Oil for 1970 Corvette LT-1

Pennzoil motor oil
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Originally Posted By: Excel
Originally Posted By: VetteLT1
I have a 1970 Corvette LT-1 with solid lifters/flat tappet.

Which oil would you recommend for this Corvette LT-1 that is driven approx 1000 miles a year going to car shows? How often would you change the oil and filter?



change oil and filter once a year weather it needs it or not
I would run 10/40 BradPenn if I could find it,Kendal is a good choice too

Why would you change it if not needed?
confused.gif
 
Originally Posted By: Merkava_4
Is a heavier viscosity a good substitute for zinc and phosphorous ? That's the 6 million dollar question.


The heavier viscosity don't have the reduced Zinc and Phosphorous level requirements like the thinner oils do. xw30 weights and lower all require the lower levels for the newest API rating. If you notice, Mobil 1 High Mileage are all of the old rating, API SL, except the 10w40 has the latest API SN. That is the reason why.
 
The one thing about those early solid lifter OEM cams is lift is they're approx .100 less(or approx .450) than anything Hi-Po from the aftermarket...

I run a new flat hydraulic cam in a Ford 306 with around .475 lift using 10w30 Rotella... So far no issues...
 
I think this applies to your situation... Take a look at the poll I started here: http://www.chevelles.com/forums/13-performance/831521-what-oil-do-you-use.html It from folks who build stout Chevy engines with spring pressure usually above what you are seeing. Many use flat tappet cams.

The consensus by a wide margin, is Valvoline VR1 "street legal (vs race only) oil. That's more than 2:1 over any Mobil 1 product. That does not say that M1 is bad, it's the number 2 choice. But the collective knowledge of this crowd is extensive to say the least.

I am inclined to believe that Valvoline got some of their VR1 technology into their High Mileage (HM) oils... The Valvoline High Mileage (red bottle, blend) is getting high marks with older engine designs running flat tappets. It's readily available and in 10W-40. That's where I might go, if VR1 is not available...

The deal is that once you start that motor, bring it up to 2,500 and hold it there for a few minutes. Cam lobes on these engines are lubed by a spray of slung oil off the crank and that is how you do a new cam. If yours sits, it will be "thin" on fresh oil on the cam lobes.

You are in Calif. Unless you live in Mammoth, Susanville or Truckee, you don't need to worry about cold start. 10W is fine for almost all of Calif. The 40 end will be good for hot day cruising and such.

Change once a year - yup. Install oversized Wix filter for the extra capacity it brings and some extra cooling area AND the better anti-drain-back valve so the galleries stay as full as possible while sitting (Napa Gold same) ...

The best thing you can do is drive it
laugh.gif


I build fat tappet BBC's and a few SBC's for fun. Never had a cam/lifter failure (yet) in 50 odd years. It can happen. Usually it's the fault of soft lifters galling and taking the lobes away. Yours is prolly early enough that it is pre-soft lifters... But, if it's been rebuilt you could be staring at this issue. A used oil analysis after a really good drive (Vegas and back...) should help you know what's going on there. Good luck, I hope it's all good
smile.gif
 
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Originally Posted By: bigt61
Merk - that Chevron 20W-50 is nothing special. If the OP wants to run a conventional 20w50, Kendall is way better for his application.


Kendall 20W-50 is better than Chevron 20W-50 ? Interesting.
 
Personally, if I had to go with 20w-50, I'd choose the VR1. Why go for something that may or may not have elevated ZDDP levels, when you can get a product that you know has elevated levels?
 
From Kendall: GT-1 High Performance with Liquid Titanium, SAE 20W-50, also contains a boosted level of zinc dialkyldithiophosphate (ZDDP) additive to provide additional wear protection and enhanced oxidation resistance in the most demanding applications. It is particularly recommended for use in turbocharged engines and in high-performance engines with flat-tappet camshafts, especially during the critical break-in period.

Applications
• Gasoline-fueled passenger cars, light trucks and sport utility
vehicles that do not require an ILSAC GF-5 oil for warranty
coverage
• Older vehicles and small four-stroke cycle gasoline engines
found in lawn mowers and garden tractors, where the engine
manufacturer specifies monograde engine oil (SAE 30, 40)
• Competition engines and high-performance street engines
(SAE 20W-50, 50)

....BTW - I used to use Kendall 20W-50 in my race cars before switching to Mobil 1 15W-50.
 
