I have a 1984 Corvette 350 with 4bbl and Edlebrock intake in my boat. Runs great and cool all day long.

What do you think is a safe max operating speed and a red line rpm?

Thanks guys.

KT

Everybody loves the pics

that'd be fast in a 914.

I would say to be safe 5500rpm if it's a stock motor.

If it's ballanced then 6500rpm should be fine.

Not exaclty sure but this is where i would be if it were mine.

Shouldn't the prop size and pitch be chosen such that WOT puts you at your peak HP? Assuming you keep the boat in the water (no James Bond type stuff) it would then be impossible to overrev the motor, and you should get the best top speed possible. (I could be wrong about this, it's just what makes sense to me... I'm no boat expert)

True about prop pitch. I'm 15x21 and 4400 rpm WOT.
4400 rpm is the right speed for the stock 305 Volvo Penta with a 2BBL @ 200hp.

I expect I have 300hp easy.

KT

If I were you see what kind of rpms with current prop and then prop up from there. rule of thumb 1 up in prop pitch=200-300 rpm drop. Hope this helps you?

I run a blueprinted jet behind a pumped up 454 - 5500 RPM is the limit for me.

You mean V8s make power above 5000 rpm?

Off Peak power - still enough to pull the impeller thru the water - as the cam could feasibly go to 6500.

Yeap... our old Chrisovich had twin crusaders I used to see about 5400 WOT

that made about 35 Knots... fast for a big ole wood boat

I'd prop it to turn around 5000-5200 at wot.

I wouldn't make a habit of running it around firewalled all the time though.

4400-4500 is probably a good everyday limit.

So,,, Where's the picture of the boat!

I had a 283 in my wooden flatbottom. It would go to about 5500. (60mph or so).

Should be safe for 6000 or so with stock valve train.

Ok, the kettles' black. I can't find a pict of my boat anywhere. But, it was pre-digital age...

If all goes well. The boat will be on the water tomorrow afternoon. I'll get some shots for y'all.

20' deep v-hull cabin cruiser w/ bimini top, trim tabs, Volvo 280 drive. It'll do 35 mph. Fun boat. Weighs about 4000#.
'77 fiberform.

here's something.

Had it on the Napa river for about an hour.
Revved it up to 5000 rpm's for short intervals and criused at 4400rpm's.

Got up to 38mph, fastest ever!

Cruises at 30-32 mph.

Notice the Corvette badge above the tow hook?