Which Heads for 500 EFI's ?
 

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

Re: Which Heads for 500 EFI's ?
 

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

Re: Which Heads for 500 EFI's ?
 

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

Re: Which Heads for 500 EFI's ?
 

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?

Re: Which Heads for 500 EFI's ?
 

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.

Re: Which Heads for 500 EFI's ?
 

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

Re: Which Heads for 500 EFI's ?
 

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).

Re: Which Heads for 500 EFI's ?
 

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.

Re: Which Heads for 500 EFI's ?
 

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.

Re: Which Heads for 500 EFI's ?
 

He'll cook an outdrive at those rpms.

Re: Which Heads for 500 EFI's ?
 

I'm getting ready to do a 500-540 HP program with my 502's. I run in salt so Aluminum heads are not an option(not sold on the long term reliability of the anodizing). I'm going either 320 Merlin or 308 Dart iron eagle. My cam is a 761. Any thoughts on the pro's and con's of these 2 heads???

Re: Which Heads for 500 EFI's ?
 

I'm currently running the merlin vr's (315/320 cc int runner). If you buy the vr's it is quite a good value because they come with inconel exhaust valves,good springs and titanium retainers,10 degree locks. The only bad part is the exhaust is raised over stock and can cause exhaust alignment problems and they don't flow all that much better than stock heads,have a intake to exhaust ratio around 65%,flow about 300intake at .600,200 exh at .600,Smitty

Re: Which Heads for 500 EFI's ?
 

thanks Smitty- have you had any problem with the valve covers leaking with the merlin heads? I hear that the rail is so thin that there isn't enough room for the o ring gasket to seat properly. I've heard that this is also a problem with the iron eagles. Is anyone familiar with this? Is there an easy fix?

Re: Which Heads for 500 EFI's ?
 

I pulled my 500 down at 300 hrs and found head gaskets going away and several cracks in the heads around the valve seats. The descision to buy new head was a simple one. I looked at price, performance gain and reliability. I ended up buying the edelbrock marine heads. The are hard anodized and come with inconel exhaust and stainless intakes but no springs and hardware. They should be matched to cam choice anyway.I had my engine guy clean up the ports a little before I installed them. I installed good felpro marine head gaskets and went to 1.8 to 1 rocker arms for a little added lift and duration(stock cam). Raised the fuel pressure about 3 lbs until I had a nice color on the plugs and it has run perfectly. One thing I found was the variation in factory compression ratios cylinder to cylinder. The lowest worked out to 8.56 to 1 and the highest was around 9.1 to one so I had the combustion chambers worked to give me exactly 9 to 1 on each cylinder. Without a remap I am hitting the rev limiter so I will need to do that over the winter. The motor picked up some serious grunt from 3500 up. Total cost was around 5000.00 canadian bucks but I did all the wrenching.

Re: Which Heads for 500 EFI's ?
 

I believe Innovation Marine did the DPX600 for Volvo. A Gen VI 540 with a single plane MPI system very similar to the Holley.
I'm sure they could help you out with some various choices.

Re: Which Heads for 500 EFI's ?
 

A little disappointed with my phone conversation with Innovation today. Not sure if I caught them at a bad time, but they made me feel like they didn't really care if they got my business or not. And they quoted $3K more than I was told last week?

So I went to plan "B", and think this may be better than what Innovation was offering.

I just got off the phone with Tyler Crockett, http://crockettmarineengines.com.

It was refreshing to talk to someone that acts like they really want my business.

I have heard a lot of good things about him also and he offers a 500 EFI package that he as proven to be reliable. Funny, but he thinks differently than Innovation and says that a complete rebuild is probably not needed. He will do a leak down, but says that the bottom end of the 500's is very strong and he likes that I run the Mobile 1 15W50 and that I should not have to worry about the lower end.

He adds Brodix Aluminum coated heads with a very strong proven valve train. They work the heads in their stop on their CNC machines. He changes the cam, all new gaskets, reprogram the ECM in house, dyno and out the door in 2 to 3 weeks.

Heads $0000.00
Rework $ 000.00
Cam $ 000.00
Gaskets $ 000.00
Labor $0000.00
Dyno $ 000.00
_________________
Total $0000.00 per engine

I left the prices blank, but very fair in my opinion. Give Tyler a call if you want more details.

I really like this guy. He answers the phone and is very willing to tell you exactly what he as found to work and what he will do. He says they will dyno at 600 HP and I should easily get another 300 hours out of them.

Just wanted to share this with you guys. Thanks for all the good information