SoCal Jet Boats
Tech Talk => Projects => Topic started by: OCJeeper on July 15, 2013, 10:48:48 PM
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New to these forums so sorry about being a noob. So bought a 81 Biesemeyer jetboat with a 454 BBC years back when money was good, long story short its sat for the last 3 years without seeing water and I almost never started it. Well decided time is good enough to start throwing money at it again. Interior needs work and the hull isn't as pretty anymore but fired her up today and she ran like a charm. Couple questions I wanted to throw out, first of all is there a switch I can use that would pull fuel from both tanks at the same time? Always got tired of the fuel gauge working on one tank only. What would really be the point of switching between tanks? Why not pull fuel from both all the time? Another is the trailer brakes, I'm not sure they ever worked where would I even start in attempting to repair / replace those? Should it be better to take it to a boat/trailer repair shop? And I guess lastly, I need to most likely rebuild my jetdrive, I had the engine built up a couple years after I bought it and never rebuilt the jetdrive / matched the impeller up to the new hp and torque shes putting out. Anyone recommend any shops in the OC area for working on jetdrives or are they pretty easy project to rebuild myself? Thanks again guys!
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We like pics!!!
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1). You can just use a Tee at the transom, but use a valve on each side. They will draw together, but usually not equally, and you might run out of gas and still have a 1/4 tank on one side...close empty side and head to the gas dock.
2).Surge brakes I suspect- If the 'bore' in the master cylinder is good, get a rebuild kit, bore diameter should be on the plunger/piston- 1 & 7/8ths, etc. the older drum brake shoes were mustang, 9" dia. x 1.75" or 2"
I think like 64-68 or 69. There are kits to upgrade to surge disc brakes, or even electric drum or disc brakes. Kinda depends on your budget and your tow vehicle, if you even need them, but I tow with a dually.
3). What RPM were you running before the build of the motor? and after? where do you WANT to be? You would be surprised at how well a 'fresh' performs over a 'loose' pump.
Refreshing a pump is pretty simple, might need an impeller puller and some gaskets. A pump will absorb whatever horsepower you're willing to throw at it...think dyno. Some shops- no particular order- MPD-Costa Mesa, GS Marine-Corona, B-1 Racing-Anaheim, I think
Dan'l
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Thanks for the info Dan'l. If i remember correctly since i dont have the dyno sheet infront of me at the moment the engine dyno'd at around 469hp and 520 tq after the rebuild and I believe if I remember correctly that's was at 4400-4600 rpm. I'm assuming that's where I want my rpms to be. I got nooooo idea what the impeller was set for before...I can tell ya that when I get her up to speed she feels like she has a helluva lot more power to go. I can almost feel the wasted HP at the impeller. As for the surge brakes they'd be nice as I pull with a lifted 4door jeep wrangler lol...big tires plus boat and trailer makes stopping entertaining.
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What pump is it? Berkeley?
If that's your float in your avatar pic, I'd go with a 'AA' American Turbine brand impeller, stainless if ya got the coin. Good 'out of the hole' for a heavy cruiser, and top out at ~5000 rpm. The A/T impeller is slightly bigger than the Berk 'AA'
You might think about going electric, (drum or disc), surge kinda sucks on a smaller tow vehicle with a heavy trailer/boat. (your jeep hasta have some whoa before the surge will react, electric reacts right NOW)
Find the dyno sheet, too.
See what impeller is in it, or at least what is was built with.
Pics too
Dan'l
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Yeah its got a Berkeley jet and ya that's float in the pic I'll try to find some pics when I get home. How difficult is it to do the impeller job yourself , I'm decently mechanically inclined, but mostly towards off road vehicles.