what is the difference between 500 efi and 525 efi
10-02-2008 | 03:40 PM
#13
Registered
Joined: Aug 2005
Posts: 256
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From: Carrollton, TX
The 525 has all forged internals and a full roller valve train. It's a very stout package and only pumping 8.25:1 compression ratio, it's hardly working. Plus it run's on Regular 87 octane gas (Mercury Recommended)
I think the header issue has only come into play in saltwater useage. I know of several freshwater 525's that are still operating trouble free.
I think the header issue has only come into play in saltwater useage. I know of several freshwater 525's that are still operating trouble free.
10-02-2008 | 05:52 PM
#15
Charter Member#203
Joined: Oct 2000
Posts: 21,289
Likes: 19,968
From: Ft.Myers, Fl/ Atlanta, Ga/ Worldwide
Ask the racer's that run the 525 in OSS SVL, they will tell you it is a great motor package. some of the team are running the same motor for the 4th season, with just oil changes and plugs.
10-02-2008 | 07:00 PM
#16
JB Marshall
Joined: Mar 2006
Posts: 939
Likes: 0
From: Hudson Valley, NY
When you say rebuild top end at these hrs is that for the guys who are running WOT and pushing all the time? I know so many that have exceeded these hrs and have not touched a thing and they keep on ticking....
10-02-2008 | 07:30 PM
#17
Charter Member #34
Joined: Oct 2000
Posts: 7,151
Likes: 2
From: Beautiful North Carolina
Both are great motors but personally I like the 500 because you don't have all the problems with sensors sending it into gaurdian mode. It is VERY easy and only requires a few minor changes to get a lot more power out of the 500 then what the 525 makes.
Heads, Cam and ECU reprogram and you are at 600 HP and it looks stock and idles like a stock motor.
I have seen a few motors have top end problems at or around 200 hours but very few. I know of several 500's with many more hours that have been trouble free. A mercury tech at the miami show told me that most if taken care of will easiely do 400 to 500 hours.
Heads, Cam and ECU reprogram and you are at 600 HP and it looks stock and idles like a stock motor.
I have seen a few motors have top end problems at or around 200 hours but very few. I know of several 500's with many more hours that have been trouble free. A mercury tech at the miami show told me that most if taken care of will easiely do 400 to 500 hours.
10-02-2008 | 08:21 PM
#18
Charter Member # 55
Joined: Oct 2000
Posts: 20,255
Likes: 2,504
From: Omaha/LOTO
The main differences are the cam, ECM, aluminum heads and closed cooling on the 525EFI.
10-03-2008 | 02:00 PM
#20
Registered
Joined: Nov 2000
Posts: 2,287
Likes: 8
Both are great motors but personally I like the 500 because you don't have all the problems with sensors sending it into gaurdian mode. It is VERY easy and only requires a few minor changes to get a lot more power out of the 500 then what the 525 makes.
Heads, Cam and ECU reprogram and you are at 600 HP and it looks stock and idles like a stock motor.
I have seen a few motors have top end problems at or around 200 hours but very few. I know of several 500's with many more hours that have been trouble free. A mercury tech at the miami show told me that most if taken care of will easiely do 400 to 500 hours.
Heads, Cam and ECU reprogram and you are at 600 HP and it looks stock and idles like a stock motor.
I have seen a few motors have top end problems at or around 200 hours but very few. I know of several 500's with many more hours that have been trouble free. A mercury tech at the miami show told me that most if taken care of will easiely do 400 to 500 hours.
