Dock Holiday

I have a pair of 2002 Merc 500 EFI's completely stock with 260 hours on them.

The motors have been rock solid and very well maintained.

I want to replace or rebuild the heads (Top End) this winter.

Looking for good advice on what you guys have found that really works. The way we use our boat dependibility it most important. If I get some more power and can move up to a pitch larger on props that will be great also.

A mechanic I trust does not like aluminum heads and wants to just rebuild the stock heads and work on them some.

A couple of other guys have convienced me to look into replacing the heads with CanField of AFR coated heads.

I like the idea of the aluminum heads but want to talk with someone that has done it and can share results with me. I understand that with the aluminum heads that I will have to reprogram the ECM's because they will flow better, which again means that I need to find someone that has done a setup and knows how to program for those heads. We do use our boat some in salt water, but very little, 98% is in fresh water.

I sure this has been discussed before, sorry for not just searching, but would like some current information.

Thanks in advance.

Doc

tomcat

Airpacker just did this with hard anodized aluminum heads. He should be able to shed some light.

Dock Holiday

TTT

Tomcat, thanks I hope he will share his results.

This is the kind of information I'm looking for. A buddy had this information but I would like to talk with them to confirm.

Innovation in FL. They seem to be the undisputed king on that particular engine. Top end rebuild, cam change, port the heads, re-program the ECU for 565 horses for $5800 per side.

Any one familiar with this company? I do not know how to get in touch with them? Any information would be appreciated.

Thanks

Dock Holiday

Talked to one mechanic that recommended the following.

Change to 540 Cubic inch, change cam and switch to Dart cast iron heads with the good stuff. He said I did NOT need to reprogram the ECM.

Sorry, I do not have the exact specs in front of me that he came for these items.

He said the ECM did not need to be reprogramed that the 500's are set up rich and that I would not get into a lean condition. Should dyno around 560HP.

Any thoughts on this set up?

jdnca1

Dock;

for $5800 a side why not just spend another $500 a motor and go with injected whipples? should put you with AT LEAST 675hp. Only things I would suggest if you went that route is new springs, head gaskets, and lifters.
What you'll find is the biggest power killer in the 500EFI set-up is the highly restrictive intake manifold...you can spend tons on great flowing heads etc, but if they can't get air efficiently its money wasted. I looked into changing heads, cam, etc on my 500EFI's and that was the consistent response I got back. Now if you are willing to scrap the FI and go with a single plane and carb you'll really wake up the motor with head and cam changes you suggest.

Dock Holiday

jdnca1,

You are right, but I'm not doing this for performance. I really do not want blowers.

With the hours we have on the boat I just want to freshen up the top end for reliability, and if I gain a few horsepower that will be great.

Just wanting to make a good decision and see what has worked well.

Thanks

jdnca1

Dock,
No problem, I was in the same camp you are last year. Someone could make a killing if they put together an affordable intake and utilize the 500EFI componets.

I would have you valve seats cleaned up, springs, head gaskets, and lifters with the time on your motor.

I did mine @155hrs and had a head gasket going, springs would have probably made it another 50hrs or so but a few were getting soft. I plan to change my lifters out this winter (185hrs).

CAVelocity

Hi Dock,

You may or may not be familiar with my boat- Velocity VR-1 ex-race boat with single 2002 500 EFI. When I bought it, Velocity had sent the motor to Innovation to do their tricks (top-end, porting, custom cam, and ECU) and freshen up the bottom end. Long story short... an installation error led to a blown head gasket at 20 hours. Both Veloctiy and Innovation fully stood behind their products and rectified the situation immediately. I went down to Innovation's facilities in Sarasota and was very impressed. I could not be more happy with the guys at Innovation and plan on going back to them again for all of the motor needs. The motor dynoed 550 hp immediately after rebuild with all accessories on it. I was told it would gain a little more after it loosened up. I have since put another trouble-free 125hrs. on the engine. It sounds awesome (especially at idle!), has 500+ ft/lbs. from 3000 on up, and the boat gets better than 2 mpg at 55mph cruise.

Talk to Rick (president) or Dennis (vice-president) at Innovation (941) 355-7852.

C.A.

Dock Holiday

Thanks C.A.

I just got off the phone with Innovation and I am very impressed. They are definately the guys for me.

Have had two other people contact me to recomend them since I started this thread.

They know the 500's and 525's like the back of their hand and what to do to build them better and still be reliable.

They quoted what I think to be a good fair price. It includes all new bearings and rings, new cam, all the head work, rebuilding water pump, new paint, dyno tune and remap the ECM.

Thanks for all the help.

cuda

He'll cook an outdrive at those rpms.