Mobil 1 for old-tech engine?

[toolboy62]

Hi all,

I've been reading good things about this new Mobil 1 5w40 and am considering trying it for my next oil change in my Porsche 944. I'm currently running M1 15W50 and am thinking it may be a little on the thick side, but don't want to use a xW30 due to a) factory recommendations and b) it gets HOT here!

So now to my question. I also have a '55 Studebaker coupe with a '63 Stude engine transplanted in it. I've always used Rotella 15W40 for my old stuff but amazingly this engine does not seem to leak oil at all, and I'm going to be doing a cam swap in it anyway at some point in the future (at which point I'll upgrade to a neoprene lip-type front main seal) Since it seems to be so good at retaining oil, I was wondering if the M1 would be a good choice for it as well? t does burn some oil however, at the moment it is sorely in need of valve stem seals and produces some really impressive smoke pulling away from a stop light after a long period of idling. How does the M1 work in an engine that burns a little oil? Better/worse/indifferent compared to a dino oil? I'll probably run dino at least for the first couple hundred miles or so (car was sitting for several years before I got it, so all the whirly bits need to get reacquainted) but after that, since it doesn't seem to leak...?

thanks!

nate

 

[sgtgeek]

I thought about this prior to posting and kept coming back to the same place....I'll share in a second...first I have to make a "heat statement if I may...
... I'm in South Texas. Your shoes melt walking across the parking lot. I run a highly modified LS1 in a 04 GTO....cam/heads/headers/3200 stall etc.. (you get the picture)...so I have heat inside and out...I run the Amsoil 0-30 and the GC 0-30...temps are never any issue at all as both of these oils perform fine.
The Mobil 1 5-40...**** fine oil....I would drain and fill with it...and watch it....you be the judge how it is performing.....your sure as heck arent gonna hurt your car/engine with it that is a certain.....

 

[Mr Nice]

sgtgeek,

What does your GTO run in the 1/4 mile ??

 

[Frankie]

I'm using Mobil 1 15W-50 in my '57 Ford Y-block engine. It has been overhauled, but I used the same pistons and simply honed the cylinders. I use this thick oil because the piston fit is on the loose side of the spec. and because of measured .002" to nearly .003" rod and main clearances, and because I live in Oakland, CA which has a mild climate year round. Oil pressure is 22 psi hot @ 500 rpm and 60 psi hot over 2700 rpm. I haul a camper on the truck this motor is in, and frequent places like Nevada in the summer. So all things considered, I think the 15W-50 is a reasonable choice for my application. The engine uses virtually no oil- maybe 1/2 quart in 3,000 miles, and doesn't leak.

For your Studebaker, I think I would stick with the Rotella 15W-40 or some other conventional "Diesel" oil. Unless you change the valve stem seals when you do the cam swap, you will probably burn a lot of expensive synthetic oil for no real benefit. You may improve your oil control by changing the seals as long as the valve stem to guide clearances are still OK. If you do decide to swap the cam, break it in on the 15W-40, then drain and re-fill. If you opt not to swap the cam, you can still change those seals out pretty easily on a Saturday if you know how.

Besides, your problem sounds more like leaky or stuck rings to me, especially since the car has been sitting. Everyone seems to have their favorite method of freeing sticky rings. I have seen everything from pouring Marvel Mystery oil down the carb throut to putting diesel in the oil and everything else in between. You may want to try and free them up in some fashion using the solvent of your choice applied in the manner you deem safe and effective. Anyway, valve seal/stem/guide problems usually show up under high vacuum conditions such as when you lift off the throttle and vacuuum goes up, pulling oil past the guides into the intake manifold.

If it's still running fine and you aren't fouling plugs, enjoy that fine old car as it is and use the Delo or Rotella. The oil usage may decrease with a little driving all by itself if you change the oil regularly.

[ June 15, 2005, 11:45 PM: Message edited by: Frankie ]

 

[toolboy62]

thanks for the replies guys, I am using the Rotella 15W40 for now and getting good oil pressure, even with a 180 degree thermostat (even though that results in some scary looking readings on the uncalibrated factory gauge! - stock thermo was a 160 in '55, 170 in '63, but 170 stats are NLA it seems) I will probably do the valve seals next time I have a chance to work on it, it is not a hard job if you have shop air. I dunno about the rings maybe I will run a compression test on it at the same time. It does seem odd that it smokes only when accelerating after idling. I have not put enough miles on it yet to have any idea of oil consumption over mileage; add to that I have had several oil spills since getting it running! (first was a cracked hose to the gauge tube, then I put on a fuel pump from a supercharged car as my original was full of crud, it had a bad stem seal and started blowing oil out the boost reference fitting - lots of scary smoke!)

I guess the real point of my question is, let's say you have an engine that burns oil, for whatever reason. Which burns "cleaner," Mobil 1 or Rotella? i.e. which is more likely to leave nastiness in my rings and spark plugs?

Drifting away from the original topic... that reminds me of several other questions I wanted to ask.

1) Is there a real advantage in oil cleanliness and engine wear to using a 180 degree thermostat over 160? Gut says yes but I don't have any data to back that up. I can probably recalibrate the gauge to stick with a 170 or 180 degree thermostat just by adding a resistor in series with the sender wire.

2) I put an aftermarket aluminum valley cover on this engine, is there typically enough "splash" in the lifter gallery of a pushrod V-8 that oil would enter the PCV system? The stock stamped steel valley cover had a baffle around the PCV hole, the aftermarket one does not. Am considering adding a homemade baffle when I do the cam swap if it seems worthwhile.

thanks again,

nate

 

[Frankie]

An engine running at 180 degrees will keep the oil cleaner, have less condensation and less wear than one using a 160 degree stat. I would venture to say running 195 would be even better, though I run a 180 in my Ford. You COULD run a mechanical gauge to see the actual coolant temp.

There is plenty of splash in that lifter gallery- that's why the baffle is there. I can't remember where I saw this, but somebody made a plexiglass valley cover for some early V8 to test this very same question. Reportedly they couldn't see a thing through all that oil once the revs went past about 2,000. I think it's a really good idea to cobble something together. Maybe the lack of a baffle is the root of the smoke when you pull away from a stop- try disconnecting the PCV for a test run.

I don't know about convetional vs synthetic with regard to deposits resulting from consumption.

 

[toolboy62]

thanks Frankie, that squares with my gut feeling but just wanted to hear others' thoughts.

Anyone want to chime in on the clean-burning issue? I've been watching the thread on the Honda oil-burners, but unlike the OP of that thread this car really isn't going to see a lot of use so oil change cost really isn't an issue - will probably end up changing oil based on time, not mileage.

thanks again,

nate

 

[sgtgeek]

quote:

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Originally posted by LT4 Vette:
sgtgeek,

What does your GTO run in the 1/4 mile ??

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Ran a 11.4 last time out.....crappy 60ft though...

 

[Big Jim]

If you have found sometihing that is good and works well for you, why change? Until you can no longer find what you are using (which isn't likely any time soon) don't mess with success.