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-   -   Cylinder bore thickness (https://forums.maxperformanceinc.com/forums/showthread.php?t=863663)

charlie66 12-28-2022 04:30 PM

Cylinder bore thickness
 
1 Attachment(s)
I recently had a 1970 400ci block Sonic tested. Is there anyone here that can tell me what the common cylinder thickness numbers would be on a block of this year typically would be.? I attached a picture of the results to compare. Any input on this will really appreciated.

Thanks

blueghoast 12-28-2022 06:22 PM

Quote:

Originally Posted by charlie66 (Post 6396416)
I recently had a 1970 400ci block Sonic tested. Is there anyone here that can tell me what the common cylinder thickness numbers would be on a block of this year typically would be.? I attached a picture of the results to compare. Any input on this will really appreciated.

Thanks

I've seen better but for a .040 over already it's not real bad,I would like
to see more between the bores. Maybe some one else with more knowledge
might chime in.

GT

charlie66 12-28-2022 06:27 PM

Quote:

Originally Posted by blueghoast (Post 6396451)
I've seen better but for a .040 over already it's not real bad,I would like
to see more between the bores. Maybe some one else with more knowledge
might chime in.

GT

What worries me is the front of a couple of the bores . How thick have you seen them?

Thanks for your input

Joe-Touring 01-03-2023 04:16 PM

My (limited experience) opinion is depends on what you’re doing with it. Since this is the race section, probably a strong build? From what I’ve seen those numbers would be just fine on most street builds. If you want some other opinions, here’s a thread I started on the same topic:

https://forums.maxperformanceinc.com...d.php?t=857000

My numbers were quite a bit worse, and I think it was about 50/50 go/no go. The most important part is the thrust side, and yours are plenty thick.

charlie66 01-03-2023 06:32 PM

Quote:

Originally Posted by Joe-Touring (Post 6397716)
My (limited experience) opinion is depends on what you’re doing with it. Since this is the race section, probably a strong build? From what I’ve seen those numbers would be just fine on most street builds. If you want some other opinions, here’s a thread I started on the same topic:

https://forums.maxperformanceinc.com...d.php?t=857000

My numbers were quite a bit worse, and I think it was about 50/50 go/no go. The most important part is the thrust side, and yours are plenty thick.

Thanks for the link . I wasn't aware of that thread . You got a lot of opinions . What did you wind up doing with the block ?

Mine will be a street motor. We have no tracks over here ....

Joe-Touring 01-03-2023 11:32 PM

Quote:

Originally Posted by charlie66 (Post 6397754)
Thanks for the link . I wasn't aware of that thread . You got a lot of opinions . What did you wind up doing with the block ?

Mine will be a street motor. We have no tracks over here ....

It’s still hung up at a machine shop. I think he’s putting it off since it has a cracked sleeve and needs to be re-resleeved haha. I just had a 400 done at another nearby shop so I’m in no rush. If the resleeve turns out good, my plan is to make it a low comp 87 octane truck engine. I’m thinkin a short fill with block filler and I’ll be a-ok.

chiefbigb 01-04-2023 12:09 AM

That's worse than any I have tested. The shop I do business with doesn't like to see anything under .125 at finish bore size. The block is your foundation. Starting with a weak one is probably not a good idea.

charlie66 01-04-2023 08:51 AM

Quote:

Originally Posted by Joe-Touring (Post 6397817)
It’s still hung up at a machine shop. I think he’s putting it off since it has a cracked sleeve and needs to be re-resleeved haha. I just had a 400 done at another nearby shop so I’m in no rush. If the resleeve turns out good, my plan is to make it a low comp 87 octane truck engine. I’m thinkin a short fill with block filler and I’ll be a-ok.

Do they make thick sleeves for racing like they do for the Honda blocks. You interlock them . I like that idea.. Did you sonic test the new block?

charlie66 01-04-2023 08:52 AM

Quote:

Originally Posted by chiefbigb (Post 6397821)
That's worse than any I have tested. The shop I do business with doesn't like to see anything under .125 at finish bore size. The block is your foundation. Starting with a weak one is probably not a good idea.

