What Do You Use For High Octane Fuel For A Hemi?

[mr. hemi]

Waiting in line for my turn at the Av Gas pump, circa late '80's.

Cheers,

mrhemi

[birdsandbees]

Same.. LOL

My father use to bring me home open barrels of 100/130, that were for the MNR helicopters, to mix. Past 25 years I've just had my own tank in the yard...

[mr. hemi]

Same drill, different day.

[Kern Dog]

My understanding is that an engine with a MORE efficient combustion chamber needs LESS ignition timing. Wouldn't that mean that a 10.5 compression ratio HEMI would require LESS octane than a 10.5 to 1 440? 93 octane or thereabouts ?

[Bronzedodge]

That answer gets a little complex.  There's efficiency, and then there's surface area.  More area needs a bit more octane (and lead time.)  Iron heads need more octane than aluminum as they sink heat more slowly.  In general, over 10:1 w iron heads needs something better than 97 octane.  Others on here can answer better than I can.

[mr. hemi]

It is indeed more complex than that. 1st and 2nd generation hemis do not have a "squish" region in the combustion chamber to induce turbulence, (as a "wedge" does). This leads to requiring a slightly higher octane. I believe the 3rd generation hemi's combustion chamber is designed with that in mind. A properly tuned 426 with the timing set at 35 deg. total, as per spec., will detonate using Sunoco Ultra94, which is 99 RON. Getting the octane number just above 100 RON by introducing lead via adding 100LL av gas to the mix will usually take care of detonation. The second generation hemi is efficient at packing air / fuel into the cylinder, but not necessarily combusting it.

[2592 creston]

I get the Sunoco 110..works for me!

[mr. hemi]

If I could get 110 Sunoco at a pump in Ontario I would be using it as well.

[2592 creston]

   Can't get it at a pump, order online around 450.00 for a 54 gallon drum and between 95.00-120.00 shipping depends where u are.

[hemigeno]

"Back in the day", I would fill up with 100LL avgas... until the local airport's FBO got persnickety about such when Missouri's emissions testing requirements were enacted.  Then, I had to start using a couple of 5 gallon cans and pretend that I was working on a Benson gyro-copter homebuilt (there were several guys around town working on those near-death-traps).

I eventually started using pails of VP Racing fuels (didn't need the lead, bought it for the octane), but the closest vendor was 45 minutes away.  A tank sounds like a good idea, but are there problems with condensation or fuel quality degradation?

[birdsandbees]

You do want to be using it up, if it's in a vented tank like mine (but I've got it taped off pretty tight with tin tape that will let go if it needs to). About 3 years is the limit and by then losses to evaporation seem to degrade it's BOOM ability. I found that out when my airplane wouldn't start in the cold, but the fuel still worked okay in the summer. I now make sure I'm emptying the tank within 1.5 years by doing more flying and hopefully soon putting it in the cars again. I use about 20% AV to 80% Shell 93.

[1974dodgecharger]

run it till you hear marble in a can 

[Challenger340]

Yep, FAR more to staying safe with the fuel/octane requirements in a Hemi than the obvious, that said.... more than "one way to skin a cat".

Just me, but I never liked 100LL, it's designed to burn at 10,000 ft. 
You ever had egt's hooked up to that thing ?

[birdsandbees]

100LL is NOT designed to burn at 10,000 feet. 99.8% of aircraft that burn it never go higher than 2000. Many of us stay within 500 feet of the ground at best..   We also have a mixture lever to lean out at altitude...

[Kern Dog]

B O O M.....That was a lesson!

[Q5XX29]

I usually run half and half Sunoco 110 and 91 premium pump in my Hemis (except for my 14.5:1 604 Hemi in my LO23 Dart- that gets VP C16 )

[c00nhunterjoe]

I run vp when pump gas (93) wont do. No reason a legit stock type hemi cant run 93 at a near sealevelish conditions.

[metallicareload99]

Beautiful car btw!

You ever had egt's hooked up to that thing ?

What happens?

"Back in the day", I would fill up with 100LL avgas... until the local airport's FBO got persnickety about such when Missouri's emissions testing requirements were enacted.  Then, I had to start using a couple of 5 gallon cans and pretend that I was working on a Benson gyro-copter homebuilt (there were several guys around town working on those near-death-traps).

I eventually started using pails of VP Racing fuels (didn't need the lead, bought it for the octane), but the closest vendor was 45 minutes away.  A tank sounds like a good idea, but are there problems with condensation or fuel quality degradation?

I used to do the 5 gallon can thing when I had iron open chamber wedge heads.

What do you guys pay per gallon for race gas?  Last time I checked here it worked out to $20 a gallon  

[c00nhunterjoe]

I pay 10/ gallon for vp c12

[Just 6T9 CHGR]

Waiting in line for my turn at the Av Gas pump, circa late '80's.

Cheers,

mrhemi

Is your car R4 with R6 interior?  Does it have the V08 Variance code on the tag?

[mr. hemi]

Waiting in line for my turn at the Av Gas pump, circa late '80's.

Cheers,

mrhemi

Is your car R4 with R6 interior?  Does it have the V08 Variance code on the tag?

Yes and yes.

[Kern Dog]

That is a nice looking combination. Wow, I'd be proud of that!

[moparstuart]

Waiting in line for my turn at the Av Gas pump, circa late '80's.

Cheers,

mrhemi

Is your car R4 with R6 interior?  Does it have the V08 Variance code on the tag?

Yes and yes.

Mopar Hound   on here  my buddy Lonnie has a 318 car with that same variance and color combo   

[Just 6T9 CHGR]

Waiting in line for my turn at the Av Gas pump, circa late '80's.

Cheers,

mrhemi

Is your car R4 with R6 interior?  Does it have the V08 Variance code on the tag?

Yes and yes.

Cool.  When I was running the 69 Registry, I only had 1 440 R/T and 2 318 base model Chargers with that color variance (R4/R6) registered....

I also had 2 440 R/T's that were Y4 gold with C6T tan interiors.....another V08 variance color combo

[Ghoste]

Im in Ontario but a border city so I can slip over to Detroit and get Sunoco 110.