500 EFI Modifications ???
 

What modifications have yall been doing these motors?? I am fixing to pull the motors to freshing and try to get more power .I figure around 650hp maybe ?I do not want to go with blower right know but the mods need to work with a blower :)

There has to be some racers that's done some stuff , I have [heard] of off set ground cranks ,longer rods,raised compression in the factory 2 classes. One racer said that Sterling had built some 740hp Factory 2 class motors back in 2001 when SBI did not tech motors.

I already know about the ecm,throttle body mod. What else is there?

What and which cam and with a bigger cam will it work with the reprogrammed ecm?

Some have said up the compression but if I add blowers next winter I do not want to change pistons and rebalanced the motors.wasted money :(

Also some have said to up grade to aluminum heads with the coated water jackets. But most of the heads I have seen they raise the exhaust port .500 so this will be a problem with the CMI headers lining up with the tail pipes?


Thanks


Rob

Re: 500 EFI Modifications ???
 

The edlebrock marine heads have stock port location. They come with inconel exhaust valves already so you just need to add keepers, retainers and springs to match your cam selection. Use good head bolts or studs. You can blue print the combustion chamber sizes to achieve a true 9.0 to 1 ratio as well. Mine were anywhere from a bout 8.4 to 8.8 to one before we did them. Use a 1.8 to one rocker arm for a little more lift and duration, add an adjustable fuel pressure regulater and you can make 570 hp with no ecm mods.

Re: 500 EFI Modifications ???
 

I've looked into this before. I thought about porting the heads or going to aluminum, cam change, and bumping the compression. Did NOT consider making it a stroker. I was trying to find ~125hp. What I learned is the biggest obsticle to overcome is the "highly restrictive" stock intake manifold. I talked with someone who's done the above mods and could only make another ~30hp due again to the intake. He then put on a single plane intake and 850 carb and picked up ~100 hp turning 5800.

FYI, the 500EFI makes ~520HP stock.

Re: 500 EFI Modifications ???
 

The motors have already been into so it has some stuff already like arp head bolt ,bigger oil cooler ,oil thermostat.bigger oil pan.the aremotive fuel pump,fram race style oil filter system..


Airpacker which fuel pres regulator you talking about??? . it already has the ASM on it and its not a very good way to go using parts on the old one . I would not mine a new design all together.


On the rocker arm I plan on buying new cam anyway so I would not need the 1.8 rocker arms. at 1.8 and higher i would think that would put more stress on the guild.


I don't think 570 is going to be enough??

Re: 500 EFI Modifications ???
 

If the Intake is so restrictive ?what happens when they put the Whipple blower to make the so called 828 hp they claim with other parts. I know its forced in but restriction is heat. Extrude hone it??prob not worth the dollars..


I plan on redoing the ECM's again when we Dyno the motors.

Re: 500 EFI Modifications ???
 

- The whipple forces the air in so the restrictions are in a sense reduced.

- I'd check with Lingenfelter, they have alot of similiar engines with bigger power.

- The HP500EFI is 500 crankshaft hp / 470 propshaft hp per Mercruiser

Re: 500 EFI Modifications ???
 

Does anyone know if the 500 EFI has changed in any way since it was first introduced (I believe the first model year was 1999 when both the carb version and the efi version were offered)? I am interested in a 1999 model boat with these engines and wondered if there is anything I should be aware of.
My present boat is a 1999 model with T-500HP carb motors and I experienced the imfamous valve spring problem typical of these engines. If I pursue this other boat with the EFI's, just want to know in advance what to lookout for.

Rich

Re: 500 EFI Modifications ???
 

1999 and some early 2000 EFI's didn't have the additional mechanical fuel pump (the one driven by the raw water pump). Our 2000 500 EFI doesn't have the mech. fuel pump, just the electric. I called Merc Racing and they verified my serial number as an early 2000 and they said that some had the additional fuel pump (added to late 2000's). Supposed to help alleviate vapor lock that was experienced on the models without it. Also, 1999 and early 2000's may have the same Crane valve springs, not the "redesigned" comp cam valve springs. There appears to be no distinct, clear cut, "changeover" for the early 500 EFI. Looks like they used up the old carb motor "stock on-hand" until it was all gone.

Re: 500 EFI Modifications ???
 

Also, 1999 and early 2000's may have the same Crane valve springs, not the "redesigned" comp cam valve springs. There appears to be no distinct, clear cut, "changeover" for the early 500 EFI. Looks like they used up the old carb motor "stock on-hand" until it was all gone.[/QUOTE]


Does this mean that on later model motors (2001- 2002) you do not have the valve spring issue? I have a 2002 with 175 hours and am wondering if I need to replace the springs this winter or next. Is it still recommended that around the 200-250 hour mark this be done??

Re: 500 EFI Modifications ???
 

Merc says yes, you still have to change the springs..... They say, check your springs at 50 hours, then every 25 hours after that. Once you see a crack, you know when your driving style denotes them to be changed.

He went on to say racers need to change at 50, and more pleasure boaters will need it around 300.....

Personally, checking the springs, at least on a 500hp carb, sucks, cause you need to pull the risers and manafold.... Not sure on the efi... Sounds like to much BS... Change them around 200 and you know you wont loose seat preasure witch is what you need to keep you valve train happy in that motor.

