Forums
NautiqueParts.comNautiqueSkins.com - Correct Craft Upholstery and Part
  New Posts New Posts RSS Feed - Standard rotation dist in Rev rotation 454
  FAQ FAQ  Forum Search   Register Register  Login Login

Standard rotation dist in Rev rotation 454

 Post Reply Post Reply   
Author
ShyDookie View Drop Down
Newbie
Newbie
Avatar

Joined: March-30-2016
Location: Hoover, AL
Status: Offline
Points: 5
Post Options Post Options   Thanks (0) Thanks(0)   Quote ShyDookie Quote  Post ReplyReply Direct Link To This Post Topic: Standard rotation dist in Rev rotation 454
    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.
Back to Top
KENO View Drop Down
Grand Poobah
Grand Poobah


Joined: June-06-2004
Location: United States
Status: Offline
Points: 11119
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

Back to Top
KENO View Drop Down
Grand Poobah
Grand Poobah


Joined: June-06-2004
Location: United States
Status: Offline
Points: 11119
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   
Back to Top
KENO View Drop Down
Grand Poobah
Grand Poobah


Joined: June-06-2004
Location: United States
Status: Offline
Points: 11119
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

Back to Top
ShyDookie View Drop Down
Newbie
Newbie
Avatar

Joined: March-30-2016
Location: Hoover, AL
Status: Offline
Points: 5
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!
Back to Top
KENO View Drop Down
Grand Poobah
Grand Poobah


Joined: June-06-2004
Location: United States
Status: Offline
Points: 11119
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
Back to Top
ShyDookie View Drop Down
Newbie
Newbie
Avatar

Joined: March-30-2016
Location: Hoover, AL
Status: Offline
Points: 5
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!
Back to Top
KENO View Drop Down
Grand Poobah
Grand Poobah


Joined: June-06-2004
Location: United States
Status: Offline
Points: 11119
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
Back to Top
 Post Reply Post Reply
  Share Topic   

Forum Jump Forum Permissions View Drop Down

Copyright 2024 | Bagley Productions, LLC