Spun the coupler so I had to pull the motor. OEM 502 was tired with 400 hours. I decided to upgrade. Have not built a motor in a while and I guess I lost my touch. As you can see from my sig, I put a lot of time and $ in this project and have not had good results. So I'm looking for some advice/information from the experts. Suggest you read my sig before you read the rest of this.

First issue is oil pressure. I installed a high volume oil pump, 10 quart stroker marine oil pan and oil pump pickup from CP performance. I did the inital two 30 minute start up periods with Royal Purple break in oil. I ran it on the water for the first time last Friday with 10 quarts of 15W-30 non synthetic oil for the 10 - 12 hour break in period recommended by CNC. Started out at idle with 80 psi oil pressure. At 4200 RPM the oil pressure was bouncing between 10 & 20 psi. Never got past 4200 rpm because of low oil pressure. So I drained the 15W-30 oil out and put 5 quarts of straight 50W Valvoline non synthetic racing oil in it. The 15W-30 had a lot of black residue in it for running for less then an hour. I put less oil in it thinking the crank may be slapping the oil since there is no windage tray attached to the mains. The windage tray is built into the oil pan with 2 trap doors to slow the oil from rushing to the rear of the crank on acceleration. Also installed a thermocouple on my K&N reusable SS oil filter to get an idea of oil temp. Started out at idle with 80 psi. At 3400 RPM had a solid 60 psi with a 125° oil temp. Accelerated to 4200 rpm and oil pressure dropped to around 30 psi. Went WOT (4800 rpm) and the oil pressure went to 20 psi and stayed pretty solid dropping to around 10 psi only momentarily a few times. NEVER went to 0 psi. Max oil temp seen for the day was 169°. Pulled back to 3200 rpm for a good 15 minutes and had a very solid 60 psi. Did some mild and hard turns to see if pump would loose suction. The pressure never changed. I guess my ? is does the pressure really vary that much with HIGH VOLUME oil pumps? Should I be concerned running WOT at 20 psi? I put the other 3 quarts of 50W oil back in the motor and now have 10 quarts in the pan. Will see what happens tomorrow.

Next issue is power loss. I have no increase in RPM from 3/4 throttle to WOT. Idle to 3/4 is OK but about the same as the old 502. I expected more! I had the OEM TB enlarged by TPiS. The most I can get out of the 540 is 4800 rpm running a B1 24P, the same prop I ran on the old 502. It would go to 5100 rpm. Have complete MSD ignition per sig and the base timing is 10° BTC. I have a Rinda tool to set base timing and checked for codes. Had MAP sensor code. Reseated the connector and that went away. I have no knock and am running 87 octane marine gas. Running iridium plugs. Plug insulators have very light brownish tint. Have freshwater cooling with a solid 175° temp when running above idle at all rpms. Idle is 160°. MEFI 3 was upgraded to sweeten the timing, raise the rpm limiter and reduce the FI on cycle since Mercury runs there motors rich. Have not done compression test but am going to do today. My thinking is I might have the valve lash set too tight. I have new Comp roller lifters, roller rockers, pushrods and cam (see sig 4 details). I was told by Comp to spin the pushrod until tight and then turn adjuster 1 full turn. They said this could be done with primed or unprimed lifters. I did it with unprimed lifters. Nothing new, have done this before on SBC and BBC motors. I did install valve covers that can be removed while the engine is running. If I readjust the valves, I will attempt to do with the engine running.

Final issue is fuel pressure. Replaced the fuel cooler but kept the fuel pressure regulator and the rest of the fuel system in tack. With 502 I was running a solid 42 psi fuel pressure. I have a fuel pressure gauge on my console. With the new cooler and no other changes, I now have max 36 psi. Not sure what changed but I know fuel pressure affects performance from other EFI toys I have. Will investigate more but looking to get a Aeromotive fuel pump rated at 45 psi and completely bypass the OEM fuel system.

There you have it. Any suggestion or advice would be appreciated.

Ed
'99 Sonic Prowler 260
540 CNC Motorsports Racing Short Block/9:1 CR
Dart PRO-1 Aluminum Heads/SS Intakes/Inconel Exhausts
Cometic SS Head Gaskets
IMCO Aluminum Exhaust/Hardine Polished SS Risers/SS Gaskets
Comp Roller Cam: .547/.547 Lift – 230°/236° Duration – 112° Overlap
Comp Roller Lifters/ Roller Rockers/Push Rods (.375")
ARP Main &Head Studs/Rod Bolts
Hardine 10 Quart Marine Racing Oil Pan
High Cooling Capacity Oil Cooler
Remote Oil Filter (Transom)/K&N Reusable SS Oil Filter
Complete MSD Ignition/Cooling Fan
Denso Iridium Plugs/MSD Plug Wires
TPiS 68mm Throttle Body
K&N/Hardine Marine/PWR Air Intake
ECM Upgrade
San Juan FWC
RACOR Fuel/Water Separator

Have you had any luck? Did you check your timing advance? Ou might also make a wot pull on clean plugs to check for lean. And the oil pressure sounds like a bad pump. But possibly a restrictive setup.

Got the problems figured out, I think.

OIL PRESSURE: Oil pressure problem is caused by the pickup being too close to the bottom of the pan. That would be the only reason the oil pressure drops as RPM increases. I'm limited right now to 3000 RPM. Oil pressure at idle is 80psi and at 3000 RPM it is bouncing around 20psi. Can do hard turns and it does not change. I installed an aftermarket HV oil pump and Hardine Marine oil pan with Hardine marine supplied pickup. Possibly too many non-OEM parts to match up. Did not check oil pump pickup/oil pan clearance. Pulling the motor again (Gotten good at this) to do this.

POWER LOSS: Contacted Marine Power Services about my problem and sent them my motor specs. They told me the reason I was not getting any throttle response from 3/4 throttle to WOT was lack of fuel. Plugs verified that by not having hardly any brown residue on insulator, even at idle. Sent MEFI to them and they installed 525 tune. I checked the 525 cam specs with my new Comp cam. Mine falls just below the 525 specs. So it should run good with the 525 tune.

FUEL PRESSURE: Am going to remove the OEM fuel filter, fuel cooler/pump and lines and wiring. Installing an Aeromotive EFI fuel pump and regulator. Can adjust fuel pressure from 45psi to 70psi. Already have a Racor fuel filter/water separator that I'm going to put between the fuel transfer pump and the new fuel pump.

Ed