496 mag ho
 

So i have a couple questions...Hoping someone can help me out here..
1. I have a 2006 27' with a 496 MAG HO..Whats the best plug to put in it? E3, Bosch AC Delco....and if anyone has the correct Number for the plug that would be great....

2. Can you put the Pro Charger or something like it on it without doing internal upgrades?

3. Is the Whipple, Pro Charger or the Raylar kit the best way to go....Not trying to blow it up just wanting a little more power out of it....

Thanks for any info you have....I am trying to do it right, not just go crazy

I put a Procharger on one and it lasted about 10 hours. The whipple is a better way to go. Honestly if you want a reliable boat either leave the 496 alone or upgrade to something else. Sorry man i know its not what you want to hear.

AC Delco 41-983 platinum already gapped at .060".
I've had great luck with these in mine.

Procharger does not make a bolt on kit for the later year 04+ 496's. Whipple makes an excellent kit that is very well thought out. That being said it cannot mask the fact that the stock pistons/rods were not designed for boost. The pistons are hyperutetic with very tight ring end gaps of .009-.018".

The Raylar 525HO kit is also an excellent kit. I am running their Cool Gap intake and stainless rockers. Impressed with quality and customer service from Larry. This kit is most friendly to the stock pistons of the choices you asked of.

What is your budget and end HP goal? There is no cheap way to get power out of these motors. The stock heads/cam/intake suck. Period.

Good reading.....

https://www.offshoreonly.com/forums/general-q/330907-why-gen-7-496-such-bad-platform-build-5.html

Leave the 496 stock. You will be much happier.

Run the stock spark plugs and leave those engines stock.
https://www.offshoreonly.com/forums/...ark-plugs.html

Depending on your ability, Raylar and several others offer forged piston and connecting rod kits. Without forged pistons you wont last long. Once you have the bottom end upgraded you are good for any of the three - Raylar 600, Whipple or Pro Charger.

I would not recommend adding forced induction to a 496 if it has stock internals. I had a Whipple on a stock motor and it ran great for a while until it cracked a couple ring lands (I knew it would happen eventually).

Since then, I have built the 496 with custom forged Diamond pistons, Callies rods, forged crank, ARP head studs, and Cometic MLS head gaskets (along with some other things) and it has been an excellent and very reliable engine. Running about 7 lbs. of boost.

If you ever do decide to build your internals, Diamond still has the custom piston design available. The piston is sized for standard ring sizes, not the stock 496 metric crap. It also has a much thicker top ring land and full floating wrist pins with a rod length to completely keep the pin out of the oil ring.

In the very past we would do the pro charger and other kits - but really it seemed that 50 percent if not more within a 2 year window did not last as problem areas took place for a jist of info. I would leave it stock or swap out for a 502 inwhich has many reliable hp gains plus the huge available performance parts

spark plug wise what I posted in the link --- NGK is the way to go. NGK makes some of the AC delco plugs anyways. I have known about that for years.

oh will add ----- I read the RAYLAR info in the link from above that I quoted. Not to sound like I need to correct them but - with DIS ignitions do not use anti seize on the sparks plugs period. Matter of fact the top 3 spark plugs makers even tell you not use anti seize.

Also he lists the Denso spark plugs. I would not use them - reason was IN THE PAST when Denso plugs were installed in new engines --- WE HAD PROBLEMS WITH THEM.

There is even some on OSO that called me with 496 engine stumble / miss running issues and the first question I always asked ---- does it have the Denso plugs installed ? When the answer was Yes - change them and see what happens, Many 496 engine stumbles cleared up after getting rid of the Denso spark plugs.

I went Scat H-beam for rods and SRP forged for pistons when I rebuilt my 496. I went with AC Delco 41-983 platinum just like it had from factory. They went 400 hours so I figured don't fix what wasn't broken. . .

here is one of the issues with Anti Sieze but there is more. also some other info added. All spark manu's and even OEM engines currently want all spark plugs installed with a torque wrench plus follow the specific torque specs when installing.

NGK Spark Plugs

and I can not tell you how important the spark plug gap is for the 555 controlled engines. The fine wire spark plugs we do not touch the gap period unless it is off spec - but we just grab another new plug - sending the out of spec gapped spark plug back to NGK and or if it even a slightly defect.

We check the gaps - very easily plus look at the gaps and its related parts including the fine wire on all new plugs with a spark reader, actually with a real doctor Odoscope before they are even installed. Fixed so many rough idles and or misfires from whomever changed plugs and gapped them or even spark plugs that were not manu perfectly. Not uncommon to see this when one works on multiple boats per year.

read the NGK link above post especially about fine wire gap. Anyways I hope this helps whomever.