unique oil needs

[rockyrunner99]

hi, I have a 99 dodge neon, that I have rebuilt and modified. It has High compression, 11.5:1, and has some rhodes bleed down lifters.

I am looking for an oil like Mobil 1 0w-30, that will be as close to the same viscosity at start up, and normal operating temperature, as possible. I would also like to avoid having large amounts of polymers in the oil, because of the high compression. At one time I heard that full synthetic oils do not use polymers to modify the viscosity, is this true?

I am also fueling this with E85, I don't think I need anything special because of that right? the engine was just rebuilt, so there is no build up of deposits from gas too wash down in the oil. thank you

 

[JAG]

Most synthetics these days have polymers in them. The way to minimize them with common brands is to use 10W-30, not 5W-30 or 0W-30. If the oil is synthetic and the viscosity index is less than around 150, it likely uses a relatively small or no amount of polymers. Amsoil has an oil called ACD which qualifies as 10W-30 but uses no polymers.

With high compression engine, if it will be running right near the onset of knocking, it will be advantageous to pick an oil that will minimize combustion chamber deposits. These can come from metallic additives in motor oil or carbon deposits, which some metallic additives help minimize, so it's a tough call for what will work best. You may have to experiment with different oils if this becomes a problem.

E85 can cause issues with water buildup in the oil when driven short trips often in very cold weather. The water sinks to the bottom of the sump, then freezes and during startup the engine croaks. That's a rare, extreme thing but worth mentioning for the heck of it. Otherwise, no worries and consider using Fuel Power fuel additive called FP Plus.

 

[rockyrunner99]

does the FP plus help with the water issue? This car will not be driving short trips, I have a 35mile commute! I may not even be driving this car in the winter, at least much, or the really cold days.

 

[JAG]

I think FP+ is adverstized as being able to solubize water in the gas tank but water that ends up in the oil from blowby is another matter. So I think the answer to your question is no but you shouldn't have an obscene issue anyway with 35 mile commutes.

 

[Steve S]

I would recommend that since you are wanting syn oil for your engine to run the ACD Amsoil as well.Don't worry about the start up viscosity and all that.It really does not matter in the whole picture of things. "untill it is cold enough for the oil to take a long time to get to the pump , like sucking a thick milkshake through a straw".

 

[Bob The Builder]

With that high compression ratio you're running, wouldn't you want to use a high octane gas? I don't think water in the oil is something you'll have to worry about.

 

[Gary Allan]

Quote:
that will be as close to the same viscosity at start up, and normal operating temperature,


this is such an unusual condition/requirement ..I need to ask why do you consider this important? A 30 grade synth will have about 6.5X the visc @ 40C as it will @ 100C.

Now if you've got some high oil volume and your limit is very close to your idle HOT pressure ..the only remedy is to use lighter oil.

 

[rockyrunner99]

To answer some of the questions above and clarify some things.

E85 is high octane 100-105 octane depending on the mixture of gas and alcohol, supposedly it can very from 70/30 to 85/15.

The reason I am concerned about the viscosity on start up is the bleed down lifter I have. For those of you who may not be familiar with those, they are sort of like a shock absorber. There is a cylinder, within a cylinder filled with oil and a spring. At low RPM's as the lobe of the cam starts to lift, the lifter gives in. Reducing the amount of lift the cam has, and smoothing out the idle. At high RPMs the cam opens and closes again fast enough, the lifter gives very little, retaining the full lift of the cam. When I first start the car, the oil is thick, and the lifters don't give nearly as much as when the car is warm. This is causing a little bit of a tunning and drive ability issue. It idles really rough when first started. After it warms up though, it is perfect! I guess that is the trade off for that big of a cam.

 

[Quest]

Originally Posted By: rockyrunner99
is the bleed down lifter I have. For those of you who may not be familiar with those, they are sort of like a shock absorber. There is a cylinder, within a cylinder filled with oil and a spring. At low RPM's as the lobe of the cam starts to lift, the lifter gives in. Reducing the amount of lift the cam has, and smoothing out the idle. At high RPMs the cam opens and closes again fast enough, the lifter gives very little, retaining the full lift of the cam. When I first start the car, the oil is thick, and the lifters don't give nearly as much as when the car is warm. This is causing a little bit of a tunning and drive ability issue. It idles really rough when first started. After it warms up though, it is perfect! I guess that is the trade off for that big of a cam.


