Propane / Blowoff Valve

[jmd]

Hey all. I came to this forum because I've been around the Turbo Buick community since 96 and figured on there being some good knowledge here.

A friend has a late model GM pickup with the gas V8 and runs it on propane sometimes.

In the event of a propane backfire, the ~90 degree elbow from the TB to the propane injection block gets blown up. At 50$ a pop.

Is there anything technically wrong with fabbing an elbow (of aluminum) and installing a blowoff valve set low since the truck is naturally aspirated?

Between that and rebuilding a trans., my Sunday may be busy.

Thanks for any technical input. In case this is a good plan and someone in Phx. area might have a source on an affordable and effective blowoff valve, speak up.

-Matthew

 

[motorhead]

I can't see why it wouldn't work?

Although venting propane vapour under a hot hood couldn't be the wisest move.

If you were to do it, I would recommend recirculating the expelled gas/pressure back into the intake tract well ahead of the throttlebody.

One thing is for sure, it is going to be one loose poppet valve to be an effective N/A "burst panel".

PS. Monte Carlos Rule.

 

[Drac0nic]

A typical "dual fuel" setup has it so that the vaporizer feeds in before the carb/EFI system at some point. I'd probably end up trying to find some sort of low pressure high volume relief valve. As long as it's upstream of the feed for fuel, I wouldn't worry about it too much personally. If you're concerned about it, just run a piece of hose below the engine level. If you've got backfires it sounds like something's not right in the first place IMHO. We've got a 460 that's a bit goofy, but other then that we've got a trio of 429 based F-750s, and a pair of F-150s that run on LPG and none of em have issues with backfires.