I'm new to South Jersey. What are some recommendations for where to get my 502 Mag MPI refreshed? Also want to add headers and upgrade ECM.

Gary, unless you are changing the cam and head configuration along with the headers, there is no reason to have the ECM reprogrammed. I'd also not recommend having your ECM reprogrammed unless you are willing to let the person doing it put it on a dyno and do an engine specific mapping or unless you follow their exact engine build requirements for something that they have done in the past. At best, your system is good for 540 HP and that is with some pretty serious headwork. The Mercruiser intake is very restrictive. If you are looking for more reasonable priced HP, put a carburetor on it.

Rod

Thanks rpm. I appreciate the advice.

Not looking to get crazy on the hp (450 hp would be nice). Just want to gain modest improvements to performance while retaining reliability/dependability. Don't want to spend big $$$, but want it done right. I like having EFI and want to keep that. Nothing wrong with motor currently. Has 328 hrs and want to make sure she stays in good shape so I don't have down time during the season. It's been well taken care of. I like to run it, but don't push to extremes for extended periods.


More suggestions???

Goboat, I think RPM is on the right track. You might talk to Jim at Arizona Speed and Marine before you change anything. I would try to find someone in the area who can do a leak down test and check the oil filter for any contamination. I have seen many engines like yours with TIMES the hours on yours, so, if they check OK, why bother. Jim can help toward your hp goal, though.

HP 500 EFI roller cam, lifters and rockers, 2.25 intake valves, CMI headers and ECM remap will cost you about 5k and you will get 470-500 HP depending on how well your shortblock is done. When all is said and done you will probably spend between 8-10k depending on how much you do yourself.

Rod

We offer a carb package for that engine, in which we completely rebuild the engine, change the camshaft, port and polish the heads, change the valves and all hardware, and easily make 600 HP, this package is very reliable. $6500.00

We also offer an EFI package in which we rebuild the entire engine, change the camshaft, port and polish the heads, port and polish the intake, change the valves and all hardware, and make about 525HP. $6000.00

We also build complete engines from 500 to 1000 HP, and we take trades.

Both of these packages are custom built to your application w/ reliability being the major focus, come with warranty, and are custom painted w/ House of Color paints ie, Kandy, pearls, airbrushing, etc.


Feel free to call me with any questions.

Thanks,

Steve

GOboat I am with you. I live across the bridge in Phila and I have no luck looking for a trust worthy place. Where do you boat? drop me a line. I was told a good place to go for work is WWW.KURTSMARINE.COM

I have a 2000 28 sunsation with a 100% stock 502 mag/mpi I'm looking for a exhaust,msd, and labbed prop looking for a good shop I really don't feel like doing exhaust myself. Lazy i guess