454 spark plugs?? What does Dennis Moore like?

[Matt L]

Help a brother out! I need to know what plugs to ues in my 1990 HO 454.
Which ones does Dennis Moore Reccomend? I lost my copy of his tuning article. Can anyone e-mail or post a link to it?
I just need a little more speed. Just enough to edge out my Brother-in-law's new boat.
Thanks.

[gnarley]

I gota say that plugs ain't going to do it unless your in dire need of a tune up. Maybe a real good tune up & don't forget to look at your spark arrestor. NGK's are the shitz if you really need to read them if not whatever the factory recommends should be sufficient if it's a stock'r.
Dennis is a smart guy but there are many here who are probably even sharper when it comes to performance, he just wrote a book with lots of info already readily available and did the work so many of wouldn't have to.

[Matt L]

gnarley,
I didn't mean to imply that the plugs would do the trick! I just figured since I'm in there I might as well tune it right and incorporate his recomendations (most everyone here knows more than I do).
Anyway, the question is still open? What plugs should I use for a 1990 Indmar HO454. It has a Pertronix Ignitor II on a Mallory YL, Taylor 8mm wires and a accell 45,000 volt coil. Gap and timing advance suggestions are welcome as well.
Any suggestions? Lake Mead houseboat trip comming up! I need this baby to run!
Matt

[gnarley]

I'd try 1-2 ranges colder of the equivalent NGK that the stock plug cross-referenced to.
Timing I'd go with stock + 1 degree for each additional 1000 ft of elevation change that Mead is at for start, then adjust that up if possible by adding 2 degrees at a time if you can turn it to max RPM without detonating & on the best pump gas you can put in.
If your specs say 16 degrees BTDC @ 850 RPM or whatever add your additional to that number & you then should put the light on it & find out what the total timing is at the point in which it stops advancing to find out the total timing. Which should be somewhere between 32 & 38 degrees I am guessing. Once you bump it up a couple of degrees you could hear the detonating if you ever do it’s time to stop & back it down 2 degrees & run it again to make sure you eliminated the detonating. You could end up with 36 to 40 degrees of total timing but just remember you want to run as much timing as you can without detonating. If you know how you should also be checking the plugs between tests without idling the engine after the WOT pass.
Don’t forget to service ALL filters, check float levels (if Holley) & ignition parts.

[Matt L]

gnarley,
Thanks!
I'm new to trying to get the most out of my rig. Just so you know. It will never really go fast. It is a 1990 Mastercraft 240sc true inboard. It is a strange boat (but I love it), 24'10" (not including the swim platform) true inboard ski boat with a cuddy cabin. The fixed prop angle will prevent any really meaningful topend. The harder I push it the wetter it runs.
The dirty little secret of ski boat owners is that they all secretly wish for true topend speed. So if I can whip my Brother-in-law just by a little I'll be grinning from ear to ear!
How do I check the plugs? What am I looking for?
Also I'm thinking about changing to a lagrer carb. I think it is running a Holley 650 w/ vacuum secondaries. Will something larger help? What about an 850 DP? and is there any real difference from a marine Holley VS. a street Holley? My cousin ha many laying about for his street rod(s). His 64' Olds 442 w/ a 455 sporting 650 crank HP without a blower. He is an engineering genius. That engine was built in 1975, get 13MPG and hasn't lost a single HP over the years. So I've got help. I just need to know what to do!
Thanks again,
Matt

[gnarley]

Don't put on an Auto carb on a boat there are differences. To determine best Carb size go to Holley.com to find out what is the best size & I bet you find you are fine with a 650 unless real built up. Do a search here about plugs & read Dennis's book it will help you understand some more about high performance
here are a few links
www.autolite.com
http://members.uia.net/pkelley2/sparkplugreading.html

[Hal]

This a good site ..
I would also like to find a site that gives the plug #s to start at for different combos with BB chevy engines. If anyone knows of one?
Good info on plugs
Other good tune up info
Cross referance
[ June 07, 2003, 08:39 AM: Message edited by: Hal ]

[powerplay230]

Contact Procharger and see what plugs they reccomend to go with the blower kit and buy that too! pig_flyi

[Ctuck]

I torn down Street and marine Holley's and the only difference I can find is the "J-tube style vent in the horn of marine carbs. A street carb, some copper tubing bent into a U amd some epoxy puddy will save some bucks...

[rrrr]

Ctuck:
I torn down Street and marine Holley's and the only difference I can find is the "J-tube style vent in the horn of marine carbs. A street carb, some copper tubing bent into a U amd some epoxy puddy will save some bucks... Not true at all..... You endanger yourself and those in the boat if you plop an automotive carb in a boat. Some bucks aren't worth it, ever been to the burn unit?
There seems to be a pretty cavalier attitude about using marine approved parts among performance boaters, why would you spend thousands of dollars on your boat and risk blowing it up and killing people? I'm not just blowing shit, my wife's best friend lost her brother in a boat explosion at the refueling dock on a beautiful Fourth of July morning......