Ignition Coil Question for 455 Olds

[John_Simms]

I need a reccomendation for an aftermarket ignition coil for my boat. It is a '75 17 ft. Sleekcraft Montery with a 455 Olds. The engine was built up almost 10 years ago, but has very few hours on it because all my summer weekends have been spent watching my daughter play softball. Now that she's finished playing ball every weekend of the summer, I'm trying to get back into the boating and skiing.
The Olds was built with 10.25:1 TRW forged pistons, Zero Gap Rings, cross drilled-nodular iron crank, stock rods with notches added for improved oiling, dual valve springs, Accel Dual Point Distributor,Edelbrock Performer intake, Mondello high volume oil pump, 10 qt. pan, and a Quadrajet that was reworked by a local speed shop.
The boat is equipped with a Jucuzzi YJ and I belive a "B" impeller if I'm not mistaking. The boat idles great and pulls hard out of the hole, but runs out of power around 4800-4900 RPM's. It will run in the mid to upper 50's with only a driver and minimum fuel on board. According to the Jacuzzi pump curves, this indicates a HP rating around 375-380 HP. I know this engine should be capable of making tons more power so I'm looking at upgrading the ignition system and hopefully the fuel system, starting with the ignition system.
Now it just has a stock GM coil and I want to get a High Voltage after market unit. I also want to eventually get an MSD 6AL ignition module. Does anyone have a reccomendation for a coil that I can use now with the points type system but will also work with the MSD box? Also, what should I be looking for in a carb? Holley, Demon, etc.
Sorry this is so long, just wanted to give some background to help in the decision making. Thanks.
John

[sleekvino]

I need a reccomendation for an aftermarket ignition coil for my boat. It is a '75 17 ft. Sleekcraft Montery with a 455 Olds. The engine was built up almost 10 years ago, but has very few hours on it because all my summer weekends have been spent watching my daughter play softball. Now that she's finished playing ball every weekend of the summer, I'm trying to get back into the boating and skiing.
The Olds was built with 10.25:1 TRW forged pistons, Zero Gap Rings, cross drilled-nodular iron crank, stock rods with notches added for improved oiling, dual valve springs, Accel Dual Point Distributor,Edelbrock Performer intake, Mondello high volume oil pump, 10 qt. pan, and a Quadrajet that was reworked by a local speed shop.
The boat is equipped with a Jucuzzi YJ and I belive a "B" impeller if I'm not mistaking. The boat idles great and pulls hard out of the hole, but runs out of power around 4800-4900 RPM's. It will run in the mid to upper 50's with only a driver and minimum fuel on board. According to the Jacuzzi pump curves, this indicates a HP rating around 375-380 HP. I know this engine should be capable of making tons more power so I'm looking at upgrading the ignition system and hopefully the fuel system, starting with the ignition system.
Now it just has a stock GM coil and I want to get a High Voltage after market unit. I also want to eventually get an MSD 6AL ignition module. Does anyone have a reccomendation for a coil that I can use now with the points type system but will also work with the MSD box? Also, what should I be looking for in a carb? Holley, Demon, etc.
Sorry this is so long, just wanted to give some background to help in the decision making. Thanks.
John
if your running an olds at 48-4900 rpms and only into the 50's then i look at the hull for hook or rocker sounds like your pump isnt loading.how old is the pump?

[1975sleekcraft]

i have a sleekcraft with close to the same 455 setup.going to gps soon but it feels like low 60's @ 5300 rpm's.I have a msd coil (looks like a stock coil ,red with"msd" on it).
I know i have a "b" impeller.I'm thinking i need an "a" impeller to bring my rpm's down and my speed up!
anyway thats what I'm going through.If anyone has any sugestions please post or pm me.
oh,by the way how can I get ahold of those ,"jacuzzi pump curves"

[DeputyDawg]

I am not real familiar with the Jacuzzi pumps so I don't know what you should be turning a "b" impeller with the power you have, but if your 455 is a stock iron headed deal at 10.25:1 with the other mods you listed it isn't going to make much more than 375hp if any. I am not trying to rain on your parade just being realistic. There certainly is nothing wrong with upgrading ignition components for better spark but my recommendation for a every day play boat I would say keep it simple and reliable so that when you bump the key it starts! As mentioned by sleek-vino you should check your boats bottom and make sure it is straight and doesn't have any hook in it. Having even a little hook can really hurt the top end and if it has a lot of rocker it can porpoise a lot and handle funny.

