What Oil?

[retfr8flyr]

I wanted to know what oil guys are running in their built and blown engines. I’m old school and we always used heavier weight oil in a built motor. Ford uses Motorcraft 5w-50 in the GT and GT500 and I am thinking of using that in my setup for the extra protection at higher temps. Does anyone know of some reason this oil won’t work in the 3v?



Earl

 

[don_w]

I'm running 20W-50 synthetic (Lucas). No problems whatsoever.

 

[MSgt46270]

5W-20 Royal Purple synthetic

 

[US-1]

I've always had excellent success with Royal Purple. From 5W-20 up to 10W30...no problems. We use the 10W30 in damn near everything including Dad's 512" big block T-Bird (8.90's @150). For most of my modular stuff I use 5W-20 until it is pushing 100,000 miles then I will switch to the 10W30.

 

[MikeVistaBlue06]

5W-20 Motorcraft Semi Synthetic & Motorcraft 820S oil filter. I change both every 3000 miles.

However I don't do a lot of racing.....

good oil site: www.bobistheoilguy.com

Mike

 

[G.T]

i guess what really matters is the temperatures the oil will be exposed to..
Mustangs sold here (Dubai) run 5W20 oil.
the dealership uses 10W30 generally.

i've been trying to find out what works best for me.. and i still have no definitive answer

 

[Buzzystang]

i guess what really matters is the temperatures the oil will be exposed to..
Mustangs sold here (Dubai) run 5W20 oil.
the dealership uses 10W30 generally.

i've been trying to find out what works best for me.. and i still have no definitive answer

Keep me posted. Summer here is 110+ on the commute home. Wondering if thicker oil may do some good during those months in the stock engine. Currently running thicker lube in the manual. (50/50 blend of redline ATF and MT-90 (75W-90) and loving it).

 

[MikeVistaBlue06]

I'd be careful with very thick weight oil in these engines. Personally, I would not go over 10W-30 even in hotter climates, and I would use a full synthetic (Mobil 1) if I ever use 10W-30 in mine to ensure good oil flow on cold starts.

I have heard/read, for what that is worth, that the tolerances on these OHV modular engines are much tighter than their old siblings (5.0L pushrod engine), and it is very important that the oil flow easily, especially if it is cold. Of course any synthetic oil will flow better than dino oil.

Of course this is a huge debate/can of worms that has been hashed to death here:

www.bobistheoilguy.com

Also, a wide range in VI can cause the oil to shear down and create sludge. Synthetic oils are not as prone to this issue.

Did you know that 5W-30 will quickly turn into a 5W-20 oil just from the shear?

Anyway, just thought I'd pass along what I've read/heard. If you want to spend hours reading the debates, hit that website above!

Mike

 

[MrClean]

I swear that yesterday, when I did the oil change from Mobil 1 5W20 to RP 5W20 (both full synthetic), the thing felt stronger with the RP.
Regarding heat, the synthetics don't change properties as much as "dino-oil" and therefore under extreme heat (or cold) they continue to perform as they should.
BTW, both synthetics and "dino-oil" start out as petroleum, so in fact both are dino-oil...the synthetic goes thru a process where they extract the molecules they don't want in the oil (molecules that change the properties of the oil as the temperature changes), synthesizing it to meet their specifications, hence the name...this from a Texaco engineer involved in the processing.