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914World.com _ 914World Garage _ Oil or CHT, which is more important

Posted by: Tobra Aug 25 2005, 07:44 AM

Oil or CHT, which is more important, or is this sort of an apples and oranges thing? Seems to me if the CHT never goes to high, the valve seats don't make any ill advised trips into the combustion chamber. I know both are important obvously, just something I was pondering. Response won't keep me from installing CHT and oil pressure guages(whose idea was it to put a light instead of a guage, must have been some german accountant)

Posted by: redshift Aug 25 2005, 07:56 AM

I trust the green light. I like to know when I am welding.

M

Posted by: BMartin914 Aug 25 2005, 08:24 AM

Are you talking about cht temps and oil temps? If so, cht is very important for longevity of your heads. On the other hand oil temp is also very important for the proper lubrication/function of internal parts. If it gets too hot and too thin, this is when you spin bearings etc.

So short answer would be equally important for different reasons.

Posted by: tat2dphreak Aug 25 2005, 08:33 AM

QUOTE (BMartin914 @ Aug 25 2005, 09:24 AM)
Are you talking about cht temps and oil temps? If so, cht is very important for longevity of your heads. On the other hand oil temp is also very important for the proper lubrication/function of internal parts. If it gets too hot and too thin, this is when you spin bearings etc.

So short answer would be equally important for different reasons.

oil temp alone is not enough, and CHT alone is not enough... why? you can have great oil temp, and be cooking your heads, you can have nice, cool heads, and your oil be boiling... 1 gauge is not enough...

Posted by: Demick Aug 25 2005, 08:53 AM

I have both. But if I had to choose only one, it would be oil temp.

Demick

Posted by: redshift Aug 25 2005, 08:58 AM

I can tell by foot, and ear when oil is hot. When you can tell by ear that heads are hot, you may have -60 seconds to respond..

That said, I have neither in my current car.

M

Posted by: tat2dphreak Aug 25 2005, 09:15 AM

QUOTE (redshift @ Aug 25 2005, 09:58 AM)
I can tell by foot, and ear when oil is hot. When you can tell by ear that heads are hot, you may have -60 seconds to respond..

That said, I have neither in my current car.

M

but didn't you HAVE an engine blow?!

Posted by: Demick Aug 25 2005, 09:39 AM

Sorry, but the green light or your ear or your foot will not tell you when your oil temp hits 250F.

Posted by: BMartin914 Aug 25 2005, 10:01 AM

QUOTE (Demick @ Aug 25 2005, 07:39 AM)
Sorry, but the green light or your ear or your foot will not tell you when your oil temp hits 250F.

But the knock will let you know you've spun a bearing.

Posted by: Jake Raby Aug 25 2005, 10:06 AM

BOTH!!!!

Posted by: Tobra Aug 25 2005, 02:03 PM

QUOTE (Jake Raby @ Aug 25 2005, 08:06 AM)
BOTH!!!!

How did I know you would say that? Car has oil temp guage, but light for pressure Gonna get the console and put CHT and oil pressure in there, and trust the oil temp guage in there with the gas gauge

Posted by: dmenche914 Aug 25 2005, 03:42 PM

oil temp anit as important as oil pressure for the following:

If oil temp gets too high, oil pressure will drop, so a high oil temp will be indicated as a probelm by the oil pressure gage.

If oil pressure drops from say a bad bearing, low oil level, bad oil pump, the pressure gage will indicate a problem. However an oil temp gage will not indicate a problem of low oil level for instance, at least not until it is much much too late.

That covers oil, if only one gage for oil, pick pressure, ad temp gage for oil as an extra.

CHT is a seperate issue from oil temp or pressure. The head temp is somewhat independent of oil, and can change rapidly. add a CHT gage.

With that in mind, if you can't have all three, and only two gages, do CHT and oil pressure.

If only one gage is in our future, then you will be missing some data. i personnally if only allowed one gage select oil pressure, reason is that it will notify me of oil loss, say if a seal went out and the oil pee'd away while driving, you certainly wouldn't notice any problem until it is too late.

One could also argue for CHT as the only gage if you can have only one, but i just think the likelyhood of running low on oil is greater than something causing the head temp temp to change, but heck, anything could happen.

good luck