500 EFI's
 

I posted in the technical section, but wanted the exposure here.

I am looking at a Top Gun with 500 EFI's and it is not enough power. Any easy ways to boost power with that engine ? rebuild top ends?? add supercharger ?? can I keep the injection with a supercharger like the new 600 or 700's?

thanks for the inlut in advance

500 EFI,s are a very good candidate for rebuilding with more H.P. I think they were getting pretty close to 600HP without supercharging.

I would guess that you talking about a non-stepped TG?

A buddy has a 94 gun with 500 EFI's...68-69 is all she'll do.

Depending on the hours on the engine, Vortech and Whipple make great kits without getting into the engine. I do recommend to get the heads off and do some maintenance and upgrades while you are at it either way. If you want to stay N/A, you can build a mild 650HP setup with 540ci's and Dart Alm. Heads.

Are you buying another one. I thought you were just wrapping up a redo on your Gun ??

Tyler Crockette was working on a upgrade to the 500 EFI when he boosted my carbed 500 to 650 hp. I would contact him. I think what you want to gain can be done without a problem. Then you might want to make sure your drive(s) are good that will be the next weekest link. Mine have been gone through as well and now I run turn key no problems well into the upper 90's with the boat full of fuel and people

Actually there are a few TS TG's with 500's out there. The 500 boats are usually 2000, 2001 or early 2002's.

I am just wrapping up with the re- do of the '98, but I want to get into a twin step. I just don't want to be afraid of the 500's and so far the input has been good that I can get anywhere from low 600HP to 700 HP without major overhaul, which will put me into the 90's !

Just what you're looking for:
http://www.whipplesuperchargers.com/...sp?ProdID=1150

I'd be interested in the EFI intake pieces.

There are always pros and cons to any project but it all comes down to budget vs your goals. If your looking to just bolt on power, superchargers are the best way. However, if you are willing to pull the engines tare them down and have them completely rebuilt, internal mods are the best way because you can tweak those 500s to push over 600hp. If you do decide to do any internal work, I know a buddy that owns a shop in Cleveland. Gellner Engineering was recognized as a "top notch" engine builder in Powerboat magazine and has been well known in the boating and auto racing world. Call Dean at 216-398-8500 tell him PK told you to call. He can also give you more information about getting more power out of those 500s. He tweaked my 454 from 385hp over to 550hp N/A!!!

SMoooch

Ill trade ya for them 500 efis. if thay have low hrs. 540 ci 950 hp.420 mega blowers with chillers bowtie blocks all good stuff. to much for a 30 ft boat. I took in on trade looking for some 500 efis. I was going to detune them if I didnt trade them off.

Your hooked !!

http://www.offshoreonly.com/forums/a...1&d=1190416649

engine shot of my ol' 1996 Gun
Still running great for it's current owner.

I Whippled mine this spring. I love the package, and it looks the best IMHO. Loads of power!

That's the set up !!! :D Very nice and clean.

Damn it Otis, I am hooked...... and now shopping :D:D

I put a vortech on my EFI 500 after 60 hours. It now has 240 hours and the only problems I've had is two broken drives. Comprestion is still good in all eight.

Tanner..... The way I've seen your 98 Cig run you need to take those engines out & put them in a twin step.
I would think you would be over 100 mph.

LS

I whippled my 500,s and I'am very happy with the power and durability. But you will have to go to bigger props or taller gearing to see the gains you want for the money. Expect to have some drive failures.

You can do some internal mods, raise the compression, and install some aluminum heads and make 600 hp. That is about all the stock 500 EFI intake is good for. Sure you can extrude hone and port it, but that's not going to be worth much more.
For about the same money, you can install the Whipple and make way more power and do it a lot quicker and easier. It is the best bang for the buck.Plus you can always go back to stock to sell the boat and install the Whipples on the new boat.Hope this helps, Eddie.

Thank you Eddie, it does help, and I think if I end up with a 500 EFI motor the whipple is what I will do.

Just waiting for mine to be complete and put it in the classifieds. I pick it up from paint this week !!!!

I did think of that, but my engines are a great set up for the 98 boat, an I kind of like the fuel injection. Whoever ends up with my boat wwill have new engines and drives for alot of worry free boating.