RIFE SENSOR BLOCKS AND ALCOHOL-BASED FUELS
TL;DR – If you are running alcohol-based fuels, order the correct sensor inserts.
All of the wetted parts on RIFE Sensor blocks are made of 3 materials, 316 Stainless steel (the sensor body and diaphragm), Hard-Anodized Aluminum (the sensor insert body) or Viton (the sensor O-Ring) While the aluminum and stainless have shown themselves to be impervious to the various alcohols used to fuel race cars, we want to spend a few minutes talking about the O-Ring. The Viton O-Ring cooperates well with virtually all automotive fluids, but has couple of “non-ideal” qualities when it comes to Ethanol and Methanol.
Viton absorbs alcohol and tends to swell, in fact, over time the O-Ring can swell up to 30% depending on the grade of Viton used. Because the O-Ring in the RIFE Sensor block is “static”, meaning it does not move in relation to the bore, this is generally of little consequence. If the insert was ever completely disassembled, the O-ring would have to be replaced before reassembly. Typically, sealing is not affected.
The second issue is a phenomenon called “compression set” this is the tendency of the O-Ring to “harden” and lose seal over time as it reacts with the working fluid. Alcohol, because of its lower compatibility with Viton, can exhibit this behavior over a long period of time.
To solve this issue, we worked with Parker Hannifin, the world-leader in O-Ring technology, to provide an O-Ring material that addresses these issues and will provide exceptionally long life. The downside is that this material is 10 times more expensive and requires changes to our manufacturing process, so it comes at an added cost, the princely sum of $5.00.
How do I know which is which?
All of the sensor inserts that have the alcohol-compatible O-Ring package are marked on the sensor body with an “A” following the sensor range. For instance, a sensor marked “100” will be a 100 PSI sensor with the standard Viton O-Ring package, a sensor marked “100A”, has the alcohol-compatible O-Ring package.
What about the sensor(s) I already have?
If you already have a RIFE Sensor block and are running an alcohol-based fuel, the chances of you ever seeing a problem are very small. However, if you are concerned, give us a call and we will work with you to get it swapped out.
The alcohol-compatible sensors are stocked in 60 PSI, 100 PSI, 150 PSI and 200 PSI, all other ranges are available on a special-order basis.