Prop testing Formula 402
 

Here is my setup,

Engines are 454's with weiand 177's, roller cams, alum heads, etc. TRS drives

Engines make peak tq around 4500. Before the alum heads with slightly smaller cams, they made

4500 566TQ 485HP
5000 553TQ 526HP
5500 527TQ 552HP
6000 491TQ 561HP

Was running a pair of worked 26 Maximus props. On Flat water with 3/4 tank of fuel I was getting about 4700RPM and 63MPH.

Last night I strapped on a pair of box stock 23P revolution 4 blades. Flat water, still 3/4 tank of fuel. Got 66MPH, 5400RPM.

The rev props planed so much better. The maximus actually cavitated quite a bit coming on plane, while the rev props did not, so planing was waay better. Obviously cruise speed is down from the maximus. With some chop under the boat, obviously mph goes up, along with another 2-300 rpm.

My goals are not so much for top speed, but to make life easier on the drives, and engines. I am thinking a set of labbed 25p rev props should put me where i want to be. My goal is to be around 5200 or so on flat water, and around 5400 in the chop.

Would like to hear anyones input.

sound like the rev 4 25P should work, try them out of the box first, might work OK, If you need a little more, have them worked over.

Cool boat...Any pix?

Ran the boat yesterday with 25P revolutions. Heavy load of fuel, nice chop, got 72mph and 5500. What a diffence a little chop makes with this barge. Really picks up speed and rpm since the boat gets loose. Considering I had just about a full tank of fuel(240) gallon tank, that will scrub some rpm and mph.

Im thinking of trying my buddys labbed 28P bravos. still want to be around 5300-5400 in perfect conditions(light fuel, 2ft chop). Wish merc made a 27P revolution that i can get tweaked.

here ya go

That is a cool, huge, rare boat. Great to see. 72mph sounds great...

I love the old 402 Formulas.