[Fot] How many times can you line bore a block?

[vfracing at aol.com]

 Thanks, Lunker, and everyone else who responded.  Good ideas on shortening the chain and using a vernier cam sprocket.  I'd be a little nervous about my ability to get the chain permanently back together.
This particular block has been decked as well (requiring special cylinder "O-ring' gaskets from Mordy again), and my machine shop says to watch out for "hidden" damage to the block, as it takes quite a bit of force to break a crankshaft, which is what happened. And then there is the problem of alignment with the transmission input shaft.   I'm going to start afresh with another block and more robust cylinders.

Again, this is a great group.  Your collective wisdom is much appreciated!
Regards,
Phil
    On Monday, August 3, 2026 at 11:06:13 PM EDT, Lunker Hilyer <lunkercars at icloud.com> wrote:   

 
This cam sprocket from my wall of shame exemplifies how Ford bean-counters turned engineering’s well planed creation of the smallblock 400 from the 351W into the corporate debacle it became. 
When made “right” they are great engines.




> On Aug 3, 2026, at 7:53 PM, Lunker Hilyer <lunkercars at icloud.com> wrote:
> 
> Regardless of who started the thread, TeriAnne Wakeman would probably like it for her ever evolving tech-tips and Chuck just on GP.
> Lunker
> 
>> On Aug 3, 2026, at 7:46 PM, Lunker Hilyer <lunkercars at icloud.com> wrote:
>> 
>> Hi Phil,
>> Was it you or Chuck who originated this thread?
>> My simple toung-in-cheek reply was that my fix is something Kas never had to deal with.
>> My fix has been mostly with OHC engines where excessive head grinds (thinning) has resulted in similar but opposite problems but the technologic difference is identical.
>> Easiest fix is to replace hogged out sprockets with fresh/tighter ones.
>> If that doesn’t work, remove one link from the chain, reuse a hogged out crank sprocket and a quality Vernier cam sprocket adjusted as tight as possible and then stiffen (or double up) the chain tensioner and you are good to go. Sometimes just giving the OEM tensioner a bigger “landing pad” inside the cover is sufficient. YMMV etc. etc.
>> I’ve got plenty of anything you may need except luck - a guy can never have too much of that ya know…
>> Best,
>> Lunker
>> 
>>>> On Aug 3, 2026, at 6:35 PM, Philip Gott <vfracing at aol.com> wrote:
>>> 
>>> Lunker ;
>>> I did not….
>>> Regards,
>>> Phil
>>> 
>>> Sent from my iPhone
>>> 
>>>>> On Aug 3, 2026, at 5:16 PM, Lunker Hilyer <lunkercars at icloud.com> wrote:
>>>> 
>>>> Did any of you receive my oversimplified approach to repair of this not uncommon issue?
>>>> Lunker
>>>> 
>>>>>> On Jul 28, 2026, at 8:25 AM, Chuck Gee <chasgee22 at gmail.com> wrote:
>>>>> 
>>>>> I could be wrong, but I don’t think line boring affects that dimension.  I understand it to be making the caps a little shorter then reboring to match the upper diameter in the block.  
>>>>> 
>>>>> Otherwise, a bunch of other dimensions would be goofed up too.
>>>>> 
>>>>> Chuck Gee
>>>>> 
>>>>>>> On Jul 27, 2026, at 4:56 PM, Philip Gott <vfracing at aol.com> wrote:
>>>>>> 
>>>>>> Or another way to ask the question is “how much misalignment between the crankshaft and transmission input shaft can be tolerated?”
>>>>>> I had a block completely gone through, including line boring and it ran very well until number one cylinder liner suddenly split. The engine hydro locked and broke the crank and front main bearing cap. I have a new cap; to use it requires the block be line bored again. I’m wondering if anyone else has a similar experience and can tell me either that it worked out well, or that I should throw the block away.
>>>>>> Thanks as always!
>>>>>> Phi
>>>>>> 
>>>>>> 
>>>>>> 
>>>>>> Sent from my iPhone
>>>>>> _______________________________________________
>>>>>> fot at autox.team.net
>>>>>> 
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>>>>>> 
>>>>> _______________________________________________
>>>>> fot at autox.team.net
>>>>> 
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