Gauges, oil press, oil temp, Cyl head temp |
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Gauges, oil press, oil temp, Cyl head temp |
ChrisReale |
May 13 2004, 12:02 AM
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#1
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Sleazy Group: Members Posts: 2,665 Joined: 20-January 03 From: San Francisco Member No.: 176 |
What do you consider a necessity, besides a fuel gauge?
Porsche obviously felt an oil temp gauge was important in the 914, and a pressure/temp in the 911. I know Jake Raby likes the cyl head temp gauge, but Porsche didn't seem to think it was as important. Now that I think about it, Rich Bontempi's race car has all three, plus exhaust temp on all 4 exhaust ports.... |
ArtechnikA |
May 13 2004, 04:10 AM
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#2
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rich herzog Group: Members Posts: 7,390 Joined: 4-April 03 From: Salted Roads, PA Member No.: 513 Region Association: None |
QUOTE(ChrisReale @ May 12 2004, 10:02 PM) What do you consider a necessity... necessary for what ? for engine development and front-row of the grid performance tuning, you need all that stuff and a 5-gas exhaust analyzer. for driving a street car once the engine is developed, gas gauge (or odometer), oil pressure warning light, high-beam indicator. just like my '53 ... |
Jake Raby |
May 13 2004, 09:22 AM
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#3
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Engine Surgeon Group: Members Posts: 9,394 Joined: 31-August 03 From: Lost Member No.: 1,095 Region Association: South East States |
Oil temp and head temp. Even more so than oil pressure!
Head temp keep engines alive. |
tat2dphreak |
May 13 2004, 09:32 AM
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#4
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stoya, stoya, stoya Group: Benefactors Posts: 8,797 Joined: 6-June 03 From: Wylie, TX Member No.: 792 Region Association: Southwest Region |
QUOTE(Jake Raby @ May 13 2004, 09:22 AM) Oil temp and head temp. Even more so than oil pressure! Head temp keep engines alive. so, instead of removing my clock for a oil press. gauge, I should go for a cyl. temp? is the oil-press light good enough? |
ArtechnikA |
May 13 2004, 10:34 AM
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#5
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rich herzog Group: Members Posts: 7,390 Joined: 4-April 03 From: Salted Roads, PA Member No.: 513 Region Association: None |
oh yeah - and an alternator light! (on a /6, it indicates cooling system failure...)
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Dave_Darling |
May 13 2004, 11:06 AM
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#6
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914 Idiot Group: Members Posts: 14,984 Joined: 9-January 03 From: Silicon Valley / Kailua-Kona Member No.: 121 Region Association: Northern California |
For a street car running an engine that is known to not have problems:
-Tach -Fuel gauge -Oil & alt warning lights -High beam indicator (legally required in CA!) ...All others are "nice to have". For a street car with an engine of unknown reliability: -Tach -Fuel gauge -Oil & alt warning lights -High beam indicator -CHT -Oil temp ...Any others are "nice to have". For a race car: -Tach -Oil & alt warning lights -CHT (1 per cylinder) -Oil temp ...and any other stuff is a distraction. --DD |
Jake Raby |
May 13 2004, 11:52 AM
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#7
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Engine Surgeon Group: Members Posts: 9,394 Joined: 31-August 03 From: Lost Member No.: 1,095 Region Association: South East States |
Porsche didn't want you to see that your head temps can range 200 degrees over a single mile and spike to 400F when you hit a hill...
I cannot think of any car that had a CHT from the factory... Just aircraft.. The oil temp is worthless from the factory. Buy a CHT, best tool you can invest in. |
Rocky |
May 13 2004, 01:27 PM
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#8
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From the cockpit Group: Members Posts: 341 Joined: 24-March 04 From: Gig Harbor,WA Member No.: 1,845 |
Great advice. What CHT ranges should we be looking at in a stock set-up? Which cylinder runs hottest?
Tim |
kenpolives |
May 13 2004, 01:35 PM
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#9
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Member Group: Members Posts: 167 Joined: 31-December 03 From: Albany NY Member No.: 1,479 |
What is required to install the headtemp gauge?
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Jake Raby |
May 13 2004, 01:39 PM
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#10
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Engine Surgeon Group: Members Posts: 9,394 Joined: 31-August 03 From: Lost Member No.: 1,095 Region Association: South East States |
with stock cooling #3 is typically 40 degrees hotter than any other cylinder.. use it and MOUNT THE THERMOCOUPLE UNDER THE SPARK PLUG AND NO WHERE ELSE!
Heads should run 325-350 at cruise and hit 400 on a hill and no more.. You will soon see how 5th gear and hills get along, and how not going fast enough for 5th is a bad thing in a teener... all load and no fan speed. |
dmenche914 |
May 13 2004, 02:15 PM
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#11
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Senior Member Group: Members Posts: 1,212 Joined: 27-February 03 From: California Member No.: 366 |
If I had only one gage it it would oil pressure. If you over heat, the oil pressure will drop, and if you loose oil, the oil pressure will also drop. If you have an oil temp gage, it may stay somewhat cool even with loss of oil pressure (eventually it will heat up, but by them the engine bearings are probably toast) Head temp tells nothing really about the oil (until it is too late)
In my car all three are used, great monitoring on the engine. The volt meter is nice, but really not needed in my opinion. order of nessesity: oil press., oil temp, head temp. dave PS the head temp will let you see the effect of lugging the engine, it heats up real quick as soon as there is load, and not enought fan speed. |
Mark Henry |
May 13 2004, 03:45 PM
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#12
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that's what I do! Group: Members Posts: 20,065 Joined: 27-December 02 From: Port Hope, Ontario Member No.: 26 Region Association: Canada |
Can't agree with that one!
