motor mount placement [Archive] - The Donzi Registry

View Full Version : motor mount placement

smokediver

04-12-2005, 08:20 AM

Does anyone know how far the front motor mounts need to be moved when going from a V-6 to a V-8 ? Can the V-6 mounts be used ? thanks in advance! Hopefully , I will be dropping in a 350 mag mpi . I am also changing the drive ratio from a 1.81 to a 1.62 ... would changing to a 1.47 be better ?

MOP

04-12-2005, 08:36 AM

Check Waynes post he just did the swap, maybe PM him for details.
http://www.donzi.net/forums/showthread.php?t=38144

On your ratio ? lower is better the closer you are to 1.1 the greater prop selection is, the lesser pitched props make the boat feel and handle better. Less roll up in turns and quick throttle chops. Some say it also helps to reduce chine walk, I would go as low as you can. My .02 cents

Phil

gcarter

04-12-2005, 08:36 AM

Wayne (Onesubdrvr) just did this in his Regazza. I'm sure he knows the answer. :biggrin:

Lenny

04-12-2005, 11:34 AM

I'd be going to the 1:47 (1:50) as well. The small boat with 300 HP will be able to turn a lot of prop. I would even think about the 1:34 and running 19-21" of pitch.

Rootsy

04-12-2005, 11:45 AM

BUIZILLA

04-12-2005, 12:40 PM

1.47:1 @ 300 pshp will have you spinning around 21 to 22" of prop in the 16...you will need a 23 Mirage +, or a 22 Turbo, at the very least....

JH

smokediver

04-12-2005, 04:23 PM

thanks for the help guys , root , i look forward to the diagram!

onesubdrvr

04-12-2005, 09:01 PM

thanks for the help guys , root , i look forward to the diagram!
Sorry, I was digging around, trying to find where I wrote the dimensions down,..... couldn't find it, so you are better off waiting for the diagram from Rootsy. On the note about motor mounts, mine were the same on the V-6 and the V-8, I imagine they are the same for you.

If you need any help, give me a shout, I'm in Port St. Lucie

Wayne

Verdugo

04-13-2005, 01:32 PM

16 Classic? i have a diagram at home on the puter with the motor mount layout i did for Burton when he installed a V8. I'll see if i can dig it up...

1.47:1 @ 300 pshp will have you spinning around 21 to 22" of prop in the 16...

If you find the mount layout could you also share it with me? I am upgrading my 16 which has the 4.3L to the 5.7 v9 Vortec

Thanks in advance rootsy

Verdugo