502efi to 540ci ?????
 

Want to upgrade the 502efi to a 540. Is that possible and is there someone out there reputable that can perform this task or sell's a "package kit" to make this happen???

Read the answers to DiveBoys' post about HP500EFI head work. There is a lot of real good information on the limitations of EFI motors.

Well, it's definatly possible.

You would need a new crank, new 4.5" pistons and rings. Bore the block .030", hone.

while you're there new bearings throughout. Might as well get some head work and get a bigger cam. Remap the ecu and get bigger fuel injectors.

so, lets see;
5, plus.....carry the one....

should be able to do that for about 4 - 5 thousand and thats using a cheaper crank. Not a Callies, Lunati or names like that.

Depending on which pistons you get, to determine your comp ratio and how much head work you get and the cam you decide on... you could expect an additional 100 hp.

just my .02
DAVE

Going from 502 to 540ci means new everything and heads too...thats not to mention that a short deck 540 isn't the best combo.
Lot of parts getting **** canned there.
Sell the 502 or keep it for when you want to sell the boat and start from scratch with a tall deck block and good parts...It will last a heck of a lot longer.

Sounds like what I did !
First off ..**** can the stock injection set up. It will be nothing but money and headaches.

I did the whole conversion for around $8000.

Eagle rotating assy. $1300
Merlin oval ports (cnc ported by Sterling) with new valves and springs
Brodix intake (w/porting)$3000
Jesel shaft mounted rockers $1000
Msd ignition and distributor $300
1050 Dominator $600
Solid roller cam and lifters
( the only bad choice) $700
Fuel system $300
Machine work ;)
Plus some other numerous things , that you always forget about $$$

The boat went from 64mph to 80.7mph !

I guess I should add this also:
Add on hydralic steering $1100

If you have friends in the business and are willing to do allot of work yourself it can be done fairly cheap:)

Hey Baja27,
I’d have to agree with Dave F., it’s not real cheap and I’m not real sure about the ECM issues with the Merc unit.
You can get a full Rotating assembly for $2600-$3000 for that motor with a one piece rear main seal crank from Callies or Crower. At the time, Callies was a 5140 and the Crower was a 4340 crank. I believe the Callies are now 4340 also. These kits include pistons, rods, cranks, rings, bearings etc….You can get cheaper assemblies but I didn’t think this was a place to cut corners
I personally went with the Crower because of the material at the time. The rods are 6.385 rods and the combo (ratio) has been proven to be stout and is also the same one used by Volvo in their DPX600(540ci) with a two year warranty. (Actually built with Crower internals by Innovation).
I don’t have any clue as to why you would need new heads unless you just wanted better. I run the same Edelbrock ovals (fully worked) that I ran on my 454 and spin an effective 5500 rpm with the 540. A little massaging by JV to your existing heads would certainly do the trick.
Obviously I think it is a great setup and you already have the block. The only draw back would be your ECM and cam. You would need a much better/bigger hydraulic roller cam and I guess you could have the ECM reprogrammed. I have an MPI system but it is not Mercs or ASM. It’s a single plane manifold with injectors in the ports as JV spoke of on the other thread. It gives me much more flexibility.
Hope this helps,
Dave

:D

I built the exact engine you're wanting for a customer a couple of years ago. It was a 540, ported Rectangle port heads, mild Crower hydraulic roller and the Merc MPI setup. We had the ECM reprogrammed and installed an adjustable regulator. It had incredible torque up to about 5000 RPM, then layed down pretty quickly beyond that. I Never got to dyno it, but I would say it was easily 570-580 HP. We later swapped the MPI to a Dart Intake and a 950 Holley. The boat picked up about 2 MPH and would continue to pull up to about 5400 RPM. However, it lost a ton of low end torque! The EFI setup was definitely the more desirable setup.

Bob