As long as I have my idiot lights my first gauge I want is an oil temp, 2nd would be CHT. I've ran bugs for years without an oil pressure gauge, the idiot light (really I use a pro-light in the bug) is very fast to react, faster than most gauges. I also don't like the dual pressure sensor/idiot light senders. I may put a pressure gauge in my teen sometime, but I will keep the stock idiot light sender. |
Jake Raby |
May 13 2004, 03:47 PM
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#13
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Engine Surgeon Group: Members Posts: 9,394 Joined: 31-August 03 From: Lost Member No.: 1,095 Region Association: South East States |
If you lose oil pressure- The engine is already munched...
If you see heads spike to 410 and you back out of it, you have just saved the engine. Like I have said before, the CHT is a tool more than an instrument.... You can dial your engine in with it, and coupled with EGT you can do it almost as good as I can on a dyno. |
lapuwali |
May 13 2004, 03:59 PM
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#14
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Not another one! Group: Benefactors Posts: 4,526 Joined: 1-March 04 From: San Mateo, CA Member No.: 1,743 |
If you really want to get picky about it in terms of NECESSITY:
One light to tell you when you're low on gas. One light to tell you to pull over (oil press, oil temp, cht, whatever, is out of the usual range) Nothing else is really necessary (except for obscure legal reasons you'll never be called on). I've certainly spent enough time behind the wheel of various cars with a non-working speedo to know that not having one is only a minor annoyance, at least in any urban setting. However... Since engines are never really in "known good condition" (how many people have had freshly rebuilt engines explode?) and since it's far cheaper to have a few gauges warn you of potential problems before they cause the engine to start smoking or spluttering, esp. when, like me, you're used to listening for bad noises and would really like to KNOW if that noise or smoke or spluttering is something really serious, or something you can wait to fix until you get somewhere comfortable, then having as many gauges or other indicators as you can afford and cram into the dash can be very handy. This goes double if you've sunk a substantial sum into the engine. Having at least a CHT gauge on the hot cylinder gives some mental relief, and it seems to function as something of a mixture guide (useful for carb setups). I'm reasonably happy with the idea of the oil pressure light doing its thing, as long as I know it works (and I'm not sure mine does, never lights up even key on/engine off). However, a pressure gauge also functions as a loose temp gauge, since pressure is higher when cold, lower when hot, so at least you know when the oil is up to temperature. A voltmeter has manged to solve a couple of puzzling problems for me in the past, and I think they're nice additions (cheap and easy to install, too). On an Alfa I had a few years ago, oil got onto the alt drive belt and caused it to slip noiselessly, esp. when the engine was cold, and the voltmeter caught that even though the alt light didn't (volts stayed at 12v with the engine running, rather than running up to 13-14v as it should). Could have had a nicely dead battery and no idea why otherwise. Certainly having CHT and EGT on every cylinder is overkill except for serious tuning situations, or for those who really push the envelope on engine builds. |
ArtechnikA |
May 13 2004, 04:03 PM
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#15
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rich herzog Group: Members Posts: 7,390 Joined: 4-April 03 From: Salted Roads, PA Member No.: 513 Region Association: None |
early 911's don't even have an oil pressure idiot light; i suspect no matter how low they dialed them down (and i've seen some down as low as 2,0 psi) the lights would come on at hot idle and scare people...
the car does have a pressure gauge and as long as you're seeing about 10 psi per thousand rpm (hot) it's no -real- cause for alarm... it's got the obligatory alternator light, and if that comes on cruise and you switch off right away you'll probably save the engine -- air-cooled cars don't last long with no cooling fan ! |
mike_the_man |
May 13 2004, 04:07 PM
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#16
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I like stuff! Group: Members Posts: 1,338 Joined: 11-June 03 From: Regina, Saskatchewan, Canada Member No.: 809 |
So, where is the best place to buy a CHT? How much can I look at spending, what do I need (what size of thermocouple, etc), and who has the best price?
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Jake Raby |
May 13 2004, 04:12 PM
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#17
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Engine Surgeon Group: Members Posts: 9,394 Joined: 31-August 03 From: Lost Member No.: 1,095 Region Association: South East States |
www.westach.com
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lapuwali |
May 13 2004, 04:23 PM
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#18
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Not another one! Group: Benefactors Posts: 4,526 Joined: 1-March 04 From: San Mateo, CA Member No.: 1,743 |
aircooled.net has probably the best price for the VDO CHT gauge, but Westach can sell you a dual gauge in the standard 2" round size if you want to keep an eye on both banks, or even a quad gauge in a larger package if you want to do all four.
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mike_the_man |
May 13 2004, 04:24 PM
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#19
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I like stuff! Group: Members Posts: 1,338 Joined: 11-June 03 From: Regina, Saskatchewan, Canada Member No.: 809 |
Thanks Jake. What size of thermocouple do we need for a TIV? I think I might order one right now.
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Jake Raby |
May 13 2004, 05:31 PM
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#20
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Engine Surgeon Group: Members Posts: 9,394 Joined: 31-August 03 From: Lost Member No.: 1,095 Region Association: South East States |
14mm
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