Dezod Motorsports.

I was affiliated seperate back in the day.

 

does that mean you dont work for them no more ?

 

I work for Paul here at Dezod.

 

Sorry for the tone of my previous post. I've just never been a fan of 10w40 because of the wide viscosity range and the extra polymers needed. I prefer 10w30, 15w40 and 20w50 but TBH I'm not sure which viscosity oil is best for newer engines spec'd to run 0w20 and 5w20. Is it really safe to run 20w50 in these engines?

BTW, I didn't mean to necessarily recommend high Zinc content oil but was merely commenting on it's metal to metal protecting properties.

 

I would only run much thicker weight oil on a rebuilt motor that was intended for boost.

Built engines for boost applications are intentionally built with looser tolerances compared to built motors for NA applications.

Our stock motors are built with relatively tight (not as tight as a Honda B18C) but I wouldn't recommend much heavier than 10w-30 unless you've rebuilt the motor with not as tight tolerances.

 

I understand,

I like 10w40 because on tighter toleranced engines that are still factory it allows for a little more protection from thermal breakdown than a 10w30. It still retains identical low temp viscosities as a 10w30. It's the higher end I'm more concerned about. As it heats up from the added heat of a turbo charger it will resist break down. Besides if you want to protect from coking up and things like that just let the engine idle for a minute before the turbo shuts down so heat is not concentrated on the turbine shaft. This will also help prevent sludge build up in the engine. Also, almost all 15w40 engine oil I have seen is Diesel engine only and not formulated to run in a gasoline engine. Will it work, maybe but I have never tried it.

I also think the main point you guys tend to miss here is not that I'm concerned with the mileage, as that is what thinner oil was designed for. Im concerned with bearing failure on high horsepower cars or engines that were never designed to be turbo from the factory. These engines have to withstand hell when being tuned.

For instance.

Here are the recommendations from a 1991 Toyota Celica All Trac with a 3S-GTE turbo engine taken from the factory service manual.

API Grade: SG multigrade or better and recommended viscosity SAE.

Use the chart below to determine SAE viscosity by temperature range anticipated before next oil change:

Temperature Range Viscosity
Above 0°F 10W-40
Above 0°F 10W-30
50°F and Below 5W-30

Now, here are the bearing clearances.

Connecting Rod: 0.0009-0.0022"
Main Bearing:0.0006-0.0013"

That is a thousandth to a thousandth and a half of acceptable clearance.

Seems pretty damn tight to me.

Now.

Here is the clearances of an 07 Scion TC 2A-ZFE

Connecting Rod: 0.0009"-0.0019"
Main bearings: 0.0007-0.0016"

As you can see here the two engines have identical clearances. The only difference is the maximum serviceable clearance.

Tens of thousandths of an inch are not going to make the difference that you people are thinking.

The number one reason thinner engine oils were ever developed was for tighter federal emissions and fuel economy regulations.

Also here are the clearances and oil recommendations for a 1991 Mitsubishi Eclipse with a 4G63T one of the strongest four cylinders ever produced.

Main Bearing:0.0008"-0.0020"
Connecting Rod: 0.0008"-0.0020"

For a long time factory fill for this engine in those years was 20w50. In 1991 they revised that with a TSB (technical service bulletin) that stated the use of 10w40.

 

Thanks! Very informative post. For many years I ran 10w40 and 20w50 exclusively but in recent years I went to 10w30 synthetic instead. I've been running 5w20 Mobil One in my Scion but after I get my turbo installed, I'll switch to 10w40 synthetic.

BTW, I haven't used 15w40 in a car but I use it in my motorcycle because of the wet clutch and tranny. I don't want "energy conserving" oil in it. FYI, I have a jug of Shell Rotella T 15w40 here that is API rated for all gasoline and diesel engines. It carries the highest possible ratings of SM and CJ-4.

 

Hmmm I need to read shell rotella jugs more.

 

In addition to this the EPA has reduced the maximum allowable amount of zinc and phosphorus the oil manufacturers can put in standard oils. Racing formulated oils such as Valvoline VR-1 series or Brad Penn have higher contents because they are intended for racing use. As for oil clearance, on blue printed small journal engines (ie import) I shoot for .002 on the mains and .0015-.002 on the rods. On the large journal stuff (ie domestic V I set both to .0025-.003. This is applied to everything from B18 to 2jz or 350hp small blocks to 1500+ hp big blocks. And I cant stress enough the importance of oil coolers. It does not matter how much you spent on your parts, get the oil too hot and its all junk.

 

I agree.

In addition to what you said about Valvoline and Brad Penn. Those oils were introduced because as newer service oils have become thinner they have also limited the additive packages such as zinc, moly and phosphorous as well. Older engines with heavy valve trains and high spring loads were now experiencing lubrication issues. Older domestic engines were having cams being wiped out etc. So makers like valvoline, brad penn and joe gibbs are manufacturing these oils for use in older engines that were designed to operate with oils high in zinc and phosphorous.

It would seem as oil technology was advancing that it was leaving behind alot of the old engine technology.

 

So very true. We have been pushing retrofit roller cams heavily for the last couple years because one in three flat tappet cams will go flat within a year.

 

Run a synthetic oil with an ACEA rating of A3 and forget about the API. The A3 rating is designed for high performance cars in Europe. Something like Castrol 0W30 European Formula good be my choice (has to say Made in Germany on the back). This oil has more anti-wear additives (zinc and phosphorous) than most "Energy Conserving" oils out there. It's operating viscosity is 12.1 cst, which makes it almost a 40 weight. The HTHS (High Temperature High Shear) Viscosity is at least 3.5 mPa.s, as dictated by the A3 rating. All "Energy Conserving" oils will have a HTHS viscosity of less than 3.5 mPa.s. Lastly this oil carries specific manufacturer approvals from Merc, BMW, VW, GM, etc.

Also do regular oil analysis. There's no way to know if the oil you're running is protecting your engine unless you have it analyzed by a lab. If you can spend thousands on a turbo, you can spend $20 on an oil analysis.

More info on oil analysis and motor oil in general can be found here --> http://my350z.com/forum/engine-and-d...-and-info.html

 

Good info

 

How do you remove the head from the motor. Is it hard for a novice? I have to replace a valve i bent. Anyway any help will be greatly appreciated

 

You need a triple hex socket to remove the stock head bolts. Obviously you need to remove the timing chain and covers. After that it's not that difficult.

 

what ever happend to Joe?

 

That's Dezod West. He is still around.

 

https://www.scionlife.com/forums/vie...639&highlight=

don can you please look at this thread and let me know what the correct information is ? please I cant seem to find it unless I take a motor and rip it apart. you seem more familiar with it.

 

Need a head thats not on a motor in order to get a chamber cc. Chamber cc is not part of the engine displacement calculation.

 

I know. I was trying to figure something out to figure out how to get a turbo that will be the most efficient.