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AV fuel or race fuel??

B
Mar 13, 2009
38
4
8
Libby Montana
I appreciate all the responses, but I checked with some friends who own a gas station and they said its about 350ish for a barrel of race. I don't mind spending the extra money to keep my sled running good.
 
B
Mar 13, 2009
38
4
8
Libby Montana
Guess I'm the unlucky one on this thread. I ran straight 100LL at 10psi on an s/c Vector and ended up with 50% leakdown in all 3 holes in 300 miles. It was always rdden above 9,000 feet & the AFR's were good. I also had an s/c & water temp guage so I know it didn't get hot.

I had a reputable shop do the work & they blamed it on the av gas.

So did they say if the fuel took out the rings or the valve seals or both? You would think that the lead would be more helpful to the valves at least.
 
W
Dec 3, 2007
14
1
3
wyoming
Detonation took out my rings and pistons. The valves themselves survived they were able to lap them back in.

I'm not totally convinced that it was the 100LL, but I'm still not taking that chance again.
 
G
Feb 27, 2008
20
0
1
Mixing race fuel and mogas basically gives the same octane as 100LL Av gas (assuming 50/50 ratio) but assures you of other wonderful additives such as ethanol/ methanol. How fresh was the Av gas and how was it stored?? I run nothing else in my MCX nytro or my 2 strokes (as well as my cessna) and the only place I find it drying out is out my tail pipes :)
 
I

ikold

Member
Dec 2, 2007
119
10
18
49
avgas

One of the benefits of avgas is its ability to stay fresh for a REALLY long time. So if the AvGas was less than 3 years old it was still fine.
 

Gager

Active member
Premium Member
Dec 1, 2007
136
38
28
Palouse, WA
Question for those turbo'd Phazers that have failed: Did you ever get the knock sensor warning light? I run 50/50 race gas/premium pump gas and have only seen the knock sensor once and that before the engine was warmed up good.

One problem with over boosting the Phazer is the way the cylinders are cast. The cylinder is connected to the water jacket only at the bottom of the cylinder. The cylinder has no support at the top where the presure is the highest. Over boosting with cause cylinder to baloon and fail.
 
B
Mar 13, 2009
38
4
8
Libby Montana
Question for those turbo'd Phazers that have failed: Did you ever get the knock sensor warning light? I run 50/50 race gas/premium pump gas and have only seen the knock sensor once and that before the engine was warmed up good.

One problem with over boosting the Phazer is the way the cylinders are cast. The cylinder is connected to the water jacket only at the bottom of the cylinder. The cylinder has no support at the top where the presure is the highest. Over boosting with cause cylinder to baloon and fail.

I realize that the phazer motor is two 250's slapped together, but the head should hold the top of the cylinders together. I only run 10#'s so I should be safe.
 

Gager

Active member
Premium Member
Dec 1, 2007
136
38
28
Palouse, WA
The head should hold the top of cylinder together, but it doesn't. The contact between the head and cylinder is completely flat and provides no support for the cylinder walls. I think you are safe to 15#'s, but above 16 I think you're asking for trouble.

Mine runs best between 12 and 15lbs and I run 50:50 race and premium pump.

Btw, I have a phazer head shim I would let go for $25.
 
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