Another SBC OMC Question (Circa 1980)

[Galaxie_406]

Being that I have no actual wiring schematic for the engine and the local boat shop went out of business (What do expect? I live in the middle of the desert). I have tried to figure out what a specific electronic part on my engine did or does. Basically it's a OMC 260 V-8 (SBC) built in 1979 attached to a 800 sterndrive sporting a quadrajet and the old Mallory YF marine point distributer. This part is located on the intake manifold just behind the back of the carb bolted along with my throttle cable bracket, looks like some kind of CDI? anyone have an idea? it's not the coil.. it's black attached to a bracket and has transistors and a circuit board. I plan to modernize the ignition with the HEI Voyager system and wondering if I can do away with the unit or could it be wired in as a safety of sorts like a RPM Governor.

[RMSOSF]

follow the wires and tell us what they are hooked to. Sounds like it might be a noise filter of some sort.

[Galaxie_406]

Will try to trace them when I get back into town, currently driving my land yacht.

Definitely not a noise filter, a little bit bigger than you computer mouse, full of diodes and such with a water proof epoxy resin over the circuit side. Pretty sure that the unit has something to do with the ignition system.

Is there a place to post photos on this site?

[RMSOSF]

That is a shift assist module, you will want to leave it atached.

[Galaxie_406]

Ah Ha!
OK, how does it work? Looks like I found some reference on this part and may explain why I have a difficult time putting the boat in drive while running a Mallory Unilite Distributor.

Copied Link:
file:///C:/Documents%20and%20Settings/Administrator/Desktop/AUTOMOTIVE%20DEPT/Hammond%20Boats/Mallory%20Wiring%20Diagram.pdf

Has anyone tried this or should I just put my old points set back in?

[RMSOSF]

Ok, I forgot you had a Stringer 800 series. I appears someone has put a newer motor in that boat. That shift interupter is only needed with the Cobra sterndrives. You should be able to do away with that black box.

[Galaxie_406]

Maybe and maybe not on the newer engine as it appears the boat retains the original wiring harness and everything is plug in and appears unaltered.

If this did in fact come with this shift assist module then I should keep it hooked up I would think if in fact it even works

Would you happen to have a guess as to when these critters first came out?

[RMSOSF]

they came out in 1986

[Galaxie_406]

The Cobras came out in 86, but what about the module use on earlier 800's

[RMSOSF]

the parts books do not show any modules earlier than 1986

[Galaxie_406]

This get's more and more interesting. Another source stated that they put them on Stringers too. My bracket part number is 910631. Here's a link: http://www.crowleymarine.com/product...oke_switch.cfm

Here's another situation I ran into yesterday on a rebuilt "Marine" 350 I picked up too replace my cracked block engine. The engine is/was a reverse rotation engine, I removed the gear drive, checked the cam (which turned out to be a Isky 201264) installed my new cam & crank gear with roller chain, checked the crank to make sure it was not different (Forged Steel ) assembled everything back, painted the engine then it dawned on me that if the cam had been turning in reverse, the engine oil pump would would have been a reverse rotation pump and would be pumping backwards!. Ok disassembled the pan, checked the pump "melling 55" ran the numbers and could not find a reverse pump option so I pulled the pump filled it with oil and spun it to the right and had the correct direction of oil flow spun it to left and it emptied through the screen - weird. If the engine had been fired up under a reverse rotation I don't think it would have ever had oil pressure or am I looking at this wrong, somethings bugging me here, spin crank to left causes cam to spin to right that would spin dist and pump to right and pump would be correct! how does the cam achieve running the engine? could this cam be a reverse cam or would the valve timing have been corrected via gear drive? just would like to know. Seems to have compression as you turn the engine clock wise.