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uiuc240
12-10-2001, 02:49 AM
OK, guys and gals. Here's a question for ya.

For those of you with SR20DET, how did you go about installing the sender unit for an Autometer temp gauge? The system I have going right now is on the jenky side of things. The temp sender unit is siliconed into the coolant burp hole because we couldn't get any brass fittings to work right. Because of this, we are getting large quantities of coolant leakage and therefore overheating. I don't trust the RTV http://www.freshalloy.com/ Don't laugh. It wasn't my idea. http://www.freshalloy.com/ Anyway, I just want to know what you've done. Is it accurate? Would you try something else now that you know more? http://www.freshalloy.com/

Please tell.

Oh, and could you also give me the part numbers or any model information of the electric fan(s) you are running?? Thanks a billion

Eric

JimStinksAtDorifto
12-10-2001, 03:41 AM
Most people run a hard pipe between the radiator and motor. This pipe usually has a threaded bung on it which can be used for a temp sensor, or you can tap it yourself. Basically, take your long radiator hose and cut it into 2 smaller pieces and stick a pipe between the 2. The only downside to this method is that it does not sense the actual temp until the thermostat opens up, so if your t-stat fails, you won't know.

BTW, I ran the 16" hi-perf Perma-Cool fan on my RX-7 and am going to use it on my SR swap, it works great for me. If you can afford it, buy a Spal or a Perma-Cool Black Magic fan.

stock4door
12-10-2001, 04:40 AM
I took out the factory temp sensor from the housing. Please make sure you differntiate between the guage sensor and the efi sensor as once you have the housing off the engine it could be a toss up. I had the hole tig welded up. Then I drilled a hole through the welded up area, tapped it for 1/8th NPT and put the autometer sender in. The trick was to get the hole full of solid weld material enough to get a good thread bite. Use some teflon tape on the sending unit also just incase there are some air pockets in the weld material. The only downside to all of this is that the factory guage will no longer work. The autometer and stock sending unit are so far off from each other. I tried both in a boiling pot of water.

uiuc240
12-10-2001, 09:59 AM
OK, I like the hard line idea, because that's easiest. Do you think I'll have any thermostat problems though? And if so, what do I do then? Could I just take the thermostat OUT? I mean, the engine runs notoriously hot anyway. Wouldn't it be just fine to let coolant flow at all times? http://www.freshalloy.com/

And about the welded example. How much did that cost you? We have some time now while we wait for other parts. Maybe if this isn't horribly expensive, we'll go this route.

Isn't there ANY way to adapt that burp hole to the sender? A threaded brass spacer of some sort? I'd assume if someone machined that part, EVERY SR20DET owner would want one. Any machinists out there that want some business http://www.freshalloy.com/ http://www.freshalloy.com/

Eric

JimStinksAtDorifto
12-10-2001, 10:10 AM
<BLOCKQUOTE><font size="1" face="Verdana, Arial[/img]quote:</font><HR>Originally posted by uiuc240:
OK, I like the hard line idea, because that's easiest. Do you think I'll have any thermostat problems though? And if so, what do I do then? Could I just take the thermostat OUT? I mean, the engine runs notoriously hot anyway. Wouldn't it be just fine to let coolant flow at all times? http://www.freshalloy.com/ Eric<HR></BLOCKQUOTE>

If you have a good Nissan t-stat, you should be fine, but I was just saying. Leave the thermostat in, it is necessary to let the car warm up and it regulates the temperature to a certain effect. If you remove it, your car would take forever to warm up and in winter time it might never fully warm up. Only racers remove the t-stat so they can get more coolant flow, or they knock out part of it so it still lets it flow, but still restricts it some.

uiuc240
12-10-2001, 10:14 AM
<BLOCKQUOTE><font size="1" face="Verdana, Arial[/img]quote:</font><HR>Originally posted by DriftinJim:


If you have a good Nissan t-stat, you should be fine, but I was just saying. <HR></BLOCKQUOTE>

Is the SR thermostat duplicated by any other motor? What if it goes bad? And as of now, it seems that the motor heats up FAST in the winter as long as you give it boost http://www.freshalloy.com/

But I know what you're saying about leaving it in. Good point. I'm just afraid of leaving it in, having it fail, and not knowing about the coolant temp until the whole thing boils over and I warp the head. Grrrr.

