Oil coolers really nessessary on turbo engines?

[TurboFiat124]

My old (as in pre 1983) Fiat's called for an "unusual weight" from the factory, 15W40. Well maybe for a gasoline engine but seems like most diesels use this grade.

I've always used 10W30 but started using the Shell Rotella 15W40 thinking it might have some benefit when using a turbo (since most diesels are turbocharged).

I never installed an oil cooler on my Yugo when I turbocharged it about 10 years ago. I did run one on my Fiat 124 Spider for years. When I decided to build a custom A/C system for it back in 2010, the condenser went where the oil cooler was located.

It's hard to tell how many miles are on each of these engines. The Spider's engine was rebuilt back in 1992. The Yugo's 1500cc engine came out of a 79/80 Fiat X 1/9 with unknown mileage.

Just curious if an oil cooler is really nessessary. I've yet to "rig up" a temperature sensor in the oil pan to see how hot the oil is getting but I did aim one of those thermal heat pens after I pulled into my garage and I don't think the oil any more hotter than the engine (~200F). Seems to me I read oil starts breaking down above 250F.

These cars are not raced, just street toys. So it's not like the engines are constantly pushed to their limit.

 

[ccb056]

When the engine was designed, it was designed with a specific oil film thickness to be used.

The engineers knew what temperature the oil was going to be operating, and then decided on the oil viscosity which would give that film thickness at the operating temperature.

Adding a turbocharger increases the oil's operating temperature.

To keep the oil at the designed film thickness you typically need a higher viscosity oil at higher temperatures.

 

[Blueskies123]

You turbo charged a Yugo? How did that work out for you?

 

[expat]

How about fitting an Oil Temperature Gauge?
Without one, you are shooting in the dark.

Or you might consider an Oil/Coolant heat exchanger.

 

[6starprez]

Originally Posted By: Blueskies123
You turbo charged a Yugo? How did that work out for you?


I'd like to know how that worked too. Lol

When I was stationed at McGuire AFB, NJ in 1993, a civilian lady at my job had a yellow one. OMG, that car was a P.O.S! The engine was gross. I remember oil being everywhere. It always had trouble starting in the afternoon for some reason. When it did, it would smoke up the entire parking lot.

 

[TurboFiat124]

Lets just say this will be the last front wheel drive car I will ever hop up.

Here are some photos:

http://s222.photobucket.com/user/turbofi...696105450850746

I used a 1500 Fiat engine. This gives me an additional 25 HP over the original 55hp 1100 engine. The 1100, 1300 and 1500 engines are basically the same. If you can imagine swapping out a SBC 305 for a 350. The Yugo is basically a Fiat 127 clone with a different body and uses about 90%+ of the same parts as a Fiat 128/127. The engine drops right in with little mods. I did have to swap items like the oilpump and pan because the motor is tilted at a 22 degree angle versus the X 1/9.

The T25 turbo came off a 1991 Saab 9000. At 7 lbs of boost (safe limit for Fiat engines) gives an additional 35HP. Or a total of 110 BHP, double the car's original power. I used the Yugo intake manifold and carb (rejetted), the exhaust manifold was from a fuel injected X 1/9. I cut the downpipe flange off and had a friend weld a SS flange in it's place.

Diesel fuel pump (15 to 20 PSI), Maserati bi-turbo fuel pressure regulator, GM 5 pin HEI control module for boost retard.

http://s222.photobucket.com/user/turbofi...752089493854454

There were some other hurdles to cross like the pulley system.

The downside. I'm estimating around 110 BHP. Because car weighs 1800 lbs, the front end is very lightweight. The front end "scoots" and I can spin the front tire at 30 mph in 2nd gear at full throttle at 7 lbs of boost. Front tires last 3000 miles. I don't do burnouts. Torque steer is horrible.

No doubt installing wide front tires might help but just finding a descent 13" tire these days is hard enough.

I posted a video years ago on Youtube. I can't post the link directly from this computer (company filters) but enter "Turbocharged Fiat powered 1500 Yugo", it's a 27 second video clip doing hot laps around a parking lot.

 

[punkndisorderly]

Never thought I's say this in my lifetime but, [censored] that's a cool Yugo!

 

[tomcat27]

very cool work! creative and industrious! theoretically it would be best to run an oil cooler, but you have a few things going for you if you dont: you are not running alot of boost, you dont push it hard, there seems to be plenty of cooling, and you already have a track record of success with these cars.

 

[Texan4Life]

It has everything to do with oil temperature and you will need a oil temp gauge to judge whether you need extra cooling or not.

oil temp also plays a critical role in oil life.

Does it also play a role in deposit formation? I'm not sure, just wondering out loud.

 

[rhondas]

you don't want to burn out the high RPM turbo its the heat , so it needs the extra cooling

 

[TurboFiat124]

I doubt 5 seconds of boost every now and then is going to increase the oil tempertature but I was wondering if oil constantly circulating through the turbo would increase the temperature.

I shouldn't be that hard to rig up a temperature sensor where the oil drain plug goes.

As of now I've never had any issues. The oil does not get any darker than any of my other cars. I don't know if that is any indication.

I have had some cars that the oil would turn black with 100 miles of changing it!

 

[Jetronic]

The oil temperature is mostly rpm dependant, so unless you drive at higher speed than before it won't be much of an issue. If the oil does get slightly hotter, the amount of heat shedded by the oil pan will be higher aswell.

did you do anyhing with the gearbox or tyre size?

