Hi all...I'm looking to do an experiment with oil viscosity in an attempt to get my car to run a little cooler. I normally use Brad Penn 20/50 but I want to try 10/40 or even 10/30 to see if it cools better. Which brand should I use for this experiment? Must be available at a FLAPS. Could be dino or synthetic...
Thanks,
Mike

If you want to see if oil viscosity changes the cooling then you should use the same brand oil at multiple viscosity's. So I would suggest you get Brad Penn in different viscosity since you have some history with it all ready.
You also want to sue something you can stay with, which means it need higher zinc levels similar to Brad Penn.

I have been using Swepco oil that has the zinc our engines need.

Jim

Sorry....forgot to mention that the car is a 74 2.0 liter D-jet.
I don't think I can get Brad Penn 10/40 here...

Brad Penn dealer in Calgary.

Classic Performance Inc
27-1410-40 Ave NE
Calgary, AB T2E 6L1
Canada
Carmine
(403) 216-6060

If they won't order it in for you I can get you a case.

Thanks Mark...I buy my oil from Classic these days but I'm pretty sure he doesn't stock anything other than 20/50. I'll call him today....
Mike

You'll be sorry. The oil's a symptom, NOT the cause of your temperature problems, if there are any. If a thinner oil provided better cooling, Porsche and VAG would have either used it to begin with or issued a service bulletin changing the specifications. You're just gonna end up with oil pressure issues.

The Cap'n

I'm also a believer in the new synthetics. With the temperature variances of these air cooled engines, the synthetics do not break down with high heat like the dino's do. Even the good dino's (re: Brad Penn) will break down due to thermal conditions.

New synthetics also have the proper zinc additives to make old air cooled engines last.

The Joe Gibbs stuff is the expensive version and I believe there's a new Valvoline that is less expensive and can be purchased over the counter at your FLAPS. Look for the synthetic with zinc additives.

If you just mean "cooler" than it currently is and, it's currently running within spec.; I'd simply make sure I was using a great oil and be done with it. If you mean "cooler" because you're having overheating issues; head John's advice and find the real problem. Hint: It's not your oil.

http://www.valvoline.com/products/consumer...ing-motor-oil/9

https://www.google.com/search?q=Valvoline+V...680&bih=892

Looks like our friends at JC Whitney (haven't bought anything there in 35 years!) have the best price. 10% off today and free shipping. SAE30 or 20-50:
http://www.jcwhitney.com/vr1-racing-formul...dDetailTabPanel

Good points guys...thanks. I was thinking lighter weight equals better flow through the cooler...

Do a google search on viscosity vs oil temps. You'll find some interesting reading.

Eric on the Valvoline oils, do they have enough zinc? If they are meeting the current guidelines they may be below 800 ppm. But seeing it is a racing oil they are likely higher but I did not see a level in the descriptions.

I am currently of the belief that some oil manufacturers are putting zinc into the 20/50 weight of oil but not into the 10/40 weights

I think the valvolene racing dino is this way

I'm putting break-in miles on my home rebuild 2.0 FI using QS Defy 10-40, which is labeled as added Zinc. When I get all the bugs worked out I'll switch over to Royal Purple HPS 10-40. I'll be interested to see if any differences happen in cylinder head and oil temps and gas mileage going from dino oil to synthetic in general and RP in particular.

Before I tore this engine apart I switched from PO unknown oil to RP 15-40 and got a significant increase in gas mileage, tho I only went thru two tanks of gas before I pulled the plug. I switched from dino to RP in my 225k mile Toyota MR-2 and also in a Miata I had for awhile and got a definite 10% increase in mileage. I wonder if that will be the case with this rebuild and if so, will it show up in oil temp?

I'll be interested to read your results.

brandt....what makes you think that?

eyesright....does Royal Purple have the right amount of zinc?
Mike

the zinc wording and labeling is different between weights within some brands...

the valvolene vr1 20/50 uses different labeling about zinc than does the valvolene vr1 in other weights...
(look at the bottles side by side)

the regular royal purple does not have the necessary zinc.
but the royal purple hps, and race do have it
I use the hps in my race car

(my engine builder has a couple dozen motors on this and it is info direct from the RP tech department)

brant

I agree. Different weights of the same brand will have different zinc content, at least on the label. QS Defy comes in several weights but only 10-40 is labeled added zinc.

And the RP people answer emails quickly, tho I'm sure they are canned responses to the same questions. They say that regular RP has the max allowable zinc, and that HPS has XXXZinc...I think they listed the amount tho I have forgotten specifics. And its only $0.50 or so more than regular RP.

