5w20 in High Performance Turbo Engine

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I just rebuilt a 4g63 turbo 2.0L DSM engine with higher compression pistons (forged wiseco units) stronger rods, obviously new bearings, oil pump and so forth. I was thinking i would run a good synthetic 5w20 (M1 Amsoil redline royal purple, the high dollar ones) after a proper break in on dino. I plan on running around 20lbs of boost through the engine, but the car will be mainly a daily driven weekend warrior so it wont see wide open throttle for more than a few seconds on a daily basis and on weekends it will streatch its leg a little. do you guys think i am crazy for wanting to run a 5w20?

PS
if you need any more info on the engine just let me know.
 
How much did you enjoy the re-building process and would you like more experience with it?
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At a minimum, I'd run a thicker, ACEA "A3/B4" rated, xw-30.

TS
 
I love 5w-20, but the only one i would run in that motor is Red Line. With 5w-30 i'd run any good brand synthetic, extra peace of mind with the 30w since the motor will no question shear the oil down pretty good.

BTW, is it a 6 bolt or 7 bolt?

[ September 16, 2006, 06:41 AM: Message edited by: sxg6 ]
 
If the original engine design allowed a typical 10cSt, HTHS 3.0 cP oil to provide the necessary film thickness to provide a reasonable amount of wear, then if you keep the oil temperature at least 10°C cooler than what was considered it's max temperature, you could conceivably get away with it. You'd also have to insure you had adequate oil flow to all the critical components.

Now if this engine is modified to produced power levels way beyond it's original design, all bets are off. NASCAR engines are a good example. Take an engine design, double the operating RPMs, triple the HP, run them on oil half as viscous, and they last only 500 miles before they need a rebuild.
 
I had a 92 Talon TSI with a 16G and ran Valvoline VR-1 10w-30. I helped a few guys with rebuilds etc. I personally would not go any lighter than a 30 weight in a 4G63 if your running major boost from a big turbo, which it sounds like you'll do!!

But I do agree with 427ZO6; IF you have a thermostatically controlled LARGE oil cooler with an oil temp gauge and the oil never gets above like 220 -230, then you'd likely be OK. These motors do have a huge bearing footprint to distribute the load.

FWIW though, I guy I knew with a 20G and everything to support 25 lbs - his oil would skyrocket to 260 during hard runs so with 20 weight, you have less safety margin.

These motors can safely/reliably handle 400+ hp all day long on the factory mill, even when abused, but man o man, I just think you'd be pushing it with 5w-20. Redline 5w-20 is a different animal though
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Motorman 358, what is it with your fascination with 5w20 - are you just looking to get max hp even to the point of wanting to cut oil pumping losses (hence the 20 wt oil)? I figure it's either that or you're operating in an especially cool environment - I note that you live in Milwaukee. As a boy I lived in Two Rivers and I can testify that it does indeed get rather cool there.

Howvever, there are other oils you might consider in the 30 weight range that would hedge your bets against an oil related failure - GC comes to mind because it is robust and relatively easy to find. Pscholte is the main sponsor of this oil but I can tell you the stuff is great. It passes my freezer test with ease and I have used it in cars going across west Texas in 111 degree heat (while driving 90+mph!). LIke some of the other posters here I wonder why you want to use 5w20.......
 
Are you going to do a couple of uoa's and let us know how the oil does? If you step up the use gradually you'll have a better chance of getting a uoa before it blows up. When the 20 weight gives it up, you might still be able to get enough oil in suspension to get a final uoa. We had a guy in the shop that tried 5w-20 in a hopped up 1.8 VW with a turbo. He went right out on Saturday night and came home on a tow truck. He did not get even one uoa. I looked at the engine and it blew up the turbo. He made a high speed run on the freeway, pulled into the local burger joint. He said that when he slowed down it made a terrible noise and a lot of smoke and went bang when he shut it off. He said that when he asked the dealer, after looking under the hood, about the warranty, the service manager just laughed. When they tore the engine down they found a lot of the valve train in the pan, in little tiny flakes and a siezed turbo. I wonder if the thinner oil just gave it up, when a thicker oil might have saved the day.
 
