having some problems with my advanced combustion

[d.marty]

Okay spudders. question... i used the burnt latke meter calculator and figured out that for my cannon (358 cubic inch chamber) required a 12" 3/8 meter pipe that is pressurized to 89 psi. i launched my first shot and it fired perfectly. my second shot however did not... the mixture wouldnt ignite. i vented it thouroughly for about two minutes and tried it again. filled to 89 (or close to). What could be happening? i know my spark is working. (i have a visafire) and i know its a big enough spark. What else could it be?

[Gun Freak]

Do you have a chamber fan? You might need one.

[saefroch]

Vented thoroughly how?

I really can't think of any other reason the mixture wouldn't ignite...

[d.marty]

i have a chamber fan and i had it running to vent it out.

[jackssmirkingrevenge]

have a read through this thread:

http://www.spudfiles.com/forums/ignitio ... 22725.html

if you still don't figure it out let me know.

[Technician1002]

The chamber needs to be opened so the old air is expelled and new air is taken in. Leaving the chamber sealed and just running the fan won't do the job. Was the chamber opened for venting?

If it did not get fresh air inside, it won't work.

[d.marty]

well if you look at my cannon, the chamber has a 4x2 reducer on both sides... could it just be that its not venting out fast enough? im thinking that if i add another fan... but an external one.. on the end closest to the handle with another 4x2 and a section of 4" pvc. would it draw in the air better? here is the link
http://www.spudfiles.com/forums/name-please-t22784.html

[Rhawk14684]

1) Gun is pretty complicated and I can tell a lot of work has gone into it. Remember - the fancier the widget, the more likely things will go wrong.

2) Did not see anything about the timing of when the spud was loaded. If loaded too early, the spud will restrict the air exchange.

3) What is the direction of you fan air flow? Are you creating positive chamber pressure or purging the fumes?

4) RPM/CFM rating of the fan: Even if you have blockage, a high rated CFM fan can overcome the restricted airflow (not desired but will work).