Does anyone have experience with Royal Purple oil, in either late model cat cars or old school Hotrods or Race cars?

Any comments good, bad or otherwise?

For anyone who has used Royal Purple Racing Oil or XPR Racing Oil, in addition to any other comments, how clean did the engine look inside after running that oil for some time?

Thanks for any input you may have.

 

I'll be the first guinea pig.

The racing teams I hang out with routinely use Royal Purple in all their serious stuff. Now this is the race stuff..like the R-11 and 41 etc type oils. Basically pours in like water...good for one race. They nickname it WD-40 for it's viscocity. Engines hold next to nothing for oil pressure at high idle...maybe 40-45psi through the lights at 9000+ rpm. Yet bearings etc always look brand new. I've never seen a mark on them.

I witnessed the teardown of a roundy pounder motor. It was in the team owners car and he seldom won. But that night he was ahead and nothing was going to stop him. The engine lost a headgasket and he kept running it even with no water in it. They were hoping there would be no cautions and he could quickly finish the race. But they had two of them and he ended up coming in to pits. They dumped water in it while it was running and hit the track again. He ran the rest of the race pretty much with no coolant in it. He said temp gauge was pegged...but it had to be steam...because there was no water. Anyway, they finally hydraulic'ed motor while filling it up and it died. Couldn't get it restarted in time to get back on track. So when engine was pulled, everyone expected the worst. It definitely had the smell of an engine that had run hot...the headers were severely discolored. Paint was cooked off motor (they used very little anyway...most of them run block unpainted to reject heat better). When head was pulled I saw a 1" section missing between two cylinders. But when we pulled pistons...I swear they looked perfect. There was no scuffing, the bearings looked fine...we mic'd everything and all was reusable. They welded up head, gave it a quick hone and freshened it with rings and bearings. Even ring lands were fine.

I've seen engines torn down with melted pistons from nitrous..and all else was fine using RP.

Of course all of that is anecdotal..not scientific. But from what I've seen..it works.

I use it sometimes when going to the track. I'll throw some 10-30 street type in it. So far no problems...but over the years I've yet to be able to translate an oil change to a measurable difference on a timeslip regardless of what magazine dyno test say. I think it's just one of 20 things that all add a couple of Hp and they all combine to win a race.

I can't say I've ever really run it along time to see how inside of my street motors looked. Nothing stood out bad to me. I DID notice that when I ran Mobil 1 in my 427 and my 540 there was always a grayish film inside on everything. Nothing bad....but it was there. I had run the 427 for 20 years and had seen inside of it many times with dino oil. Never an issue, but I ran Mobil 1 the last few years with it and there was the scum. I've used it in the 540 a couple of times..and bingo..gray film again.

I've also been involved with some Co's that used RP in their Million mile diesel fleets and swear by it. But again...I've also seen a lot of million mile diesels on Dino oil that look just as nice.

This whole oil thing is a mess. For sure there are higher quality oils out there, but for average use, I think it's tough to narrow it down. Even Valvoline says 500 mile intervals on their non street use race oils. What's with that? I've read all the stuff on Mobil 1, and I truly believe they can make excellent oil. Just not sure how much of it is hype. By the time you need to worry about 350*+ oil temps...you've got other problems. For sure that's nice to have but c'mon.....

Then there is the argument over *stickiness* and quick cold flow. It sounds great to have light weight oil flow immediately on startup...but is it better than already having a cushion there to start with. I have witnessed how *dry* many of the new oils are when you pull valve covers off. Think about the average 800+ cubic inch diesel. It uses 15-40 weight oil..winter and summer. -30* to 100+ degrees. They start and lubricate just fine in cold weather. Sure you don't want to wind them up..but many truck drivers don't care. They fire them up and they hit the pedal to the floor to start getting air pressure up and get heater warmed up. As much as I cringe....I've yet to see wear I could attribute directly to that practice.

I can also tell you I work for a large leasing Co. We use the same Chevron oil (it's a higher grade of normal Delo) in the 18 wheeler trucks as we do in the gas engine pickups. We've done it for years..no catalytic converter issues to speak of....and no wear issues either.

There is another racer on another board that has been testing Walmart Tech 2000 in his 900+hp low 7 sec dragster. So far..the last two years he swears no issues and bearings look fine! Go figure....

I think we should all just pick a good oil that works for you and be done with it. There isn't a *magic* one I've seen yet that can do it all. Even that $60 per Qt stuff Ferrari tells them to use.



JIM

 

Good info Jim, thanks.

 

My fathers engine shop has used Royal Purple on occasion, both in street engines and race engines. Never used the XRP oil. Normally we don't use synthetics but for those customers who just have to have it, RP has done well in our engines. We haven't had any problems on those engines v/s our normal dino oil engines. Honestly they look clean when we pull them down, of course so do our dino oil motors usually. Maintenance is more important than what oil you run anyway. Our dirt late model engines get the oil changed every weekend, same for asphalt late models and most all of our oval track engines. Drag cars get the oil changed every 2-3 weekends depending on the Hp of the engine and componets inside it. I agree with 427HR - pick a good oil, stick with it, and follow an appropriate maintenance schedule for your type of engine.

My fathers uncle owns Bell Labs which makes Mix-A-Go fuel additive, MBL oil additive and a bunch of other stuff. They do and have done a lot of testing on different oils over the years. Royal Purple is good oil when compared to other oils. The only testing I have ever been a party to personally was a demonstration they did on a friction brake and some oil did well while others started squealing and smoking almost right away. Royal Purple lasted a while before it broke down as compared to the other oils he had to test that day. I don't have the times from that test but RP was amoung the best of the oils tested and from what I know in all his test it always is, some how after that test a few weeks later a few cases of RP showed up in my dads back supply room and we have used it when synthetics oils were requested ever since... we used Mobil before that.

Incidently I don't rember seeing the grey film in one of our Mobil 1 race engines, but about 2 years ago I DID notice that grey film after running it in my motorcycles. I also started burning up clutches in my bikes so I started using Rotella T in them. We also only use Rotella 15/40 in our flat tappet cam racing engines.

The only draw backs I see from using RP
1. Is on a race car that gets maintained as vigirously as we recommend, it gets very expensive in a hurry. Real street cars are another story as the extended oil change intervals can offset some of the cost.
2. Also brg clearances should really be tighter (than I like to run on a race engine) if your going to use synthetic oil. Toally acceptable for a street car IMO thou.
Will

 

I've used RP in my 76 Vette and 02 Silverado 5.3 and noticed a little improvement mileage and pep in both engines. Nothing major but close to the difference of driving with the a/c on and off.

The Vette did start leaking around the fuel pump and the rear main leak seemed to get a little worse. Seal compatibility may be the issue. I was told I should have used one quart RP with regular oil and then transition over to all RP. I plan to rebuild this engine over the summer and will be breaking it in with another type oil for the rings and cam to wear in properly.

 

Mobil 1 passenger oil has never been intended for motorcycle use. You cannot use a motor oil (in a wet clutch situation) that has friction modifiers. Mobil 1 passenger car oil has friction modifiers and lower levels of Zn and Phos (as I recall). Their MX4T (now called something else) has no friction modifiers, and comes with the full-blown Zinc and Phos everyone's so crazy about.