Comfy cruising RPM on a SBC

[RYPiii]

What is a comfy cruising RPM for a 327 SBC and speed? At 3500 I’m cruising 26-27 and it feels good. Being told that’s too high RPM for cruising.

[Striker543]

Mine cruises between 3200-3600 depending on conditions with max rpms at 5200. Not much you can do to lower cruise rpms other than adding more pitch, which will also reduce your overall rpms.

[RYPiii]

Thank you. I'm between 3500-400 comfy. may add some pitch to see how she responds.

[One Eyed Gator]

Just to ask what is the gear ratio you're running what prop and length and what is your current WOT?

[RYPiii]

Just to ask what is the gear ratio you're running what prop and length and what is your current WOT?

Precision gear box 1.9:1 with 76” water walker. Only ran the boat twice since I bought it. So I’m not sure about the WOT. I’ve had it up to 5000 rpm and it had some left. Didn’t check the speed.

[Striker543]

For what it’s worth when I bought my boat it had a 2.38 Gear and 3 blade 78” NGH. With that setup it cruiser closer to 4000 rpms. I changed it to a 2.68, added one blade to the prop and turned it into a 4 blade 80”. That made a big difference in overall push and also brought my cruise rpms down.

[One Eyed Gator]

The Falcon I believe max out at 2450. With a 1.9 at 5,000 engine rpm your turning the blades 2632 rpm.

4,700 with a 1.9 ration put you at 2474.

You said you still you still had pedal left at 5,000 so you're turn those blades over there max.

I would see determine my WOT rpm. Then make your prop with a sharpie, take your tools to repritch the prop. Add a little pitch at a time and see how it feels. I look for the sweet spot for my riding style.

PM Sent

[RYPiii]

The Falcon I believe max out at 2450. With a 1.9 at 5,000 engine rpm your turning the blades 2632 rpm.

4,700 with a 1.9 ration put you at 2474.

You said you still you still had pedal left at 5,000 so you're turn those blades over there max.

I would see determine my WOT rpm. Then make your prop with a sharpie, take your tools to repritch the prop. Add a little pitch at a time and see how it feels. I look for the sweet spot for my riding style.


PM Sent

Tried calling you bud.
While sitting on wet hard ground, I stuck it. Surprising. I thought for sure an aluminum boat with a gear box and big prop would go anywhere. I guess the 327 is under powered for the weight of the boat. While stuck, I had it pegged and it wouldn’t pass 4700 RPM. I don’t think adding pitch will help any. If anything, maybe take pitch out???? Curious what the experts have to say

[kwanjangnihm]

Is your 327 stock and is this a 2 blade falcon? Where is the pitch mark set at now?

[OneBFC]

Curious what the experts have to say

Easy, not enough power at 4700 rpm. That could be under 300hp pretty easily based on exact build.

[NorthWestFloridaBoy]

On my old gilileo 1600-1800 rpm. That's direct drive though, probably not data your looking for though.