Mercury #6 Drive Chronology
 

Just wondering what the chronology is on the #6 drives. When did they come out, when did they go to dry sump, when did the swept skeg come out, etc.?

Michael

I'm no expert on the Speedy 6 but here we go.

The speedmaster VI was originally designed by Fred Kiekhaefer back in the mid 80's when he was head of Kiekhaefer Aeromarine. It was released in 1988 as the Kiekhaefer K drive and only available to qualified race teams. Needless to say, it was a tremendous sucess. Mercury soon after bought out Kiekhaefer Aeromarine pretty much to gain the drive and re-named it the Speedmaster VI. Not sure when they were dry-sumped or the swept back skeg.

first dry sump #6 was done by pat wiessman (shifter) in 95, i think. it was a modified wet sump drive. We had them on our first 36 skater, ct peppers, 1996 world chamopionship, !st place. we continued to use them until swapping to imco extremes in 2000.

What exactly is a "wet sump" and a "dry sump" for us guys that can't afford $20k - $40k drives???? :D

Similar in the Dry sump pan set up for High performance BBC I am guessing. I am learning of these and am soon to install a set on my next set of engines. Supposed to be a 30 hp gain at the crank.

Nice thread, be nice for Shifter to chime in.

Cougarman

A wet sump engine stores the oil in the pan. The oil pump itself is ran from the distruibutor shaft. Bouncing in a rough sea can intermittently starve the power plant from oil.

A dry sump engine has an external mutilstage pump that is driven from the crank. The oil is stored in a separate external tank which may hold up to 4+ gallons of the precious fluid. The oil is scavaged from the oil pan back into the tank then pumped from the tank and pressurized through the system assuring a constant smooth flow of oil. The external tank also allows some moderate cooling of the oil.

Advantage: Less chance to starve the vital components of the engine from oil.

Disadvantage is throwing a blower belt and it also taking out your dry sump belt.

Good info.

We had a set of K-drives in 88 on a 32 Skater....

1. Mercury copied the #6 by buying it in 1988.
2. Mercury copied the dry-sump concept from Weismann in 1997.
3. Mercury copied the swept-back skeg from Herring in 2000.
4. Mercury's now looking for something else to copy.

Nice.....I was thinking 2,3,and 4 myself.

Ok,

The first time I saw a Kiekaffer drive was in 1989.90 on Rainbow(SDA) we were running 4 engines 4 2-speed gearboxes 2 dropboxes and 2 drives. The vertical shafts were twisting off like a tootsee rolls.

We did the first dry-sump 6 in 1994 for Mr. Serralles. We ran it on a boat for the first time at lake X and no-one knew who we were or had a clue what we were testing. (Don Q) we only had one (drysump) drive on and the boat and one stock so the boat was running really sideways at speed. To get the boat to run straight Felix had to hold the sticks 2 inches different.

In the first race in Puerto Rico (San Juan) we had a 2.5 minute advantage on the first lap. By lap three Felix and Juan lost steering and by lap 6 they lost trim too, both drives.(long story) They won the race with throttle control to get through the corners. Everytime he lifted the drives would trim out.

We have an internal pump in the upper with 2-stages (scavenge and pressure) driven by the counter shaft (6) or the upper tube (6a) with a 2.5 gal Patterson/Peterson tank in the boat. The upper and lower have a spraybar system.

We had several skeg mods (Rolla) parallel front and rear angles/ #5 type Full wedge shape/ Welded tips 5 inch extention shark fin / Eikert no Skeg spacer fin behind prop(scary) to the Herring type. As the rear of the skeg got further from pivot the steering got tighter. The welding of the housings severly distorted the bearing bores and seal bores and annealing the housing.

There was one other dry-sump drive that I know of done by Sonny Hawkins and George Linder after they came though my shop as official tech people from the APBA. They drove their pump off the driveshaft inside the boat (I think) I never saw it in person just rumor. I never saw the Flying Tiger boat break 100 so I do not know if it worked. Maybe someone that knows them or that project can chime in and fill in this part.

pat W

Pat,

Thanks for the nice post.
Was anybody at Lake X taking notice of your testing there?

