Reverse Rotation

SBC 350, Single engine. Marine-Power S5.7VR. Older Chris-Craft, water in two cylinders, pulled risers, sandwiched St. Stl. between common gaskets, hopefully take care of the water problem. New to Reverse Rotation, owner purchased wrong starter, noticed distributor rotor turning CCW. Further review i guess these cams are cut to run valves in 12756438 spark timing, interesting, but cam gears are cut to turn dist in normal rotation. Still working at it, been a gear head, marine is definitely different, hope to get it smoking soon.

Reverse rotation GM motors were usualy gear driven not chain driven but the dist both turn in a clockwise direction.
Firing order from #1 going clockwise is 1,2,7,5,6,3,4,8
Another way that easier to understand is place the wires going CCW using 1,8,4,3,6,5,7,2 from #1 position

Marine is a new experience but a challenge. This particular setup is a closed system? Ok understood as standard coolant, antifreeze, for the engine with fresh water circulating through the expansion tank and risers on exhaust manifolds. On the timing mark it appears to be a notch on the cover? So as far as the use of a timing light i guess it is sighted on the notch only without advance or retarded timing?

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mackrs767 said:

SBC 350, Single engine. Marine-Power S5.7VR. Older Chris-Craft, water in two cylinders, pulled risers, sandwiched St. Stl. between common gaskets, hopefully take care of the water problem.
Typically the seawater transfer ports between the Manifolds and Elbows are completely blocked off IF the Manifolds are included within a Full Closed Cooling System.
This would prevent E/G coolant from exiting via the Elbows.



New to Reverse Rotation, owner purchased wrong starter, noticed distributor rotor turning CCW.
Yep.... turning a REV RH Rotation SBC over in the Std LH Rotation direction would certainly cause the distributor to rotate CCW.

Further review i guess these cams are ground to operate the valves in 12756438 valve timing
Yes!

interesting, but cam gears are cut to turn dist in normal rotation.
Basically, Yes! There are several methods used to rotate the REV RH Rotation engine camshaft.

Chain/Sprocket drive:
These turn the camshaft in the same direction as the crankshaft...... therefor with a REV RH Rotation engine, the "drive" and "driven" gear helical cuts must be opposite.

Four gear set up:
I. E., crank gear, cam gear and twin idler gears..... these do same as the Chain/Sprocket drive.

Twin gear drive:
Twin gears turn the REV RH Rotation engine's camshaft in the STD LH direction....... therefor the "drive" and "driven" gear helical cut remains the same.


Regardless of engine rotation, the distributor and oil pump will always rotate CW.

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mackrs767 said:

Marine is a new experience but a challenge. This particular setup is a closed system?
Do you have what is called a Half or Full Closed Cooling system?
Half = Engine/cylinder heads only
Full = Exhaust manifolds within the CCS loop.

Ok understood as standard coolant, antifreeze, for the engine with fresh water circulating through the expansion tank and risers on exhaust manifolds.
The term Fresh Water is a misnomer. There is nothing fresh about Ethylene Glycol.
Think in terms of either Closed Cooling System, or Open Cooling system or Raw Water Cooling system.

On the timing mark it appears to be a notch on the cover? So as far as the use of a timing light i guess it is sighted on the notch only without advance or retarded timing?
Spark Timing is extremely critical.
See your OEM Ignition Advance Curve for the correct specifications.
Set BASE and then double check your Progressive and TA using harmonica balancer degree markings and a good ole standard strobe light.....
This will allow you to see REAL degrees in REAL Time.

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