 

[Yah-Tah-Hey]

Originally Posted By: 6starprez
Originally Posted By: Blueskies123
You turbo charged a Yugo? How did that work out for you?


I'd like to know how that worked too. Lol

When I was stationed at McGuire AFB, NJ in 1993, a civilian lady at my job had a yellow one. OMG, that car was a P.O.S! The engine was gross. I remember oil being everywhere. It always had trouble starting in the afternoon for some reason. When it did, it would smoke up the entire parking lot.
Consumer Union said the Yugo was a waste of natural resources. Probably the worst vehicle to ever be driven on US streets.

 

[TurboFiat124]

Originally Posted By: Jetronic
The oil temperature is mostly rpm dependant, so unless you drive at higher speed than before it won't be much of an issue. If the oil does get slightly hotter, the amount of heat shedded by the oil pan will be higher aswell.

did you do anyhing with the gearbox or tyre size?


The gearbox is holding up fine. I've yet to blow it. As far as tire size goes, the car came with 13" SR145 tires. All tire stores will tell you this size is NLA and the closest is a 13" 80 series 155. I have these mounted on Fiat X 1/9 alloys. I think the original steelies were something like 5" where the X 1/9 alloys are 5.5" or 6". Don't quote me on that. They offset is a bit difference.

Good quality 13" tires are a thing of the past. Replacements are made in China. They don't ride smooth and they are hard to balance.

However I did find a source for 13" SR145 tires from a place in the US called Coker tires. I wanted the correct tire for my Trabant. They are made by Vredestein and seem to be a really good tire.

 

[TurboFiat124]

Originally Posted By: HosteenJorje
Originally Posted By: 6starprez
Originally Posted By: Blueskies123
You turbo charged a Yugo? How did that work out for you?


I'd like to know how that worked too. Lol

When I was stationed at McGuire AFB, NJ in 1993, a civilian lady at my job had a yellow one. OMG, that car was a P.O.S! The engine was gross. I remember oil being everywhere. It always had trouble starting in the afternoon for some reason. When it did, it would smoke up the entire parking lot.
Consumer Union said the Yugo was a waste of natural resources. Probably the worst vehicle to ever be driven on US streets.


Consumer Reports also got blasted over their "tip over" reveiws on the Suzuki Samurai.
http://en.wikipedia.org/wiki/Suzuki_Motor_Corp._v._Consumers_Union_of_the_U.S.,_Inc.


Of course if you jerk the steering wheel on a vehicle with a high center of gravity you are going to flip it. That's just common sense.

I've owned a 84 Bronco II, a 1994 Jeep Wrangler with short wheel bases and two Ford Explorers. I'm aware of their handling capabilities.

I'm not going to say that the Yugo is a "great" car but I wouldn't call it all that bad either. The same could be said for the VW Type I (aka Beetle). Noisy, poor heater, lack of power. Hey that sounds like my Trabant!

I don't put allot of faith into reviews and all much less Consumer Reports magazine.

 

[ccb056]

You pulled the turbo from the SAAB 9000. My SAAB 900 also has a turbo and oil cooler, it is thermostat controlled. If you do add a cooler, you might want to look into a thermostat as well.

 

[A_Harman]

You're still using the Rotella 15w40? I always recommend that full synthetics be used in turbocharged gasoline engines. Especially ones that don't have oil coolers. If you stayed with a 40-weight, possible ones to use are M1 HM 10w40, PUE 5w40, M1 0w40...

 

[CT8]

That is a great question. How hot does your oil get? and how is the car run?

 

[SHOZ]

On my turbo Genesis Coupe I had an oil cooler that was plumbed off a thermostatic sandwich adapter on the oil filter mount. It had a small bi-metal spring that was closed at 160F and open otherwise.

The only time I found that I needed the cooler was when I was on a road course and in hot weather. Otherwise the oil ran too cool for me and in the winter would not even hit the 160F usually.

The oil temp readings I was using were from the OEM oil temp sender located up at the top of the head by the oil operated cam control solenoid. I have since added another for a aftermarket gauge and it is immediately after the oil filter. The two seldom read the same.

Before the cooler I would see +300F on the OEM temp sender after about 4 laps out on the track in +90F temps. After the cooler the temp dropped to 275F under similar conditions. But this is with 80% WOT high rpm driving. I had the oil tested and it came back AOK using Mobil 1 5w30, even after 5k miles. Not the best designed oil cooler either but just a 24" long x 6" wide 4 tube and fin type.

If you don't have a temperature gauge I would not add a cooler. If you don't do a lot of WOT high rpm driving and use a synthetic oil I would not add a cooler.

I do currently have a heat exchanger on the oil filter mount that uses the engine coolant to add/subtract heat to the oil.

 

[Ken2]

How hot is the oil at the turbocharger outlet? That's important. Synthetic oil (more resistant to oxidation) and more frequent oil changes (get the oxidized oil out'a there) may be OK if it doesn't get way too hot. What really cooks (oxidizes) oil is time at temperature. Very hot for a very short time can be OK. Very hot for a longer time kills oil. Rapid darkening of the oil is a clue that it is running too hot. 250° isn't too bad as long as the viscosity is suitable. 350° for an automotive oil is hot. Also keep in mind that these hot oil temperatures will shorten the life of any elastomer seals & gaskets in contact with the oil.

The Permacool engine oil thermostat opens at 180°F, a good temp to start cooling the oil. 160° is too low, that's a good temp to cool ATF. My Volvo turbo engine had an oil cooler in the radiator hot tank, with a thermostatic valve that sent the hot oil there.