Landracing Forum
Bonneville Motorcycle Speed Trials => Bville Motorcycle Speed Trials Rules Questions => Topic started by: donpearsall on June 25, 2019, 03:03:06 PM
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I sent an email about this to 'tech@bonnevillespeedtrials.com' but have not gotten a response yet.
Just checking - Has anyone passed tech inspection regarding this requirement by having a vacuum operated petcock? With this type of petcock, gas will not flow if the engine is not running. It is handlebar operated by virtue that the engine kill button is on the handlebars. Press the stop button, the engine stops, and the fuel flow stops. It is just the same as a fuel pumped engine - press the stop button and power to the pump is gone.
Any input on this?
Thanks
Don
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(Forwarded to our technical inspection team for official response)
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Thanks much Linnea!
Don
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From my experience that's only allowed in production classes.
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It seems the one I had with a vacuum petcock had a reserve position that did not require vacuum.
But that was a long time ago... Tech will get back to you
:cheers:
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I did get a response from Drew Gatewood, Chief AMA Steward for BMST. He said that the vacuum petcocks are not acceptable for this rule.
As was already discussed here, the acceptable petcock shut-offs are the handlebar mounted cable system like Pingel sells, or the electric solenoid shutoffs. So since I don't want to mess with a custom order like the Pingel requires, I am going for the solenoid.
Just thought this rule interpretation might be asked again so a search here will find it.
Don
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Watch out for the fuel flow through some of those solenoids, some are sold as 1/4 inch but the actual hole inside when the valve is open is more like 1/8 inch. I try to stay away from electrical on the salt. A cable operated fuel valve is bulletproof. I just drill a 1/16th hole in the pingel lever and attach a deralleur gear cable off a bicycle. Magura make a nice handlebar lever that gives plenty of travel. Rig up a bracket for the cable and you are done.
https://www.amazon.com/Magura-14AL7-Choke-Assembly-0550845/dp/B00230I156
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We recently put mechanical fuel pumps on the Aussie bikes , for high flow on methanol,
big capacity bypass valves needed there , used bicycle brake levers and cable setup to control it
Bicycle shop guy was great , spent a bit of time finding levers that were not too obtrusive to mount , and gave us lots of spares to create or repair cables any time
Then we shortened the lever and set up for one finger control like a hot start lever on a dirt bike
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A question I am asking now of SCTA. Should the tap stop the fuel getting into the engine, or stop it getting out of the tank?
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A question I am asking now of SCTA. Should the tap stop the fuel getting into the engine, or stop it getting out of the tank?
You should probably ask that question in the SCTA Rules forum
http://www.landracing.com/forum/index.php?board=7.0 (http://www.landracing.com/forum/index.php?board=7.0)
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That's where I started, I am now asking the people directly.
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A question I am asking now of SCTA. Should the tap stop the fuel getting into the engine, or stop it getting out of the tank?
My understanding of the rule is that if the shutoff is not at the tank then the fuel line to the shutoff must be fire sleeved.
So either should work but get the OK from the SCTA.
Don
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It still does not answer the question - Should the tap stop the fuel getting into the engine, or stop it getting out of the tank? Rule 7.B.2.5 By the way all the lines are Aeroquip.
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My understanding of the "unvalved fuel line must be fire sleeved " says in itself the fuel tap does not have to stop the fuel getting out of the tank and that any fuel line before the tap or after a return type pressure regulator in the case of efi has to be protected
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Thanks Maj. It answers the question indirectly in that UN-valved lines are allowed if fireproofed. The question of Fuel Shut-off for "fuel" class bikes still exists. A lanyard or power kill does this for EFI with both mechanical and electric pumps because the solenoids switch off. If you run Nitro then stopping the fuel getting into the engine IS the most important OFF switch you can have.
Perhaps a redefinition of the Fuel class is required to separate Nitro from non nitro. If you think about it, breaking the seal on a Gas class bike to run in fuel should require you to be tech'd as a nitro bike
I have asked all these questions and more direct to the guys who matter, lets see what they come back with after s/w
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Perhaps a redefinition of the Fuel class is required to separate Nitro from non nitro. If you think about it, breaking the seal on a Gas class bike to run in fuel should require you to be tech'd as a nitro bike
I believe it requires a re-inspection for class change....
