Hybrid fan

[WOW!!]

Iam building a Hybrid, 5' long and I need to put in a chamber fan in, the only thing is the chamber is 3" sch80 and I dont know if I should just put one in the back or 2 in there? there is going to be a inflatable bed fan for the exaust system. Thx

[SpudStuff]

umm do you plan on using a brass check valve for the bed inflator? the pvc ones are only rated to 150 PSI.
you should put one fan in the middle of the chamber

[WOW!!]

After a shot you take off the back and I made this thing and it puts air into it.

[sgort87]

You actually think you are going to want to remove the back after each shot? You are new to hybrids aren't you! Getting an air-tight seal requires a lot of teflon tape and a whole lot more torque on the end cap than anything you have ever tightened before.

I suggest simply venting your cannon with your air compressor.

[M3NT4L]

You can also atach a tube to a air compressor and drop it through the barrel, primitive but it might work.

[CS]

M3NT4L, you may have mental problems. What is wrong with Gorts suggestion? Nothing, so why the need to over complicate with your ghetto method?

[SpudStuff]

yes good point it is also cheaper to just use a cap on the rear of the hybrid instead of a plug and female adapter which cost big $$$

Somewhat off topic. i am working on a mini hybrid. should a expect it to be much louder than a standard combustion mini?

[CS]

Yes, since the higher pressure due to the up in combustion producing pressure.

[SpudStuff]

and threaded joints are only rated to half that of the pipe so only 185 psi for 3"sch 80 and 160 psi for 4" sch 80

[WOW!!]

The back is np becasue I have 75 rolls of teflon for a seal and a 2 strap wrenches and I cleand the threads for a better seal.

[cannon freak]

A litle bit off topic but with a chamber 5' long and 3" diamiter will there not be a more increased chance of DDT? I assume you are going with 3" beceause you want to use higher mixes and from what I have heard about DDT is that the chances of it happing increase with a longer chamber and with a shorter diamiter.

[frogy]

I'm new to hybrids, but why would a 3" chamber be for higher mixes? the smaller the diameter, the more pressure rated it is, so 1" pipe can withstand a higher pressure than 3" so theoretically 1" can do higher mixes...

And DDT is a lean mix correct? so cant you just make sure your propane meter is on the higher propane mix than needed, and that your air pressure gauge is a good grade so it's accurate...

[SpudStuff]

yes small pipe is rated higher. WOW! just becaise to have something dosn't mean you should gust use it because you want to. if you do reaserch you will find a cap is SOOOO much safer than a plug and female adapter, not to mention the cost issue.
For 3 inch sch 80: PLUG $12.32 Each
Female Adapter $24.04 Each
Total $36.36

As opposed to
3 inch Sch 40 Cap $3.28 Each

[frogy]

Um, why did you go from Sch 80 fittings to Sch 40 cap?

He's making his gun out of 3" Sch 80, so the cap has to be 3" Sch 80 too or it'll be a weak point, I know you know this, but why change from expensive Sch 80 fitting to cheap Sch 40 fittings? I didn't know how to bitch at you right, so excuse me for the un-organization of this post...

[WOW!!]

I might be wrong here, but DDT is the rate at witch something explodes. Accetlyen(spelling) has a higher DDT then say propane. A lean mix would give you less power becasue there is to much air in the air:fule ratio. A rich mix is when there is to much fuel, eather way it wont be as powerful as if it was the perfect mix.