Sorry, dumb as I am, never heard of such device...

Care to give me some URLs?

Q.

 

[Steve S]

I would think the high compression is good with the
E85. But you should drive easy till the engine warms up no matter which oil visc is used. I know those lifters. they are high bleed down lifters they leak oil out quicker than regular lifters which reduces the Cam lift and duration.

 

[rockyrunner99]

yeah, I agree I always drive easy till the car warms up. the issue is the drive ability. When the car is cold, it idles rough, and is very lurchy in first and second gear. I would just like to reduce this as much as possible, and I think the right oil could do that.

here is the website to the lifters. http://www.rhoadsproducts.com/
This is the first I have ever used them, they seem like a great product and a great idea, now just gotta find an oil to help them work better when cold.

 

[JAG]

Consider an oil pan heater and/or block heater.

What oil are you using now?

 

[Gary Allan]

http://www.amotion.com/tech/rhoads.html

They appear to give you the difference between a 1.6:1 and a 1.7:1 ratio rocker in one package. I've heard of them (iirc) quite a long time ago in J.C.W. Kinda neat way to micro-manage daily driving characteristics with extended performance.

I'm with Jag too. You can't get 900VI oil ..so compress the environment to compensate. You're into collisions of pressure limits, pump output volume, and oil temp and it's a bugger to "per-fect" without some concession somewhere.

 

[rockyrunner99]

right now I am using citgo 10w-30. I have used 5w-30 in the past but have been more concerned about the polymers add to oils. how much of an issue are they really? They are more of an issue with higher compression right? I have heard mostly diesel guys say they can really be bad. Anyway, I know oil is not going to solve everything, but I think there can be an improvement. Basically I just want to know what 0w-30 or 5w-30 has the least amount of polymers added. Or if you guys think I even need to be concerned with that. I am putting out over 100hp per liter, and would like to get well over 100,000 miles on this engine too!

 

[JAG]

You need to experiment with another oil to see how much it helps. Go "extreme" to test the waters and buy some 5W-20 oil. See how it does and go from there. If it doesn't help much, then you'll need to do something else besides choose the most ideal oil to resolve the issue.

 

[Gary Allan]

Lighter oil is your only simple solution to your lifter thing. Whether that's compatible with the rest of your story ..that's another thing. Long term usage in a daily driver capacity of a higher output engine (not engineered for such service at that output level) is not all that simple.

Just out curiosity here ..what's your pressure ceiling and what's your normal idle pressure hot and cold? The trick is to have all of the oil volume fit through the engine at higher rpm operation where max stress is endured. It does little to have too thick an oil only to have it slam up against the pump relief and reduce flow.

 

[rockyrunner99]

unfortunately I do not have an oil pressure gauge. According to the manual, maximum pressure should be 25-80psi at 3000.

just to be sure I understand your point. If I had 80 psi at 1500 rpm(I know I don't but for example) that much pressure would be pointless, and I could drop down to 5w-20 or 0w-20. Is that what you were thinking?

After doing lots of research the last couple days I have more general questions about oil. The polymers that are supposedly bad for engines, are the polymers them selves bad, or is it they breakdown over time loosing the oils protection?

 

[Gary Allan]

This may make sense to you. I have a grossly over sized oil pump on my 4.0 engine. I MUST use a 20 weight if the full output of the oil pump is going to go through the engine. If I use a 40 grade, I'm @ 58lbs at startup ..and will always be at 58lbs off idle. It's the same with a 30 grade ..except that I'll have a lower hot idle pressure and have to reach higher rpm (not much) for the pump to go into relief. Only a 20 weight gives me (the same) 58lbs at startup and "fits" the entire sensible output of the pump at any rpm (after full warm up).

The higher grade oils reduce the flow to the engine. Now whether this makes a difference in terms of "wear" ..that's up for debate. No matter what (in my case, anyway), I'm seeing much more pressure and flow than the stock oil pump which peaked out @ 42 cold and managed 12+/- at hot idle with a 30 grade.

Rocky ..man, get an oil pressure gauge. It will be very had to figure anything out without one. You're blind.

 

[mechtech2]

Ethanol has a high octane by itself.
But it is blended with gas, and any additives are reduced, to get to the desired final number.
So alcohol's inherent octane doesn't matter.