496 ho to 525
 

Hello I have a few questions I have a heat with a 496 ho and a bravo 1 X drive 1:50 gear ratio. I want to move up to a 525 how much work is it to switch motors etc? Also i was wondering if I could keep my outdrive or would I have to move up to a bravo 1 XR drive? How much power does the X drives handle, any experiance out there with this. In good conditions I can run 64 mph, How fast will a stock 525 in a Nordic Heat run Im thinking around 70-75? Thanks

The Merc 525 is a great running motor. They regularly dyno 540+HP at the crank. I think the Bravo X drive would be OK if you didn't thrash it too hard on takeoff and in rough water. You can upgrade the X to an XR, and I would when feasible.
Performance depends on where you live, (elevation/temps/humidity) and go boating. Here they run in the mid to upper 70s. If you're at high elevation it will be worse. At sea level and in cool weather possibly better.
The swap isn't that difficult, but I would recommend a switch to full hydraulic steering with the blue motor. Hydraulic is safer, it results in less wear on your drive, and better handling over 70.
Regards,
Steve

I did that swap and the difference is amazing. My Bravo X lasted 7 hours and my boat is lighter than yours. Keep some $ budgeted for an XR upper. Also the exhaust tips will need to be relocated.

I've done a couple of them. We did "boatingbents" 2005 Heat OB. It came stock with a 496 HO and ran about 63-64 in our test conditions. We upgraded to a Raylar 496 package and ran 70-72 under the same conditions. After that engine failed we went to a 525 EFI. It runs about 1-2 mph faster than the Raylar engine. He had corner exhaust so we had to order tailpipes from CMI. You also have to do some wiring mods and get an digital-analog converter to make your gauges work. Bent ran the X drive with the Raylar engine for over 3 years with no trouble, and the Raylar 496 has more low end torque than the 525. We did swap to an XR with the 525 "just because". No hydraulic steering and the boat handles fine, but it's strictly a lake boat.

exhaust
 

ok im confused why does the exhaust tips have to be relocated in order to put a 525 in a heat? I have the tips that are flush mounted. If so do you use the same holes?

[QUOTE=05 Nordic Heat;3493454]ok im confused why does the exhaust tips have to be relocated in order to put a 525 in a heat? I have the tips that are flush mounted. If so do you use the same holes?[/QUOTE

There isn't much room in my little Donzi and the tips needed to be moved because the 525 headers are closer together. If you have room maybe you can have custom tails made to compensate.http://i763.photobucket.com/albums/x...s096Medium.jpg

If your tips are at the corners like most Nordics you need custom tail pips for the cmi headers that make a turn out toward the tips. If they are out the back you may need an S shapped tailpipe to get things to line up. (Nordic exhaust doesn't run straight back) The stock tails are generally too long to work. I switched a 496 to 525 in a 288 Sunsation and the exhaust lined up just fine.

Bob Lloyd
Full Throttle Marine

if you need any help when the time comes i can help you with tail pipes .
mike