71 LT1 Fuel
Thread Starter
Intermediate
Joined: Feb 2021
Posts: 31
Likes: 2
From: VA
71 LT1 Fuel
Hi, new Vette owner, and new to the Forum. I recently purchased a 71 LT1, and the former owner told me he only runs 110 octane, CAM 2 racing fuel. From what I've read, it's really only the high compression engines that need leaded hi octane fuel. However, a friend of mine who is a MOPAR guy and knows tons about engines, mentioned that leaded fuel can have benefits such as lubricating valves. I had planned on running Hi Test and sweetening with 110 or octane booster. Wondering what others out there run on their "lower compression" LT1's.
Thanks.
Thanks.
Pro
Joined: Jan 2021
Posts: 624
Likes: 374
From: Treasure Coast
I was able to run my 72 LT1 with 91 octane, and didn't have an issue with pinging but I'm sure it would perform better with higher octane fuel. As far as lead goes, that's only required if it hasn't been rebuilt with hardened seats.
Le Mans Master
Joined: Sep 2003
Posts: 8,812
Likes: 2,029
From: eastern NC
It might help you to receive more meaningful answers if you told us a little about how you plan to use the car.
If you plan is to simply enjoy it as a classic automobile with perhaps some occasional spirited driving, that is one way and the need for lead substitute or high octane fuel additives even without hardened valve seats is not really required.
On the other hand if you plan to autocross your car or take it the drag-strip regularly where you will be winding it out close to red line frequently, precautions such as octane booster and lead substitute (with nonhardened valve seats) would probably be prudent.
Take a few minutes when you have some time to peruse the GM Heritage centers Vehicle Information Kit for the 1971 Corvette. A great resource and you will learn lots about your car for sure. Be sure to save a copy to your computer so you can review it anytime. https://www.gmheritagecenter.com/doc...t-Corvette.pdf
In any case, welcome to the Corvette Forum and I think you're going to love your LT1.
GUSTO
If you plan is to simply enjoy it as a classic automobile with perhaps some occasional spirited driving, that is one way and the need for lead substitute or high octane fuel additives even without hardened valve seats is not really required.
On the other hand if you plan to autocross your car or take it the drag-strip regularly where you will be winding it out close to red line frequently, precautions such as octane booster and lead substitute (with nonhardened valve seats) would probably be prudent.
Take a few minutes when you have some time to peruse the GM Heritage centers Vehicle Information Kit for the 1971 Corvette. A great resource and you will learn lots about your car for sure. Be sure to save a copy to your computer so you can review it anytime. https://www.gmheritagecenter.com/doc...t-Corvette.pdf
In any case, welcome to the Corvette Forum and I think you're going to love your LT1.
GUSTO
Thread Starter
Intermediate
Joined: Feb 2021
Posts: 31
Likes: 2
From: VA
Thanks Gusto, definitely a weekend warrior with this vehicle. That said, I want to ensure I take good care of the engine (really my primary concern). I'll check out the link, and thanks again. Really looking forward to enjoying my 71.
Dr. Detroit
Joined: Mar 2012
Posts: 10,097
Likes: 4,027
From: New Braunfels Texas
110 CAM 2 is a waste of money on a 71' LT-1. Lead additives are helpful, but if you do not put like 30,000 miles on the car.....it can live without that too.....it takes a LONG time to beat valve seats into the head on unleaded fuel.
Jebby
Jebby
Race Director
Joined: Mar 2016
Posts: 14,351
Likes: 8,158
From: Napa Valley California
I ran unleaded premium fuel from the pump in my flat bottom drag boats for years.
They were built big blocks that would spin up to 5000-6000 rpms on any given weekend.
I ran them for waterskiing and a little river racing.
Never had any issues.
They were built big blocks that would spin up to 5000-6000 rpms on any given weekend.
I ran them for waterskiing and a little river racing.
Never had any issues.
Safety Car
Joined: Aug 1999
Posts: 4,862
Likes: 118
From: Texas
'71 was the first year for hardened valve seats in factory gm heads. No need for leaded fuel or lead substitutes.
Pump premium is fine for that engine. Only caveat is 10% ethanol gas can cause major carburetor crud to develop if the car is stored for long periods of time.
Pump premium is fine for that engine. Only caveat is 10% ethanol gas can cause major carburetor crud to develop if the car is stored for long periods of time.
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Burning Brakes
Joined: Sep 2018
Posts: 1,002
Likes: 410
'71 was the first year for hardened valve seats in factory gm heads. No need for leaded fuel or lead substitutes.
Pump premium is fine for that engine. Only caveat is 10% ethanol gas can cause major carburetor crud to develop if the car is stored for long periods of time.
Pump premium is fine for that engine. Only caveat is 10% ethanol gas can cause major carburetor crud to develop if the car is stored for long periods of time.
In addition to melting your rubber fuel lines and anything else rubber in the fuel system... fuel pump bladder, accelerator pump etc.
One tank full of premium with 10% ethanol did my fuel pump and accelerator pump in.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,117
From: Crossville TN
The 'burned valves' thing is a myth for mid-60's and later GM engines. The solid lifters & cam may need zinc in the oil, but the fuel does NOT need lead. In fact, 1971 was the first year Corvette specified lead-free fuel. Quit listening to 'wanna-be's'....
'71 LT-1 engines had 9.5:1 compression. Hardly any need for fuel over 91 octane.
'71 LT-1 engines had 9.5:1 compression. Hardly any need for fuel over 91 octane.
Last edited by 7T1vette; Feb 26, 2021 at 11:41 PM.