Last Mohecian
Administrator
My lock and stitch repair went really well BUT.... :smile25:
http://www.youtube.com/watch?v=bv20MtEHDEQ
http://www.youtube.com/watch?v=bv20MtEHDEQ
The poncho is dead
- Thread starter Last Mohecian
- Start date
Last Mohecian
Administrator
Last Mohecian
Administrator
If I remember right my pistons are .040 over. Too bad they are not .060
http://dallas.craigslist.org/dal/pts/2245558914.html
http://dallas.craigslist.org/dal/pts/2245558914.html
duanehydro
Active member
sorry to hear about that. but every engine I've even seen with 1 crack has more... :smile18:
Last Mohecian
Administrator
Sharkbit said:mother F*****Is this more freeze damage?
I don't see how it could be from freezing. There is no water near that part of the block. The crack starts at the alignment pin for the main cap. Maybe I can tell what happened once I get it disassembled. Hopefully the crank is OK.
Last Mohecian
Administrator
Crusader said:
Start looking for a Pontiac 400 block. I know I said I would be building an LSX motor if the Pontiac ever turned loose but I was assuming it would let go catastrophically. I have too many good parts to start over completely. If it had thrown a rod or cratered a piston it would be different story. Basically I need a good block to get to the machine shop so I can move my rotating assembly over. Other than that new rings and bearings and I should be back in business.
Come on craigslist. Don't fail me now. Daddy needs a new Pontiac 400 block.... Cheap...
Last Mohecian
Administrator
Looks like this may be a somewhat common issue.
From a post at hotrodders.com
"In the middle of the '75 model year, Pontiac started casting 400 blocks with thinner main webbing. I have seen a couple of these blocks, that were built for performance, crack in the main webbing. The blocks to avoid have casting #500557 or 568557. All prior blocks are good."
I believe my block is a 77 model year. I'll have to go check the casting numbers.
EDIT: My casting is 500557. Glad I know what to avoid now.
From a post at hotrodders.com
"In the middle of the '75 model year, Pontiac started casting 400 blocks with thinner main webbing. I have seen a couple of these blocks, that were built for performance, crack in the main webbing. The blocks to avoid have casting #500557 or 568557. All prior blocks are good."
I believe my block is a 77 model year. I'll have to go check the casting numbers.
EDIT: My casting is 500557. Glad I know what to avoid now.
Last Mohecian
Administrator
Sharkbit said:
No. :tongue:
Last Mohecian
Administrator
Sharkbit said:
My thought as well.
Last Mohecian
Administrator
Definitely a known issue.
From 78ta.com
"The 500557 400 blocks are weaker and are known to crack at the dowels that locate the main caps, but there a few brave souls over at PY who have stroked them- go for it if you feel lucky.
Geno"
From 78ta.com
"The 500557 400 blocks are weaker and are known to crack at the dowels that locate the main caps, but there a few brave souls over at PY who have stroked them- go for it if you feel lucky.
Geno"
blazeracer
New member
neverenuf said:
I saw a 455 Poncho on CL recently. Here it is.... Not a 400 though so you gotta change rotating assembly, right?
http://dallas.craigslist.org/dal/pts/2237613164.html
That's on the edge of what an LSX would cost from Sean.
blazeracer
New member
This guy has two 400 blocks Matt.
http://dallas.craigslist.org/dal/pts/2208259478.html
http://dallas.craigslist.org/dal/pts/2208259478.html
Last Mohecian
Administrator
neverenuf said:
It is. Only problem is that block is .060. My pistons are .040. I am talking to him though. It may be cheaper to buy a new set of pistons than to have another block machined.
Last Mohecian
Administrator
blazeracer said:
That 78 is probably the same weak casting I had. The 69 is a little pricey. I just missed two others that were $100 each. Keep looking for me though. Something will turn up.