Nitrous?, Super Charging?, C.I.D. Yeah that's the ticket!

[DonCig]

What a year it has been. Bought my first Donzi 1997 Classic 18 with a Bravo 1 1.65R and fresh water only this year, advertised as a 75-mph. boat!
Well now that I know that it’s not quite a 75mph boat, what are my options?
1. Supercharging, No. It seems that my 1997 Vortec Gen + engine is a one-year wonder.
It has the same intake system as a 502 MPI.
Just like Randy Oaks'. The ECU is the first generation that does not have much latitude as far as range of adjustment.
I called Arizona Speed and they suggested that I bring the boat down to Phoenix. It seems that they have not worked on this specific one-year wonder engine. I was quite impressed with their technical abilities, but it illustrated that I was on my own as far as tweaking this engine.
Neither Whipple nor Procharger makes a unit that just bolts onto this engine. No one wants to make aftermarket stuff for a one year wonder engine.
2. Nitrous, No. Same problem, one-year engine and an ECU that does not take adjustments like the later years. It also has a different fuel rail design as compared to later years.
3. I ask Geoo and Ranman and a few others for some advice and most recommend using a naturally aspirated motor.
4. I see a number of posts on Arneson out drives and Imco shorties. Both appear that they are not the best for a boat that pulls skiers and boarders regularly.
5. I see a number of posts indicating that the Mercruiser Bravo 1 out drive on my boat is good for 500 H.P., but that it does not like to be spun at high r.p.m.. So the brilliant thought I had of building a 6,000 r.p.m. Chevy small block get dashed.
6. Christmas comes and low and behold, my Internet Explorer browser finds the answer to my dreams! All I have to do is choose between the following and I will go 75 mph.!
415 c.i.d Small Block Chevy - 465 H.P.
427 c.i.d. Small Block Chevy - 505 H.P.
454 c.i.d. Small Block Chevy - 580 H.P.
And yes, they are all small block Chevy's with iron heads and straight plugs!
So all you gear heads, give me your advice. I know that I will need to specify a cam that will not suck in the lake water. I know that I will probably have to have the intake manifold bronze lined. And I am sure that a proper exhaust system will be necessary. But Oh!,to have bragging rights on the largest C.I.D. Small Block Chevy in the Donzi registry!

Please take a look at my Christmas wish list and help me pick out the right one.

http://www.worldcastings.com/docs/03catalog/engines.pdf

My thanks for all your help this year and I am definitely looking forward to 2004.

Don

[Rootsy]

looks like you've found bill mitchells hardcore racing engines eh...

you'll have to do a few things to those motors to make em last in a marine environment under heavy continuous loads and non corrosion inhibitor coolant use.. unless of course you opt for a closed cooling system...

[GEOO]

Don,
You should Procharge your engine and add a new lap top tuneable ECU like F.A.S.T.. 500-540hp.
Run the engine for a few years then put the blower on a big small block.
I run a 439ci, M3 Procharger with the F.A.S.T. ECU. 738--750hp??
My engine made 575-600hp with out the blower.
I could help you with putting a Procharger and a F.A.S.T. ECU on her. That should put you in the high 70's---low 80's!!! :D :D

[BUIZILLA]

Don, you mention skiing and family use...

What is your MAIN intended usage for the boat...say 90% of the time?

J

[DonCig]

90% of the boats engine hours are spent running between 3,500 rpm and 5,000 rpm. The amount of engine hours spent pulling skiers is around 10%, but it still has to yank them up fast and idle with a degree of reliabilty.

Don

[DonCig]

OK George, I am willing to give supercharging a go if you think that we can do it without to many surprises. The checkbook is ready and I have 4 months to get the work done.
When I talked to ATI they said that I would have to make some of the metal ducting since they don't make a standard Procharger kit for this engine. My profession is the metal tube (stainless, carbon and aluminium) business and the metal products industry (Stainless and Diamond treadplate). So having one of my tube bending customers make up some custom piping is not that big of an issue. From what I understand installing a new F.A.S.T ECU can be done if you are patient and not color blind. Will the stock Mercruiser fuel system provide sufficient flow to handle this project?
George, you willinness to help coach me through this progect is appreciated.
Is there any more homework I need to do before I get started?