You will eke out maximum power with a 5-20, but with 20 lbs of boost, I'd use a 5 or 10-30 synthetic, and maybe a little more.
 
I don't understand how using 5w-20 could blow up a turbo. I'm not so sure the 20wt is to blame in that situation, because lets not forget.. Many 30wt's will shear down to a 20wt with use, especially in turbocharged applications.
 
I run 10/30 PP in my built motor year round and is what I would recomend. You will not gain anything using a 20 wt. With looser piston to wall clearance and the notorious lifter tap 30 wt is the way to go. Anything above that you loose MPG and turbo spool is slower.
As far as brands I have had good luck with the PP. I have tryed them all and this oil seems to work very well in my motor and its affordable.
I would also run the 90 air to air oil cooler to keep the oil happy. These motors get hot and need a good oil cooler.
 
I don't understand how using 5w-20 could blow up a turbo. I'm not so sure the 20wt is to blame in that situation, because lets not forget.. Many 30wt's will shear down to a 20wt with use, especially in turbocharged applications
Just playing the devils advocate here but what do you reckon 5w20 shears down to in a turbo application?
 
Theres no question i think most 5w-20's would probably shear down pretty good in a turbo car, which is why I would only feel comfortable running RL in that weight. I think i hear what you're saying though.
 
quote:

Originally posted by LarryL:
We had a guy in the shop that tried 5w-20 in a hopped up 1.8 VW with a turbo.

Well...there's your problem. It was a VW 1.8 Turbo. The stock, normally aspirated versions of these engines generally have a hard time surviving on anything less than a thick, sheer stable, Xw30 when driven hard. Also, look at all the additional VW oil specs on top of the already believed superior ACEA specs.

But even given all that, I find it hard to believe that the oil caused the engine to destruct in one night use unless something else was amiss.
 
sxg6, its a 6 bolt with eagle rod, wiseco piston combo at 9.0:1 compression arp hardware all around, not a huge turbo yeat a vtrim, king bearings, dks 272 cams, new oil pump with removed balance shafts (oil pressure should be absolutely wonderful), and a 90 oil cooler setup.
 
sxg6
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Member # 4140

posted 16 September, 2006 06:18
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Theres no question i think most 5w-20's would probably shear down pretty good in a turbo car, which is why I would only feel comfortable running RL in that weight. I think i hear what you're saying though.
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Posts: 1040 | From: maine | Registered: May 2004 | IP: Logged |


I may be wrong here but don't you need a butt load of vis improvers to shear an oil?
 
There's no way to know what blew up that VW engine. I don't think the 20w oil was the right oil for the job. I think that unless the engine is made for 20w oil, you should not use it. If you do, please do a uoa and let us know how it goes.
 
Even if you could keep oil temps similar to stock which I don't think will happen even with the oil cooler, your putting a much greater load on the bearings. I'd still go up to at least shear stable 30W unless you're running higher oil pressures but that would probably also cause some parasitic loss.
 
quote:

Originally posted by goodvibes:
I'd still go up to at least shear stable 30W unless you're running higher oil pressures but that would probably also cause some parasitic loss.

Oil pressure has nothing to do with it as long as the oil flow is sufficient to keep up with the needs of the hydrodynamic bearings.
 
It matters if it's a regular journal bearing turbo that relies on oil pressure to keep the wheels from wobbling.
More so if he's got the old T04B oil-cooled center housing.
Add to that the stiffer valves springs and larger cam(and higher redline?).
And a T3/T4 (or T28/T4) V-trim is good for 400-500bhp?
T04B V-trim, 402whp @ 25psi. stock cams?


I'd use a ACEA A3/B3, A3/B4, or A5/B5 oil (most are xW40?) in a turbo car. GC would be about as thin as I'd go.
www.infineum.com/information/consumer.html
 
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