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Nice ride!

I wouldn't go crazy on viscosity- even high-strung smallblock chevies don't need 50-weight oil. You can wind up sacrificing flow with an oil that's too thick. A 30 or 40 should be fine.

Normally I'm a fan of Mobil 1 0w40, but that engine is one of those that (if its up to scratch) could benefit from a "street/strip" class oil. There are tons to choose from- folks have mentioned VR-1 which has a good reputation. But there's also Joe Gibbs, Roush, Royal Purple (HPS or XPR series oils), Brad Penn... pick your poison and relax.

What I would NOT do is pick a generic street oil and then throw some high-dose ZDDP at it. The total formula matters, not just insane high ZDDP levels.
 
Last thing I'd use is any 20W-50 lard... For normal driving it needs nothing more than a good 10w30 such as the VR-1 mentioned... If it were tracked or otherwise raced, move up to a 5/10W-40 or mix in a couple quarts of VR1 20W-50 with the 10w30 to create an approximation of 15w40...
 
That "lard" has been keeping high performance SBC and BBC marine engine together for years.

A 100-hour run of VR1 20/50 beats the universal averages for wear metals of 48 hours of use every single time.

Chevy recommends that "lard" for Corvettes that are tracked.
 
If this is an original LT-1 it requires nothing special while new and tight. Mobil 1 0W-40 would be a perfect choice, but it made my high strung small block stroker a bit noisier than I liked.

BUT if miles and wear is a factor this engine could really need the 50w Lard to keep it together! Better to be safe than sorry if you don't know exactly what it's been through...
 
Originally Posted By: DoubleWasp

Chevy recommends that "lard" for Corvettes that are tracked.


Doesn't matter, since the original post specifically says, "Which oil would you recommend for this Corvette LT-1 that is driven approx 1000 miles a year going to car shows?"


For a street-driven car (and this is JMHO but based on experience) I would only run a 50 weight as a band-aid if the oil pressure falls thru the floor with a more appropriate grade... and I'd be saving up for an oil pump R&R at a minimum.
 
Originally Posted By: 440Magnum
Originally Posted By: DoubleWasp

Chevy recommends that "lard" for Corvettes that are tracked.


Doesn't matter, since the original post specifically says, "Which oil would you recommend for this Corvette LT-1 that is driven approx 1000 miles a year going to car shows?"


For a street-driven car (and this is JMHO but based on experience) I would only run a 50 weight as a band-aid if the oil pressure falls thru the floor with a more appropriate grade... and I'd be saving up for an oil pump R&R at a minimum.






My response was toward the specific content of his post, not the general topic at hand.
wink.gif


VR1 10/30 can handle this easily.

My only point was that 20/50 can be very useful in these engines. For this specific application? Not really.
 
Originally Posted By: DoubleWasp

My response was toward the specific content of his post, not the general topic at hand.
wink.gif


VR1 10/30 can handle this easily.

My only point was that 20/50 can be very useful in these engines. For this specific application? Not really.


Maybe you should go back and read what I actually posted??? Wasn't anything in it about big blocks, boat engines etc, it WAS pertaining to the OP engine and his usage...
 
Originally Posted By: bigt61
From Kendall: GT-1 High Performance with Liquid Titanium, SAE 20W-50

It's good to know there are other options out there. I wish their distribution was a bit better up here, though. It's kind of hit and miss, to say the least.
 
Originally Posted By: TFB1
Originally Posted By: DoubleWasp

My response was toward the specific content of his post, not the general topic at hand.
wink.gif


VR1 10/30 can handle this easily.

My only point was that 20/50 can be very useful in these engines. For this specific application? Not really.


Maybe you should go back and read what I actually posted??? Wasn't anything in it about big blocks, boat engines etc, it WAS pertaining to the OP engine and his usage...


Your calling it lard was a statement to the oil in general.

Pertaining to the OP and his usage, the oil and his engine would be absolutely fine running 20/50 VR1, or any other 20/50.

Plenty of old school LT1 owners run that exact oil and see exactly no penalties at all from doing so.
 
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