Thanks,

Don

[GEOO]

I'm not sure if you need to remove all your existing wiring for the Merc ECU or just modify it. F.A.S.T. has a wiring harness to control the injectors, fuel pump, ingition ect.. You will need a larger fuel pump, Adjustable fuel regulator and new injectors and should upgrade your ignition to MSD distributor and MSD 6 box.
I may have an extra fuel pump and injectors good for 500-600 hp you could use.

[Shanghied Again]

Just so you know, Vortec is coming out with a Supercharger for that set up. This will be a great set up for all the 350Mags that need a litlle pick me up.

[Ranman]

Don,

I've often wondered if a whipple system might work on our boats. You might try calling Whipple to see what they have to say. Here's a link.

http://www.whipplesuperchargers.com/product.asp?ProdID=1152


Just as a side note, and this it totally my personal opinion, as soon as you touch that motor, you will lose all of your reliability. You will be fooling with it constantly, especially if you choose to run a blower. If you like that sort of challange (and some do), knock yourself out. I prefer to turn the key and go. That's why I really try to resist the urge to modify the motor. If I do anything, it'll be an IMCO shortie. 3-5MPH gain with ZERO loss of reliability. I think the handling issues you've pointed out regarding the IMCO are not as noticable as you think. An IMCO will ski, steer, and whatever else you want, just fine. Good luck with your project.

[Rootsy]

even the alpha SS on the 18 classic will let you pull skiers...

i have to disagree with losing the reliability on the motor if you supercharge it... if done correctly with the correct components and fuel / ignition maps it should be turn key... no different than your supercharged automotive production motors... the fiddling comes from TRYING to tweak and tune it yourself by the seat of your pants, etc... kinda like tuning a carb without an O2 sensor or thermocouple...

[DonCig]

Well here it goes. I was able to track down one of the original engine tuners / developers that used to work at ATI during the time that they developed the Procharger packages for 350 MAG MPI GEN+ from Mercury Marine.

His name is Mike Kromer and he now lives in Overland Park, KS. Mike has done a couple of the first Generation 350 Mag MPI Gen+ engines and spent many years at ATI developing their Procharger packages. Mike is now employed by the Don Freeley Company in Overland Park and they are one of two companies in Missouri that ATI refers their customers to for installation of their Procharger packages. Mike is going to pull his instalation notes from his last install to this engine and let me know what additional work is entailed. Mike is the same gentleman that installed a Procharger package into an Eliminator boat, on a boat ramp, for Hot Boat magazine in 3 hours flat!
The project is gaining momentum.

dt

[Ranman]

i have to disagree with losing the reliability on the motor if you supercharge it... if done correctly with the correct components and fuel / ignition maps it should be turn key... A lot of "if's" just to end up with a "should".

Boy oh boy, how fun would a ProCharger on the 18 be? "If" I only had the money.

[BigGrizzly]

As rootsy saye supercharging does not have a problem with reliability. I own one and it idles like a stocker starts like an injection model. Yes 3 years ago I broke the motor but it wasn't because of the charger but a bad inconell exhaust valve. The company gave me a free valve but nothing else except I'm sorry. I also don't use any more fuel than Bateman's Blackhawk. Weather you go with Procharger or Vortex you will ger quality products and good people to deal with. On an injection engine I would dump the merc for one of the other adjustablw units you can buy-Geoo has ben there and done that and IS the resident expert!

[Speed-Racer]

One of the most reasonable, reliable,and gas efficient set-up in an 18' is 6.2 MPI, which runs an honest 73mph. I assume you could also add a IMCO shorty to that setup and do close to 80...