Marine transmissions which ones?
 

I am currently building some new 1000hp motors and am needing to know which transmissions to run ,they will either be going to arnessons or weismanns, triple engine set as well. Also what are the dimensions length of the transmissions to know how far to move motors forward. Thanks John

John, These are going in a 32 Hustler with Arneson ASD 8.s with 16 inch drop boxes. They are Borg and warner
72c,s Flange style with 10 graphite cluches in each. The counter rotation is accomplished reversing the port engine. The engines are 36 inches on center.

Hope this helps
Gerry

the tape reads 14.5 inches

The flange on the transmission bolts to a Two U joint
drive shaft. It measures 6 inches in lenth. There is
also a flange which the other side of this drive shaft bolts too on the spline of the inboard side of the arneson. This flange allows movement of approx 2 inches forward and backward.

These measurements added
14.5 + 6 inches = 20.5 inches total from the front of the bellhousing to the spline of the Arneson.


I would also check with Rik at arneson-industries.
He is by far the one to contact.

Good Luck
Gerry

Thanks for the info, Just have to see if I need to move rear seat up like Grand Illusion did or not, looks like it.

The question is with the power are you building what type of boat are you puting it into?

Engine placement will only be an issue based upon your application.

RIK: the power is going into a 40 hustler that already had 650hp trips with bravo's. John

ttt

bump

Just curious, with the ASD 8s and drop boxes, why did you counter rotate the engine? How much of an issue is it with cam makers to grind one for that application?
Gary

That would be because the drives he has do not counter rotate.

It just a different cam, distributor gear, starter and rear main seal that make the engine spin backwards.

Makes a V bottom much more balanced as well with both the propellers and the engines counter rotating.

Only the new ASD8 drop boxes counter rotate.

That explains it.
How about custom ground cams? Do most manufacturers have the ability to produce any of thier camshaft profiles in reverse rotation?
Gary

And one other followup.
I've seen both gear driven cam (normal rotation cam) like merc uses on their reverse rotation motors, and chain driven (cam also rotates in reverse) for reverse rotation motors. Which do cam makers grind them for?
Gary

Getting a cam made has not been an issue over the years.

Remember, in the past the majority of marine engines were counter rotated to accomplish the RH & LH task.

Today for some reason, the some ski boats use a reverse rotation engine???

Your cam manufacturer can answer these questions far better than I as they will know what they make.

I'm sure that not every grind is made in RH and LH but the real answer lies with the cam manufacturer.

Whats up Rik?

The crane cam used in these engines is the 139741
versions.The counter engine cam has a LH
stamp after the part #
The distributor gear is cut opposite of the normal rotating engine. which allows it to spin the same way as the normal rotating engine. the firing order is opposite on the counter 12756348

If you think about it the distributor would have to spin the same because it drives the oil pump.

However the rear seal is identical on both engines
in this case. Why would it have to be different?

The starters are different.

On this application the props spin inward.

I actualy had to flip the blower drive snout on one of the ( roots)mooneyhams to allow it to spin the correct way sitting on the counter engine. lukily it was symetrical.;) (Now the mooneyham sighn reads upside down) Try doing that with a whipple. I tried to get procharger to listen forget it. I was going to persue
maybe making a different bracket to allow the centrifigal to mount backwards. it was just to easy to do the roots.

The New ASD # 8,s drop boxes Would be the way to go.
Then I could actually keep a spare engine around.
Rik post a picture of one.
:)

Man some good reading here. will have to post a pic with my measurements from my hull to center of drives to see what drop boxes needed along with what height to mount at.

Gerry, whats up w/ the blue starters. Paint that chit man!:D

Why you not like my Smurf starters?

I sent them to the armature guy who does all are work at the dealership. I told them there going in my boat.
Thats what I got back:crazy:

The real catch is one of them wasnt disengageing properly after the rebuilds so he came buy the shop and saw them on the engines He said "guess I should have painted them a different color"
He probrobly thought they were going in a bayliner.

Another thing I should have left alone.

