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Discussion Starter · #1 ·
I got an " I told you so" from an engine builder I know. The Mobil 1 10-30 was thin enough so my lil 427 RAT ate it up like maple syrup. Switched back to Val 10-40 and no more smoke.

I have a "new" run-in 427 in my 67. Appox 15-20,000 miles when I bought it. Half way through life I figured by inspection of #1 rod and main bearing. I just put Mobil 1 synthetic in and really started moving oil. Espcially on the odd bank. Pulled all the plugs and they're burning well with minor residual oil fouling on the threads.

Swapped out the mobil 1 for std 10-40 and now my exhaust smells slightly rich due to the cam, but the burning oil smell is gone.

Also upped the thermostat to 180 from 160 which might've helped.

Net/net: use caution when using light synthetic oil in a run in motor. It could cuase it to start eating it. It surely did mine.
 

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Gene,
I wonder what Mobil would have to say about it ?
I started using Mobil 1 in my 85 Blazer when it had about 80,000 miles on it and never had a problem. Same with my wifes 84 Riviera, started at 45,000 miles, no problems yet ??? Not to mention the shop S-10 2.8V6 that has 180K with NOTHING ever done to the motor, but has had Mobil 1 since day one.
I wonder if there are other problems with the engines that only show up with light weight oil, no matter if it is synthetic or not. Excessive bearing clearances, or rod side clearances, will throw a lot of oil on the cylinder walls, making marginal rings unable to control it. Wonder what would happen if you tried 15w40 Mobile 1 ?? The synthetic oils meet all the SAE specs and should not be a problem on a correctly built motor. Just 2 cents worth from a die hard Mobil 1 user at any mileage.

PS. I know Wally started using it in his 93 Vette when he bought it. I think it had about 40k miles on it. It certainly does not smoke, I would have heard about it for sure !

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Bill Koustenis
Advanced Automotive Machine
Waldorf Md

1971 Heavy Chevy - original owner
Team Chevelle #100



[This message has been edited by BillK (edited 10-10-99).]
 

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i just bought a 5 quart jug of 15-50 for my next change
have previously used 20w 50 kendall,penzoil or castrol in all cars since coming to fl 20 yrs ago

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Rich
Cocoa Beach, Fla
Team Chevelle #380
[email protected]
www.chevelles.com/showroom/70_SS_454.jpg




[This message has been edited by 70 SS 454 (edited 10-10-99).]
 

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Discussion Starter · #4 ·
Bill, certainly the motor isn't real tight. And I think it's a testimony to the oils ability to flow. It certainly flows well. Let's see, I threw it into my '96 Aurora with 51,000 on it. My guess is that I won't move a drop.

I have, however, moved up the future engine rebuild/ refresh date using the original L88 4 bolt block. The motor looked fine when I decided to run it without a rebuild. Some crosshatch on the cyl walls on the thrust side was beginning to wear, but all other crosshatch intact and bearings/cam looked mint. Still, must be too loose. I never put seals on the exhaust valves, but that's just a puff on hot start up, not 1 quart every 500.
 

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I pert near ALWAYS have used Castrol GTX 20-50 in everything, I just had a long brainstorm over what to put in on the first change since I bought my Yamaha FJ 1200..... Was gonna go synth, saw price....had mild heart seizure...and went with 10-40 GTX. Old habits die HARD!!! (though I DID change viscosity!!!)

Dave H.
Houston

hmm, I said "pert near" didn't I? Just a BIT *******!
 

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It seems to be my experience that some engines "use" synthetic oil. The 355 in my 68 has been on Mobil 15W-50 since day one. I still only have about 3000 miles or less on this engine and I have to add oil between changes. I was talking with some friends about this just the other week and we all agreed that some motors use synthetic oil. I recently bought an engine from a friend who had used nothing but Mobil 1 since he bought his Suburban over 9 years ago. I pulled the engine and took off the pan and the cross hatch was still visible on the cylinder walls and absolutly no ridge on the bores. I was impressed, the motor was spotlessly clean as well. I'm sticking with Mobil1.

