Octane additives?

-

j par

Well-hung Member
Joined
Jul 2, 2014
Messages
33,093
Reaction score
20,760
Location
Portland Oregon
Since I've had this motor it's ran on nothing but 100ll. It's got 596 heads with 202 valves and from everything I read there about 68 to 72 ccs? And I know I'm about five hundred thousand out of the hole with the flat top icon Pistons. I used a 1008 Fel-Pro gasket. On paper this calculates I believe out to be around 11.2 - 11.3 to 1 compression? I have a 10 gallon fuel cell and plan to drive it on the street much more often this year. I already went down and filled a gas can with 92 non-ethanol. That's the best we can buy here out of the pump. $4.69 per gallon. I was thinking one of the first things I would do would be knocking a couple degrees out of the timing. And now I'm considering instead of buying some expensive race gas to mix in there may be trying a can of something I can buy almost anywhere, octane booster. For all I know it could possibly work just fine on the 92. The cam is very dragstrip oriented and has a lot of overlap that may bleed quite a bit of compression to compensate?
Dur@50-- 259 in. 267ex.
Dur@20-- 294 in. 304ex.
Lob see 107
Lob center 104 in. 110ex.
Lift 364 in. 377ex.
@rocker 582 in. 603ex.
Opinions wanted welcome and appreciated, thank you...
 
I got caught in the middle of nowhere northern ontario in the middle of the night and had to fill my empty tank with 87 +15% ethanol so I added enough octane booster to get it up to the 91 the 10.5-1 needs . Man it didn't sure didn't run like 91 I ended up dumping the rest in going to about 97 and dropping timing to get it to run until the next open station with real 91 .
 
I don't think you gain much more than a point with booster you can buy almost anywhere.
There are some specialty brands available online that claim a few more points. but the cost may be the same as if you just added a little race fuel to your blend.
 
yeah I dumped several bottles and each one was supposed to be for a much bigger tank than our little ABody tanks still not the same as actual octane fuel .
 
Thank you men. I was just reading some of the articles online that were supposed to be independent studies blah blah blah.
 
yeah other than an emergency I would never bother with that crap again , another miracle in a bottle gimick
 
I was thinking of maybe going with some kind of ratio? Like maybe buying a five gallon can of the 108 for $67 at Baxters auto parts and adding a gallon for every four or five 4 or 5 gallons?
 
Your best bet is mixing in a few gallons of race gas from the track or drag strip with your 92 gas. I've tried quite a few brands of octane booster and the only ones that really work turn my spark plugs (piston tops, combustion chamber) a thick coating of orange. I don't know but it doesn't seem good.
 
In the ‘80’s, I ran a SCCA MGB with supposedly 12:1 compression. With my beer budget, I ran Moroso octane boost. It pinged a little but served the purpose.
I got a chance to buy Union76 race gas at Laguna Seca, and OMG! What a difference!! Never opened the Moroso can again. Sucked it up and bought race fuel after that. My two cents.
 
I run 50\50 mix of 100ll and 91 pump works real nice in my setup . love the smell also .
 
The 45-minute trip to the airport each way with 5 gallon cans is all over with. I need a much more convenient way to refill my 10 gallon fuel cell. I was thinking I can always leave full and carry a 2-gallon can strapped down in the back to add to some super I can find on the road?
 
If you are going to do it there are only two that I know work. There is one that may work, but I haven't tested that one. That one is called Race Gas.

The one I have tested is Torco Acclerator. I know it works. You can buy it either in leaded or unleaded.

There is also a product called BOOStane. It is a copy of Torco Accelerator. I don't think you can get that in leaded. I called them and they were going to send me some info, but as of yet I have nothing on it.


Most of the stuff you can get at backstabbers isn't worth messing with.
 
100ll is easy to get addicted to and my chain saw loves it as much as I do .
I agree it is a beautiful thing it works great in the lawn mower dirt bikes everything. It's nice to mow the lawn and not get choked out by the fumes of the lawnmower.
 
If you are going to do it there are only two that I know work. There is one that may work, but I haven't tested that one. That one is called Race Gas.

The one I have tested is Torco Acclerator. I know it works. You can buy it either in leaded or unleaded.

There is also a product called BOOStane. It is a copy of Torco Accelerator. I don't think you can get that in leaded. I called them and they were going to send me some info, but as of yet I have nothing on it.


Most of the stuff you can get at backstabbers isn't worth messing with.
I think I'll start with buying a 5-gallon can of the 108 at backstabbers and mixed 1 gallon per 4 gallons of 92 non ethanol? Then I can carry a couple little one gallon cans of 108 for mixing with four gallons on the road?
 
BTW if you use the Torco you can use it with straight pump gas. Doesn't matter if it has alcohol in it or not.
Again convenience to get the product and cost per gallon? And of course performance is always nice.
The 92 non-ethanol is 4.69 a gallon and the backstabbers 108 equals out to about $13.40 a gallon. Which equals out to about $6.43 per gallon at a 4 to 1 mixture. And that's about what the hundred LL goes for. The difference in convenience between the two feels is Worlds Apart. The backstabbers is 15 blocks one way and non-ethanol is 25 blocks the other way 100ll is gas cans only all the way out to the airport.
 
If you are going to do it there are only two that I know work. There is one that may work, but I haven't tested that one. That one is called Race Gas.

The one I have tested is Torco Acclerator. I know it works. You can buy it either in leaded or unleaded.

There is also a product called BOOStane. It is a copy of Torco Accelerator. I don't think you can get that in leaded. I called them and they were going to send me some info, but as of yet I have nothing on it.


Most of the stuff you can get at backstabbers isn't worth messing with.
No cracked machinist thoughts on the overlap bleeding enough compression to run a little less octane? Or do I completely not know what I'm talking about which is highly likely?
 
I've been running 50/50 100LL 92 unleaded non eth in my 11.75 comp 360. 596 heads 252 @ .050 Been good to me so far.
 
Back off total timing a tab, put 1053 Fel pro head gaskets (about .025 thicker than 1008), run 93 octane..... there you'd be getting closer to a street car :)
 
I've been running 50/50 100LL 92 unleaded non eth in my 11.75 comp 360. 596 heads 252 @ .050 Been good to me so far.
Thank you for that! The seems like a very close comparison? I would venture that I have I bit less compression and if my math serves me correctly your concoction makes about 96 octane? And the 4 to 1 concoction that I proposed is about 95.2 ?
And as 318willwin proposes Maybe a degree or two less timing which I was already thinking about?
 
Crap I got to keep in mind that I'm not King s*** and everybody doesn't know what I have! It's a 410 Stroker. Sorry..
 
Thank you for that! The seems like a very close comparison? I would venture that I have I bit less compression and if my math serves me correctly your concoction makes about 96 octane? And the 4 to 1 concoction that I proposed is about 95.2 ?
And as 318willwin proposes Maybe a degree or two less timing which I was already thinking about?
If you are going to mix the fuel....... but straight off of pump gas you may need to pull 5* out of timing. That would be trial and error....
 
-
Back
Top