones I have worked on not just owned).....the little plastic tubing event aside....If they make the adaptor....probably thousands in use....my guess is it probably works.....

Not trying to be an A$$, but why not spend $5, get one and see for yourself if it works.....

o.k.- sorry, i wasnt clear. i have had this part in my car. the 2nd time i installed it, it broke into the head. it wasnt made by autometer as they (autometer) only make a M12x1 (not 1.5) and will not work. also, the hole though the adapter must be large enough for the tip of the sender to exstend through (about 5/16" diameter) so no matter the manufacture, a M12x1.5 threaded part w/ a 5/16" hole in it will only have .030" thickness from the valley of the threads to the inner wall of the part. i even looked into having a local machine shop take a M12x1.5 male that had a -4AN male on the other end that was made of steel. told them to mill off the -4AN side, drill out the fitting to accept the tip of the sender and tap it 1/8 NPT. i told them i knew it was gonna be thin and don't worry about destroying it in the attemp to made it, that i was willing to accept the loss of a $10 adapter plus the machine shop bill. they called me back and said that they were so sure it was gonna break that they wouldnt do it or take my money to try it.

as mitch said, i've done the leg work on trying to make these senders work w/ existing holes.
by the way, that temp sender is a 12mm socket size. thats the perfect size to make a M12x1.5 sender from. 1/8" NPT is like only a 64th of an inch smaller.

OK....I get it now....sometimes I am slow....

Sounds like one solution....not the most fun solution I might add....would be to take the head, and have the hole enlarged and put in the "larger" metric size so you can get the stronger adapter mjf454 is talking about...or hell convert it to the larger npt thread for greater access to adaptors....

have you thought of that?

well thats an o.k. idea, but keep in mind, if that head ends up on the driver side, then the stock temp sensor will not fit in that hole. the stock temp sensor is important to the computer for open loop/closed loop and proper fuel maps chosen by temp. so yes, i have thought of that.
i think my solution to tap the pump was the best. my temp reading changed 15 degrees by moving it off the pass head and to the water pump.

I put my water temp sender in the block, just above the starter. It was a lot easier for me than trying to get to the one in the head, with the headers in the way. Although this whole mess was quite a thread drift from Mitch's question of why don't they make the proper sending unit in the first place. Especially since all new cars today are metric, and have been for long enough to make a new sending unit.

You can contact Auto Meters service tech support department for a 12x1.5 adapter that does not break. if using an Auto Meter short sweep electric temp gauge, they will sell you a adapter and sender for $18.49 and free shipping to the US. If using a Auto Meter Cobalt or C2 full sweep, the adapter only is needed with no new sender for $12.00. I have installed several with great results. The replacement sender does not have an extended probe so the adapter can maintain a thicker wall thickness. It is also not in the way of headers.

Interesting info and welcome aboard!

Where to install the oil temp sender??

I note Cory's suggestion to use the adapter w/short sending unit. It'll solve the problem regarding the use of the water sending unit somewhere. (I place the water sending unit behind the starter motor and it works like a chmap!!) But my problem is where to place the oil temp sender.

This is what I did: I installed the oil temp sending unit in the top hole of the LG adapter plate. The headers are close, very close. They're SLP and actually had to be dented in at the spot where the header tube would've interfered w/the adapter itself. Installation of the adapter plate would've been impossible unless the header tube was dented or the adapter plate was gound down and the hole welded!

During the track event the oil temp sending unit must've become overheated from the close proximity w/the header tube. The oil temp gauge was pegged! A totally useless effort!

It couldn't be the true temp as the water temp was fine.

Where's another place to spot the oil temp sending unit? I'm tempted to just drill away at the oil pan, but I don't like the idea of metal shards ending up in the pan. Something my mother told me about mixing oil and metal filings causes me to hesitate. With my luck, I'd end up drilling thru the oil pick up or something else requiring the removal of the engine!

IAE, short of that solution, is there another spot to mount the oil temp probe so its submerged? How about a "T" fitting between the braided hose and the LG Radiator? Anyone have feelings about that despite it's so removed from the engine?


What a headache!

Steve

I took Cory's advice and called Autometer tech ...

With the information given in Cory's post and in front of me, the AM Tech guy didn't have a clue what I was talking about.

He said they had some in prototype and were extremely expensive, but nothing was available to the general public.

