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GotTheFever
04-20-2001, 10:02 PM
I own a 93, 32' Fountain Fever with twin 502 Magnums (Carbureted). Two summers ago I installed the Procharger, Stage I system. I did not want to stress the engines nor the out drives so I limited the boost to 3.5 lbs. I really like the blowers, but getting these engines jetted right is not an easy task. The manual suggests blasting across the lake at WOT, checking the plugs, then adjusting the jet sizes accordingly. The problem with this is; 1) You just about get 3rd degree burns trying to pull the plugs on a twin-engine application after this type of blast. 2) Replacing the jets requires pulling the carbs from the carb boxes each time. 3) The plugs show no sign of burning rich or lean (they still look brand new). 4) This does not show me how efficient the engine is during cruising speeds. Looking at the plugs after a full day of boating shows that it is burning slightly rich, but I donÂ’t know if this is the average between running lean while cruising, and rich while blasting or vice versa. Does anybody have any suggestions? The engines are stock, with the exception of CMI 2 piece exhaust, Procharger, Accell Super Coil, Soft Touch rev limiter, and Holley 750 double pumper. Thanks.

RiverDave
05-23-2001, 02:04 PM
Before you read on I am no expert but I may have a solution to your tuning problem. Bausch makes an exhaust sensor that is fairly easy to mount to your manifolds and it gives you a "neat and pretty" little read out of how rich or lean your engines are running in real time! The whole package is incredibly cheap, I used to use one on my lil rice rocket street car, I'm surprised not to see them in more marine applications. Hope this helps you, Good luck.
RiverDave

Timer
05-23-2001, 02:56 PM
GTF, they tell you to run at WOT because that's when you can do the most damage because of running lean. I've been told (and read) that the plug porcelain should be a light tan color after a WOT run, but I think if it looks like a new plug it's OK too. I wouldn't lean it out any just because you are running slightly rich at other times. 2 cents worth if it's even that much.

ponponracing
05-23-2001, 03:54 PM
The problem with those oxygen sensors in the marine application is that you have no room to insert them in marine exhaust. And if you finally can do it, the reading will be wrong because of the wet environment. You can even destroy the sensor by making it work in a
wet environment.
Sorry friends,I'm going to be a troublemaker in your discussion. Here's the process to adjust a carb by running the engine:First run your boat to warmup everything. Stop in a spot where you will be able to leave without a lot of idling or midrange. Gap and install new spark plugs( wait till the old one cooled enough for handling). Run safely at WOT for at least 3-5 minutes. Stop dead without excessive idling. Let the thing cool, time won't affect plug coloration. Take those fresh plugs and look at the porcelain. It should be tan on all plugs. In fact,it's a lot more touchy to read plugs, but if the whole porcelain is tan, then it's safe. When you get the right coloration, you have the right jets in your carb. If the porcelain is still white, you're lean: increase jets or you will destroy the pistons, very very rapidly with a blower. In the worst situations we are talking about minutes... After the jetting is right, make sure the powervalves are tuned for your engine. And finally set the idle with the idle screws. It look simple, but it's not. A blower has a big quality: power for cheap. The problem with it is that it destroy our motor as fast as an eyeblink if not tuned properly. All the engine components have to be perfect when you run a blower: fuel quality, fuel pressure, ignition, water pressure, carbs adjustments, valves springs, valves. There are many horror stories when you talk about blowers. It's power, and power is never cheap in marine application. You HAVE to learn how to use a blower before to play with one: if you are a rooky, you need a lot of help if you don't want to be part of the big book about blown blower engines.

formula93
05-24-2001, 10:27 AM
The best thing to do is send your carbs to Nickerson Performance....I just got mine back & it is perfect. The problem is that your carbs are auto carbs used in a blown/marine application and are not "optimized" for blower use. The venturi do no flow correctly no do the jets.
Dean Nickerson remachines the carb, venturis & metering blocks. Then flow matches all the venturi & jets. Mine came back perfect on jetting.
I pulled my plugs and you honestly could not see a diffence between cylinders on the plugs. An amazing difference. Dean also turn my carbs around in 3 days after reciept also.
In no way should his work be confused with "a rebuild" ...it is totally different & he has worked with prochargers for years. Your carbs will be run & tested on a engine in his dyno room & tested before it is returned to you & each carb has a registration # on it forever !
Nickerson Performance
3831 Otter St.
Bristol, Pa. 19007 215-781-1370
This is the way to go !!

