rotella t4 oil

[Chickenman]

6 hours ago, rcb280z said:

I guess I haven't either. Must just be a personal preference type of thing. 

 The domestic scene was flooded with this problem in the mid-2000's. SBC's and BBC's  were particularly prone to the Cam eating issue.  That is because they have a smaller lifter diameter than Ford's and Dodge engines. It affected Muscle Cars and Hot Rods with GM motors the worst 

In Nascar  racing, the Dodge engines had a real advantage when they first started using restrictor plate engines in the 80's. Dodge had the largest diameter lifters of the three engine Manufacturers, and it was a huge advantage for  Dodge for a while.  Ford had the second largests lifter and GM  was just screwed ( Nascar engines wee production based and based on stock dimensions )  

Restrictor plate engines required Camshaft profiles that had really fast acceleration ramps to maximise the Lift area under the valve. GM was at a disadvantage because of their smaller lifter diameter.  It increased side loadings on the Lifter and overall pressure on the Cam lobe. There were a few years in the early to mid 90's when GM SB2 engines were popping right left and center because of the Lifter design,  and even the best Racing oils ( Full synthetic )  at that time couldn't keep up with the massive Valve accelerations they were using. Of course Nascar is very restrictive, so GM was stuck ( for a few years ) with their bad design. It was around this time that Joe Gibbs Racing started developing their own purpose built oils for the Nascar GM engines.  Valvetrain failures decreased on the JGR engines and they dominated for a while. In later years GM came out with some re-designed engines. In 2007 they introduced the RO7. Nascar rules had relaxed a bit  bye then and they were allowed to build essentially " Purpose built Race engines" . The Ro7 was a major redesign of the original SBC, which was still based on the original 1955 dimensions. All that got re-designed with the RO7. One thing they did immediately was address limitations in the Valve train and  larger diameter lifters were incorporated.

Some interesting reading on the RO7. 

http://www.machinedesign.com/automotive/chevy-s-r07-racing-engine-chip-old-small-block

 

BTW... when Toyota was allowed to build a V8 for Nascar ( they didn't have a suitable production V8 ) they took full advantage and designed a clean sheet design that had GM and Ford sh**ting bricks. Toyota was so far ahead in design, that GM figured it would take them 5 years of work just to catch up. The engine block cooling passages used a foundry design that GM couldn't hope to replicate without a complete re-design of their foundries. They just didn't have the technology  Some of the Industrial espionage going on behind closed doors is very interesting. Such as when JGR suddenly switched to Toyota engines in 2007, after being a long time GM supported Team. GM was pissed. But apparently JGR had seen the design specs of the new GM RO7 and the new Toyota engines and realised that GM was fracked big time. And about a year later... a Toyota Nascar engine mysteriously  went missing while being transported back to TRD ( Toyota Racing Development ) . It's all rather Hush Hush... but apparently said Toyota engine was " accidentally " delivered to a GM Lab.... ( Not kidding its' all out in the open now.... but a huge scandal at the time  ).  

But I digress... because it's 2:30 AM and I tend to Ramble on  when I suffer from insomnia.... 

[Zed Head]

7 hours ago, Chickenman said:

Sulphur would probably eat the soft metals in the rod and main bearings. 

Another one of those things that is not as clear as people profess it to be.  Endless discussions...

 

[siteunseen]

Like "the best injectors" or "the best cam".  

[Reptoid Overlords]

I decided to try some Valvoline VR1 conventional 10W30. I have about 200 miles on it since my rear seal/oil pan gasket work.

 

So far I haven't noticed it "thin out" after running the engine for long periods of time like the oils I've used in the past have.

 

Seems like the engine heat would thin it out to the point where I could visibly see it drip off the dipstick as I pulled it out. And the consistency didn't seem right.

 

Now the oil stays the same, or at least close to, the same as when the engine isn't hot.

 

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[Mark Maras]

 Any noticeable difference in the oil pressure cold or hot?

[Reptoid Overlords]

If my oil pressure gauge is to be trusted, it reads roughly in the middle of the gauge when idling and coasting at normal engine operating temperature.

When accelerating, at higher revs over 3500 RPM it drops a bit lower than mid way on the gauge, then evens back to the middle once coasting regardless of RPM(I don't redline it, max RPM I'll do is 5800).

Cold idle reads just slightly under the middle point.

Learning how to properly decipher the gauge reading has been something I've been meaning to do.

I also have been meaning to replace the sender, but a slipping clutch forced oil seal replacements, and I totally spaced on replacing the sender.

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