I wound up going to a local hydraulic supplier and fining a fitting that had a 20 x1.5 end on it, cutting off the opposite end and tapping the 1/8NPT thread into the altered fitting.

Found a combination of seals and O-rings and sealed it into the oil level sensor port on the pan.

Maybe you can SELL your solution to AM...to better serve THEIR customers...

That's strange. I was in contact w/Cory and he sent me one. Its a nice short temp probe w/a large 12x1.5 metric to 1/8th NPT adapter. It is sturdy as the probe doesn't extend into the adapter. That was, after all, the shortcoming w/the adapters for the long probes. It is only available directly thru AM. If anyone needs one call 'em direct and speak w/Cory. That's how I obtained mine.

IAE, I need a place to put the temp adapter other than into the LG Adapter.


Steve

It's a mistake to assume that. I've seen 300+ oil temps with water temps below 200 (both measured on their way into the engine).

The gauge was pegged at the 320* limit. I find it hard to believe the oil temps could've been that high. Especially, w/the LG radiator and oil cooler combo and a 160* stat? The water temps were ~200* and the temp gauge was normal given the flogging I was giving it!

Anyone else ever seen temps that high w/the LG setup?

Steve

http://frrax.com/rrforum/index.php?act=ST&f=5&t=2027

Well, if such temps are normal, shouldn't we be in need of a 400* gauge. What use is a 320 or 330 gauge if it gets pegged?

Steve

You're supposed to back off before it gets that high.... My gauge goes the 340 but the highest I've ever let it get was 310.

BTW, I'm not saying there's no way your headers could be causing a problem with the gauge--just not to assume that it is and burn up your engine.

I use an Auto Meter Cobalt full sweep water temp gauge and love it; best of both worlds: full sweep like a mechanical gauge, yet the ease of installation of an electric gauge. This gauge is actually more "electronic" than "electric" since it uses a microprocessor to read the sensor, then drives the needle with a stepper motor.

I got the necessary adapters from Auto Barn, however I didn't use them. I first tried the water pump location, but didn't like that because you don't get a temp reading until the T-stat opens. So I moved the sensor to the head, but did not use any of the normal ports. Instead, I took out one side of the bubble tube, then drilled and tapped the hole for the size of the sensor itself. This way I didn't need any adapters, plus the sensor is in the head for the best readings. I can post some pics if anyone is interested.

Elaborate on that a bit. Not sure I follow your reasoning.

I use a 160* thermostat and the guage begins reading at 140*. I can see the guage come up very slowly, not a jump all at once to 160*, as if the thermostat just opened.

Did I misunderstand something in your post?

My gauge starts a lot lower, at only 100*. Anyway, with the sensor in the water pump where I had it, the water apparently didn't circulate over the sensor until the T stat opened, then it did shoot up very quickly to 160. (I have a 160 deg T stat also.) With the sensor in the head, the temperature comes up smoothly. You really wouldn't see this problem with the stock gauge either since the stock sensor is also in the head. BTW, the metal is very thick in the location I used, so it was easy to get a tight fit. It's also a very accessible location, you just need to have the nerve to drill and tap the cylinder head.

The Autometer gauge tracks EFILive from 100 deg F and up now. For the other head, I just cut the mount off the bubble tube and welded the hole closed, then reinstalled it on the head to plug the hole.

For everyone bypassing their throttle body, they could just as easily plug the bubble tube Y and dispense with the exta hoses. If you ever need to burp the cooling system, you can just loosen the mount bolts on the bubble tube. The tube is much too small to make a significant contribution to engine cooling.

Here's a pic:

I was curious how the gauges would read off the track and took the car out onto the street. Ambient temp was around 85* Temps driving around in a "spirited fashion" on the street:

water-- 195*-200*

oil------- 220*

Seems in line w/others. Now I don't know if the pegged 320*+ on the track was wrong. As Jon stated, it may have (unfortunately) been accurate!! OMG! I wonder how much extra that pegged needle was trying to tell me?

I wonder if the mech hooked the lines up correctly? Front line on the engine adapter goes to which radiator opening?

IOW, which engine oil hose is the outlet to the radiator -- front or rear?

Regards
Steve

The inlet of the radiator's heat exchanger is supposed to be the bottom one so that the oil fills up the exchanger and pushes the air out.

But which line from the engine adapter plate is connected to the lower radiator oil port? Front or back?

Steve

Front most ...

Thanks much. I'll check to verify proper install.

Really appreciate it!!!

Steve