My pals at O'Reilly's kept bugging me to switch to RP based on their sales rep's videos and info and that many of them were using it with noticeable MPG results. I'm one of these nuts who calculates MPG at every fillup and was skeptical...but I'm here to say. And so 10% increase in mileage should be an indication of less friction/heat. We'll see if it actually is measureable on my engine with my cheap VDO gauges.

BTW the reps say RP won't have AS much mileage effect in larger engines for whatever that's worth.

Thanks....I'll look for some of that Royal Purple...

I know the whole zinc issue has been done before and some buy into it and some don't. But if you are considering an oil check the material safety data sheet (MSDS) to verify the levels. They usually list the values in percentages. So multiply the % by 10,000 to get ppm 0.08% x 10,000 = 800 ppm.

Probably everyone knows that but thought I would pass it on just in case.

Sure looks like one to me...

Nobody can resist an oil thread! They're like potato chips.

If anybody sees an MPG difference between dino and synthetic I'd be interested to hear brands and how much mileage change and cost benefits.

What about Diesel oil? The reason it is for diesel is because it has higher detergent, and much higher ZDDP that foul up catalytic converters. However, we dont have them (most of us) and it is also cheaper per qt. I bought a 9qt container of Rotella T 15-40 for the corvair yesterday at my FLAPS. Cost as much as a 5qt of regular

I've owned my 74 2.0 for two years (this will be my 3rd summer) and ran BP 20/50 the first summer, switched to BP 10/30 for the winter and experimented by staying with 10/30 for the 2nd summer.

Because it was not a back to back experiment nor done with any scientific data recording or controls I cannot prove it runs cooler, but I would say that it does (I haven't hit oil temp redline with either).

In NH I have not had any issues with low oil pressure that some might experience further south in hotter climates. So I am not saying 10/30 is for everybody, but I am saying that 20/50 may not be for everybody either YMMV.

Stepping outside of Porsche and air-cooled motors for a minute I can tell you that if you take a heat exchanger and increase flow through it, everything else being unchanged - you are correct in assuming that it will remove more heat.

Whether there is enough of an increase to make a difference that you can see on the temp gauge in a 914 hasn't been proven or disproven as far as I know, but I am going to stick with the 10/30.

Since this is not another oil thread, I will not hijack this post by asking a newbie question of does zinc content matter if you all you want to do is daily drive, not race, and change your oil often?

Yes, it matters in flat tappet engines. It improves the shear capacity of the oil, reducing camshaft lobe and lifter wear.

The Cap'n

Yes! it forms a sacrificial layer that gets worn away and replaced, thereby protecting your flat tappet cam and lifters.
No amount of oil changes without it will protect against this wear and it doesn't matter if you baby it!

lack of zinc can flatten your cam lobe even as just a sunday driver
even an occasional use vehicle..

also it happens a lot quicker than you think
and changing oil often doesn't help reduce that wear.


(Diesel oils have changed their formula in the last 5 years and no longer contain the zinc they used to)

The chemistry involves more than zinc (zinc dialkyl dithiophosphate - ZDDP). But because this is not an oil thread I will hopefully summarize the requirements. As the Cap'n stated the metallurgy of our cams and lifters were designed to work with certain levels of zinc and other additives to produce acceptable wear properties. Modern oils have lower levels of zinc and other additives which results in faster wear.

There is great debate on what level of zinc is needed for our engines. But it seems that the range is greater than 0.08% and less than 0.12%. These values can vary greatly but seem reasonable. However, more zinc (above 0.12%) does not mean less wear. Some break in oils are very high in zinc and should not be run as everyday oil. If you use a zinc additive, some don't have the correct additives ratios (molybdenum disulphide) required to prevent wear.

What ever zinc number or oil you pick, it seems like the best guidance is to use an oil as close to what was specified by the manufacture at the time the engine was made.

Crap! It looks like this is another oil thread!

Shell Rotella T Diesel with Triple Protection, 15w40, is claimed to have 1200PPM of ZDDP, plus the other added benefits

Excellent Guys. Thanks for helping a relatively new 914 owner understand. Most of the threads on oil involved autoX or racing, so I wanted to be sure.

PS - Zinc dialkyl dithiophosphate - ZDDP..... now you're talking language this chemical engineer can understand

I you want more detailed Google Steve Maas and ZDDP. he presents a number of good references. The ZDDPlus site also has some good information but you have to keep in mind that the articles are slanted to sell their additive.

Also Joe Gibbs has a pretty good write up. I can email these if you want. PM me with you're ail if you want them.

I ran Rotella in all my drag bugs back in the day. Good to know that the Zinc levels are back up. I still am a Brad Penn user myself as it's been thoroughly vetted by Len and Jake. Wish I manage to do a back to back with Jake's "Snake Oil", but it's just too damned expensive to be messing around like that.