20w-50

[87Turbo-TWE4]

Is it alright to run this viscosity? I want to switch to Amsoil that already has the right amount of zinc and phosphorous in it. They only offer it in this weight and one other. Their 10W-30 doesn't have ZDDP in it.

 

[Heath]

I run 20w50 in valvoline racing oil for 2 years. No trouble so far.

 

[turbo nasty]

That weight oil ig fine. I would save the money on the Amsoil and just run dino and ZDDP. Your check book will thank you

 

[BlackBandit]

Run the lowest viscosity you can while wtill achieving proper oil pressure. This will lessen the use of the oil pressure bypass and give you maximum bearing cooling.

 

[gnloyalty877]

I run 20w50 in valvoline racing oil. No trouble so far.

That's all thats been in my moter ever since i got the shortblock back from anderson over 6 years ago.

 

[Boost231]

On a stock motor I say no. I would run 10w30 but if the motor is rebuilt then I would check wit your engine builder. The clearances might allow you to run 20w50

 

[Nick Micale]

That weight oil ig fine. I would save the money on the Amsoil and just run dino and ZDDP. Your check book will thank you

Seems like some people never get it.?

Just because it cost more, and the advertising guys say it is "better", does not make is so, especially in our application where frequent oil changes are more important. :biggrin:

The ad guys NEVER point out the downsides of using synthetics, specifically when used in our turbo engines.

 

[chasmat2316]

why such heavy wt oil?

 

[Nick Micale]

why such heavy wt oil?

Because it works! :biggrin:

 

[87Turbo-TWE4]

I guess i'll just stick with 10W-30 but switch over to Valvoline dino and add ZDDP. I have an unopened motor so I guess I need to stay with what is recommended.

 

[BlackBandit]

I guess i'll just stick with 10W-30 but switch over to Valvoline dino and add ZDDP. I have an unopened motor so I guess I need to stay with what is recommended.

Probably an excellent call if you still have good pressure. Your engine is the constant in the oil weight/pressure equation. If you have adequate oil pressure and you go to a heavier oil without changing the engines ability to flow oil, the amount of flow goes down. This results in less lubrication and cooling, increased front cam bearing and cam sensor wear and increased chance of engine failure. (read: spun bearing)

Now, if you've done something to change the way your engine flows oil that's a different story. That doesn't mean add an HV pump because that's changing your engines ability to PUMP oil, not flow it. I mean either wear the engine out so your internal clearances are greater or build it with larger clearances. In a situation like that going to a heavier oil without messing with the pump can restore pressure while maintaining proper flow.

One last thing to remember especially on a stock engine. The engineers that designed it did many things on purpose. One of those things was set a spec for oil pressure. If you look in the manual you'll notice it's not 25 psi@idle. It's something like 32 psi @ 2600 rpm with a designated weight oil. They did this to ensure flow and pressure were adequate. You need hardly any oil pressure at idle because there isn't any load on the engine. As rpm/load go up an increase in pressure with the same weight oil indicates an increase in flow which is good. If you hit the pressure bypass way early it can mean you're oil is too thick and as a result you'll have inadequate cooling of internal components at higher rpms when you need it most.

In summation the oil pressure and weight debate is a good bit more important and has more factors than most people realize. The next time someone says "I run straight 50W oil in my car. I have 35 psi a hot idle! By the time I get to 2000 rpm it's at 70 psi and it stays there (or only goes up a little) until readline!" realize that that is a bad situation and they probably are NOT the ones you want to get a oil recomendation from because while oil pressure on a gauge can make you feel good it won't keep you're engine alive.

 

[83ttypecooled]

Hi,
At idle,our motors can keep the bearings lubricated AND keep the lifters pumped up using about 5 to 10 pounds of pressure. At 2000 rpm, you should see 40 to 50psi ,if the motor is in good shape. At higher revs,pressure might reach 60 psi.

 

[TURBOPOWERED68]

What is/should be proper oil pressure at 160K miles @? 10W40? 20W50?


At hot idle i have a steady 20PSI
i did put a high pressure high volume pump.

 

[cruzn57]

isn't synthetic oil

supposed to resist coking, or burning in the turbo? ( like in heat soak)
I use dino in the buicks, but syn in the truck,
plus additive in the buicks,

 

[Swathdiver]

My .02 cents:

All our turbo cars used to get clean Mobil 1 10W30 every 3-5k miles and never wore out a turbo or motor.

In fact one night an oil cooler line blew on the way to the track and I didn't know it. Engine temp went up a little but didn't think anything especially since the first pass was so great, fastest ever! After the next 2 passes the coolant temp was getting way too high (180s) at the end of the runs so I finally popped the hood and checked the oil. Nothing! Saw the busted line, fixed it but only had 1qt of spare oil and 1qt of tranny fluid. Poured both into the motor and drove home 66 miles to my shop. Tore down the motor the next day and NO damage. I'll be a Mobil 1 customer as long as they make it.

In my early days of racing I did run 20W50 but it slowed the car down and blew the main seals. No need for it in a stock motor IMHO.

 

[forzfed]

In my early days of racing I did run 20W50 but it slowed the car down and blew the main seals. No need for it in a stock motor IMHO.

Same thing happened to me when I switch to 20w50 on a stock setup. I ran 20w50 in my street/strip setup and it caused problems to, but it does get a lot cooler here. In the south where the weather is really hot it probably won't hurt as much.

 

[davidf]

Well this thread just depresses me.:frown: I just put in Valvoline racing 20w50 100 miles ago {stock engine }. It gets 100 dregrees here in the summer. Maybe I'll switch back to 10w40.

 

[Bruce Urie]

So, do a lot of you guys use 10w-40? That's the oil I've stocked up on for my '87 GN for when I get it running again. Plus using ZDDP with it. Is it OK to use 10w-40 with the turbo, and not have any flow problems? My late Dad used to run 5w-30 all the time in it...don't ask me why. I use a thicker viscosity (10w-40) because of higher mileage on my GN. Am I OK using this designation?

Bruce '87 Grand National

 

[Bruce Urie]

From reading a lot of past posts on this forum and the other one, I assumed it was bad to use synthetic oil on higher mileage engines, as it'll start leaking like a sieve. So many posts were negative on switching over to synthetic on higher mileage engines. So, I took the Mobil 1 back to the store and got a refund. I do know that Mobil 1 and other synthetics are terrific for engines, not high mileage ones, as the clearances are large after years of use, with synthetic being of smaller molecular structure, thus leaking everywhere. Am I right on this, fellas? Correct me if I'm correct.

Bruce '87 Grand National

 

[Swathdiver]

All of my cars were purchased used, some had up to 72k miles on them. Their oil seals were already weeping or leaking and the synthetic probably contributed to them leaking some more or was it the additional 100hp+ and all the racing? After 250k+ miles of driving turbo cars of all years I never bothered with additives and see no need for them.