Bbc blower motor help!
01-25-2019, 08:48 PM
#51
Secondwind. My prop shaft is 2 inches above the lowest point on the bottom of the hull and I don't begin to use more than 1/4 throttle to get on plane. I just rev it to 5000 RPM and it rolls onto plane.
I have my drive "Tinkered" to allow more negative trim than stock though.
I have a terrible slip # until I get up in speed. ( 80 MPH and up is 4%)
I have my drive "Tinkered" to allow more negative trim than stock though.
I have a terrible slip # until I get up in speed. ( 80 MPH and up is 4%)
01-26-2019, 06:58 AM
#52
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Tinkerer,
I remember when you were working on the additional negative trim to get on plane. Maybe some of it is hull design. The AO has a fair amount of bow rise to get on plane. With a 34 pitch B1 prop I have to get to 3200rpm before the boat rolls over and the prop is biting until she rolls over. With two people on board it's smooth. With six professional beer drinkers it's labored. Once she's on plane everything is perfect-acceleration, turning, etc.
I remember when you were working on the additional negative trim to get on plane. Maybe some of it is hull design. The AO has a fair amount of bow rise to get on plane. With a 34 pitch B1 prop I have to get to 3200rpm before the boat rolls over and the prop is biting until she rolls over. With two people on board it's smooth. With six professional beer drinkers it's labored. Once she's on plane everything is perfect-acceleration, turning, etc.
01-31-2019, 01:15 PM
#53
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Mike Tkach,
509 dart 325cc heads fully ported exhaust runners, lightly ported intake runners, valves unshrouded and polished combustion chambers, fresh rings and bearings, dish top pistons 8-8.2:1 static compression, blower shop 871 with chiller and Nickerson 980 carbs, Imco powerflo with dry to the tip exhaust. Should I go with crane 771 or 651 cam?? Plan to run 8lbs boost
509 dart 325cc heads fully ported exhaust runners, lightly ported intake runners, valves unshrouded and polished combustion chambers, fresh rings and bearings, dish top pistons 8-8.2:1 static compression, blower shop 871 with chiller and Nickerson 980 carbs, Imco powerflo with dry to the tip exhaust. Should I go with crane 771 or 651 cam?? Plan to run 8lbs boost
Last edited by Daytona25; 01-31-2019 at 01:49 PM.
01-31-2019, 01:42 PM
#54
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Mike Tkach,
509 dart 325cc heads fully ported exhaust runners, lightly ported intake runners, bales unshrouded and polished combustion chambers, fresh rings and bearings, dish top pistons 8-8.2:1 static compression, blower shop 871 with chiller and Nickerson 980 carbs, Imco powerflo with dry to the tip exhaust. Should I go with crane 771 or 651 cam?? Plan to run 8lbs boost
509 dart 325cc heads fully ported exhaust runners, lightly ported intake runners, bales unshrouded and polished combustion chambers, fresh rings and bearings, dish top pistons 8-8.2:1 static compression, blower shop 871 with chiller and Nickerson 980 carbs, Imco powerflo with dry to the tip exhaust. Should I go with crane 771 or 651 cam?? Plan to run 8lbs boost
01-31-2019, 04:20 PM
#55
Mike Tkach,
509 dart 325cc heads fully ported exhaust runners, lightly ported intake runners, valves unshrouded and polished combustion chambers, fresh rings and bearings, dish top pistons 8-8.2:1 static compression, blower shop 871 with chiller and Nickerson 980 carbs, Imco powerflo with dry to the tip exhaust. Should I go with crane 771 or 651 cam?? Plan to run 8lbs boost
509 dart 325cc heads fully ported exhaust runners, lightly ported intake runners, valves unshrouded and polished combustion chambers, fresh rings and bearings, dish top pistons 8-8.2:1 static compression, blower shop 871 with chiller and Nickerson 980 carbs, Imco powerflo with dry to the tip exhaust. Should I go with crane 771 or 651 cam?? Plan to run 8lbs boost
01-31-2019, 05:41 PM
#56
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I’m sure there is a more powerful cam available but at what cost?? If someone has a suggestion and can verify that it won’t come at a cost of valvetrain stability or me having to replace parts once a year I’m open to suggestions!! I’ve been down the custom cam fancy lifter road on my last motor, $800 lifters that didn’t make it thru a dyno session in the trash and replaced with another set of lifters....this was for a 511” motor in my Camaro. So this time around I’m more than happy with the more tried and true setup and only having to buy parts once!! But I am still open to suggestions from anyone of you guys with more experience than myself in the offshore community as I’m still learning the curve of boat motors rather than car motors!!
01-31-2019, 05:51 PM
#57
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I’m sure there is a more powerful cam available but at what cost?? If someone has a suggestion and can verify that it won’t come at a cost of valvetrain stability or me having to replace parts once a year I’m open to suggestions!! I’ve been down the custom cam fancy lifter road on my last motor, $800 lifters that didn’t make it thru a dyno session in the trash and replaced with another set of lifters....this was for a 511” motor in my Camaro. So this time around I’m more than happy with the more tried and true setup and only having to buy parts once!! But I am still open to suggestions from anyone of you guys with more experience than myself in the offshore community as I’m still learning the curve of boat motors rather than car motors!!
01-31-2019, 05:56 PM
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Yes a morel lifter to be exact, actually two separate lifters in a set failed. Non the less cost me quite a bit of money to fix the situation!
Last edited by Daytona25; 01-31-2019 at 05:59 PM.
01-31-2019, 06:17 PM
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I’m not against solid and have considered it, just with my Imco exhaust it means pulling the exhaust loose from the head to get the valve covers off, but if that’s what is recommended for the best durability I’ll go that route. I have comp gold rockers currently so would the be sufficient with stud girdles or do I have to step up to shaft mounted rockers to get reliability?? Also at given times my boat may see 45min idle time in gear which is 6-800 rpm, is that gonna cause concern for solid roller lifter failures?? And I boat 50-75hrs a year so is a one time checkup on valvetrain in that amount of time sufficient with solid roller?? I already considered solid setup once, for the added power, and sound but was concerned about lifter reliability, considering idle time ect. My boat is used primarily for a pleasure boat idle time, cruise rpm 2700-4000 depending on situation. Don’t do any tubing skiing ect just mainly a hot rod family boat with the occasional high speed blast!
Last edited by Daytona25; 01-31-2019 at 06:20 PM.
