Time to rebuild the 502...
 

Lost oil pressure last day on the lake. Motor started to seize up so I shut it down quick. The thrust bearing on the rear main cap was toast which led to a few rods goin dry. A couple crank throws, rods and pistons are black from the heat so the machinist said we should not reuse this rotating assembly. What we have is a stock 97 MPI motor with Dana marine exhaust and a ProCharger. If the block is good were thinking a new forged 540, aluminum heads, bigger cam and ide really like to upgrade to the Holley HP EFI. looking for suggestions on parts and ideas. Also converting the tails to dry to tip.

What CR should we go with? Would it be better to drop it some and crank up the boost a bit?

If we go with heads like the AFR or Dart pro 1s, can I use my mpi EFI to end for now if need be, then convert to the Holley set up a bit later? I will be running 02 sensors so we could verify how it's running and have done changes made to the mefi 1 .. I kno this might not be ideal but I really want to build the long block right, but I have 6 months then we need to be back on the water and a guy only has so much money lol.

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Fancy heads under the factory MPI intake setup seems like a waste. You could do a carb and intake for relatively cheap if retaining EFI isn't a must.

Totally agree with building a solid long block. On my N/A 509 the builder suggested the Callies Compstar rods and JE pistons. When we talked cranks he suggested a Callies there too, Compstar or Dragon Slayer.

I have the Holley Hp controller on my 1997 502 mpi. I am running a Procharger also at 7 lbs. I am still using my stock intake with bigger injectors.

Are you able to tune the MEFI1 yourself ? If so you may be OK. If you paying someone to tune it I would definitely invest that money into the Holley Hp controller. It can be used with your stock intake now and you can always upgrade the intake later.

Trying to tune your MEFI1 to a motor with that many mods could be time consuming.

I am sure others with more experience than me will chime in.

You can't tune the Mefi 1 to work in boost. It has no capabilities to tune in boost. You would need to go to a Mefi 3 or 4, the 4 being a much better choice (or something else like the Holley ecm) Your current setup is using Procharger's rising rate regulator to "tune" in boost. It raises the fuel pressure 3:1, 5;1 or 7;1, depending on the setup. To put it bluntly, it's a band aid.

You can certainly use your MPI intake with aftermarket alum heads. We do it quite often and have made well over 900 hp with it. (547 ci, Brodix heads, modified intake and rails to accept Siemens 65 lb injectors, M3 Procharger, etc.) Build a solid bottom end with a decent cam and heads, and you can make some pretty good power.
Eddie

Thanks guys! Eddie, that's what I was thinking.. Build the 540 up like I want and if I run out of money before I get the Holley stuff bought, just throw the stock EFI back on so I can get it on the water.. Then upgrade the intake, throttle body and computer with the Holley stuff another weekend..

If my 502 block is good, how big can we stuff in there? Is 540 about it?

What CR would you suggest? Keep it at 9-1 with 7 psi or less compression and more boost? Ide like a pretty good size cam..

Not sure if you have seen MT's thread:

http://www.offshoreonly.com/forums/g...ss-please.html

Point he is making is that you may find that you can make some really good power without stepping up to the 4.25 stroke crank. Maybe find a good stock GM steel 502 crank in the Swap Shop, buy some good rods, and put the money that you save into a really good set of heads and a good hyd roller cam and quality valvetrain components to make it live a long time. Just a thought.

Well, if I have to replace my pistons, rods and crank anyways, why not go bigger for about the same price?

'just throwing he stock EFI back on' cannot be done with out programming and other mods....on a well built 540. or 502 for that matter.

A smart old man once said - for every action there is a reaction.

I realize that. It's been tuned to run with the current list of mods but I simply wondered if it could be tee tuned to work ok on the new long block to get me on the water a few times until the Holley stuff showed up. I'm a believer of doing things right so ide like to build it bigger and better now that it's apart. For a stock 502 with upgraded exhaust, fuel system and the M3 it ran decently well. I figured maybe I can send the mefi1 back to Arizona speed and maybe and have them adjust for the new heads, cam and whatever else the best they can and we run it. Swap to Holley latter. This is worst case.. What I really want is a solid aluminum headed 540 ish with a bigger cam, solid valve train Holley EFI in a multi port configuration with a stand alone throttle body that's easy to plum the charger to. I'm a Ford guy tho so I need help with ideas and a parts list here to build this motor. Thank you all four your help.

I'll help you build your 502,540,565,572 or what ever if you fix the turbo on my 6.0 :santa:

I can take you for a ride in my 700 HP/1300 ft pound of TQ @the wheels 6.4 Powerstroke. If that doesn't convince you to upgrade, we go see my buddy Rick. He builds Powerstroke all day long, we can fix you up lol.

I can tell you what was done to my 502. Bored to 509, 10.0 to 1 compression. Edelbrock marine heads. 315 intake runners. 1.89 exh valve. 2.25 intake. Crower cam part number E-44802. Modified intake runners flush with plenium. KN air filter,adj fuel pressure regulator. MSD 6m2. Imco power flow exhaust with 8 1/2 eddie marine slip in mufflers. Has Arizona Speed ecm. 14 quart oil pan. I have it in a 21ft Superboat. The boat is a beast,acceleration is amazing. Hope this helps

My 2005 6.0 with only 50K mls on it decided to go into limp dick home mode when I was pulling my TG back from Buffalo, turn the key off and on and the code goes away till the next long hill, 13K of boat and trailer with no turbo, its not good.

What code is it pulling? All stock?

little yellow openend wrench on the dash, book says, and I quote ( limp home mode ) I haven't got the exact code,............... back to your builds, contact these guys before you buy any parts, talk to Chris or Morgan................ http://www.cnc-motorsports.com/?gcli...FUNgMgodi3AAFg, their in your home state

I would suggest taking a look at this thread. "EFI for everyone". Some good info relating to your situation.

I was going to suggest cnc-motorsports to Fordtrucks also. They have good prices for what they sell, and they sell what they know works. What kind of budget are we looking at here? Ateco has a 540 shortblock blower motor listed in the classified section for $5395, and that would be with a new better block. I'm not sure if that MEFI 1 is going to be a good idea even for temporary, but maybe for break-in time if it can be setup to even run. By the time you mess with injectors, modify the intake/fuel rail and reprogram ecu or install a MEFI 3-4, you have paid for most of the Holley EFI system.
I would recommend either doing it all, or nothing. Better bet would be to get some parts from the swap shop and put the 502 back together and build a 540 for the ultimate goal. I mean with a 540, aluminum heads, good cam, M3 Procharger at 7-8 psi, you are looking at probably 900hp, so you need good parts to make it live.

Thanks for the thoughts Rocky.
I picked up another stock 502 rotating assembly for cheap out of the swap shop just to have. Still haven't decided if I'll go that route or the 540 just use. I have decided for sure on doing the Holley EFI, aluminum heads, dry exhaust and bigger cam. My question now is what size heads should I be looking at? There's different size intake runners... What are the power differences vers cost? I know everyone likes the dart pro 1s but there not cheap! Can I get a decently close head for a bit less? I want to stick with rectangle port like my stock heads are. I'm going to re use my Dana marine exhaust and just convert the tips to dry. Also, I might use my stock mpi intake and TB to get up and running, then switch to a better set up later. Not sure. No matter which rotating assembly I go with, I'll need over size pistons so those can be picked to match whatever heads we go with. Also, this is a blower motor so keep that in mind. Thanks!