Relief on a 656 Block

[Iowa 409 Guy]

Is this what you guys are calling relief or is it just the way the cylinder looks on a 409 block?

Thanks

 

[MRHP]

No, I see no relief. This must be a pass block. All truck blocks have an eyebrow shaped relief cut in the top of the cylinder under the exhaust valve.

 

[Dick MacKenzie]

This is a truck block.

 

[Iowa 409 Guy]

Thanks for the pic Dick

This is a truck block.

A picture is worth 78 words. Also i see what you mean also MRHP. I did some searches and did not find anything. I thought i had a car block by the #'s

Thanks

 

[348ShoeBox]

Truck Block?

Then a 3755011 348 block with the same deep eyebrow reliefs as the picture that Dick submitted, with a cast date of J460 would be a truck block even if there is no X on the front upper left side of engine? I think I may have been confused about the X being on all truck blocks.

 

[tripower]

Then a 3755011 348 block with the same deep eyebrow reliefs as the picture that Dick submitted, with a cast date of J460 would be a truck block even if there is no X on the front upper left side of engine? I think I may have been confused about the X being on all truck blocks.

No, All the 348 blocks have the notch in the cylinders passenger car or truck. Check out the casting codes page. Notice at the bottom there is a link. http://www.348-409.com/cgi-bin/block/csvsearch.pl?block=3755011

 

[Ronnie Russell]

Al 348 , passenger and truck, had the ex. relief notches. Some truck 348s had 2 relief notches. 409 passenger car blocks did not have the notches. Truck 409s do have the notches. Most 409s after 1962 had the X.

 

[tripower]

Here is the double notch.

 

[oldskydog]

Al 348 , passenger and truck, had the ex. relief notches. Some truck 348s had 2 relief notches. 409 passenger car blocks did not have the notches. Truck 409s do have the notches. Most 409s after 1962 had the X.

409's and 348's (962 and 655 castings) from CFD should have the X. What it comes down to, I believe, is that if it came with 333 heads, it should have one notch...:

 

[Iowa 409 Guy]

656 Casting

409's and 348's (962 and 655 castings) from CFD should have the X. What it comes down to, I believe, is that if it came with 333 heads, it should have one notch...:

Cecil

My 656 with the CFD does have the X on it. Is that Central Foundry Division? What is that?

Thanks

 

[Tom Kochtanek]

CFD link

Check the history out:

http://wiki.gmnext.com/wiki/index.php/Central_Foundry_Division

I learned that ArmaSteel was first developed in 1936 .

Cheers!
TomK

 

[Iowa 409 Guy]

Thanks Tom

Check the history out:

http://wiki.gmnext.com/wiki/index.php/Central_Foundry_Division

I learned that ArmaSteel was first developed in 1936 .

Cheers!
TomK

Interesting read.

 

[MRHP]

notch uses

If you go with a large lift camshaft, the notch is needed to unshroud the exhaust valve. My exhaust valve would touch the cylinder, so I had to cut a notch similar ,but smaller, to the truck style notch to make clearance. bang