502/415 MPI Gen VI Camshaft / Computer
 

Hello All,
Do any of you have a recomendation for Cam/spring upgrade.
Also ever seen any info on interface and software for modifying Mercruiser computer? I have done lots of this on cars but never seen any software / cable info on Mercruiser computers.
Looking for a more racing profile motor not the broomstick cam that the 502/415 has. The ocational stall at the dock is something I can deal with.

Re: 502/415 MPI Gen VI Camshaft / Computer
 

ZZ502 cam. I have one in a 9:1 454 and it works well even with my smaller valves should be even better on yours,,tons of torque,great mid range and not bad at the top considering I'm over propped. Are you staying stock compression? If so I personally wouldn't go larger than the ZZ cam. Forget the exacts but like 224/234 dur. at 50 & 527/547 lift

Re: 502/415 MPI Gen VI Camshaft / Computer
 

Thanks for info is yours an MPI ? did you have to do computer mods?

Re: 502/415 MPI Gen VI Camshaft / Computer
 

No MPI. I'm running 800 DPs from a Merc 500HP. Don't know nothin bout no Computer mods ;)

Re: 502/415 MPI Gen VI Camshaft / Computer
 

Thanks anyway . Like I said did lots of it on cars find it hard to believe not doable on Mercs

Re: 502/415 MPI Gen VI Camshaft / Computer
 

No doubt there are some guys here that can hook you up but not me. They will eventually see your thread and help. I've heard Ariz. speed & Marine does reprogramming for superchargers etc but also heard from some local mechs that they had trouble with them,,there are others,,,,,,GUYS??????

Re: 502/415 MPI Gen VI Camshaft / Computer
 

I assume you meant there are not 50 companies?
I am not talking about pre programing a solution. No two setups are the same. doesn't matter if you are talking about cars or boats. If you are tuning you need to be able to adjust parameters often or you pay someone to do it for you. I am lucky that I live close to a very good shop that does good work with a great track record however if I have them install and do the original tuning I assume it will change depending on where I go. Now I admit I am new to performance EFI boat tuning but I would think it is not rocket science, Just RPM Limits, Fuel and spark curves :rolleyes:
I would think after a good base setup it would be handy to have the ability to tweak the tuning over time and change parameters in changing conditions.
Thanks for the reply

Re: 502/415 MPI Gen VI Camshaft / Computer
 

Tell Merc that. :D I think thee are still only 4 people that can touch a Merc ECM (except the new one which there is only 1 I think)

You need to contact someone like Tyler Crockett (he's an OSO member also) about reprogramming. Even if you just want to have somthing simple like the rev limiter changed, it'll be $350-$400 to have it done. Your on the right track if you're thinking it's nothing like cars.... ;)

Re: 502/415 MPI Gen VI Camshaft / Computer
 

Ahhh those Carbs were not so bad looking back at it now :-)

Re: 502/415 MPI Gen VI Camshaft / Computer
 

I hear there will be Mefi1-4b software available for sale soon ;)

Re: 502/415 MPI Gen VI Camshaft / Computer
 

If you want to upgrade your 502 MPI, buy a proven and tested package from one of the companies that sells them. Tyler Crocket was already mentioned.
Keep in mind that it could get pricey as you may need new exhaust to run a bigger cam. The Stock Merc exhaust is likely to get reversion with bigger cams.

Re: 502/415 MPI Gen VI Camshaft / Computer
 

Hello 502SCS

I consider it a little odd that you are interested in only the "cams and springs'. Maybe you're interested in more and just stated that on this particular thread. I'm not criticizing you by any means. A single mod usually has little or no effect and sometimes can be detrimental to setup. The total package is the key to reliable power. Picking a higher performance camshaft is usually not much benefit unless you do other things as well. And, as stated elsewhere on this thread, exhaust may be critical if you change certain camshaft parameters. If you have any desire to maintain reliability with your power upgrades, get a "package deal" from a reputable engine builder. It will always be better to have a motor built by someone that knows well the combinations required for your particular engine build, boat and expectations. That could not be more true than with EFI/MPI. It costs to have reliable power in a boat.

Re: 502/415 MPI Gen VI Camshaft / Computer
 

Funny you should say that.. See the link below and find out how much I agree with you after some thought.
http://www.offshoreonly.com/forums/s....php?p=1222651

Thanks for the reply

Re: 502/415 MPI Gen VI Camshaft / Computer
 

You need to take a few things into consideration when going to a larger cam. Your 502 mag intake is fairly restrictive. If you go to a larger cam, it would be best to obviously go to a hp 500 intake or if you feel like it extrude hone yours. Then also consider roller rockers, exhaust, and injectors and so on. There should be no reason why you should be happy with a motor stalling every once in awhile at the dock. A properly tuned motor with the right combination will not do that. Your mefi 3 computer will work just fine with some reprogramming. PowerboatsNorthwest 253-627-4600.