Peak pressure gauges

[willarddaniels]

I am working out the kinks for my first hybrid and am wanting to put a gauge on it to read what the max pressure is during combustion. I think this would be extremely helpful in knowing how many multiplications of fuel/air mix I can go before getting close to my material's working pressure. Also, I plan on using metered propane with small amounts of metered oxygen mixed in. I would need the gauge to best determine how much O2 would be the most efficient. There may be charts somewhere, but cautious experimentation would be more fun.

I have found several places to get these, but has anybody found any for less monies than the price of a used car? I seems the best are digital, there must be a good one that is dial.... somewhere.
Or, has anyone even used one?

[spudthug]

i have not used one but my freind has and digital is the way to go they are alot better and alot easier to read...he told me he regrets ever buying a regular one...they are so simple yet so easy and not big at all a real space saver if you ask me...so i would personally use digital if your willing to spend a little on it...well alot it will probly take a huge chunk out of your wallet for a top of the line one that is worth buying and using

[boilingleadbath]

I've seen suggestions for modifiying a normal tire gauge (stick type) somewhere... you might try searching the spudtech forums.
Sorry for the vaugness.

Alternativly, one could manufacture "implosion capsules".
I'm thinking something along the lines of a 1/2" union with an endcap on it - just measure the pressure it takes to rupture the burst disk with a slower gauge.
The downsides being that the resolution would suck and you'd have to get a slow air source capable of producing whatever high pressure you need.

[rna_duelers]

Why not use a Compression tester for a car engine(for the piston compression)They have a guage that goes to 400psi and they also retain there pressure until you open a little bleed valve to release the pressure.

Cost is maybe $25-30 from a Auto Parts Store.