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"Perhaps a redefinition of the Fuel class is required to separate Nitro from non-nitro. If you think about it, breaking the seal on a Gas class bike to run in fuel should require you to be tech'd as a nitro bike."
Let's not confuse the issue ? there is no Nitro class. Fuel classes don't run sealed tanks. They can run Gas, tho. (Or maybe not ? forgot this is the BMST.)
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Yes, you can run gas in the AMA fuel class at BMST. You still have to comply with the fuel class safety regs - fuel shutoff at handlebars, either electrical or mechanical.
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Hi Doc
Fuel shut-off at handlebars means what,? A tap stopping the fuel getting where? Into the engine or out of the tank? Or a switch disabling the power to an electric pump. It is the definition of the details that is missing from the rules allowing interpretation which can lean to not being able to run.
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The way I read it is that the fuel/gasoline shut off is to stop the liquid from getting out of the tank,, reasoning is that if the bike is on fire one has the ability to shut off the source,,
Fire sleeve is there to inhibit the source until the rider realizes that the machine is indeed on fire,,
The Lanyard is there to shut down the engine in the event that the rider parts company with the machine,,
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For maximum safety common sense says to shut the fuel off coming out of the tank. Arguing to do the shut off any further down the line is obviously less safe. Why is anyone even trying to argue in the face of common sense?
Stay safe guys.
Pete
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PJ said: "Why is anyone even trying to argue in the face of common sense?"
:cheers: :cheers: :cheers: :cheers: :cheers: :cheers: :cheers: :cheers: :cheers:
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Sorry if I added to your frustration. I was responding to Stan Back about whether one can run gasoline in the fuel class at BMST. Hopefully you will hear from SCTA techs soon.
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Hi Peter, A 3-way valve after the fuel pump is an allowed fuel shut off. It passes tech every time despite the fact it does not shut off the fuel at the tank, it just routes it around the system and back to the tank. It is not at the tank and it is allowed.
Seldom, I am not trying to argue in the face of common sense I am trying to get common sense defined to reflect changing designs. 7.B.2.5 allows for interpretation as is specifically for the fuel class, (anything except event gas). If the power is removed to EFI injectors the fuel is shut off from getting into the engine. It just flows back to the tank in the same way as it is already allowed. i.e. like a 3-way valve after the pump prevents fuel getting into the engine on constant flow. The difficulty is, how can you test/check this in tech? If you had an electric pump, you could see or feel it's not running, if you had mechanical pump, then if the engine is stopped the pump is stopped.
With respect to safety, if the bike is on fire, then stopping the fuel feeding the flames is a must. Stopping the pump, injectors, sparks etc all need to occur. A 3-way will not stop the fuel being pumped around your fuel system if you have a mechanical pump. You would need the clutch, assuming it's not a slider, to stop the motor turning.
It seems like I am just reiterating what I have said before with no meaningful discussion.
Can define why OFF solenoids cannot be defined as fuel shut-offs?
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Any guess how long a mechanical pump could survive without any fuel circulating through it.
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Hi Vinsky. Mechanical pump life is not the question, the fuel shut off in the rules is what I am trying to get discussed.
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Hi Doc
Fuel shut-off at handlebars means what,? A tap stopping the fuel getting where? Into the engine or out of the tank? Or a switch disabling the power to an electric pump. It is the definition of the details that is missing from the rules allowing interpretation which can lean to not being able to run.
Old thread.... yeah I know, but pretty much the same question.
will the off-run-off switch killing power to an electric fuel pump pass muster for the fuel class?
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will the off-run-off switch killing power to an electric fuel pump pass muster for the fuel class?
Yup as long as it is accessible without removing hand from bars. I have my fuel pump relay and my ignition (as well as my nitrous and fuel solenoids) wired thru a kill switch mounted on the clipon on the throttle side and then thru the lanyard switch mounted on the clutch side clipon, in series.