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Bob (Creedmoor,N.C.)
65 Vette B&M Blown, Richmond 5-speed
68 Malibu B&M Blown, Turbo 350 10" converter
 

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Discussion Starter · #7 ·
Yeah, it's good stuff, but I'll stick with conventional. My lil rat is too loose. I mean it smokes out the exhaust like nobody's biz and then with conventional - nada. I'm sure I'll use it after the motor is freshened up in 2001. But next spring, I'll put the Castrol 20-50 in that the motor is used to.

Just an FYI, don;t anyone tell me to run a compression check or nothing.

Hey Dave, I've never seen "pert near" in print! I'm just a wannbe *******.

[This message has been edited by Gene Chas (edited 10-11-99).]
 

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Gene, how many times i have to tell you about this lil-ass 427...


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Partel Roos
Tallinn, Estonia, Europe
Law Student, Tartu University (a.d. 1632)
GSM cell ph: +37 250 93828
 

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Gene, how many times do i have to tell you about this lil-ass 427...


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Partel Roos
Tallinn, Estonia, Europe
Law Student, Tartu University (a.d. 1632)
GSM cell ph: +37 250 93828
 

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gene
after useing valvoline 20-50,she smoked some,went to mobil-1,smoke gone,if your motors lose,go to a 10w-40-(thats right you did)or 20w-50.I use 15w-50 syn-or 20w-50 in all 6 of my rides,no problems,even in cold weather.as for the guy callin a 427--little!
it dont always take megga inches to make horsepower,come on in to p.a.----Ill prove that to ya!good day all---67RAT member #199
 

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I have been running synthetic mobil 12w-50 in both my 427 and ls6 and have had no problems at all. CFR.
 

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I put 500 miles on a crate 350 then went to Mobil 1 - it's been 31000 and no problem. The sync do slip thru where nothing else does but the reason I use it is it's tolerance to heat. Conventional oil starts breaking down about 200 degrees - Sync can handle twice that. I have an oil temp guage and if the engine is 180 and I'm running 70 - 75 mph the oil goes to 240. It's just a little piece of mind.
 

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67RAT, peace man! mega respects for all the SBCs and BBCs, ´tis just this old friendly nag with GC that goes way back...

looking to see yer ride!
Partel.



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Partel Roos
Tallinn, Estonia, Europe
Law Student, Tartu University (a.d. 1632)
GSM cell ph: +37 250 93828
 

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I just rebuilt a '72 402 and went with Mobil 1 10W30. Maybe it's too thin because the engine is using oil (almost 2 quarts on the first 500 miles!) but now seems to be slowing down. No smoke anywhere, and good plugs, just residual fouling on the threads. Engine is real strong, but like Gene says, maybe a little rich due to the cam. The Mobil 1 seems to lube real well, maybe I just need to go to a heavier weight. Any suggestions anyone? I'll keep you posted on the oil use vs. viscosity changes, but I plan sticking to Mobil 1.
 

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I converted my 65 283 with 70k on a rebuild to NEO Synthetic 5W30 and didn't leak or use any more than the 20-50 Kendall I was using. I did hear a little noise form the bottom end at startup so I went up to their 20-50 and all is quiet.

Oh yeah, one other thing, I had a persistant lifter tick that sounded like an exhaust man. leak. After about 4-5k miles with the 5W30 it went a way and never came back even with the 20-50. I love that NEO. I've used it in everything since 1973.

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Dale P.
65 El Camino
72 Monte Carlo
"..you did you take the washer off, right?"
 

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Discussion Starter · #17 ·
Well, I'm glad to report that Mobil1 gave me 1.3 mpg more on the highway than concvetional in my 96 Olds. Don't ya love on board computers!

I wasn't starting a friggin debate. My rat don't like it, and that's that. Case closed. It was just a warning to others to be aware that IT COULD HAPPEN TO YOU.

Partel, the reason I say lil is that the serious street guys that I know of around here run 509,557,630 BBC. I feel like an imp.
 

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partel
peace here to man,thought you were busting us 427 dudes,hey bust gene all you want,some for me to,I owe him a few,did you know his chevelle is under geared,under cammed,and under carburated,and under oiled,he took out the mobil-1!.no,genes a good guy,helped me many times---good day---67RAT member #199
 
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