I'm certainly no engine builder but I've been told that the rear main seal is different on the counter rotating engines??

With the standard "Roots" style blowers you will need to rotate the front housing cover to make the blower spin the correct way while the engine runs backwards.

The other style of blowers cannot be counter rotated as one cannot move the drive pulley to change the rotation of the blower.

The new ASD8 drives cannot be mounted at an angle, rather they mount vertically. A stagger setup will require the engines to be staggered. (Of course there are ways around this)

Some seals have little "threads" molded into the rubber... these feed the oil back into the engine and facilitate lubricating the rubber seal lip... I know of several european car engines that don't have a "rear seal" as most people know it.. there is no rubber lip at all... there is a "slinger" which directs the oil away from the area that the crankshaft exits the block. Close to the surface of the crankshaft is a housing that is within .001" of the crankshaft... the crankshaft at this area has an "archemedian screw"... which are square cut threads that "thread" the oil back into the sump... Works great... just don't park on a steep hill.... If you were to convert one of those engines into a reverse rotation... then the threads on the crankshaft would draw the oil outward.... :crazy:

Answers my question, chain drive cam.
FYI on most counter rotated marine engines, the cam is gear driven so it spins opposite the crank. These use standard distributors.

As for the rear seals, some old marine engines even had grooves cut in the rear main journal of crank to push oil back in. You spin these the wrong way or use the wrong seal and you'll have a mess in your bilge.
But I did think all Mark IV BBC motors used a "yellow" rear main seal that was designed for counter rotation. Might want to check on this.
Gary

It has been a long winter in building these engines.
I have had different opions and ideas on just about everything I have asked about. From Valve train geomitry to piston wall clearance. They fire right up on the stands and set off every alarm in the cars here at the dealership. Will they stay together? Time will tell. I am currently awaiting dyno time.

In reading this post I remember I was in error in my thinking of counter. this post clarified it for me.


http://www.offshoreonly.com/forums/s...unter+rotation

The seal pictured below is the felpro 2904
this seal was on the counter and the normal rotating.
These engines had 150 hours on them before I pulled them apart with no leaks. The cranks are sonny bryant
with no machining on the rear main journal. Perhaps thats why it dosnt leak.

Now is certainly the time to find any problems.

The 72C transmissions with 6 cluches worked well for me with the 600 hp motors.However the 900 hp,s
required me to upgrade to 10 fiber cluches.

Gerry

Might be worth checking on that seal. See this post as a possible result of using the wrong seal.
http://www.offshoreonly.com/forums/s...tion+rear+seal

Do we have any pics of the asd's with the mounts inside the engine compartment transom to go with the one that is shown externally please.

I see what you mean Gary.


:confused: confuses me that it worked for over 150 hrs
(4 years hard offshore running )

The mains look as new.

Reverse Rotation
 

I am glad to see someone else is building a wrong hand turn engine.

Three things I would like to add from my experience.

1. If you use a reverse rotation camshaft with a new distributor gear, check the distributor! Most distributors are only made to handle the upward thrust of the helical gear set. This pushes the distributor shaft up into the housing and is addressed with the thrust washer behind the gear. When you change the direction of the thrust with the RR cam/and the reversed helical distributor drive gear the distributor shaft is now being pulled down into the engine. Some marine distributors have bearings to support both loads. If you don't check, it will fail the distributor and increase the wear on your oil pump.

2. Check the pistons for offset. Position two identical pistons with the "front of engine" mark in opposite directions. Slide one wrist pin into half of each piston and check for offset. If you have offset turn the pistons around on the rods, if not leave her be....

3. Use a bi-directional waterpump.


I am working to reverse rotate a 181 cubic engine four cylinder. They were never offered as a reverse rotation marine engine. However after a detailed review of the parts book the 91 and 92 pass car engines had timing chains instead of timing gears. So with any luck I can take the gears off, "slap" on the chain/ sprocket assembly, change two wires at the cap and be on my way. Well it is not quite that simple, but much cheaper than a reversing gear.....