Eric

Mav1178
12-10-2001, 10:33 AM
If you have a working thermostat, and run the proper mixture of coolant/distilled water, you shouldn't have any problems with the thermostat if you flush your system once every 12-18 months.

Running w/o a thermostat would cause your car to take forever to heat up, and until it does the car will run rich and you'd get super poor gas mileage. And while you're at it, it'll melt your cat from all the excess gas in the exhaust stream.

-alex

**DONOTDELETE**
12-11-2001, 12:38 AM
In some instances, running without a thermostat can actually *cause* overheating. The thermostat also acts as a restriction in the cooling system, slowing the flow down some so there is enough time for the heat to wick into the coolant, and the heat to wick out of the coolant into the air passing through the radiator.

Hands down, best place to install a temp sensor for an aftermarket gauge is somewhere on the engine side of the thermostat. Anywhere after the thermostat (like in a metal radiator pipe) and you won't get readings until the thermostat opens up. If you have a failing thermostat, you won't know until it's too late.

Probably a good idea to pull the water pump housing or the like and find a suitable spot to drill and tap for the sensor. This is actually not as hard as it sounds - probably a good afternoon of work.

You can also, in many instances, thread into where the stock sender for the dash goes. I'm not 100% sure, but it *might* be metric pipe thread for that hole, and not NPT. This isn't a big deal with a good Japanese gauge, but a Guess-O-Meter (Automter) gauge will use an NPT fitting. Not to mention your stock gauge won't work - I'd rather have both.

uiuc240
12-11-2001, 02:39 AM
<BLOCKQUOTE><font size="1" face="Verdana, Arial[/img]quote:</font><HR>Originally posted by fc3s7:
You can also, in many instances, thread into where the stock sender for the dash goes. I'm not 100% sure, but it *might* be metric pipe thread for that hole, and not NPT. This isn't a big deal with a good Japanese gauge, but a Guess-O-Meter (Automter) gauge will use an NPT fitting. Not to mention your stock gauge won't work - I'd rather have both.<HR></BLOCKQUOTE>

They are not only different threads, but different diameters entirely. This is why the coolant is leaking so badly.

I just have one thing to say though...Autometer gauges are used by TONS of racers and tuners. I have a hard time believing that everything they make is crap. And there is no way you can convince me that it's better to spend $200 on a Greddy gauge that tells me the same thing. The only EXPENSIVE gauge I'm planning on buying is a Blitz 43mm, because I like the little DIN panel http://www.freshalloy.com/

Anyway, I know that you were simply stating an opinion, but there's no need to make everyone running Autometer gauges feel inferior. Play nice. http://www.freshalloy.com/

Eric

**DONOTDELETE**
12-11-2001, 07:30 AM
On Autometer gauges -

The Procomp's (I think that's what they're called) are the only gauges worthwhile. On their other gauges (the Phantoms, etc.) you get what you pay for.

Case in point - I've seen rows of brand new Autometer boost gauges at a peformance shop. EACH ONE pointed to a different place in the "box" that's the zero position on the boost gauge. That points to poor quality control. By the same token, a row of Apexi boost gauges ALL point directly at the zero line.

I originally had a VDO gauge, then a Phantom boost gauge in my car, which I then replaced with an Apexi mechanical boost gauge. I was SHOCKED at the response time of the Apexi gauge - even hard, fast 1-2 shifts saw the needle swinging to vacuum and back to boost - the gauge responds that fast. Autometer and VDO couldn't touch it.

Personally, I bank my engine's *life* on my gauges - 1-2 psi of difference on my boost gauge is the difference from running fast to a blown motor. Considering the inconsistencies in the Autometer's I've seen, I don't trust 'em.

I bought a Japanese car because of the quality, attention to detail, and superb engineering. I buy Japanese gauges for the same reason.

If you want a good quality boost gauge that isn't super pricey, Greddy makes a mechanical 60mm for just over $100. Apexi's boost gauge is around $140 for the mechanical. The Rolls Royce of gauges right now is Defi - they're just stunning, but pricey. Defi's page (http://www.defi-shop.com/defilink/otdflink/otdflink/otdffrm.html)

Autometer will get you going, but if you're serious about what you're doing, get a quality gauge. Buy one and you'll understand.

uiuc240
12-11-2001, 08:11 AM
I must say, well said. You've got me thinking. But, I'm also not getting rid of my Phantom gauges just yet. I'll keep everything you had to say in mind, though.

Eric