Velvet Drive Question

[DOGGYDOO]

Looking To Mate A B/w Velvet Drive To A 455 Olds. Still Sourcing Out The Bellhousing. Question Can I Use A Universal Joint Coupling Like That Comes With A Jetboat Application? Also What Would My 71c 1.52 Ratio Accept As Far As Horsepower Torque? This Engine Is Roughly 350 Horse With 450 Torque. I Do Have A Line On A 72c 1.1 So Thats Why I'm Asking. Dave In Fort Lauderdale

[PowerTech]

it will blow the input seal on the transmition if you couple it that way.You better use the 72.And here is the bell housing to do it with.http://www.glen-l.com/inboard/8transm.html

[PowerTech]

here are your babys.http://www.boatswainslocker.com/prod...ive/71_72.html

[DOGGYDOO]

Ok So I Found A Rebuilt B/w 72c But Its 1.1 Ratio. Do I Need A Reduction Box? I Also Found A72c With A1.52 Ratio Box. I Have A Motor Rated At 500 Foot Pounds And Made To Rev 6000. If I Propped It Accordingly Would It Perform Correctly Without Thereduction Box/ My Goal Isto Keep Engine Revs Around 4200 Andobtain 60 Mph. Would This Be Best Obtained In This Setup Or With Thereduction Box And Reving To Say 5500? Dave In Ft. Lauderdale

[gonzo]

Model 71C
gas HP 310@4200RPM
Diesel HP 182@3200RPM

Model 72C
Gas HP 475@4200RPM
Diesel HP 274@3200RPM

[DOGGYDOO]

Ok I'll Go With The 72c. Its 1:1 So How Do I Know If I Should Use A Reduction Gear? The Previous Setup Had A 1.52 Reduction But That Was With A Chevy Straight Six. The Engine I'm Installing Is Basically 400 Hp But 500lb Torque At Around 3000. So Can I Eliminate The Reduction And Prop It Accordingly. My Goal Is To Keep The Engine Revs Under 4500 .. But Also Without The Reduction Gear Wouldn't I Get Better Fuel Mileage? Dave

[PowerTech]

you beter go with the 1:1.

[gonzo]

However, you'll need a bigger prop to absorb the extra HP. One way to do it is to use a 4 or 5 blade prop. It will have more blade area. If you use a bigger diameter prop, then you'll have to use more reduction in the gears. The blade tip speed is what is critical for cavitation- more diameter=more speed.

[DOGGYDOO]

ok now you're gonna laugh for sure. i am going to correct this situation, but, this is a boat that had been converted from stern drive,. one of the first things i noticed and why i decided to replace everything was that after i pulled the engine transmission combo it was at this time i noticed that the engine transmision and shaft log were slightly angled to the starboard side i.e. they are not in true dead center straight. this alarmed me. is there any reason someone would do this or is it just sloppy installation? the boat overall ,, which is a formula 23'3 1968 vintage, has been rebuilt restored reconditioned quite nicely prior to my acquisition so this one point was the only thing that looked incorrect.

[DOGGYDOO]

btw i am installing a gasket kit in the 72c tonite. having already inspected the 71 c before i must say they look very simalar internally,, so what are the 72c upgrades? more clutch plates i assume . looking for an expert advice on this one. dave in ft. lauderdale

[gonzo]

The 72C is about 1 1/4" longer and has more clutches.

[DOGGYDOO]

According To The Velvet Drive Maual The Front Pumps Are Interchangeable Between The One That Has The Backing Plate And The One Without. Does Anyone Know The Difference? Also I Examined Both Front Adapter Housings And They Appear To Be Identical Including Similar Part Numbers. Is There Any Internal Differences There Between The 71c And 72c Front Adapter Housing? As I Would Like To Swap My 72c Housing Which Is In Poor Condition To The One That I Removed From My 71c Which Is Much Cleaner And Has A New Needle Bearing. Thanks Dave

[ENZO]

ANYONE CAN GIVEE ME ADVICE. I WANDER IF THERE IS A WAY TO REDUCE GEAR RATE FROM 1.98:1 TO SAY 1.50:1 ON A S-7000 VELVET DRIVE. IF SO WHAT IS THE KIT No. AAND WHERE I CAN PURCHASE IT?

THANKS

VINCENZO D'AMICO - CARACAS - VENEZUELA

[gonzo]

The reduction gear, which is bolted to the back, can be changed. I don't know who is a dealer in Venezuela.