Cattitude

I've got a new to me 30' Daytona with 496 HO's, 85ish hrs.
Messing with setup, imco lowers, raised x and 5 blades.

I've been reading up a lot and talking with Trick/Ateco/Raylar/Basset/Whipple too- considering options.... (for conversation sake, ins is not a consideration)

1) leave alone after done with setup- most time is 65 cruise, will have to buzz the engines a little more(4kish), save a bunch of cash, still run 87 octane

2) CMI's or Basset TriY headers- kissing $8k when done 3-5 mph increase in speed is prolly realistic, still run 87 octane, some improvement in resale but not much (will liklely keep the boat at least 5 yrs) motors still stock which is good for resale. after tweaking setup might save 100-150 rpm cruise- no big deal

3) Whipple them and run 4-6 lbs (6 lbs stock) leaning towards 4 for ultra reliability I've had two whippled mercs and had great luck, I also get a deal on them but it's still kissing 16 k list price. Cruise would considerably more econnomical, but it's offset by 92 octane. You get a considerable gain for the $ vs marginal for the ex. 4 lbs would be mid 500's in power, generally accepted to be within reason for the stock long block- also nicer to my stock Bravo uppers- have XR guts in the Imco lowers. Can put engines back to stock if desired for resale.

4) I'm not consiering Raylar at this point, though I respect his work- just can't bring myself to go that deep/intrusive into an 85 hr engine X2

What's the sweet spot and what am I missing/not considering?

Raylar

That there is a 50/50 chance you will be going deep into your pockets or motor after you install any supercharger on a stock 496 block. If your a betting man its an easy call for you, just keep some bills in the kitty and the possibility of having it happen in the middle of your short boating season.

Good Luck, call us if you need internal parts later.

Regards,
Ray @ Raylar

Cattitude

Ray,
There is no questioning your knowledge or the amount of help you've been to many here.

That said, your own site/comments indicates low boost working and 550ish as a safe number for stock parts. Maybe this is overly simplified, and please share where I may be mistaken- 550 hp and say 600 lbs of torque is exactly that as far as the running gear can tell whether it is NA or has a small bit of force feeding. You stuff more air and fuel in the jugs through better heads,intake and cam, (and ex if someone chooses) a Whipple does it by pushing it thru with a few psi- in the end- the longblock sees similar amounts of air /fuel to make similar numbers- how far off am I?

Another consideration is that 85% or so of my time will be spent at no boost cruise- so the parts are happy, the other 10% is idle and 5 percent or so for boosted operating (my traffic won't permit a lot of boosted operation)

If I was pulling engines and going through them I would look at your kits differently- but given my low hrs......

Talk to me- the whole reason for this post is to help me make an intelligent/informed decision.

Pismo10

I have never heard the term "ultra reliability" used with a supercharged 496.

Cattitude

LOL- good point, there are no free rides

But I've bet you heard of conservative low boost before

often people want every digit they can get so they tweak more and more till boom- seen it done expensively with NOS, timing, compression, boost- but there is a sweet spot.

550/600 of fuel and air is exactly that, no matter how you put it there- if the engine management is "on" you should be good- no?

Sydwayz

iTrader: (1)

CMI headers
Chrome engine lids, AF tank, and a few other components (all available from Fred at Trick)
Some nice LED lighting in the engine compartment

Call it a day.

Whipple = wrenching & tweaking all the time.
Stock/NA = boating all the time.




If you are concerned about resale; take the 496s and set them on pallets in the garage.

Build a pair of NA540 Carb motors that push 600HP and run them until time to sell.

Knot 4 Me

If you want significant, realiable HP gains then going with a NA package from Raylar or Tyler Crockett is the only way to go. Otherwise, leave them stock. Superchargers and 496's do not play well together. My guess is you would be disappointed with the ROI on CMI's.

Rippem

BINGO!

Raylar

Cattitude:

Understand your dilema, but reliable power in boat engines is the real situation you need. The cast hypereutectic emissions piston that GM equips the 496 with is just fine for normally aspirated use up to about 600HP. With its .090" top deck over the top ring and its brittle nature, add a little knock under boost and its all over! Put boost on it and believe me screw type superchargers start boosting at about 3500rpms (usually below cruise rpms) and you like most all others will see piston damage and issues in usually short hours about 50-70ish. It does not happen all the time with some owners using 94 octane or racing fuel and such to insure the result.
Rework your blocks with forged pistons, rods and crankshaft and you can make a fairly reliable 800+HP with Whipples. there are a few boaters out there who have gone this direction. Check with Betitbig here on OSO, he's done the whole drill!. We sell a lot of forged pistons and most are sold to 496 owners who tried supercharging stock 496's.
Take it for what it's worth, good 496's with about 575HP will easily push your Daytona 30 with the right drive and prop setups to over 100MPH. That should be a very respectable speed for your needs and still give you easily 500hours of reliable turnkey use. We have a couple of these Daytona installs to prove it, and Whola, they are both still running!
You make the call, its your choice.

Ray @ Raylar

Cattitude

Thanks Ray,
I realized we were talking Hypereutectic pistons (did I spell it right??) but did not realize we were dealing with a .090" land- that's all the convincing I need.

My whippled engines have all made boost 3600/3700 and i've cruised just beneath that- in my 25 Daytona that was 60ish with a load etc and the hull was just above being comfortably free- figured I could get the same in the 30'.

We'll see where the dust settles after setup is done- then I make choices again, stock, exhaust or bigger results/commitment with Raylar

what can be done now to clean up the rich condition and associated dirty transom?