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Oil temp on LM Turbos
Posted by: jetcat ()
Date: October 14, 2020 02:21PM

I think my turbo engine has pretty high oil temps. After a long freeway run 260° is not unusual. Pressure will drop to 10 PSI @ idle and 35 PSI @ 3k RPM. At 220°, it's around 45 PSI.
Head temps never go above 390° and I'm using the Nash fan and a very accurate head temp gauge. The oil temp is a VDO gauge and I did try swapping it with my 110hp engine and it reads the same. BTW, the 110hp never goes above 220°.

The engine was rebuilt 700 miles ago and seems to run fine, well until now. Pretty stock but fuel injected. Max boost about 12 lbs. Compression good (140-150) and leak down between 4-8% @ 90 PSI.

Reason I'm asking, my newly rebuilt turbo is now badly leaking out the compressor side. Could be other reasons but thought oil temp maybe one of the possible contributors?????

Bob
Paso Robles, CA

Central Coast Corsa
1966 Turbo Corsa convertible
1966 Corsa 140 coupe but now with 110hp heads.

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Re: Oil temp on LM Turbos
Posted by: joelsplace ()
Date: October 14, 2020 02:43PM

Did you modify the back cover to feed cooled oil to the turbo instead of hot oil?

Joel
Northlake, TX
5 Ultravans, 113 Corvairs and counting...

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Re: Oil temp on LM Turbos
Posted by: jetcat ()
Date: October 14, 2020 02:53PM

joelsplace Wrote:
-------------------------------------------------------
> Did you modify the back cover to feed cooled oil to the turbo instead of hot oil?

No I didn't. At the time, I did not realize the turbo was fed with un-cooled oil. Actually, I was surprised how much hotter the oil runs compared with my 110hp. After my next turbo rebuild, maybe putting a small cooler in line with the turbo?

Bob
Paso Robles, CA

Central Coast Corsa
1966 Turbo Corsa convertible
1966 Corsa 140 coupe but now with 110hp heads.

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Re: Oil temp on LM Turbos
Posted by: thewolfe ()
Date: October 14, 2020 03:24PM

There is obviously something wrong with the turbo. It shouldn't be leaking, regardless of oil temp. Sounds like a carbon seal gone bad. Was that part replaced during the turbo rebuild? If the carbon seal was reused, was it disassembled and the small inner o ring replaced?

Nate Wolfe
Portland OR
65 Corsa 180

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Re: Oil temp on LM Turbos
Posted by: jetcat ()
Date: October 14, 2020 03:34PM

thewolfe Wrote:
-------------------------------------------------------
> There is obviously something wrong with the turbo. It shouldn't be leaking, regardless of oil temp. Sounds like a carbon seal gone bad. Was that part replaced during the turbo rebuild? If the carbon seal was reused, was it disassembled and the small inner o ring replaced?

I did not personally rebuild the turbo but did supply the Clark's complete rebuild kit including the carbon seal and new aluminum housing.
What should I expect to see for oil temps? A couple things I didn't mention is I'm using the Clark's pan and the ambient temperature while driving was in the mid 90's.

Bob
Paso Robles, CA

Central Coast Corsa
1966 Turbo Corsa convertible
1966 Corsa 140 coupe but now with 110hp heads.

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Re: Oil temp on LM Turbos
Posted by: RobertC ()
Date: October 14, 2020 04:04PM

jetcat Wrote:
-------------------------------------------------------
> The oil temp is a VDO gauge and I did try swapping it with my 110hp engine and it reads the same. BTW, the 110hp never goes above 220°.
>

I am a bit confused. You say gauge reads the same on your 110? 260?

Where is the oil temp sender located?

And, what is the sweep pattern of gauge?

I had a Stewart Warner gauge that had 200- 270 in the right 20% of the seep.

Never felt it read correctly.

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Re: Oil temp on LM Turbos
Posted by: jetcat ()
Date: October 14, 2020 04:16PM

RobertC Wrote:
-------------------------------------------------------
> jetcat Wrote:
> -------------------------------------------------------
> > The oil temp is a VDO gauge and I did try swapping it with my 110hp engine and it reads the same. BTW, the 110hp never goes above 220°.
> >
>
> I am a bit confused. You say gauge reads the same on your 110? 260?
>
> Where is the oil temp sender located?
>
> And, what is the sweep pattern of gauge?
>
> I had a Stewart Warner gauge that had 200- 270 in the right 20% of the seep.
>
> Never felt it read correctly.

