427/435 does it need aditives
Thread Starter
Pro
Joined: May 2012
Posts: 547
Likes: 9
From: Westminster Md
427/435 does it need aditives
Just purchases a 1968 Corvette with a 427/435 with 11 to 1 com.
What type of fuel enhancements c will be needed for this engine?
Thanks in advance,
Nelson007
What type of fuel enhancements c will be needed for this engine?
Thanks in advance,
Nelson007
Last edited by nelson007; May 31, 2012 at 03:25 PM.
CF JASOC Member
Joined: Feb 2006
Posts: 8,040
Likes: 34
From: Downtown Annapolis, MD. The Future is where we all have to live. Let's not screw it up.
St. Jude Donor '08-'09-'10-'11
I'd be more concerned about using an engine oil with enough zinc in it, like Rotella or the other brands. Some folks like to mix ZDDP with Mobil1.
Back to your question, use any of the top tier premium pump fuels, and if it doesn't ping you're good. Next full tank try the mid grade. No ping - good. And so on...
Or you can start with Reg and work your way up until the pinging stops. Using a higher octane fuel than what will keep your engine from pinging is a waste of money.
Back to your question, use any of the top tier premium pump fuels, and if it doesn't ping you're good. Next full tank try the mid grade. No ping - good. And so on...
Or you can start with Reg and work your way up until the pinging stops. Using a higher octane fuel than what will keep your engine from pinging is a waste of money.
Le Mans Master
Joined: Apr 2007
Posts: 7,353
Likes: 72
From: Graceland in a Not Correctly Restored Stingray
Agree you shouldn't waste money on unnecessary octane, but I was never able to get away with less than premium in my last L71. Your results may vary. Still, whether you hear anything or not, with any 11:1 engine on pump gas I'd certainly monitor the plugs for signs of pre-ignition or detination (google images for "spark plug reading") until satisfied everything is fine with whatever gas you're burning.
Unfortunately, not all gas is formulated the same, so don't expect just any brand of a given octane rating to actually provide the same knock resistance under your hood. Also, most readily available octane boosters don't do very much (e.g. "a full point" usually means ~0.1), other than lighten your wallet, and you won't likely find the hard stuff (somewhat hazardous and costly) sitting on any retail shelf. On the bright side, assuming it's had a valve job by a decent shop at some point in the last 30 or so years, you needn't worry about lead replacement additives.
Unfortunately, not all gas is formulated the same, so don't expect just any brand of a given octane rating to actually provide the same knock resistance under your hood. Also, most readily available octane boosters don't do very much (e.g. "a full point" usually means ~0.1), other than lighten your wallet, and you won't likely find the hard stuff (somewhat hazardous and costly) sitting on any retail shelf. On the bright side, assuming it's had a valve job by a decent shop at some point in the last 30 or so years, you needn't worry about lead replacement additives.
Burning Brakes
Joined: Mar 2006
Posts: 793
Likes: 1
From: Houston Texas
Mine is particular to the brand of gas (more probably though it likes gas from a station with a high volume of turnover/keeps the stuff fresher).
Holleys, distributor, motor et al are fresh with absolutely original stock specs. 93 octane does not detonate. Though, as corvetteload says, that good Sunoco would be the safest bet if your concerned. With that stuff you can get several degrees more lead in the timing.
Dan
Holleys, distributor, motor et al are fresh with absolutely original stock specs. 93 octane does not detonate. Though, as corvetteload says, that good Sunoco would be the safest bet if your concerned. With that stuff you can get several degrees more lead in the timing.
Dan
Drifting
Joined: Aug 2003
Posts: 1,328
Likes: 17
From: Fl
I am somewhat amazed that 93 octane fuel (with ethanol) is running a 435 HP car okay......
It should take a blend of 1-2 gallons 112 Sunoco to get it not to ping or run-on.
Maybe the new engine is allowing it run run okay - also, just becuase you can't hear the ping does not mean it isn't happening. The damage caused is severe. It will wear rod bearings down un-uniformally etc...
good luck with the car -- post a pic or two....
It should take a blend of 1-2 gallons 112 Sunoco to get it not to ping or run-on.
Maybe the new engine is allowing it run run okay - also, just becuase you can't hear the ping does not mean it isn't happening. The damage caused is severe. It will wear rod bearings down un-uniformally etc...
good luck with the car -- post a pic or two....
CF Community Team
Joined: Oct 2004
Posts: 19,371
Likes: 5,250
From: Cape Cod, Mass.
2025 C6 of the Year Finalist - Unmodified
2025 C8 Z06/7/E-Ray of the Year Finalist - Unmodified
2023 C3 of the Year Finalist - Unmodified
2021 C8 of the Year Finalist Unmodified
2020 Corvette of the Year Finalist (performance mods)
2019 C1 of Year Winner (performance mods)
2017 Corvette of the Year Finalist
2016 C2 of Year
2015 C3 of Year Finalist
You should be fine on 93 octane premium unleaded fuel. You don't need any additives.
Thread Starter
Pro
Joined: May 2012
Posts: 547
Likes: 9
From: Westminster Md
Thanks for all your help. Here is a link to the pictures. Hope it works, this is the first time I ever did this. Not a computer person.
Thanks Again,
Nelson007
http://s1060.photobucket.com/albums/t448/nslinkman/
Thanks Again,
Nelson007
http://s1060.photobucket.com/albums/t448/nslinkman/
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Every 2027 Corvette Engine Explained
Joe Kucinski
Designer Imagines A Corvette That Looks More Like a Corvette Than the Corvette
Verdad Gallardo
10 Ugly Corvettes That We Still Kinda Love
Joe Kucinski
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
CF Community Team
Joined: Oct 2004
Posts: 19,371
Likes: 5,250
From: Cape Cod, Mass.
2025 C6 of the Year Finalist - Unmodified
2025 C8 Z06/7/E-Ray of the Year Finalist - Unmodified
2023 C3 of the Year Finalist - Unmodified
2021 C8 of the Year Finalist Unmodified
2020 Corvette of the Year Finalist (performance mods)
2019 C1 of Year Winner (performance mods)
2017 Corvette of the Year Finalist
2016 C2 of Year
2015 C3 of Year Finalist
Beautiful big block in a great color combination 
Enjoy that beast 
Enjoy that beast
Le Mans Master
Joined: Apr 2007
Posts: 7,353
Likes: 72
From: Graceland in a Not Correctly Restored Stingray
Thanks for all your help. Here is a link to the pictures. Hope it works, this is the first time I ever did this. Not a computer person.
Thanks Again,
Nelson007
http://s1060.photobucket.com/albums/t448/nslinkman/
Thanks Again,
Nelson007
http://s1060.photobucket.com/albums/t448/nslinkman/
FYI, posting pics is easy, and you've already got them hosted on photobucket...
http://forums.corvetteforum.com/help...es-thread.html