Had to be an interesting ride pushing the boat sideways.

Jon

Shifter, I had heard a story at a race site where a test was done comparing measuring the drag of a wet sump 6. I remember being told it took about a 140 ft/lb of torgue to spin it at 7000 rpm. The dry sump reduced that by @ 100 ft/lb. I don't recall who I originally hear it from but it may have been some one from Alcone's team. Who else did you dry sump for in the beginning?
Jim

Hate to sound like a dummy -but here it goes.

I've yet to find a tank for the drive sump 6's in the NorTech. I noticed what I assume is a hose coming from the transom plate inside the hull - that basically runs inside the inner plate - but I can't find where it goes. Am I missing something?

The hose goes to the reservior tank which is there for wet sumps. The drive is self contained and has a filter hidden in it too. Pretty cool design. It is dry because all the gears are not submersed it still collects at the bottom but uses a lot less fluid.
Jim

So no external tank like the 850's - right?

I didn't mean to hi-jack this thread - but it's been buggin the hell out of me how we check/maintain the fluid in the drive.

And that's where the arguement is:

If you want a true Drysump then that is what Pat / Weismann developed. As he mentioned his has the pump above and he uses a scavenge line to keep the bottom sucked dry.

Mercury left there own pump in the bottom and it's submerged in oil. So only the top case is truely dry.

The lower has all the oil and keeps the pump submerged and flooded. It's a lot better than a full wet sump.

But it's not a 100% Drysump like Weismann developed.

This is how I have been educated so take it for what it's worth. :D

Jon

So what does it take and cost to convert the older wet sumps to dry sumps?

True Drysumps ? 10 G each :D

Cougarman

The level check is just below the split between the upper on the right side of the drive. Look for parts on the magnet (drain plug) most of the junk will collect there and water. The tube inside is a vent line. When the drive was filled to the top the aerated/super heated oil would expand into the reservoir. With the level dropped there was no need for the expensive transom plate and the oil is allowed to expand inside the drive submerging the spur gears and the upper gearset. Let the drive settle for a couple of hours or longer before checking so the water is on the bottom and the air is out of the oil giving you a proper level.

If you notice that is halfway up the side of the drive. 3 shafts and 4 gears are submerged in approx 4 quarts of oil. The upper gearset /spur gearset and inputshaft are out of the oil.

What this has to do with dry-sump I do not know.

The idea behind dry-sump is to get the oil out of the way of the moving parts, remove the air (centrifuge) and inject oil on critical points.

Testing loss is difficult. We did a freewheel test (no load) just to check parasitic loss. The numbers will vary depending on ratio and input speed. We also checked the running temp on the boat.

That is only part of the problem. Bevel sets , Timken bearings ect...

When we were testing the first drives one of the Victory other teams decided to test back to back to check our gain. They did a full speed run from start with the wet-sumps, craned out, drained both drives and tried to run. It got on plane and melted the upper sets. :D

The easiest way to see how much we gained back is the performance of the teams we worked with after they ran our stuff. The World Championship list is on our web site.

Look at it this way also how much power will you gain if you put 10 g in your motor?

pat W

I brought this back up to help people understand what is a true dry-sump and what is a marketing ploy.

pat W

30 hp gain at the crank.:cool: Try again BIG Daddy

Hey Shifter;

Can you tell us about your expierance with skeg shape?
More important to me is 'crabing' issue on a single engine set-up with big HP. Do you know if you can counter prop walk with a narrow but long sleg or is the wider standard length skeg the way to go. On O/Bs running 130mph it is just a matter of fashioning a torque tab and some strategic shaping.

We have tried just about everything it depends on bullet height. Where are you going to put it.

Here is one where I cut the cav plate off to clear the prop diameter and stretched the fin a little.:crazy: it worked with a very high x dim. or Z axis in the macining world.