Sorry, confusing. The gauge from my 110hp also displays 260° on the turbo. My 110hp motor runs at 220°. The sweep is ~ 90°. Temp sensor in the Clark's oil pan on the turbo and in a Otto pan on my 110hp engine.

Bob
Paso Robles, CA

Central Coast Corsa
1966 Turbo Corsa convertible
1966 Corsa 140 coupe but now with 110hp heads.

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Re: Oil temp on LM Turbos
Posted by: RobertC ()
Date: October 14, 2020 06:26PM

Sorry, I am not going to be much help.

I was interested in your post because of my experience with an oil temp gauge decades ago (110 engine). It read a little high, not 260, and once up to temp, it hardly moved (not much sweep left) - even pulling long mountain passes. The engine lasted a normal life and failure was not oil related.

The only thing I can come up with is your engine is new and not broken so it might be running a littler hotter. Also, your carb may be running slightly lean at freeway cruise.

You need someone here who has run an oil temp gauge on a turbo.

But, as you might guess, I consider oil temp gauge readings “relative”.

Good luck.

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Re: Oil temp on LM Turbos
Posted by: 63turbo ()
Date: October 14, 2020 06:57PM

Oil leaking into the intake is bad news, it has the effect of lowering the octane of the fuel, and this alone can make the engine run hotter than it should. Nate is right, it is probably a toasted carbon seal. High oil temperatures by themselves will not make the turbo more leak prone on the intake side, but just having a turbo in good working order will cause the oil to run hotter, as there are places within the turbo that heat the oil quite a bit more than if it were an NA engine.
I have to tell you though, when a draw through configuration is converted to EFI and now has dry air going through the turbo, you will run into weird oiling problems you never thought of!!! Theres a crankcase ventilation tube that is connected between the intake of the turbo and the crankase. Theres a near continuous stream of small oil droplets going into the turbo intake at part throttle because of this tube... When the carb is on and working, these little droplets get washed off from the gasoline, but now that it is "dry" these oil droplets tend to collect in weird spots like at the junction between the turbo and cross over. Eventually, the hose connection will get all slimy and not seal well. I got so sick and tired of this I installed a air oil separator, and it definitely cleaned up the mess, and improved the detonation resistance, and the oil tends to stay much cleaner this way!!

------------------------------------

Kevin Nash
Friday Harbor Washington
63 Spyder, Daily driver, EFI read about my project here: [corvaircenter.com]
first test start on EFI here:[www.youtube.com]
first official EFI boost test here:[www.youtube.com]
My new fan! [corvaircenter.com]
engine less 62 Spyder
Canadian 64 Monza Parts car



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Re: Oil temp on LM Turbos
Posted by: roger65180 ()
Date: October 15, 2020 05:44AM

I have an oil temp gauge on my turbo car and for years i thought the oil temp was a little high , driven far enough or autocross on a hot day i would see 250 oil temp taken from the pan like yours not long ago with the reading at 250 i used a laser temp gauge and shot the pan at the sender it was just a bit over 200, so in my case it was the gauge . my car is not stock in any way , I cut the oil filter off and plumb to remote filter and then an oil cooler and back to the engine were it then goes to the factory cooler .

Roger R
Madison Wi
62 ct pg turbo
65intercooled 180 4sp,autocrosser
62 Rampy

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Re: Oil temp on LM Turbos
Posted by: v8vair ()
Date: October 15, 2020 06:02AM

I dont have an gauge on my Turbo but with full heater tin 400 on the heads at speeds is norm. The racer runs 280 oil with a big cooler. With the turbo fresh oil sooner than later is probably wise. I wouldnt worry about 250 with todays oils especially if your running full synthetic.

1965 Crown V8 Racer
1964 Bill Thomas Monza Replica Racer
1964 Spyder Street Car
1979 Mazda RX7

Mike Levine

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Re: Oil temp on LM Turbos
Posted by: dryenko ()
Date: October 15, 2020 06:49AM

Agree with Mike, 260F in the pan is normal.

