Crrank shaft Question
Thread Starter
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Senior User
Joined: Jan 2005
Posts: 123
Likes: 1
From: Mine Hill NJ
Crrank shaft Question
I've got a 360 FE that I’m stroking out with a 390 crank, pistons, and 428 rods.<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com
fficeffice" /><o
></o>
I got the crank by swapping my old 360 crank with my machinist's shelf stock. <o></o>
All the resizing and machining is done so here’s my problem.<o></o>
While assembling the crank, rods, and pistons I found the front bolt on the crank was the incorrect length because when I tried to back it out it damaged the internal threads. There was galling on the bolt and when I chased the internals there was some damage there too.<o></o>
I Dare not run the new correct bolt into the hole as I'm sure it would be screwed up too. Basically I don't trust torking on them to turn the engine by hand. <o></o>
The thread size is 5/8 x 18.<o></o>
The wrong bolt was 2 inches the correct bolt is 1 3/4 long. The factory pilot hole in the crank is 2 1/2 inches deep. Where as the threads only go the 1 3/4 inches. <o></o>
So is my crank shot? <o></o>
If not what size threads can I re-cut to safely and have strong new threads?<o></o>
OR <o></o>
Do I need to just take it back to the machinist?<o></o>
<o></o>
Thanks <o></o>
John
fficeffice" /><o></o>I got the crank by swapping my old 360 crank with my machinist's shelf stock. <o
></o>All the resizing and machining is done so here’s my problem.<o
></o>While assembling the crank, rods, and pistons I found the front bolt on the crank was the incorrect length because when I tried to back it out it damaged the internal threads. There was galling on the bolt and when I chased the internals there was some damage there too.<o
></o>I Dare not run the new correct bolt into the hole as I'm sure it would be screwed up too. Basically I don't trust torking on them to turn the engine by hand. <o
></o>The thread size is 5/8 x 18.<o
></o>The wrong bolt was 2 inches the correct bolt is 1 3/4 long. The factory pilot hole in the crank is 2 1/2 inches deep. Where as the threads only go the 1 3/4 inches. <o
></o>So is my crank shot? <o
></o>If not what size threads can I re-cut to safely and have strong new threads?<o
></o>OR <o
></o>Do I need to just take it back to the machinist?<o
></o><o
></o>Thanks <o
></o>John
Posting Guru
Joined: Oct 2003
Posts: 1,955
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From: Quesnel, BC, Canada
i would recommend posting this in the FE forum, as its very FE specific. The people in that forum will be able to help you out the best.
N try n loose the excess pink smileys..lol its distracting
N try n loose the excess pink smileys..lol its distracting
Thread Starter
|
Senior User
Joined: Jan 2005
Posts: 123
Likes: 1
From: Mine Hill NJ
I figured it it belonged under General Engine Building as it is a question about a crank.
Thanks though I will repost under the FE forum.
John
PS. I didn't insert any smiles when I wrote it. The arrows popped up after I submited the post.
Thanks though I will repost under the FE forum.
John
PS. I didn't insert any smiles when I wrote it. The arrows popped up after I submited the post.
