Premium Fuel selection same guela

[skewby]

when i had my 2.5's i always ran klotz 64:1 and roger has ran his 260's and 280's at 64:1 without any problems. per glenns recommendations

[hooken203]

This is one of my favorite engine/mechanical discussions. We need to set the stage a bit. Most of us are not buying racing fuel for our fishing boats. Yes there are a ton of variations of race fuel designed to get an engine builder where he needs to be. I would not run 98 octane fuel in my stock outboard engine. Run it in your lawn mower your chainsaw your snowblower. Two things it smells good when it runs and it's cheap to fix when its broke.
I know TB21 has seen this a lot more than I have but I watched it on a dyno comparing a stock motors HP running on 87 and then using various octane racing fuel. I saw the 87 make more HP. So I believe that to be fact.
The next part is where I ride the fence higher octane burns slower and colder. I have read about this until my eyeballs fall out and you can find articles that go both ways on it. I know and understand the theories that explain it both ways. I wish I could see the testing on it. I know someone has done the combustion chamber pressure and flame time testing to prove it but I have not seen it.
As far as trusting what you get at the pump yeah it may be a crap shoot but like everyone says buy from high volume stations and you will be better off.
Hey DBR do some testing for us you have the equipment to solve this mystery.

[90 5.0]

I was definitely not happy about moving to 112, it is completely unessesary at the compression limit in our class. My combination hits much harder tuned for pump gas.
We were running 98 last season as it was the lowest available octane race gas and I was ok with that. Slowed it down a little but not too bad.

I understand the need for spec for fuel testing at tec

i was thinking he had the dbr mods on his motor??

But fuel quality can be a concern and 98 would be to much but quality guaranteed

[Joeandthetomcats]

Where can you purchase aces?

[AllyFishing]

In OHio where you are from and from Todd at Hydromotive. Darn I forget the name of the place in Ohio. I think it's where it's made or designed actually.

[catfish123]

Klotz at 40:1.....Hmmm...tell that to Glenn Reynolds. I bought some one time from him when I had my 1996 Merc 225 Promax and he wrote on the bottle 65:1 which I thought was a little bit light on the oil side. I ran Merc Premium PLus at 40:1 on that motor as per Tony Brucato's instructions.

I run Klotz KL333 in my 280 at 40:1 and I'll stick with Lee Sanderson's recommendation.

[90 5.0]

I know for a fact another guy running a similar motor combo also runs 28:1, but his crew chief is also a tunnel boat roundy round guy.

I wonder if they are used to doing that because of the longer WOT running in those conditions?

[TB21]

Contrary to what most believe , less oil does NOT make more power. Keep in mind above piston compression is referred to as secondary compression with a 2 stroke , primary compression is below piston (crankcase pressure) and it means the world for charging the intake ports! more oil does somewhat dilute the gas but , the benefits in CC pressure are higher. Did lots of dyno testing on oil ratios year ago and was shocked to see what we discovered. We use to just laugh at guys at the track when they'd brag about running lean oil ratios. Me and Glen talked about this last summer at the rally and he fully understood the theory when I explained it to him.

[Cartes Custom]

If gasoline that is 87 oct is mixed with 100 Oct does the Octane rating follow the mixture ratio e.g. Can you reach 93 Octane with the correct blend? Do you race guys know the mix ratio and or formula?

[hooken203]

So more oil in the mix works better because it seals thing better or takes up space or makes things slippery so they move easier? I was always told more oil means leaner fuel ratio.

[Props4u2]

when i had my 2.5's i always ran klotz 64:1 and roger has ran his 260's and 280's at 64:1 without any problems. per glenns recommendations

As I recall, Klotz claimed at one time that you could run it at 100:1, not me.

A 7500 and below, 65:1 is probably ok, but @ 10K 40:1 is all I will run personally.

I know Glenn always runs light on the oil, not me. LOL

[Props4u2]

I know for a fact another guy running a similar motor combo also runs 28:1, but his crew chief is also a tunnel boat roundy round guy.

I wonder if they are used to doing that because of the longer WOT running in those conditions?

The roundy round guys are running 8-9000 rpms for several laps, I can see why they would run a rich oil mixture.

[Props4u2]

If gasoline that is 87 oct is mixed with 100 Oct does the Octane rating follow the mixture ratio e.g. Can you reach 93 Octane with the correct blend? Do you race guys know the mix ratio and or formula?

I'm told that's where 89 octane comes from, 87 and 93 mixed. I have no idea on ratio's.

[Joeandthetomcats]

BND auto. Emailed them but no response.

[hooken203]

If your mixing fuels to obtain an octane number aren't you more or less guessing where you will end up. Did the engine burn down on the last run? Nope. Then we must be good. Here in the great corn state if you buy 89 you almost for sure got 10% ethanol.

[90 5.0]

The roundy round guys are running 8-9000 rpms for several laps, I can see why they would run a rich oil mixture.

Makes sense to me, his F1 motor would turn 11,200.

They ran it at somewhere in the neighborhood of 16:1 at one time but it would fail fuel tec. Said it was noticable faster, had something to do with the additives in the Merc oil. I don't remeber the specifics though.

[Cartes Custom]

Just another data point. Suspecting I had bad gas with water I sipohned as much gas out of the tank that is possible going through the fill tube. I thought about removing the plate located in the top center of the tank...didn't do that. Found a very small amount of water in the gas. Drained the fuel from the filter / fuel tank on the side of the engine...no water but some sand and small particles. The fuel drained from the filter / tank on side of the engine was cloudy; I've never seen cloudy fuel. Went to another Exxon station that is the most busy place therefore thinking they would possibly sell more premium resulting fresh fuel. Put 10 gallons in the tank and went fishing. Engine ran perfect, no more vibration and rough running. Still looking for a total confident source of clean 93 octane.

[90 5.0]

The shell station @ 1960 and timber forest in atascocita ALWAYS has fresh premium I have never had an issue with it.

The Old Citgo that used to be @ 1960 and pinehurst drive used to always have fresh performer 94, we always ran that. When they closed we used the Exxon at west lake Houston and the XR-2 would not even run

since then I have bought all my premium at the shell on timber forest for the last 20+ years without an issue.

[AllyFishing]

One of the fishing TV shows that I DVR had an ad for star tron additive stating that for every 10 gallons of gasoline pumped into our tanks 1 gallon of that is ethanol at 10% like indicated on the pumps. I never really looked at it like that but it sure is a lot of alcohol!!! I use my Mercury products religiously. I try to buy ethanol free but throughout the season I will use ethanol if I have to. At the end of the year though I will only fill with ethanol free after I've run a tank of non ethanol first before I store my boat.

[Props4u2]

Makes sense to me, his F1 motor would turn 11,200.

They ran it at somewhere in the neighborhood of 16:1 at one time but it would fail fuel tec. Said it was noticable faster, had something to do with the additives in the Merc oil. I don't remeber the specifics though.

Take any Mercury 2-stroke oil and try to burn it by itself, it won't even hardly smolder. It probably makes it slicker though.