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Standard rotation dist in Rev rotation 454

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    Posted: April-09-2020 at 3:28pm
I’m replacing the distributor on my ‘85 Southwind due to the weights on the original Mallory (with electronic conversion) being seized. I’ve been having some popping, surging, and cutting out entirely above 3,000 RPMs, so with the seized up weights, i figured a new electronic distributor wouldn’t hurt. When I pulled out the original to install the new one, I found that the original has standard rotation gears (/////) instead of (\\\\\). How is this possible? The pulleys turn CCW and prop CW and the engine tag shows 1-2-7-5-6-3-4-8, which is how the wires are attached.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote KENO Quote  Post ReplyReply Direct Link To This Post Posted: April-09-2020 at 3:39pm
You're doing too much thinking/reading about reverse rotation Fords

Chevy handles reverse rotation differently and for a Reverse Rotation PCM Chevy and most other RR Chevy's the same distributor is used in both with the same gear because the cam still rotates in the same direction in both engines.

There's more to the story, but the short answer is that the same gear is used on both

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Post Options Post Options   Thanks (0) Thanks(0)   Quote KENO Quote  Post ReplyReply Direct Link To This Post Posted: April-09-2020 at 3:45pm
The slightly longer version is that Chevy uses a 2 gear setup instead of a timing chain to drive the cam on a Reverse Rotation engine, so the cam is turning the same way in both engines.

The gear setup makes the cam turn backwards as compared to the crankshaft rotation so it's turning the same way as the standard rotation cam.

The cams aren't interchangeable from Normal to Reverse Rotation because they're ground with different firing orders

It's confused many people so don't feel like the Lone Ranger   
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Grand Poobah
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Post Options Post Options   Thanks (0) Thanks(0)   Quote KENO Quote  Post ReplyReply Direct Link To This Post Posted: April-09-2020 at 4:05pm
Here are a couple of pictures

First one is a normal rotation Chevy cam drive setup, the crank and cam turn the same direction





Second one is Reverse rotation cam drive setup, the cam turns the opposite direction from the crank

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Post Options Post Options   Thanks (0) Thanks(0)   Quote ShyDookie Quote  Post ReplyReply Direct Link To This Post Posted: April-09-2020 at 4:17pm
Extremely helpful. I just ordered a standard rotation gear to swap out. Thanks!
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Post Options Post Options   Thanks (0) Thanks(0)   Quote KENO Quote  Post ReplyReply Direct Link To This Post Posted: April-09-2020 at 4:28pm
It's not really that easy, the direction of the thrust on the distributor shaft would have been in the opposite direction on the RR distributor you just bought

You should return the whole distributor and get the correct version

This is also hard to explain

Was this a DUI HEI by any chance?

Here's somebody else's experience with this issue in the link

link

I'd call DUI or whatever brand you bought and explain your situation
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Post Options Post Options   Thanks (0) Thanks(0)   Quote ShyDookie Quote  Post ReplyReply Direct Link To This Post Posted: April-09-2020 at 5:54pm
It is a DUI. I spoke to them earlier today. They suggested the gear swap. I had one in my 78 Nautique that was reverse Rotation but that was a commander 351, and the swap is quite easy. Thanks for all the help. Too bad I didn't see that thread before ordering this one!
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Post Options Post Options   Thanks (0) Thanks(0)   Quote KENO Quote  Post ReplyReply Direct Link To This Post Posted: April-09-2020 at 7:26pm
Hope it all works out

Just remember...............it's a lot easier to ask first, buy after that
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