[olbiezer]

i agree with u guys but a 35 dollar msd coil will not make it not start every time u bump the key......

[Moneypitt]

Does your nozzle have the adjustable angle feature? If so, have you tried a different angle. Unless you plan on adding a bunch of fuel to the existing set up the additional spark voltage isn't really going to do anything, if it's firing the fuel now, it won't go any higher/faster with additional spark voltage. Are you running that GM coil battery voltage through a ballast resistor? If so, what is your running primary coil voltage? I have an Olds 455 in an old hydro, 12% over geared, 12-15 3 blade, GPS'd 78.5 at 5300 RPM. This motor is all there with 2 600 Edelbrocks on an old Offy intake. Stock single point distributor, and a standard ol' down the road type coil. When you change to a hotsy totsy ignition box, and expect to see a drastic improvement in performance, the instructions will tell you to add fuel.......lots of fuel........MP

[DeputyDawg]

olbiezer posted--
i agree with u guys but a 35 dollar msd coil will not make it not start every time u bump the key...... Agreed, but what I was refering to was the ignition box. I hook them up right and protect them properly and therefor have had good luck not killing a lot of MSD boxes. In this guys set up I just don't think an MSD box is a needed expense. There are a lot of other little things he could spend the money on right now. Build the bad ass motor then step up to the MSD or Crane box.

[455Rocket]

When I got my Olds 455 I ripped out the point/resistor set-up and replaced the internals of the Mallory single point distributor w/ a pertronix electric unit, added a Mallory box (which puts out more volts than the MSD 3AL for less money), and run a MSD high vibration coil... it turned my boat into a true "turn key," for sure... I noticed less hesitation off the line and the thing fires even after sitting for a month. More spark to the plugs w/ the box = better fuel burn and a more equal/even spark, and that can only be a good thing!

[Floored]

The YJ jacuzzi is not a real performance piece and 50-60 is doing good with them. You could put 1000 hp into it and maybe pick up 10 mph so why waste the money. I use a stock single point with an Accel supercoil and it always starts with just a bump and EGT's are in the 12-1350 deg range. Same plugs for 5 yrs and never a hiccup. 750vs holley, torker, 2 in open spacer 36 deg timing pump prem.

[SmokinLowriderSS]

Afraid I'm gonna bring another cloud into what looks like a real rainstorm. :idea:
The ignition upgrade is a nice idea, but will only make any real improvement if your stock system is not working well. Yes, starting MIGHT be a BIT snappier, MAYBE a BIT less "hesitation" from an idle to WFO slam, but more HP, No. I'm still running a 27 year old Prestolite Single Point Marine distrib on my 454. She's cold-blooded first start of the day (no choke) but she idles just fine warm, never even makes a single full revolution restarting after picking up a skiier/tuber, a real "bump"-starter. The points are good, so is the condensor, cap & rotor are also, coil is a 3 yr old stocker (orriginal lasted 24 years). I usually get at least 5 to 7 years out of plugs, then changing them only because I think she MAY START GIVING TROUBLE, but she never has. The wires are new (last winter), the others were orriginal 1978, and still worked great. :chi:
I'm installing a Petronix Flamethrower dist & coil setup this winter simply because the springs in the centrifugal advance are getting weak and advancing at idle of 900 RPM.
To get much more speed out of the pump, you need to go to the "mixed-flow" design of the WJ Jaccuzzi. You can do this 2 ways I know of: :clover:
1- Energiser kit, which replaces everything but the suction housing with different parts. Kinda 'spensive.
2- Replace it with a mixed-flow pump (Berk, Dominator, Agressor, etc) from scratch. Replaces EVERYTHING. Kinda 'spensive.
Yes, I also agree that you could easily have hull issues. Hook pushes the nose down, BAD for speed. Look there too and make sure you aren't fighting a battle on the wrong field. :lightsabe
A diverter of some sort is a great thing. Trimmable down for rougher water conditions to fight porposing, I think it is a better spot for hole-shot also, and trimmable up to lift the hull out of the water to reduce drag & pick up speed (10 MPH on my Taylor /Berk "F" from trim down to up, that's at 4,000RPM CRUIZE!!) :mix:

[John_Simms]

It sounds like uprgrading the ignition isn't going to buy me much until I'm able to add a bunch more fuel also. To maintain drivability and optimum fuel economy, I'm probably better off just keeping what I have and looking for a hook in the hull. Thanks for the replys.
John