You probably meant diesel engine. The compression pressure of those is around 300-500psi, and that's sufficient to heat the air to a few hundred degrees and ignite the injected fuel.
For comparison, what happened in this sub was 10x that pressure.
(Yes, 2-stroke diesels also exist, and sound absolutely amazing.)
Much higher than that. The external pressure was ~6000psi, but water has inertia. The peak pressure as the bubble imploded was many orders of magnitude higher than that.
For comparison, what happened in this sub was 10x that pressure.
(Yes, 2-stroke diesels also exist, and sound absolutely amazing.)