Engine options for a 1989 R25 King Cobra

[Ezzy]

Sorry to say that my first posting on this forum is about my OMC 5,7 King Cobra cracked by freezing... ...block and manifolds...

I really appreciate reading the threads in this forum about all different Donzis...

How about engine options for my Ragazza 25 that is suitable for the boat and compatible with the King Cobra drive?

Appreciate your help as I am not that familiar with these engine alternatives as I only have had diesels before...

Mats

[Barry Eller]

Welcome to the Donzi Registry!

The "King Cobra" drive is a good drive. I have one. It has been more reliable than my engine!

I would think you would want to re-power with a big block to get the 25' boat to perform the way most of us "Donzi" nuts here would want it to.

Good luck, send photos and ask questions. This is my support group.

Who needs a therapist with all of these guys!

Barry

[MOP]

Hi and also welcome to the board, small or big block Chevy can be bolted up to the bell housing you currently have. My only question would be if it is an early or late King before deciding on how much power, the early Kings were beefed up clutch dog units not a great improvement. The late King is a very good unit well respected, if you drive has a pronounced hump on top you have the good one.

Phil

[Ezzy]

Thanks for your replies!

The KC is the early version without the hump.

A follow-on question on the drive is that the boat is hard to keep on course in low speeds (around 5 knots) she turns from from left to right and back...

Any ideas of if it is some adjustments that needs to be done?

Thanks,
Mats

[mrfixxall]

Sorry to say that my first posting on this forum is about my OMC 5,7 King Cobra cracked by freezing... ...block and manifolds...
I really appreciate reading the threads in this forum about all different Donzis...
How about engine options for my Ragazza 25 that is suitable for the boat and compatible with the King Cobra drive?
Appreciate your help as I am not that familiar with these engine alternatives as I only have had diesels before...
Mats

i have used gm performance engines and have worked out vary well...i reccomend using a 7qt oil pan tho because thease engines will only hold 4.5 qts of oil and will suck the pan dry with the higher operating rpm's,been their and done it...all my customers that ive installed thease engines picked 4-7 mph because of the extra hp...

http://www.crateenginedepot.com/350-Crate-Engine-330-HPBase-HO-with-Iron-Vortec-Heads-12486041-P18C2.aspx

[Cuda]

Thanks for your replies!
The KC is the early version without the hump.
A follow-on question on the drive is that the boat is hard to keep on course in low speeds (around 5 knots) she turns from from left to right and back...
Any ideas of if it is some adjustments that needs to be done?
Thanks,
Mats
You'll be much happier with a big block. A used 454 Mag would be a great step up. Even a 454 330 horse would be a big improvement. Torque is the name of the game in marine engines, and it's almost directly related to cubic inches.

As far as wandering at low speed, it's what a lot of us refer to as "hunting" at low speed. Every boat I've owned with a single engine will do it. Most of them, if you just point the boat straight, and not touch the wheel, will correct itself. Pressure builds on the side that it's turning to, and makes if turn back the other way. Try it one time.

Good luck with her!