On the single boats we run below transom for the ski boat guys and reduced skeg for less drag. Mainly they run them aground alot and they do not seem to notice the difference.

I have not put any shape (like outboard) to make the boat go straight. We have run parallel to the leading edge full wedge, #4/5 style, hering, none with rudder ect....

The singles are difficult because whatever you do to react against the power will react when you lift.

Leading edge angle changes quite a bit also and # of blades, prop rake, rpm, cup, dia, ect....

I would not start modifying until you test. Old style used to blow out at around 120. The swept skegs use less input to react because trailing edge is farther from pivot center. Stock swept is not as good as aftermarket. Aftermarket weaker from welding and housing deformation and deheatreating.

I hope this helps.

pat W

Thanks Pat;

A couple more if you don't mind.
With light weight boats, the issues of blow-out (on both axis) show up sooner. I am afraid of both. I don't know how much bow lift I need to get the the numbers I want, but right now at lower speeds I need positive trim control and therefore I need the drive a little lower. That exposes the first blow-out issue of the case popping up and trying to ride on the top. I'm told that does not happen with the weight of an I/O.

The one the scares me more is the crab angle blow-out from prop walk. With the heavy hydraulic steering on these drives I can't 'feel' the blow out coming.
At lower speeds I have tested and found that an 'airfoil' shaped skeg works the best, the wedge shape does not make sence on a single. It was suggested that, at 150, the water does not converge once being spead apart in the thickest portion of the skeg, and will not close up behind the skeg if you have the fish shaped skeg. If that is true, what aspect ratio do you need to control the laminar flow over the skeg. Or, is it all crap, am I going to have to test out my own situation myself.

Last one, what about the verticle angle of the leading edge. I don't need any tail lift so I think I would want as straight up and down and rudder like leading edge as possible. Or does that make the steering twichy.

Mark??

Mark,

baseline the boat and increase the speed gradually each test. Data aquisition will help you can put in parameters and turn on lights to tell you when your slip is climbing.

We looked at putting in a spacer with a additional l shape to hold a rudder inboard with no skeg. The pivot point on a rudder is normally close to the leading edge. We are now talking 30 to 40 from center and offset from centerline. It might be a little strange but arneson runs them offset and so does flexitab.

It is a lot of work.

Shape........ props are a wedge with a kicker.

Good luck,
pat W

Thanks again;

Yes the RC stuff are for the most part offset rudders. Makes sense, you don't use accelerated water (and its drag) to turn.

Can we talk shop here?... I like your WMD drive very much. I just did'nt know about the skeg. Questions...
Do you have a spacer system to change drive height?
What is the foot print of the Transom plate (hight from crank to top?)
Maybe you can e-mail me pricing.

The data aquisition thing is a great idea.

so seeing that some of us like to pose what "they/we" think is a stupid question... here's mine... has anyone ever drysumpped a #5 Speedmaster? and if so what were the gains? I'm curious and I have a pair sitting here waiting if this could be worthy of doing?

I would be interested in dry dumping my SSMV's also

dry dumpping!! bahaha that's funny :santa:

I wanna say Tom Gentry was dry sumping the #4 drives many years ago.

That just made me LOL and I didn't even know I wrote it! But it makes sense.....in many ways....dumping more money, with my luck just to break the drives anyways.

Would be cool to learn more about dry sumping the #5s though....semi dry or full dry.

Available after the 2015 Miami Boat show; after successful 2014 Race Testing:
SSM VI "QD" model
Quick Detach for easy service.**

**comes with reinforced tie bar mounts, standard

https://fbcdn-sphotos-f-a.akamaihd.n...54d7654ce91093

(Pic credit goes to CashBar)

The new forward facing Volvo drives have that feature too , only without the tie bar option

..but the Volvo IPS legs won't sink your boat when they detach... :poopoo:

tell me about it... that would make them faster than a six :wizard:

Dry pumping? What?