I changed my crane springs over to comp at 110 hours.. they were three years old, and they looked like new, but all had lost about 30 pounds of seat preasure except 2. No cracks or any wear.

If you are changing your spring, put in titanium retainers to reduce the unsprung load on each valve... costs about 50 bucks extra....

Re: 500 EFI Modifications ???
 

What are the part numbers for the replacement springs and where do I get them and how much? Which retainers and clips? Thanks.

Re: 500 EFI Modifications ???
 

Merc uses comp cams 929's Its 1/4 of the price to buy comp cams than mercs box. Call teague custome marine... they can get you the springs, keepers and retainers for less than 250.... plus fifty if you want titanium...

B

Re: 500 EFI Modifications ???
 

Hey Strip,

Call Kevin Brady at Dell Marine (Formerly Port Jackson SeaRay Fountain) in Jacksonville, Florida.

This guy really knows his stuff. He has been the only guy to touch my boat and I have been very pleased with his work, as has many others I know.

He will not blow any smoke, he knows what works and what dosen't.

I have plans to leave my boat with him this winter. I have stock 500 EFI's with 240 hours on them. Kevin has ridden in my boat a lot and he was at the Emerald Coast Poker Run and we talked about this exact same thing.

We are changing the heads out completey, going with a different cam and some tuning on the ECM. I'm also adding extension boxes to my setup.

I will not get the horsepower you are looking for, but we just want to keep a VERY reliable boat that always finishes the poker runs!

Kevin Brady
Dell Marine #904-730-9968
Cell #904-477-4142

Tell him Doc told you to call.

That is Kevin on the right of this picture in the tan cap.

Re: 500 EFI Modifications ???
 

ISKY 8005-A XP Endurance springs. They're about 155 on the seat.

Re: 500 EFI Modifications ???
 

With Regards to the Wipple Charger mentioned earlier, I have one on a 02 HP500, and at only 6# of Boost I picked up 16mph........Would not have believed it unless I owned the boat myself.

Only other modification are a Aeromotive Fuel Pump and Filter, Steel Braided lines and AN fittings, Boost Sensitive Regulator, and a boost and fuel pressure gauge.

FYI it is also the new larger compressor that sits on top of the HP500 Engine, not strapped to the side with the little intercooler.

This set-up performs flawlessly, and I have not had any problems to date. It is funny how I run past people that are doing 70, 80, and 90 mph and then when they catch up and look at the engine they can't believe how much power it makes, yet how stable it idles, and runs.

Good Luck with whatever you decide, but in any chance definitely do the Whipple!!!

Re: 500 EFI Modifications ???
 

call paul phaff in cal. he has a lot of packages for a 500efi

Re: 500 EFI Modifications ???
 

Is that the one with the built in innercooler? They tell me the Whipple requires a new computer not a recalibration.$900.00 :eek: what about the 50lbs injectors??2 bar map sensor?throttle body modification?


Pro charger is a lot cheaper,

Re: 500 EFI Modifications ???
 

I have been looking into this to find out all I can. I also want about 650HP out of the EFI's. I think if you are trying to use the 502 blocks you can only get about 675-685HP out of the motors with good reliability. I think you will need to go to a 540 to get 640-650hp. I think the criteria on either setup will be getting the compression to 9.5, a larger cam, ECU program to increase the rev limiter to 5700RPM, new heads, & port matching the intake to the heads.

There are pro's & con's on each way. On the 675HP version, JE does not make a 4.5 bore piston that will get you in the 9.5 range. The pop up they make ends up being in the 9.9 range that is to much for pump gas. You could open the heads up, but I think a custom made piston would cost less. Heads are another issue, the Edelbrock heads look to be the best way to go other than I think a steel head is better for salt water. I have not used them so I have little knowledge of there performance. With the stock exhaust location, the short turn radius can't be much better than stock heads. I like the Iron Eagle 308cc heads because they are steel that will last longer and have a .300 raised exhaust port. Dart tells me this is the same cast as the Pro 1 but thicker surfaces. The problem is it takes a .250 longer intake valve and needs new push rods. That is not a big problem, but the 500 valve covers will not seal with the ORing gasket they use due to the taller valve train setup. I think they may seal with the GM steel composite gasket first seem on the 502s. The AFR head is the best, but I think the cost does not justify the result in a pleasure style engine. The AFR head has the same alignment issues as Darts.

JE SRP makes a small pop up piston for the 540. It has a 6cc dome that gets you right to 9.7 CR area. Clean up the chambers, add in a Eagle Gen 4 early style crank that is externally balanced with the seal adapter, ARP rod bolts on the 500 rods, balance the assembly and you have a 540. Be careful not to buy the 1 piece style crank or a rotating kit unless you want to buy a new flywheel and balancer. All those kits are internal balanced. The GM 502 rods are 4340 and hold up well. The Eagle Cranks generally take a .001 over main bearing set. Measure well here. There are good savings using the Gen 4 crank setup without giving up power.

The EFI unit is suppose to flow 1300+ CFM. If you think of that, is bigger than any Holley dominator or any air flow calculation needed by the engine. Arizona Speed tells me the 540 will need bigger injectors and reprogramming the pulse to the injectors. Port match should help any flow issues.

There was a guy I talked to on the phone from OSO that was doing the 540 upgrades and was suppose post the result on the board. I did not see them or missed them. Did anyone see his post? I want to find out all I can before I start this winter.