Did, ok looking at the first chart viscosity at 100ēC for 20w says 5.6

Now look at RX7 Rages viscosity at 100ēC for 10-30w 7.46 for the 4k mile/right side

said 1000mile/4000mile

So the oil thinned out some, but its still thicker then 20w. This is at 4k miles, I really do not see what the problem is here. I must have a low IQ

If you change your oil every 3k I don't see why anyone would have a problem.

 

I understand that, but what is being changed inside the rotor housing's after we add the single turbo, stand alone, fuel, and bolt on's?

The oil pump is still flowing the same amount of oil, so we have more fuel/air coming in due to the added air flow from the single turbo, but still the same operating temp's and spark.

We have removed all the tiny ovens in the engine bay (cats, twin's with manifold, intercooler) so the engine bay now should run cooler then coming from the factory.

vented hood, intercooler out of the engine bay, no cast manifold, new radiator, and 1 turbo.

I would think now with the factory heatsink being removed off of the block, lower AIT's, exhaust gases getting out faster, and lower coolant temps the oil should be a little bit cooler then before when these cars rolled off the showroom floor.

 

the oil has 1,000 miles on it (the engine has 4k), it's already down to a 20 weight: not good

http://www.bobistheoilguy.com/visc.html

 

Oh so it's the other way around.

 

Ok since its the other way around its 7.66 for 4k and 7.46 for 1k, that can't be right. A oil can't decrease in viscosity and then increase.

After 1k miles the oil broke down in viscosity quiet quickly, but it maintained it well for another 3k. It only dropped .20, and you should change your oil by then. If you are paranoid about this and want to stay safe you should try a 40w oil. It will be above a 30w after 1k and 4k miles if your engine is like RX7 Rage's.

 

The 7.66 were the readings prior to the latest reading which is on the left. I took the sample on the right at 1500 miles and the samle on the left at 1000 miles.

 

Oh, right on. I would like to see a 3k data sheet to see what the viscosity is then, to see if running 10-30w is pushing the limit or not.

 

I'm actually interested in taking a bit of gasoline and a few unused oils to see what fuel dilution does to viscosity for several engine oils. We have a brookfield viscosometer at work and I might be able to measure the viscosity of the samples for free. This would investigate:
1) how much viscosity change is actually caused by the gasoline
2) to see if one oil holds viscosity better in the face of fuel dilution.

One thing that isn't clear to me is whether the viscosity loss is due mostly to fuel dilution, shearing in the engine, or both.

Dave

 

i support your cause :

 

A worthy endeavor indeed! Here here! If you were to take this on and report, we would all be indebted.

 

You should measure out the total oil it takes to fill the pan in a FD, and measure out 3% of gas and then mix the 2. Test it, I think it will answer 1) because then you can compare it to RX7 Rage's, he drove the car for 1k miles and got 3% dilution then 1500 miles and showed 2.5% dilution. Then you can do a comparison between used and unused oil.

For 2) should be easy to see which one of your selected oils mixes with gas the best. Pour gas in a container, and then pour the oil into the container containing the gas. A clear container would be best.

I'll be very interested in seeing your results, its great if you can get the samples done for free

 

I make no promises. If it's going to risk damage or contamination of our brookfield tool I assure you it won't be happening.

Dave

 

acknowledging Rich's previous comment about shear forces in these engines, I think it's pretty obvious the viscosity loss is almost entirely due to fuel dilution, the oil isn't going to shear down that fast after only 1,000 miles

from p. 3:

http://www.performanceoiltechnology...._0702_2004.pdf

http://www.analaboratories.com/commo...e/oiltests.asp

http://www.machinerylubrication.com/...up=Lubrication

 

This is one of the best articles discussing oil temperatures, viscosity and weight that I have found. It will really give you a new perspective on our oil selection.

The “Cliff Notes”:
We need flow not thick viscosity.
More flow cools bearings better.
Cold start up is toughest on wear.
Our filters are by-passed on cold start-up longer with high viscosity oil.
Viscosity selection should be determined by pressure at RPM in relation to oil temp. (Manufacturer’s specification 50psi @ 3000rpm minimum)
Racing temperatures require higher viscosities.
Most manufactures recommend 10psi per 1000rpm.
http://ferrarichat.com/forum/showthread.php?t=136052

Barry

 

Well then someone with a good oil pressure and oil temperature gauge (mine's just stock) could provide some interesting data by tracking how that changes over the life of an oil change. Watching oil pressure decrease could be useful in determining when an oil change is due.

 

I would like to know the idea for this post and all the information in this thread, are you guy's saying no don't use 10-30w? If so what's your reason for using something else and not 10-30w?

We know all this stuff about oil and what the test result's mean, but what should we do about this fuel dilution situation? Go to a thicker oil? Synthetic? If we go to a thicker oil then what about the added pressure and stress on the omp? Is there any type of modification or upgrade we can do to help combat this contamination?

 

Idemitsu 20/50 synthetic from Rotary Performance

 

agree 100%...even with a stock gauge, I notice the difference

 

What are the bearing to shaft clearances like on your engine compared to stock?

 

I am going to give this oil a try, since it's produced for our applications

It's priced good to

 

get your dilution tested, change your oil in very frequent intervals and you shouldn't need to run a thick oil. Myself and others have posted why you shouldn't run a thick oil, others have posted why you should run a thick oil, don't go with someone who just drops an oil weight in a post and doesn't explain why, he runs race engines that see very high heat that warrant a thicker oil. Are you running a race engine or a street driver?

 

how about using single weight oil in year roung warm climate (PR)? sae 40 or 50? most ppl use 20w50 for rotaries here

 

I am talking about using the brand idemitsu, I run 10-30w. The FSM says to use 10-30w so that's what I use.

I have read a lot about ernies setup and what he does with his car. I am in no way going with what someone else says to use, I research before I decide on what type of oil I will be using.

 

Race engines = very short oil change intervals and little concern for engine wear.

In the practical world we don't change oil after every trip.

 

All I was trying to say was race engines typically use higher viscosity because of high heat, wider clearances, and no concern for cold start wear.
But even that might be debated since high rpm's requre a ton of flow. So yes, it would be nice to watch oil pressure with different weights of oil like you were mentioning.