OMC Converging Ring Question

[DOUGLAS G. ROBERTSON]

I have a 1979 Johnson 70, 3 cylinder, 70EL79R.  I have been running the stock propeller 13-1/4 x 17.   I recently ordered a new old stock OMC stainless prop, 13-3/4 x 15, PN 389949.  This is the part number shown on the factory parts diagram.  The old prop has the converging ring.   The new prop does not have a converging ring and the exhaust outlet is bell shaped, like a Mercury prop.  It doesn’t look like the ring will fit.  The part number on the hub of the prop is the correct part number, so I think I have the propeller I ordered.

My questions:

1. Does this new prop use a converging ring?
2. If it needs the ring, can I run it without the converging ring until I can install the ring?
3. What are the pros and cons of the lexan ring vs. the aluminum ring?

I don’t have the ring yet to see if it fits, but it looks like it won’t.

Regards,

Dr.Volts

[Bob Wight]

Stainless steel props typically do not use a converging ring.   With the bell shape on the exhaust, you do not need a converging ring.

Bob

1937 Champion D2C Deluxe Lite Twin
1954 Johnson CD-11
1955 Johnson QD-16
1957 Evinrude Fastwin 18
1958 Johnson QD-19
1958 Johnson FD-12
1959 Johnson QD-20

“Every 20 minute job is only a broken bolt away from a 3-day project.”
"Every time you remove a broken or seized bolt an angel gets his wings."

• This reply was modified 2 years, 9 months ago by Bob Wight.

[frankr]

People used to remove the converging ring and turn it around backwards to make it bell shaped.

[Author]

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