Author Topic: FLYWHEEL BOLT PATTERN  (Read 1005 times)

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allrightmike

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FLYWHEEL BOLT PATTERN
« on: January 18, 2025, 03:15:21 PM »
Do any of you have FE flywheel bolt pattern dimensions either in XY straight line charting or in degrees ( I believe all holes are on a common BC dimension). I am making a flywheel balancing mandrel and do not wish to transfer locations from a flywheel, might end up with a bad copy of a poor original!

allrightmike

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Re: FLYWHEEL BOLT PATTERN
« Reply #1 on: January 19, 2025, 01:58:13 PM »
Answering my own question. Charted with the rotary table on the mill.. If the photo will come through here it is.

frnkeore

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Re: FLYWHEEL BOLT PATTERN
« Reply #2 on: January 19, 2025, 05:21:35 PM »
A BIG THANK YOU!!! :)
Frank

Dr Mabuse

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Re: FLYWHEEL BOLT PATTERN
« Reply #3 on: January 19, 2025, 08:27:39 PM »
One hole offset, so it can only go on one way?

allrightmike

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Re: FLYWHEEL BOLT PATTERN
« Reply #4 on: January 19, 2025, 08:31:52 PM »
You are correct sir.

Urgefor

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Re: FLYWHEEL BOLT PATTERN
« Reply #5 on: January 19, 2025, 11:42:02 PM »
One hole offset, so it can only go on one way?

I would assume that was in relation to the externally balanced 428s of the day.  That makes me wonder if all FEs were like that from day one?

mike7570

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Re: FLYWHEEL BOLT PATTERN
« Reply #6 on: January 19, 2025, 11:44:13 PM »
When I find it, I use permanent marker on the crank and flexplate to make it simple to R&R.

allrightmike

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Re: FLYWHEEL BOLT PATTERN
« Reply #7 on: January 20, 2025, 09:21:18 AM »
All FEs have the same flywheel bolt pattern whether internal or external balanced.

galaxiex

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Re: FLYWHEEL BOLT PATTERN
« Reply #8 on: January 20, 2025, 02:14:26 PM »
One hole offset, so it can only go on one way?

I would assume that was in relation to the externally balanced 428s of the day.  That makes me wonder if all FEs were like that from day one?

Every Ford engine that I have seen, small medium or big block,
Has one offset hole on the crank flange.
Regardless of internal or external balance.
Every 20 minute job is 1 broken bolt away from becoming a 3 day ordeal.

My427stang

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Re: FLYWHEEL BOLT PATTERN
« Reply #9 on: January 20, 2025, 03:30:32 PM »
It is funny, there really is no reason to have them like that from the early internally balanced FEs...but you are correct, it makes the externally balanced ones much easier to put where they are supposed to be!
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galaxiex

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Re: FLYWHEEL BOLT PATTERN
« Reply #10 on: January 20, 2025, 04:05:54 PM »
Actually it’s not just Ford.
GM and Mopar also offset one hole as well.
I imagine the same applies to the imports too.
Every 20 minute job is 1 broken bolt away from becoming a 3 day ordeal.

WConley

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Re: FLYWHEEL BOLT PATTERN
« Reply #11 on: January 20, 2025, 08:51:47 PM »
There's a reason most everybody does the offset hole.  You want your super expensive engine machining line to handle an external balance version.  Engines tend to grow over time, and external balance is sometimes the only way to economically get that longer stroke.
A careful study of failure will yield the ingredients for success.