Racing Ray
05-25-2001, 04:47 PM
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[This message has been edited by Racing Ray (edited March 12, 2002).]
[This message has been edited by Racing Ray (edited March 12, 2002).]

ponponracing
05-26-2001, 05:33 AM
Ray, there's no doubt in my mind that you know a lot more than the average guy in engine tuning. But I don't feel this forum is the right place to discuss points that are way too complicated for the average guy to understand. When (in my mind) I'm sure about what I am saying, I'll take the time to try to help people that seem to need help. I won't aswer dumb questions, I'm just trying to help anyone asking for it. I'm not Smockey Yunick, or even close to his level.
But since you took some of your time to comment my reply, I'll also take some of my time to discuss with you.
This guy was just looking to know how to set the carb jetting in his engines. Drag racing is very different than boating. In a single day of boating, GotTheFever will put more hours on his engine than you in a whole racing season. He also has to make sure that he brings the boat back to shore at the end of the day.
Your time is around 8 seconds in drag racing. That suppose you have power in your motor: you're not playing. So I'm sure you dynoed your motor, not to have a nice big number on the sheet at the end of the day, but to find out what are the right adjustments to get the max power from it, and to make sure it will last a little longer than the staging line. The dyno gives you the right timing for power. It also tells basic jets numbers so you can fine tune at the track. And it finally tells you if all the components are working right: ignition, fuel pump, headders, etc..
You didn't mention about what fuel you use in your car. But your plug reading technique look very professionnel to me.
With 8 seconds blast, there is not a lot of time to color a spark plug. So you have to be very accurate when you read it. But 8 seconds runs are so short that a lean engine won't melt a piston: it's like a dyno pull, not long enough for the heat to destroy the whole thing, unless you're way besides the right adjustments. When you ask the engines to push a 8000 pounds boat in water, it's a different story. 5 minutes are long enough to color the plugs, to melt a piston, or to blow the whole motor if it is wrong. Remember that it is still a blower motor, burning cheap pump gas. It's a lot more tricky than how I explained it to read plugs, but if GotTheFever see a than coloration on them after 5 minutes, then it's safe, and I helped him finding a decent adjustment.
Two more comments: the dyno always told me that a lean engine, like a rich engine, looses power. Also, I never saw anyone changing plugs at the end of the track. Usually, people are tow back in pit after a hard run so they save the motor and they can have a look at it without getting false readings from idling or part throttle operation.
Nice discussing with someone serious, but a little long to use the keyboard.

Racing Ray
05-26-2001, 07:32 AM
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[This message has been edited by Racing Ray (edited March 12, 2002).]

ponponracing
05-26-2001, 08:55 AM
Ray, the usual set up I use in a marine blower engine is quite simple. There are some variations depending on the boat size. For less money in a small boat that the owner wont be able to keep at WOT for a long time because it's scary to go 100mph in a such a boat, I start with 7 and a half cr. pistons, 10 pounds of boost, al. heads. I did own a Warlock 25 a few years ago, and that combination was excellent. In fact, I think I went WOT about 5 times during a season. In such a small boat, I can't say that it was really confortable at 108 mph.
For a bigger boat that can stay at WOT for a longer time, 6 pds. of boost is the max. I'll work with. If the guy is very demanding, I'll add a chiller.
In my race boat, I run 15 to 1 comp. ratio on alcohol. That juice is excellent for the engine and once you're used to the bad sides of it, it's not any scarier than high octane gas to use.
Back to the blower engines: don't forget to keep the engine cool if you want it to last.

RiverDave
05-30-2001, 09:30 AM
PonPon, I am one of those average guys that doesn't know a whole lot about marine tuning but rest assured I felt your guy's coversation is one of the more interesting ones I have read!! Please feel free to go above and beyond the average guy, I'll do a little research, understand it later and maybe someday be a little more knowledgeable.
See ya at the river.
Dave
Ray, there's no doubt in my mind that you know a lot more than the average guy in
engine tuning. But I don't feel this forum is the right place to discuss points that are way
too complicated for the average guy to understand.

ponponracing
05-30-2001, 02:52 PM
Thank's RiverDave,
it takes time to write those replies, and sometimes I wonder if it's appreciated. As a lot of people on this planet, I have to work for a living, and I'm burning my spare time to reply. Plus the fact that I'm french speaking. And that keyboard is killing me.
I did goofs and problably it will happen again but I learned the hard way. And when everything was going bad, did I wish someone wuold have give me right advices!
So, if I can help someone, I's rewarding to me because I remember....

AZ_Eagle
05-30-2001, 04:18 PM
Hey ponponracing,
Keep the posts coming! It's more value to us "newbies" than you could ever imagine!

GotTheFever
05-30-2001, 06:54 PM
Thanks everybody for your response. IÂ’ll take your advice and continue to get these engines dialed in.

h2oedits
05-31-2001, 01:32 AM
Great posts, guys....thanks for the participation
Kevin
Hot Boat