Texas Diesel power air shutoff, well sort of.

Dalpilot

Dalpilot

Joe Nobody!
I am using John Robinson's idea for an air shutoff, otherwise know as the "Oh Chit System". Since I have two bottle mounts in the back, I am going to run one for Nitrous, and the other I am running CO2. The CO2 tank is plumbed just like a nitrous system, right into the intake horn. If I get a runaway, instead of using a guillotine style air shutoff, that basically destroys your turbo, I will hit the big red "Oh Chit" button, opening the solenoid and releasing the CO2 into the motor, basically starving the motor of O2. John tried it on his truck, and it worked great. Anyone see anything negative about it, or have another gas they can recommend to use?
 
Never heard of a mechanical air shut-off trashing a turbo... I know several people that have had theirs accidentally shut though LOL Turbo's lasted a long time after...
 
Just need to make sure the Co2 system can keep the flow up high enough for a runaway well above your operating rpm.
 
Greg invented that. Works great, unless you run out of Co2.

I would like the guillotine back up for an ohchit, OHCHIT, scenario.
 
I imagine most race organizers would as well. That way you have one that will for sure stop it..
 
Sledpuller said:
Greg invented that. Works great, unless you run out of Co2.

I would like the guillotine back up for an ohchit, OHCHIT, scenario.
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Greg gets around. CO2 shut off systems were used by Teledyne in their engine dyno rooms for potential runaway's while testing new tank engine designs over 20yrs ago.
 
my main problem...if you trash an oil seal in the turbo, are you going to have enough co2 to kill the air until it runs out of oil?
 
Once the engine stops it should not matter if the oil is still going. Without compressing it it shouldnt burn, just remember to find nuetral.
 
I don't like the CO2 system as if you have an issue with your 12V what is going to activate the system? You could use a normally open solenoid, that would be the fail safe way to go. Just remember to shut the CO2 off before you kill power to it.
 
The CO2 system will work if sized appropriately and everything works as planned when called upon. With that said, it's not as fail safe as a mechanical linkage to pull a pin and allow spring force to slam a gate shut. If you are worried about snapping a turbo shaft (which has happened), set your gate up to close over a couple seconds instead of slamming shut (think of a tiny version of a car strut). Should prevent turbo carnage.

And for the use of the other bottle mount? Should be obvious... Another Nitrous bottle!!!
 
zstroken said:
I don't like the CO2 system as if you have an issue with your 12V what is going to activate the system? You could use a normally open solenoid, that would be the fail safe way to go. Just remember to shut the CO2 off before you kill power to it.
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I have a 6.0 which is electrically controlled, but if I do pop an oil line or something, I will have a normally guarded push button that will be uncivered just before the run. Its hooked to a nitrous solenoid, and if needed, you hit the panic button, and it will empty the bottle. With a -3 line that should take 10-15 seconds to empty. I like the idea of a mechanical shutoff as a back up as well.
 
Question, if the top of the piston is 1500 degrees, how cool would a 10 second burst of Co2 make it?

And is there a chance of hydro locking with unburnt fuel or water?
 
Sledpuller said:
Question, if the top of the piston is 1500 degrees, how cool would a 10 second burst of Co2 make it?

And is there a chance of hydro locking with unburnt fuel or water?
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Fist question is good...second one, well I think that already happens from time to time when an air shutoff is pulled...at least I've heard of it happening.

I like the idea, but I think I'll still be using a mechanical valve for my 1/2 ton...and I like the shock/strut to slow it's closure a bit too!

Chris
 
Signature600 said:
I like the idea, but I think I'll still be using a mechanical valve for my 1/2 ton...and I like the shock/strut to slow it's closure a bit too!

Chris
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Something like this fully extended mounted on either side of a blast gate. Just put a fitting in the air port with a tiny hole in it. Let the gate slam shut and have to force all the air out of the cylinders. Trial and error with hole sizes to get it to close in the time required.

And it's cheap...
 
As some of you know I have worked in the Fire Protection Engineering field for the last 13 years. Some of this engineering work was in CO2 systems for both buildings/Rooms like those Chris talked about and some Racecars/large vehicals such as boats.

Co2 will work and work well it is the standard for many industrial type applications. The trouble like Gene said is the thermal shock that the motor will take. These systems can run off electric in just about any voltage and many have mechanical backups.

Other Gases/Chemicals are out there that work also. Halon was used for years but its popularity has went down due to its environmental impact. You can still get Halon 1211 systems but they are pricey to refill. I would stay away from any "Powder" type systems due to the trouble they are to clean up after. The same effect could be used with a Nitrogen or Argon gas system also.
 
JerrodGlover said:
.

Co2 will work and work well it is the standard for many industrial type applications

The trouble like Gene said is the thermal shock that the motor will take..

.
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I didn't know that, I was just asking.

Its hard to believe, I know, with all I have accomplished, but I dont quite know everything. I have a couple chapters left.:hehe:
 
Dalpilot said:
I have a 6.0 which is electrically controlled, but if I do pop an oil line or something, I will have a normally guarded push button that will be uncivered just before the run. Its hooked to a nitrous solenoid, and if needed, you hit the panic button, and it will empty the bottle. With a -3 line that should take 10-15 seconds to empty. I like the idea of a mechanical shutoff as a back up as well.
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i think the 12v he was refering to was battery power (volts). he was saying what if something happened to batt.+? then you can't energize the solenoid.:doh:. unless you have a mechanical back-up.

Joe
 
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