Big Johnson Performance Engines

Getting the balance on for a pair of 509 marine blower engines

Another low hr marine build that didn’t make it due to clearance issues.

That’s a wrap, twin 700 hp marine 540s all dressed and ready to roll.

And just like that, ready to roll. 4 passes with minor air bleed adjustments, the 950 QFT was jetted up 10 sizes front and back prior to firing it going off of the first one we did the other day when it was 16:1 AFs . Over 700 hp FTW. 10.2 compression and mild hyd roller cam, those Profilers certainly did their job all on 89 Sheetz gas

Initial firing and low load break in seems to be all good, timing set (34 degrees) no leaks, ready to make a pull .

Another set of recently rebuilt 500EFIs from the bay that didn’t live a very long life.

565 Marine BBC #2 done, fired, broken in, leak checked and a safe tune put in it to ensure it, and #1 , lives a long happy life.

A little dyno time today. Getting a safe tune in one of our marine customer’s engine.

Before and after of tear down of a marine 500EFI. Going to be a new and improved with much upgraded horsepower 540 when it and another one just like it leaves for its home on the bay in a 38 Cigarette

#2 marine 565 ready for the dyno. ( No you’re not seeing double from the last pics of the first one )