Given that a functioning oil cooler will drop the oil temp 60-80 degrees.

This places the oil temp close or less than to what the oil manufacturers recommend for oil temperature delivered to the bearings.

Which is from 190 to 210 degrees F.

For Dino based oil.

Plus over 21" will evaporate any condensed moisture accumulated in the oil, decreasing sludge formation.

Synthetics oils can tolerate even higher pan temperatures.

One thing to check is that the oil cooler bypass valve is not stuck open, in your case.

And the oil cooler air is not obstructed or leaking around the cooler.

Some folks install some metal shields to alleviate this issue.

Bob C aka Dryenko
Dobson, NC 27017

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Re: Oil temp on LM Turbos
Posted by: dryenko ()
Date: October 15, 2020 07:05AM

Over 212 degrees F

Bob C aka Dryenko
Dobson, NC 27017

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Re: Oil temp on LM Turbos
Posted by: jjohnsonjo ()
Date: October 15, 2020 07:44AM

I [www.trailerlife.com]

I hit about 240/ 250 on a warm day, what I run has worked well, $22 bucks a gallon

J.O.

65 Corsa Turbo Vert
79 Honda XL 500S
69 Honda CL 160 D
2010 BMW F 650 GS
2003 Bounder 36D
2013 KIA Optima SX turbo-AKA ZIPPY (wife,s car)
69 Newport Holiday Sailboat
Baja 150 dune buggy cart
Coleman HS 500 UTV
2016 KIA Sorento SXL Turbo

Bethlehem,Pa


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Re: Oil temp on LM Turbos
Posted by: mspeters ()
Date: October 15, 2020 08:35AM

I use a dual gauge from westach. Summer cruising on 2 lanes (55-65mph) I'm around 200*-220*F, on the highway (75-80ish) it can get up to 240*-250*F if I'm getting on it.
It is reading right at the junction that feeds the turbo, so my pan temp is likely a little lower.
No lower shrouds, but stock carb and turbo.
Pressure is rock steady at 40psi, might drop to 20-25 at idle if its really hot, but not below that. (standard oil pump, 1k idle rpm)

Matt Peterson
Ada, MI
65 corsa vert 180hp

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Re: Oil temp on LM Turbos
Posted by: jetcat ()
Date: October 15, 2020 01:33PM

Thanks very much for the response. Now I'm not as afraid of my 250-260° oil temps. BTW, I use BradPenn oil. Been using it since it was Kendall GT1 from the 70's. I guess it's OK. Never had any problems, yet.....

Really like that Westach oil temp/pressure meter!

Bob
Paso Robles, CA

Central Coast Corsa
1966 Turbo Corsa convertible
1966 Corsa 140 coupe but now with 110hp heads.

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Re: Oil temp on LM Turbos
Posted by: Phil Dally ()
Date: October 15, 2020 03:29PM

Yours is a modified YH fuel injection throttle body right Bob.

Therefore the turbocharger is not dry and has fuel in it Y/N?

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Re: Oil temp on LM Turbos
Posted by: jetcat ()
Date: October 15, 2020 03:55PM

Yes Phil, it's a modified YH as a throttle body. No fuel flows through the YH or turbo. Injected at the base of the stock intake crossover.

One thing I found is the small crankcase vent tube (recently replaced with repo) to the turbo has a 0.10" diameter orifice. I found out it should be 0.089". Not sure if that makes much difference.

Bob
Paso Robles, CA

Central Coast Corsa
1966 Turbo Corsa convertible
1966 Corsa 140 coupe but now with 110hp heads.

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Re: Oil temp on LM Turbos
Posted by: Phil Dally ()
Date: October 15, 2020 03:57PM

Got it...Nash Man gets to be right.

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Re: Oil temp on LM Turbos
Posted by: jetcat ()
Date: October 15, 2020 04:24PM

Phil Dally Wrote:
-------------------------------------------------------
> Got it...Nash Man gets to be right.

Nash knows all smileys with beer

Pictures of the turbo. A bit of oil pooled in the coupling hose, thin coat of oil in the compressor housing and dirty oil on the bottom of the hot side. Carburetor dry.

Bob
Paso Robles, CA

Central Coast Corsa
1966 Turbo Corsa convertible
1966 Corsa 140 coupe but now with 110hp heads.

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