Are you taking about Joes block or mine ?

chiefbigb 01-04-2023 12:08 PM

.138 on a standard worn bore 400 is the thinnest reading I have seen. I have checked probably 12 stock blocks over the years. The 455 blocks seem to test a bit thicker than the 400s. I have a 400 block with xx in the casting that is well over .200 everywhere.

chiefbigb 01-04-2023 12:15 PM

At least around me blocks are still around. I would invest in another one.

Joe-Touring 01-04-2023 12:26 PM

Quote:

Originally Posted by charlie66 (Post 6397841)
Do they make thick sleeves for racing like they do for the Honda blocks. You interlock them . I like that idea.. Did you sonic test the new block?

You can absolutely pop some big sleeves in your block, properly done, it should be much stronger than a stock block. I believe the interlocking sleeves on Hondas are because those blocks are open deck, whereas Pontiacs are closed deck. Main issue with sleeving is cost, if you do all 8 cylinders, you’ve probably sunk more on that block than if you bought an aftermarket block.

I’m sure the shop did sonic the 400, but I’ll need to look for the paperwork. Would be interesting, I’ve seen people say on here that 67 400 blocks have the thickest walls and webbing.

hurryinhoosier62 01-04-2023 02:44 PM

Quote:

Originally Posted by Joe-Touring (Post 6397894)
You can absolutely pop some big sleeves in your block, properly done, it should be much stronger than a stock block. I believe the interlocking sleeves on Hondas are because those blocks are open deck, whereas Pontiacs are closed deck. Main issue with sleeving is cost, if you do all 8 cylinders, you’ve probably sunk more on that block than if you bought an aftermarket block.

I’m sure the shop did sonic the 400, but I’ll need to look for the paperwork. Would be interesting, I’ve seen people say on here that 67 400 blocks have the thickest walls and webbing.

‘59/‘60 389 blocks have thicker cylinder walls, webbing and bulkheads.

charlie66 01-05-2023 08:09 AM

One thing i forgot to mention is that this block has a 4.160 bore. I think that's .035 over ..

I did this last minute after having it machined . Not the way to go about i know. But at least i know where the blocks at for cylinder thickness..

charlie66 01-05-2023 08:22 AM

Quote:

Originally Posted by Joe-Touring (Post 6397894)
You can absolutely pop some big sleeves in your block, properly done, it should be much stronger than a stock block. I believe the interlocking sleeves on Hondas are because those blocks are open deck, whereas Pontiacs are closed deck. Main issue with sleeving is cost, if you do all 8 cylinders, you’ve probably sunk more on that block than if you bought an aftermarket block.

I’m sure the shop did sonic the 400, but I’ll need to look for the paperwork. Would be interesting, I’ve seen people say on here that 67 400 blocks have the thickest walls and webbing.

A friend of mine got a aftermarket block sonic checked and had some .170 - .180 numbers . I was surprised . So to me if you can beef up a stock block it might not be so bad . Seems like you never know what you're going to get even if it is a aftermarket block as well..

If you get any numbers on this 400 please share them .. That's why i started this thread , so i could compare my numbers to other blocks but it seems like theirs not to many people besides you and bluleghost...

Dragncar 01-05-2023 04:29 PM

Quote:

Originally Posted by charlie66 (Post 6398155)
One thing i forgot to mention is that this block has a 4.160 bore. I think that's .035 over ..

I did this last minute after having it machined . Not the way to go about i know. But at least i know where the blocks at for cylinder thickness..

.040 over.
How much did this cost Charlie ? I have a .060 over 67 400 that I would like to get checked out.

charlie66 01-05-2023 05:21 PM

Quote:

Originally Posted by Dragncar (Post 6398258)
.040 over.
How much did this cost Charlie ? I have a .060 over 67 400 that I would like to get checked out.

125.00

charlie66 01-05-2023 05:24 PM

Troy , if you get it done please let me know what the results are .....

Dragncar 01-06-2023 04:21 AM

Quote:

Originally Posted by charlie66 (Post 6398281)
Troy , if you get it done please let me know what the results are .....

No problem but I am not sure anyone around here does it. I will make some calls.

Half-Inch Stud 01-06-2023 09:49 AM

Odd thinness at the For/aft CYL clock positions. Nice sonic measure awareness.
Hard-block up to the water pump hole edges and freeze plug edges out to reduce CYL worries.


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