• When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.

106 vs 100 octane

Joe66satellite

Well-Known Member
Local time
10:25 PM
Joined
Nov 30, 2018
Messages
255
Reaction score
125
Location
Las vegas
My new satellite has a 440 with 11 to 1 compression and the Builder told the previous owner to put torco in 91 octane pump gas to get it up to 106 I have 100 octane racing gas in my neighborhood is that too far of a drop or would this be safe to run I don't plan on racing much just trying to drive the car to local shows and such
 
I'm not an expert, but you should be fine. If anything you might need to tweak the tune to run on the 100.
 
Torco? Is that one of their additives? If so that won't bring the octane up that much.Aluminum heads? 100 octane will be fine with aluminum heads.Put a little more octane in it if your going to race it but should be fine either way.Cast heads and a bunch of timing may be different... Listen for pinging
 
Google race fuel calculator for how to mix and what outcome will be in gallons. As others have said listen for pings. Timing can be retarded as well. I have a hemi that is similar comp that loves 110 but 100 it pinged. Detonation is bad and will do bad things.
 
Good rule of thumb: better to have more octane and not need it than the other way around!
Higher octane gas is cheap compared to an engine rebuild.
 
And be CAREFUL about octane additives since all of them I've seen have deceptive labelling. When they say "raises octane 3 points", they mean that it raises octane 0.3 points. Gasoline's octane rating is accurate though.
 
Joe, look up Rocket Racing Fuel. Not sure if they still do but it was sold in Vegas at a downtown fuel depot.Lots of different octanes leaded or un-leaded.
Or head out to the Las Vegas track and buy Sunoco fuel in 5 gal cans. I get 114 out there and mix it with 91 for my car.You can play with mix ratio 1 to 5 or what ever works best for you.
 
At a true 11.0 CR should be OK on 100 octane, even with iron heads. For sure good with aluminum heads, IMHO.
 
My new satellite has a 440 with 11 to 1 compression and the Builder told the previous owner to put torco in 91 octane pump gas to get it up to 106 I have 100 octane racing gas in my neighborhood is that too far of a drop or would this be safe to run I don't plan on racing much just trying to drive the car to local shows and such

I'm always skeptical of third hand info, especially when it comes to what a motor is suppose to be.

Start by building personal knowledge about the motor. Do a compression test and report back.
 
I'm always skeptical of third hand info, especially when it comes to what a motor is suppose to be.

Start by building personal knowledge about the motor. Do a compression test and report back.
Well I did speak to the Builder it's BEP performance out of Santa Ana California and he's a very nice guy and was very helpful and he pretty much repeated what the seller told me and I tried to get back to him about the hundred octane gas but I haven't heard back from him yet
 
Well I did speak to the Builder it's BEP performance out of Santa Ana California and he's a very nice guy and was very helpful and he pretty much repeated what the seller told me and I tried to get back to him about the hundred octane gas but I haven't heard back from him yet

Nothing against the builder and the previous owner, but at the end of the day, they simply might not know. There are a lot of things that can effect the fuel requirements, and contribute to ping or detonation issues. Many of these contributing factors are beyond what the builder put in the motor. So you can either ask a bunch of people what you can and cannot do or should do, and opinions will vary, or you can start to own it.

So if you tell us the cylinder pressure and head material we can tell you something meaningful on fuel requirements. Otherwise everyone is just guessing.
 
Can someone explain why aluminum vs iron heads would require a different octane rating.
 
Nothing against the builder and the previous owner, but at the end of the day, they simply might not know. There are a lot of things that can effect the fuel requirements, and contribute to ping or detonation issues. Many of these contributing factors are beyond what the builder put in the motor. So you can either ask a bunch of people what you can and cannot do or should do, and opinions will vary, or you can start to own it.

So if you tell us the cylinder pressure and head material we can tell you something meaningful on fuel requirements. Otherwise everyone is just guessing.
I know you're right BSB it has aluminum heads on it I can't think of the name right now it was decked online owned balanced and blueprinted I'll do a compression test in the near future and get back to you it's going to take a little while even in Vegas it's cold right now
 
Being an older muscle car guy,I can recall
Numerous cars running around in the 60s
not completely stock running that compression.
They had no problem running on 100octane gas.
Of course they had lead back then,helped run
cooler.
I'd add some 110 turbo blue to 93 if available,
works for me.2gals blue to 6gal 93.
 
I know you're right BSB it has aluminum heads on it I can't think of the name right now it was decked online owned balanced and blueprinted I'll do a compression test in the near future and get back to you it's going to take a little while even in Vegas it's cold right now


Okay.

At 2000 ft elevation, aluminum head, larger cam (late intake closing) and proper timing, it is possible that you could get away with 93 octane premium pump gas, if that is available to you. Smaller cam, probably not. Definitely run on 100 octane, and a 50/50 mixture of 100/91, and probably a 25/75 mix of 100/91. You'd need to trial it to find the lowest ratio. But I'm still speculating based on some assumptions. Let us know when you get the cylinder pressure.
 
I'd add some 110 turbo blue to 93 if available
Torco is one of the best, highest octane number raising additives...
Mixing race fuel with pump premium is the best, least expensive ways to raise octane. Also look at Royal Purple octane boost. It shows the numbers, not points that it will raise octane.
 
Can someone explain why aluminum vs iron heads would require a different octane rating.
Aluminum heads transfer heat of combustion quicker than iron. Old rule of thumb, aluminum head wants 1+/- more static CR to make the same power as an iron head with the same chamber configuration. 10:1 aluminum = 9:1 iron.
 
I know you're right BSB it has aluminum heads on it I can't think of the name right now it was decked online owned balanced and blueprinted I'll do a compression test in the near future and get back to you it's going to take a little while even in Vegas it's cold right now
A cranking compression test won't really tell you much, other than if some cylinders are weak. Won't give dynamic CR which relates to detonation in my understanding. I used to mix aviation gas with pump premium before race gas was readily available. 100 octane AV gas allowed more than 11.5:1 with iron heads.
 
Auto Transport Service
Back
Top