Which oil Weight?
Thread Starter
Pro
Joined: Aug 2002
Posts: 611
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From: Girard Ill
Which oil Weight for a LT1?
Just bought a LT1 1972 vette. Has 85,000. miles on engine. Which oil weight should I go with? Thinking about Castrol GTX in 15-40 or 20-50. Only will drive it in spring,summer, and fall and will store it in winter.
[Modified by yankees1, 4:24 AM 8/18/2003]
[Modified by yankees1, 4:24 AM 8/18/2003]
Race Director
Joined: Dec 1999
Posts: 16,945
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Re: Which oil Weight for a LT1? (Steve Grodin)
everyone's gotta run what they like but I never use anything like 10W30. There's so much VII in there to keep it from thinning out more than a 30wt (on high temp), and VII don't lubricate. I always ran 10W50 and now 10W60, have tried 5W50 too. No problems at all.
[Modified by Twin_Turbo, 3:42 AM 8/18/2003]
[Modified by Twin_Turbo, 3:42 AM 8/18/2003]
Safety Car
Joined: Jun 2001
Posts: 4,004
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From: Severna Park Md
Re: Which oil Weight for a LT1? (yankees1)
Mobil1 10w/30. Thinner oil will flow at a higher volume. Good protection is about volume not pressure. More volume will keep bearing surfaces cooler.
Safety Car
Joined: Jun 2002
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From: Buckeye, AZ
St. Jude Donor '12-'13
Re: Which oil Weight for a LT1? (yankees1)
I went through this awhile back. According to all of the major oil manufacturers sites, as well as an independant sites explaining viscosisty, older cars or high mileage cars should opt for 20W50. After researching, I switiched to 20W50, and now have no usage and better pressure. The articles also noted that the additvies used in today's oil are much different in years past, and that the oils today are designed for much tighter tolerances in the engine. Some of the manufacturers actually now make a older car, high mileage oil which is supposed to mock oils of yesteryear. I checked my owners manual (78) and Chevy shop manual which also shows 20w50 reccomended down to 40 degrees. It seems to be working for me. I have a buddy with a '74, and he switched and noticed his consumption drop as well. As long as you follow the manufacturere guidlines, I don't think you can mess up.
Race Director
Joined: Apr 1999
Posts: 15,146
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From: NM
Re: Which oil Weight for a LT1? (gliot1)
I checked my owners manual (78) and Chevy shop manual which also shows 20w50 reccomended down to 40 degrees. It seems to be working for me. I have a buddy with a '74, and he switched and noticed his consumption drop as well. As long as you follow the manufacturere guidlines, I don't think you can mess up.
tom...
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Instructor
Joined: May 2003
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From: Willows Ca
Re: Which oil Weight for a LT1? (Surfer69)
Interesting Reading. I went with Mobil 1 15-50 cause thats what Team Penski uses in all there race cars
:steering:
http://www.bobistheoilguy.com/
:steering:
http://www.bobistheoilguy.com/
Melting Slicks
Joined: Nov 2001
Posts: 2,668
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From: Eastern US XX
Re: Which oil Weight for a LT1? (yankees1)
Just bought a LT1 1972 vette. Has 85,000. miles on engine. Which oil weight should I go with? Thinking about Castrol GTX in 15-40 or 20-50. Only will drive it in spring,summer, and fall and will store it in winter.
[Modified by yankees1, 4:24 AM 8/18/2003]
[Modified by yankees1, 4:24 AM 8/18/2003]
Team Owner
Joined: Feb 1999
Posts: 34,454
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From: Republic of Texas
Re: Which oil Weight for a LT1? (fst_c3)
I purchased a 1990 Chevy single cab stepside truck w/ a 350 and it had 95K miles. It blew a couple puffs of smoke upon start up (valve seals). I switch to Castrol HIGH mileage 25W-50 and run a 1 qt Lucus oil and no more smoke. I put 50K miles on it in the last 1.5 years with no problems. :thumbs:
