possibly repowering

[jimbo36]

prowlerfish, Sorry to disagree but every twin installation boat I have owned, 5 of them, has had a port counter rotater.

bostenjake has port counter rotation too, according to his post.

I looked at the diagram in your link. It shows the port engine turning left (arrow) but calls it standard rotation. Go figure?

Jimbo.

[Eddie-O]

Prowlersfish is right motor rotation is checked looking from the front of the motor or pully end of motor prop rotation is checked looking from the back of the motor or flywheel end of motor port engine turns right and starboard engine turns left port prop turns left and starboard prop turns right

[prowlersfish]

I stand by what I said and every source I have checked suports this ( I checked before posting ) every inboard I have worked on has been that way ( when the gear box is not used to change direction ). or both my engines turn the same way but right side engine (starboard ) gear box is in "B" postion (reverse if you will ) when going forward . Don't try this with your velvet drive as it has to match engine rotation . Many gas engine builders have gone this route in recent years . ( I don't think you will find a counter roation new style smal block )

[Stripermann2]

Let me add this to the mix.

Mercruisers are generally reverse rotation on PORT side.

Crusaders are generally reverse rotation on STARBOARD side.


I'm going for popcorn now...

[bostonjake01]

ok here is something I just noticed whe i went back to the link i posted, it said prop rotation not engine rotation?????? not sure if its the same or what but is there another way to make sure without the engine running? this motor has been partially taken apart.

[prowlersfish]

Do you have the engine numbers ?

[jimbo36]

I hope a big light comes on here real soon. At your end, or mine.

Answer this; if you are looking at the front of the port engine, running, and the pully's are turning right would the engine not have to be turning left? Counter-clockwise? The output shaft would be turning counter-clockwise off the crankshaft? The propshaft and prop turns counter-clockwise? Yes? Is this not COUNTER ROTATION?

Look at your starboard engine running from the front. Pully's turning left? Engine turning right? Just like the STANDARD ROTATION 327 in the old chevy.

Bostenjake The counter rotating engine, turns counter-clockwise, (left) this means the crankshaft, camshaft, distributor, timing gears, starter, etc. and the firing order are unlike your other engine. All boat engines I have worked with include the model number that includes an "L" for left (counter-rotating) engine. Did I understand you say your engine number is confirming your port engine is an "L"?

I could be wrong but IMHO (thanks Rick) this is the way I have always understood it to be.

Jimbo

[willietrojan]

Here are all your rotation answers

http://www.boatpartsinfo.com/engine-rotation.html

[prowlersfish]

I think you got it backwards Jimbo as far witch is the counter rotation engine .

[chucka]

I'm not surprised at the debate over this topic. It seems like everywhere I've seen this discussed, there are disagreements.

Here is a direct quote from the velvet drive transmision owner's manual. You can read it for yourself here:
http://mysite.verizon.net/vze6mxo8/down ... Manual.pdf

Modern marine engines are available with Left-handed (L.H.) or right-handed (R.H.) turning crankshafts. An engine which rotates clockwise when viewed from the front or timing end would be described as having counter clockwise rotation when viewed from the rear or flywheel end of the ngine. It is therefore important that a position be selected from which rotation is described so that confusion will not exist. A transmission may be moutned either to the flywheel or timing gear end of the engine. See figures 16 & 17. it is therefore necessary to descrobe the engine rotation with respect to the transmission when selecting an engine and transmission combination. Trnamission selection will be simplified when the following method is used to describe engine rotation. This method may not agree with the method used by the engine manufacturer.

Face the end of the engine on which the transmisison is mounted and describe the rotation as right hand if the engine rotates clockwise. Describe the rotation as left hand if the engine rotates counterclockwise.

The manual goes on to describe transmission shaft rotation and propeller rotation. You can see that based on the above description, the same engine, could be described as RH or LH depending on the appliation. No wonder everyone has a different opinion! Keep in mind that what they describe as modern marine engines was current back in the 1970s. It's not true for newer twin screw installations, where both engines usually rotate in the same direction and the transmission reverses the shaft rotation on one.

Possible ways to identify rotation:
o The engine tag - if it is there and legible.
o Crank it with the starter and watch which direction it turns. - may be difficult on a partially dissassembled engine.
o Someone smarter than me might be able to figure it out by looking at the gear that drives the distributor.
o Research owner's manuals - may not be reliable if original equipment has been replaced.

Here is some more detail culled from a post on the Marine Engine discussion board. you can take it at face value or go back there and try to contact the original author, David George Clay. http://www.marineengine.com/discus/mess ... 6155.shtml

I am not an expert, but I have tinkered w/ my twin Chrysler LM318 engines for about 16 years. I am going to post more than you wanted for two reasons: Others might find it useful now or later. Also, I am starting an engine rebuild project and I need a record in the ship’s log so I do not forget.
The Basics:
This applies to a classical Chrysler direct drive twin-engine installation. As viewed from the rear of the boat (the flywheel end of the engine) the port prop rotates to the left (CCW) and there is an “L” encoded into the engine nameplate model number. The starboard prop rotates to the right (CW) and has an “R” in the engine model number. The #1 cylinder is at the upper left of both engines. The left bank has the odd numbered cylinders and the right bank has the even numbered cylinders (like GM - not Ford). Both distributors rotate CW.
The port engine (which I call standard rotation because it is the same as a car engine) has a firing order of 1-8-4-3-6-5-7-2.
The starboard (reverse rotation) engine firing order is: 1-2-7-5-6-3-4-8.
Finding TDC:
One way to find #1 TDC is to remove #1 plug and poke a coat-hanger wire into the hole while rotating the engine by hand. I use a dull screwdriver (so it does not nick the teeth) and cog the engine one flywheel tooth at a time using the timing hole in the bell housing. The piston comes to TDC twice in the 4-stroke cycle. To distinguish between the beginning of the power stroke (which you want) and exhaust-intake stroke (which you do not want), take a hose and blow into the #1 spark plug hole. If it flows freely, you have the wrong TDC and need to rotate the crank another turn. With some cams, you may have to blow just before or after TDC to get free air flow.
Prestolite Electronic Distributors:
In a marine environment, these distributors frequently get very rusty on the inside. Then the flyweights stick and the engine will not develop full power. If you ever get inside to clean it, be very careful about how you re-assemble it. On the shaft, just below the rotor, is an 8-lobed iron piece called the reluctor. It is keyed to the distributor shaft w/ a small pin made by rolling up a thin piece of sheet-metal. Hence, it is called a roll pin. There are two grooves inside the reluctor. You must use the correct groove. Last spring, I missed the mating grove in the shaft with the roll pin and almost destroyed an engine. Hence, my comment about being careful.
Also, after assembly, you must adjust the gap between the reluctor and magnetic pick-up coil. Chrysler Service Bulletin # 249 dated 9 Jun 77 says that the gap should be 0.006 to 0.0075 inches as measured w/ a non-magnetic shim. That tolerance is impossible to hold because the bearing clearance of the shaft is much more than that. This tight tolerance is necessary because the OEM ignition module is so marginal (particularly at high RPM). I STRONGLY recommend that anybody w/ a 1970s vintage Chrysler electronic ignition upgrade to a modern aftermarket, USCG approved system. Also, there are much better coils on the market.
Buying Chrysler Marine Parts:
For some unknown reason, Chrysler parts catalogs refer to the damper pulley end of the engine to distinguish directions of rotation. Thus, my port engine (standard rotation – code L) is called CW. The starboard engine (reverse rotation – code R) is called CCW. That is exactly backwards from the conventions above.
I hope this is helpful,
Dave

Chuck

[jimbo36]

It is clear to me now. The big light has come on at my end.

Having reviewed this over and over I see that I have associated counter-clockwise rotation with counter-rotation when, in fact, the port engine, turning counter-clockwise, is actually standard rotation and the straboard engine turning clockwise is the reverse turning engine.

Thanks guys.

[prowlersfish]

I think you got it ! I was so sure of my self I had to keep checking over and over . it will drive you nuts . I even check my truck engine ( normal turn of course ) I checked it not once but twice

[Don Lumber]

It explains about the Chrysler confusion I had as well. Well, one good thing about trying to wrap my head around that is that now I need a drink!

[Ken]

Before you rebuild your engines a question I have is why ? Being from the Northshore area of Ma. their are several good machine shops as well as some exchange shops that may work better for you. Do the motors run ? Or are you wanting to replace them due to age and uncerteinty of their condition. I replaced one moter last year. I did not replace the other one. (budget item) I pulled it apart and put head gaskets and intake manifold gasket (my weak link) in. The chrysler 318 is a very reliable motor. I would not go with a slant six. The power loss would be great. But there are several budget friendly options.

[bostonjake01]

Ken the reason I am considering rebuilding both is that the boat took on water and i am uncertain if the water got into the motor. One is was already being disassembled before I got it so I figured there was a reason the other one is still together but the stringer under the motor is soft and the glass that is covering that stringer is broken so I figured I should just remove both and atleast do the heads, exhaust manifolds and carb plus I figured it would be a good to do the clutches on the trans and replace the stuffing boxes with the newer sealed units I was told I would need to do this to beable to insure it.

maybe I should do some thing different what do you think?????

I am planning on removing the motors in about 2 weeks so if there is any other options please let me know.

Thanks
Rich