10w 60 Full Synthetic Castrol?!?!?

[RipperXX]

Well I just purchased a crank scraper, so this sounds pretty good, can anyone make any recomendation? DSMLink estimates 302hp now, however it's not tuned yet. And my goal is 380-400whp.

I was thinking royal purple OR if I can find it ams oil. But what weight oil?

 

[95 'clipse RS]

i have actually heard from the local machine shop, that it's bad to run high weight oil in these engines. because of the temperatures the engine runs at, and there isnt an oil splasher to get the oil up onto the cylinder walls, and because of lack of oil on the cylinder walls the oil rings are basically useless. he said 10W50 max in the summer, is this true? if so, would that worsen the conditions if you put a crank scraper on the engine?

thanks

 

[TSIfreek]

Ripper In your climate area I would go with Mobil 1 0/40 amsoil is just a pain to get . Us guys up north cant get away with the stuff you guys use down in florida climate. A fifty weight is not needed and will just put added stress on the oil pump and cause HP loss and increase spool time. PP 10/30 is what I use.

 

[TSIfreek]

Crankscraper is a waist of time. I had one on when I first built my motor and all it did was leak oil around the pan. I took it off and saw absolutly no HP diffrence.

 

[RipperXX]

Well I already have it, so might as well try it out. The idea behind it is sound, and Porsche uses them on a lot of there engines. Also Pontiac used to use them way back in the day of the "big bore" performance blocks. So even if your butt dyno shows no change, it is likely reducing stress on the engine. And I'm trying to "improve" my engine, not just make more power.


Either way i'm going to install it and see for myself. I might even do a right up on it.



Also concerning the 0w 40, isn't a 0 weight oil on the thin side? I mean kinematic viscosity is the first rating correct? which unless I'm wrong is how thin/thick the oil is.
Is there such a thing as 5w40? I would feel more comfortable using something closer to factory spec.

 

[TSIfreek]

The thinner oil the better. Thick oil doesnt cool as well as thin oil because light oil flows so well. You dont want oil sitting on a part you want the oil to do is job and leave to cool so you have a cooler engine part weather its a bearing or cam lobe.
Thicker oil was used back in the day because the engines were set up so loose you needed that thicker oil to make up the clearance. The tighter the clearance the thinner the oil needs to be used.
All you will be doing with heavy oil is straining the oil pump because it needs to work harder to pump the oil. You will lose HP and gas mileage that you will notice.
Thicker oil does prove to give more wear protection. The addditives the quality of the base oil and the oil temp is what protects the engine.
Yea you want a heavy oil in a air cooled engine since it sees such high temps such as harleys but then again the engine clearances are set up for the thick oil.
You will see in a few parts stores now its hard to find 20w50.. 10/40 is the thickest any car engine will need.
If you want the best protection go straight to redline oils.
To answer your question yes there is a 5/40 synthetic but there hard to find.
Castrol syntec 0/30 is an excellent oil you may want to consider. Its a thicker 30 wt oil that is made with high quality base oil and quality additives.
Sorry for the rant but alot of people think they know motor oil but are far from it. I am not saying im an expert but I keep up to date on oil technology.
Got a question on oil I will be glad to help or guide you to someone who can.

 

[yukondoit]

I was just curious about this since I done some journal bearing design. Since rating is divided by load as we increase torque we increase the load on the bearings. while i understand light oil flows the best but it shears the easiest and i would rather loose 5-10 ft lbs just to make sure i dont spin a rod bearing.

TSi freek, that the kind of response i was looking for, as thicker oil you make loose protection on your cylinder walls. I will to dig into my books some more and do some more research.

As of right unfortunatly there isnt crap for castrol syntec in my area, so i went with the 5w40 mobil 1 . I havent noticed a difference from 30, maybe less lifter tick.

 

[TSIfreek]

What kills rod bearings is detonation no oil can help you there.
If that was the case with your load theory then Shep's engine would need some real heavy oil but I have seen in person what he runs and its nothing special.
As far as the oil breaking down thats why we run synthetic to prevent this. Yes I have heard synthetic oil breaking down over its time in the engine royal purple comes to mind.
As far as lifter tap goes yes you will notice a quieter engine with a heaver oil but lifter tap does not harm the engine in any way you may get some knock from it but make sure you have the 3g lifters and there not a 100% either. Its just the way the lifter gets its oil is poor.
The M1 5/40 should work real well for you.

 

[RipperXX]

5w 40 it is, now lets see how much it burns when I go from M1 10w 30 to 5/40

 

[TSIfreek]

Your going to find it will burn less since its a thicker oil. Mobil 1 is a thin oil to begin with.

 

[TSIfreek]

With your car being in a southern climate I would go also with a 40 wt oil. If your still having problems with it using alot try a diffrent brand you may be surprised.

 

[Defiant]

If you have oil questions, look around on http://bobistheoilguy.com

Before the myths get too deep.