No problem 93'. Apparently these mixed part units flow about 930-980 cfm. I just cant remember the number. My motor didnt melt down because of the carb. The block and intercooler were plugged with mud from the low water pickup........ can you imagine that?

HPjunkie....do they have swamps in illinois??? where else can you run in water that shallow !! Just kidding, how did you pick up that much sand & muck without destroying the outdrive too???? or did you? What ever, it sure sounds nasty tho'.....

Antioch Il. Every thursday night at Blarney Island ( a bar in the middle of the lake accessible by boat only) at 6pm they have 1/8 mi drags. About 15-30 boats show up along with about 300 spectator boats, about 300 bikinis and lots of cold beer, etc. etc.
Can you say wet t-shirt or no t-shirt? Drag boats from 350 hp 600 lb.outboards to blown alcohol 700 cube direct drive 17' hydros (cool ****). Anyway the channel out to the "island" is 2' deep thru the cattails, well 1 night we were cleaning up the boat (the cops wait at the ramp) I looked up and saw the bouy kept cleaning and bagging and looled up and the bouy was still there. The drive was in the mud . Ran great for about 20 more hours never over heated. then ran it hard for about a minute or so that did it.Oh well lesson learned. It used to run 83 on gps. Greg

I'm new to this board, I saw this topic and wanted to add to an already great topic. have a Procharged 22 foot Donzi with a 502 and 5 psi of boost. The unit has 698.5 HP and 700LBS of torque. This engines idles like a stocker starts like it is injected and has descent fuel economy unless you stand on it. I am using a Demon 825cfm carb. and this is one of the nicest engines I've had. The hole thing is setup, Garry Grimes in Georga Did the carb majic. The way this one runs I see no reason to go injection. When I say the way it runs I'm talking drivability not just speed. The speed isn't all that fast (80+) but the idling the smooth acceleration and mid range power is great. The wife likes driving it better than the stock engine.
The biggest advantage of the carb (for me) is when I change cams for more power I don't have to redo the ECM, Just jet and go. BTW the powervalve in this motor isn't used because there always positive pressure on it. the jetting isn't that different than the rest of you use, 84 primary and 110 secondary.

This is really a great disscussion. All the ideas are really good and everyone is contributing and not taking any offence when they are not agreed with.

Randy

[ 01-16-2002: Message edited by: BigGrizzly ]

Welcome to the Board, Randy. We are always happy to have another source of experience and opinion. It's great to hear about your successful package, since I would also like to blowthrough about 5 psi into 502s, basically GM 502/502 engines that have been marinized. I'm a little concerned about the 9.4:1 C.R., but they tell me it can be done. What engine parts combination do you have?

Tom

My engine has Procharger blower with 5psi boost in a basic stock(not bored) 502 GM/Merc block, 9.5 forged pistons, GM hp rods with 7/16 rod bolts, larger than stock oil pan, a mild Garry Grimes desigened Twister cam and GM HP aluminum heads. I have been building motors for my race bikes and cars since the early 1960's and this engine is great. Under normal circumstances I would have done all the work but Garry is close with a great reputation around the race circuits and Lake Lanier. Under his guidance, the very capable dyno man in his shop Johnny Waddel did all the dyno work while I watched in awl. This engine is more than I hoped for. This is as, Garry says "A mild motor". It is all in the combination. You go too far in on direction and not enough in the other you get into trouble or it just doesn't work right. Every body thinks this is a injected motor, even after I show them. It has drivability like a car. You see Garry and Johnny are anal about drivability. Garry said to me "If your wife can't drive it your in trouble, and you don't need that kind of trouble" and he is soooo right. The fuel economy isn't that much different than stock untill you start to rock and role, than it is substantial. best fuel economy is about 2800->3400, while the engine is under a load. I also have the best luck with the Turbo props and I have tried over 15 different props from different makers. This includes the famed lab finished BravoI props. I'm not saying they are not good just telling what worked best for me. The other next best was the Hydromotive, they were neck and neck. BTW I have tried all the different props in the Turbo and Merc line up. Hope this helps your desicision
Almost forgot there are more props than these makers advertise in their web sites.

Randy

[ 01-18-2002: Message edited by: BigGrizzly ]

[ 01-18-2002: Message edited by: BigGrizzly ]

Hey Tomcat, Maybe it is something with your carb itself like flashing, dirt, corosion. These others are having good luck with their carbs. I like the demon carb. Allmost woorth getting one and try and see what difference it makes.

I haven't supercharged yet, but when I do, I will send my new 800 marine Holleys to Nickerson and pay the money to have an expert drill them. I don't know why some are having better luck than others, but the beauty of the Board is you get to learn from others and avoid problems.

When I started this post, I was looking for a solution that was truly tracking air density and adjusting fuel accordingly. But, as I said before, a good carb tuner can make the best of the situation, and that may be all that is easily available.

The electronic fuel bowl was the best idea for tracking air density and adjusting the richness of the main circuits, which are themselves tracking air flow. If there was enough demand, a call to Holley by one of the centrifugal supercharger companies might provoke a reintroduction of the concept, designed especially for this application.

Tom, There is a carb that uses electric fuel injector type meetering in stead of conventional float bowls. it was debuted at the Indy show just before Christmass. I saw it run on an Eliminator cat at 127mph and they were still braking the motor in. It is ECM controlled. The unit was on a suck through blower. I know the inventor. I saw some impressive numbers on the dyno. He took a HP900 and swapped the intakes and pulled big number difference. They also did removed a injection system and bolted this on with a conventional intake and pulled more numbers. This has got my attention. If he does produce it I will be the first in line. Imagine all the advantages and power of the carb and no floatbowls. They are thinking of sending it to the Miami boat show and pit with another company.

Randy

[ 01-19-2002: Message edited by: BigGrizzly ]

Tomcat
When Garry Grimes sets up an engine for a Procharger he makes other changes to the combination than just fine tuning the Demon carbs he gets. You may want to contact him, I'll get his number for you. He's got Procharger motors stacked like cord wood that he is fixing for people that didn't get them set up right !