Gas and Oil recommendations for '70 LT-1?

[Dave's LT-1]

First I want to thank everyone for their input on my decision to buy a 1970 LT-1. You can see some of my previous posts under 1970 LT-1 vert or pulse amplification box. I would ecspecially like to thank Cal, Rainman, tomtom72, Stingray70, VetteheadMikey, and MidShark. You all provided me with great info. that influenced my decision to pass on the ratty '70 LT-1 Vert that I believe at one time was a true LT-1 but now there is so little left of it and it would take sooo much time and $'s to get it back to even being close to what it once was that I decided instead to buy a '70 coupe that is IMO about 85-90% correct, including original stamped correct block, heads, intake, etc. etc. It wasn't cheap but I now own something that I can drive while I'm redoing some things. It is missing some things that I will be out there shopping for like the carb, smog system, (if I ever want to have it judged), and some things that need resto. I may do seats, doors, etc. time and $'s permitting. The car now sits in heated storage waiting for warm weather. Living where I do it's a short season but I dream about getting it out and driving it! Do any of you guys have a recommendation for gas and oil? Once the car is out of storage I plan on changing the oil, coolant, etc. I don't know if the exhaust ports have been redone in stainless and don't want to damage them before/if I have this done. There are some local race shops that I can get leaded or racing gas during the season but don't know if that is the best way to go. Also is using pure synthetic oil the best way to go? Any thoughts and comments are appreciated.
Thanks, Dave.

 

[Vettehead Mikey]

Putting gas and oil in the car is always a very very good thing to do.

Regarding lead in the gas, you do NOT need any for the benefit of the valves. You MAY need some to boost the octane rating (or other chemical compound that does the same thing) to avoid preignition/knocking/pinging etc. This will depend on how the motor is tuned and what gas you can buy locally. If it doesn't ping, additional octane boosting compounds are a waste of money and achieve nothing.

For oil, and at the risk of being flamed once again, synthetics are of no benefit unless you're going to leave them in the motor long enough to overcome the price disadvantage. My background is in the aviation engine manufacturing field, and I've spent 27+ years looking for proof that synthetics make engines last longer than regular dino oil. So far, there is no proof, only indications that it makes no difference what you use. The engine will still need an overhaul every 100-150-200 K miles (however good your luck is) The need for this overhaul is usually not prompted by some lubrication related failure or normal wear and tear. Perhaps the only real benfit is that it makes the owner feel better thinking he's done something good for the car. Sort of like buying $6 bottles of imported bottled water when the locally bottled stuff is .99 cents. It's not spelled 'naive' backwards for nothing

 

[CapTen]

Dave,

I recently had my 70 LT-1 motor professionally rebuilt to original specs with the addition of the typical upgrade goodies such as stainless valves, roller timing chain, screw in studs, etc. Compression is still 11:1.

Although I did not drive the car during the peak summer heat, is does not ping or knock using 93 octane pump gas. I have mixed in a little CAM 2 from time to time(around 5 gallons per tank full occasionally) and DID notice a difference. No huge, but it just seemed to idle and run smoother. Is it worth the extra $$$? The jury is still out on that but I think it probably is. The true test will come when the weather gets real hot.

As far as oil, I tend to agree with Mikey. My experience in the auto and marine industries has always lead me to believe that if you change your oil often enough, synthetics are a waste of money. Plus, my Vette mechanic has always recommend against sythetics in both my 89 and 70. He says synthetics can actually cause oil leaks. Either way, I'll save the money and just change the oil twice as often.

Good luck - Paul

 

[rainman]

I agree with what has already been said. My experience with my 70 and 71 is that you may get by with 93 but for best performance you might want to increase the octane. As for the oil, my 71 never leaked until I used synthetic.

 

[Swamp Donkey]

I will add as far as the oil goes--I use conventional--but I always use a 5-30--as most of the engine damage is done in the first 30 to 40 seconds after startup and I like the low number to get to the upper end of the motor as soon as possible--if they made a 5-40 I probably would go with that. I change oil and filter often and the oil seldom even looks dark--just the way I like it.

 

[Dave's LT-1]

I appreciate all the expert advice! Sounds like I can save some $'s on the synthetic oil and use it for more parts! I just wanted to make sure I didn't damage anything in the motor by going cheap.

 

[MidShark]

Dave

Congrats on your purchase!

I concur with those giving advice here. I use Valvoline 10W-40 myself. Gas is not much of an issue with my car because of the lower compression in '71. Mikey said it best- "If it does'nt ping" - well, then there's no problem to fix.

Rich

 

[JJS]

I appreciate all the expert advice! Sounds like I can save some $'s on the synthetic oil and use it for more parts! I just wanted to make sure I didn't damage anything in the motor by going cheap.

Congrats on your purchase, Dave. Sounds like you're patience paid off, and you found a great car!

I use Mobil 1 in mine. I know it costs a little more than the regular stuff, but I'm more than willing to pay a little more for the added protection it provides.

One thing you should know about using Mobil 1, or probably any synthetic for that matter, is that if there's a leak to be found, it'll find it. My engine was rebuilt and blue printed (by previous owner) during a restoration, so I haven't had those problems (yet).

I also use the highest octane I can find, which is Sunoco 93/94 around here. Anything less than that, and the engine knocks. In fact, my car knocks when I use Mobil 93, and that's why I don't use anything other than Sunoco these days.

Good luck with that new car, and please provide some pictures!!!!

-John

 

[Vettehead Mikey]

I appreciate all the expert advice! Sounds like I can save some $'s on the synthetic oil and use it for more parts! I just wanted to make sure I didn't damage anything in the motor by going cheap.

Don't think of it as 'going cheap' at least with respect to oils- think of it as making a wise consumer decision rather than getting sucked in by the marketing BS. Let the yuppies buy the $6.00 bottles of water, it's good for the economy.

 

[Lucky 3]

You may not need the octane booster,but unless your heads have been redone with hardened seats you should run some lead in your gas for valve lube. not every tank, maybe every third one. as far as oil your engine was built and clearaced for 10W-30. 5W-30 may be too light in hot weather, you may see low oil pressure at idle. Bill

 

[Vettehead Mikey]

You may not need the octane booster,but unless your heads have been redone with hardened seats you should run some lead in your gas for valve lube.

Bill,

This belief was disproven years ago. The only driving conditions that loaded an engine enough to burn the valves were impossible in a Corvette. Tow vehicle/motorhome maybe, but Corvette never.

 

[Lucky 3]

thanks, i learn something every day on this site. Bill

Bill,

This belief was disproven years ago. The only driving conditions that loaded an engine enough to burn the valves were impossible in a Corvette. Tow vehicle/motorhome maybe, but Corvette never.

 

[Tom73]

This belief was disproven years ago. The only driving conditions that loaded an engine enough to burn the valves were impossible in a Corvette. Tow vehicle/motorhome maybe, but Corvette never.

Don't know about that, but with old heads that have run for years on leaded gas, there should be enough lead build-up on the valve seats that there will not be a problem. Now if you were running new heads with hardened seats then you could have an issue.

tom...