Thread Tools Search this Thread Display Modes
Old 10-27-2019, 05:07 PM   #1
biggerseagar's Avatar
Join Date: Dec 2010
Location: central Illinois
Posts: 2,102
Default Prop questions

I am looking to get new aluminum props for next season. I have 18 3/4 by 21 props on there now on my 01 3000 scr 5.0L carbs bravo 2 outdrives. They work very well but I think that they are worn out. Original equipment.

My first question is: how close to the original diameter (18 3/4) do I need to get to. It seems like I see 17 3/4 alot or even 18 1/4. I am happy with the 21 pitch.

I have found a store on line, The Delta Prop shop in Cleves Ohio that is close and prices are reasonable as a possible store to buy from.. Any suggestions in a make or manufacturer or prop shop that you know of or recommend?


biggerseagar is offline   Reply With Quote
Old 10-27-2019, 05:57 PM   #2
mmwjr's Avatar
Join Date: Feb 2012
Location: Essex, Maryland
Posts: 7,451

IMO if you go with the 18 1/4 and 21” pitch you shouldn’t see much change in performance. I would go this way instead of the 17 3/4.

1997 2400 SCR
5.7 Vortec / Bravo 2
mmwjr is offline   Reply With Quote
Old 10-28-2019, 02:52 PM   #3

Join Date: Apr 2008
Posts: 4,566

For Prop diameter sizing you want the space between the anti-ventilation plate and the tip of the prop blade to be 15% -20% of the prop diameter (20% being ideal). I'd start with how much you have now and calculate what that value with be with a different diameter prop.

18.75 x .15 = 2.8125"
18.75 x .20 = 3.75"

17.75 x .15 = 2.6625"
17.75 x .20 = 3.55"

Decreasing diameter may impact performance similarly to decreasing pitch. 1" of diameter is not insignificant.
shrew is offline   Reply With Quote

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Powered by vBadvanced CMPS v3.2.3

All times are GMT. The time now is 02:37 AM.

Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2019, vBulletin Solutions, Inc.