We were discussing octane earlier. Note the (R + M)/2 you see on pumps in U.S. This average of the RON & MON ratings is also called the PON rating referenced earlier where I stated:
In your 1964 Owner Manual on page 36 it indicates to use Minimum of 100 octane RON, or 89 octane MON. If you do the math to get the PON # that comes out to 94.5. So..that means the 93 Octane Premium in the US (PON) and the 99 Premium in the UK (RON) are both just tad lower than the recommended minimum octane for our 10.5 to 1 compression engines. My 64 CDV runs fine on 93 Octane, however, adding octane booster seems to give it more power. Keep in mind that the 94.5 would be a minimum recommendation and not an average or maximum recommendation.

Facebook Facebook

Views: 321

Comment

You need to be a member of 63/64 Cadillac Website to add comments!

Join 63/64 Cadillac Website

Comment by Che Gallagher on February 11, 2022 at 5:52pm
Thanks for all the comments it has definitely been helpful i now have a good knowledge of how it all works and what i need to do. Thaks everyone
Comment by Michael Vogler on February 8, 2022 at 9:56pm

The lead in gasoline helped reduce engine knock and acted as a lubricant on the valve guides in these old engines.    

I was told by mechanics on each of my vintage cars (two '65 Mustangs and two '64 DeVilles) that running the car without the lead additive may, over time, damage the valves, resulting in an upper engine rebuild (unless the engine was rebuilt with modern stuff). 

I always put in the highest octane gas I can find and lead additive when I fill up.  Certainly doesn't hurt.   

Mike

Comment by Che Gallagher on February 7, 2022 at 6:30pm
With the 429 engine can you just run it on a unleaded or do you have to add a lead additive to it
Comment by Jason Edge on September 2, 2012 at 9:22pm

I'm not sure how much lead additives raise the octane (if any). These higher compression engines were made for higher octane gas than the 80 something regular stuff they sell now. There is a lot of information on octane and engine compression out on the web. The best my car ever run (well before I rebuilt the engine) was on a strong dose of the 100+ octane AV Gas. I can remember here in NC growing up in the late 60's and early 70's where Hi Test was 95 to 98 octane and 93 would be more or less mid-grade.  The diffference was there were still many high compression engines on the road and being produced and the low compression 9.0 to 1, 8.5 to 1 and lower compression engines were just starting to replace these older high compression cars.  The new cars with low compression engines and electronic ignition that can automatically adjust timing as needed can burn the low octane stuff but I would never recommend putting regular in a 10.5 to 1 compression 390 or 429. 

Comment by Jason Edge on September 2, 2012 at 2:54pm

tagged as octane, octane rating, and fuel rating and set-up URL http://6364cadillac.ning.com/photo/octane for easy reference.

Photos

  • Add Photos
  • View All

Forum

Steering slack/play

Started by Nile Bolen in 1963/64 Cadillac Specific Discussion. Last reply by Dennis P. DiBari 13 hours ago. 4 Replies

I checked the Help page and did a search on the site but didn't see any subjects on steering play/slack.  Since I had someone complete a front end rebuild (Kanter kit, all the control arm bushings,…Continue

Tags: box, play, steering

Front grill

Started by Phillip Hill in 1963/64 Cadillac Specific Discussion. Last reply by Dennis P. DiBari 17 hours ago. 9 Replies

Hi everyone im currently restoring my my front grill due to some previous clown painting it with silver frost paint and doing a dodgy job I would like to know what parts of the grill are anodised.it…Continue

Add cruise control/Aftermarket Cruise control

Started by Logan Robb in 1963/64 Cadillac Specific Discussion. Last reply by Michael Vogler 17 hours ago. 12 Replies

Late in the evenings, I wonder about things I will probably never do as I am not that crazy. However, I know someone out there has tried it or wanted it bad enough they have done it. My 64 Fltwd did…Continue

Uniroyal Tire Brown Discoloration

Started by Sonny Butler in 1963/64 Cadillac Specific Discussion 18 hours ago. 0 Replies

Hi all,I'm glad I read Jason's recap of last nights Zoom call. I had the same problem with a set I bought for my 63 SDV. The white never got better than a pale yellow and would turn brown with in 5…Continue

Tags: Uniroyal

Blog Posts

1963 RHS A/C kick panel - photos needed

Posted by SK on June 2, 2025 at 2:20pm 2 Comments

Could someone post front and back photos of the 1963 right-hand kick panel with A/C?

My car didn’t come with the original kick panels, so it's a bit of a mystery to me how I should cut the backing board and carpet to fit around the A/C.

Many thanks,

-Samu

Edelbrock Carb Block off Plates

Posted by Chase on March 12, 2025 at 2:05pm 14 Comments

Hey guys,

I have installed the same Edelbrock carb and have done everything the same as Jason’s carb and intake project. In the spring and summer months the car starts, runs and idles great! In the fall and winter months on a cold start, the car starts awful and wants to die until it warms up. I have to keep my foot on the throttle until it warms up or it will idle just terrible and try to die. Once it’s warm, it runs fantastic! Whats going on here? I was thinking of removing the…

Continue

'63 Tailfin Tales

Posted by Mark Mata on February 22, 2025 at 5:00pm 9 Comments

New old stock seat material

Posted by Ray Schick on August 22, 2024 at 6:25pm 2 Comments

I bought this seat material thinking that it’s…

Continue

Videos

  • Add Videos
  • View All

© 2025   Created by Jason Edge.   Powered by

Badges  |  Report an Issue  |  Terms of Service