496 HO swap for 525 EFI
 

I have a 2008 Donzi 27 ZR. The boat and motor have about 50 hours on them. Love the boat, but am considering upgrading to more power. I've been reading quite a few threads about this, some in favor of bolt on power upgrades, and some not. I guess I am leaning against bolt on and towards a completely new engine (one that will for sure handle the extra power). I'm just concerned that if one is going to add 100+ hp, upgrading the internals would be a good idea for peace of mind. And when you start doing that, you might as well bump up the horsepower to maybe 600, and then I think you open yourself up to tuning issues, and the cost starts to get up there. So, I'm leaning toward a complete engine.

I also understand I'll need to beef up the rear unit to handle the extra power.

Having said all that, where would be a good place to go to purchase a new (or maybe even low hour) 525 EFI or comparable engine? Any ideas on where I might go to sell my existing low hour 496 HO? I live in Wisconsin, and I don't think there are too many high performance marine engine guys around here. So any advice I could get from you guys would help a lot. Thanks.

I would go with the raylar 525 kit....when its all said and done you will save money over upgrading to a merc 525...alot of those used 525s are abused and you might find yourself sinking more money into the project after you spend 15 k on a used one.

Offshore performance specialty in fort myers fla.
( Don Carter sr. ) they have new motors in crates
every size .

The 496 needs forged internals......and dont let anyone tell you otherwise!! Price out the forged rotating assembly and Raylar kit, probably 10k +/- some.
You could probably sell your 496 for around 7k +/- some.
Price in the labour to tear down and reassemble the motor and where do you sit price wise???
Now you are not far off the price point on low hour 525......got ya thinking now eh??
Anyway, if you are not in a rush or you have the funds there is lots to think about.

yeap... +1

p
 

pm me with the price you are looking to get for your 496 if it is a ho!!!!!!!!!

The place to buy and sell used is right here on OSO.

Used low hour 525EFI's are going for about 20k. Used 496HO's are in the 8-9k range.

Go with the 525 EFI for sure and don't look back! I got a 2007 vintage one here with about 40 hours two years ago for $20,000. I sold my 496 to a guy in Germany. Had to crate it and take it to the shipping company near Detroit Metro Airport. I had to have my exhaust tips relocated and purchase new tails to keep the Q&Q. I also beefed up the hull. I also promptly grenaded the stock Bravo 1X upper. Other than the exhaust and switching to analog gauges the swap was a bolt in. Don't waste any money on the 496. My boat is a 2005 22' Donzi Classic. I'll dig up the link to my project.

This documents my swap. It got off topic somewhat and raided by the steering popos (Zeiger steering is on now) and a former moderator took some posts with him when he left the site ;) but you may find it helpful if you sift through it.: http://www.donzi.net/forums/showthread.php?t=57025

Yikes, I just re-read that thread. And I thought things got out of control HERE sometimes. At the least it is an entertaining read and if you just read my posts you will see how I did the swap. Good luck. I hope you do it.

Check w/ Mel Riggs, he is in WI.
Also, El indio on this board is now owner of a large Merc dealership in WI.

+1 for swapping to a 525,,,,, although the Raylar kit is nice.

It will be alot easier to get rid of when resale time comes around

Stock power always sells faster

Which dealership is this?

Thanks for all of the input on upgrading power from a 496HO. I've since been doing quite a bit of research on this. And I think that the comments here about upgrading to forged internals is probably a must. I don't want to have to worry about whether the motor internals will handle the extra power from a Raylar kit or a Whipple kit. And when you start factoring in the labor to re-build the internals, you might as well just spend a little more to upgrade to the 525. Plus, I don't like the idea of tearing the motor apart. Anytime you start doing that it just seems like it's never the same again. So my thinking is that if you are going to upgrade to 525hp, might as well spend the money once, buy the blue motor, and get it right. Not sure how to get hold of Mel Riggs or El Indio. If anyone can help me with that, that would be great. I have spoken with Shipyard Marine in Green Bay (they are a Donzi dealer), and the service guy there sounded pretty knowledgeable. One thing I'd be curious about. With the 2008 Donzi 27ZR that I have, I pull about 3,400 rpm's on takeoff until plan, and 5,050 at WOT. I top out at 72 mph. I'm running a 28 pitch Bravo 1 with 1.65 gear ratio. I think my prop and gearing a pretty good, since i'm getting what I think is the most out of this boat. Assuming I go with a 525, I know I'll get more top speed, but what about rpm's while getting on plane. I'd like to see a little quicker plane time. I would think that with the extra hp and torque, and assuming a re-prop, I should be able to turn a little more rpm while getting on plane. Any thoughts on this?

[QUOTE=tomahdonzi;3227855]Thanks for all of the input on upgrading power from a 496HO. I've since been doing quite a bit of research on this. And I think that the comments here about upgrading to forged internals is probably a must. I don't want to have to worry about whether the motor internals will handle the extra power from a Raylar kit or a Whipple kit. And when you start factoring in the labor to re-build the internals, you might as well just spend a little more to upgrade to the 525. Plus, I don't like the idea of tearing the motor apart. Anytime you start doing that it just seems like it's never the same again. So my thinking is that if you are going to upgrade to 525hp, might as well spend the money once, buy the blue motor, and get it right. Not sure how to get hold of Mel Riggs or El Indio. If anyone can help me with that, that would be great. I have spoken with Shipyard Marine in Green Bay (they are a Donzi dealer), and the service guy there sounded pretty knowledgeable. One thing I'd be curious about. With the 2008 Donzi 27ZR that I have, I pull about 3,400 rpm's on takeoff until plan, and 5,050 at WOT. I top out at 72 mph. I'm running a 28 pitch Bravo 1 with 1.65 gear ratio. I think my prop and gearing a pretty good, since i'm getting what I think is the most out of this boat. Assuming I go with a 525, I know I'll get more top speed, but what about rpm's while getting on plane. I'd like to see a little quicker plane time. I would think that with the extra hp and torque, and assuming a re-prop, I should be able to turn a little more rpm while getting on plane. Any thoughts on this?[/QUOTE

You will want to go a little easy while planing if you want the drive to live but once up you will see a HUGE increase in acceleration that will put a big smile on your face!! :)

http://www.offshoreonly.com/forums/g...gnum-mark.html

Mr. Marine in Fon Du Lac(?).
When i spoke to him a few months back, this was in the working... he mentioned it being one of the biggest dealers.

Do the 525. I wouldn't touch a jacked up 496, and most others wouldn't either.
+1 for Don Carter. Stand up guy!

My thoughts are the same !!

Storm,

Any website to MM's new company?


thanks
Mange

Don't think it's been updated.
http://mrmarineinc.com/

As far as plane time goes... I have a 28 ZX which I know is a different hull, but assuming Donzi didn't totally re-invent the wheel on the 27 then these things just are not really made for quick planing.

The X dimension on the drive(s) is pretty aggressive for a factory setup and the stepped bottom is just not well suited for quick planing.

I did the 496HO swap to a 525.

Things to consider. You should/need to upgrade to a XR drive to handle the 525. You'll need headers. You'll need to rewire/replace your electrical harness. More time and $$ than you initially think but You'll pick up about 10 mph.

I would go for the Raylar HO 525/600. After you do this proven upgrade you will have a solid, turn key 600 HP engine. The advantage of going this route is you have a zero hour engine again. There is nothing wrong with blue engines when they are new but most of the low hour used I imagine are have been rode pretty hard. No telling what you might be getting into. I have always been told that going cheap will be expensive. Either do a complete rebuild with the Raylar or new Blue!!