Casting Number Help

[argo]

I just scored a Goodwrench engine that came from an 86 K5 Blazer for $150.00. It has stickers on the valvecovers that say "New Goodwrench 6.5L" The engine block has these numbers cast into it:

J266 Passenger Side Bell Housing Flange

12555506 Drivers side bell Housing Flange

F15 Rear Block Face, Driver's Side

So is it a gem or is it junk? Is it treasure or is it trash? Is it a diamond in the rough or cubic zirconium?

Inquiring minds want to know!

[DmaxMaverick]

If it's a diamond in the rough, there'll be a diamond in the valley (Navistar logo). If the 4 digit code is the date code, looks like an earlier casting (not late Navistar), and just a 506 block (too few digits for a late cast). There are a couple stickies/threads in the 6.2/6.5 Tech Forum to help with block ID.

[Robyn]

October 26, 1996 most likely.

A 96 block could very well be an early squirter block with large outer main bolts all the way through plus large oil squirters.

These blocks had many issues including cracks in the mainline through the squirt holes as well as the center outer main bolt cracks.

BUTTTTTTTTT for $150 yank it apart and look it over well.

If there are no cracks in the lower end its usuable.

Just chamfer all the oil holes and all the main bolt holes lightly to help eliminate the stress risers.

Beyond this its a GM 506 casting.

I posted a thread on the late AMG castings and their numbering system. Its in the 6.2/6.5 tech forum

The GM castings have the letter first A through L which is Jan - Dec

Then comes the Day of the month (2 digits) followed by the year (1 digit)

4 = 94 and 5 = 95 6 = 96

GM did do a couple changes along the way in the numbering sequence, but this is pretty much what was happening at this point in time.

The 506 blocks, IMHO, were about the worst of the lot, but again, condition is everything.

There are no sweet ones until you get to the stuff with the Navistar <> cast into the valley.

Now the late AMG/GEP stuff is a 506 casting, but these are fine pieces.

The main webs are thicker, the castings are made of a different material and the decks are thicker too.

Even on the brand new castings from AMG/GEP I would go over them well and "Dehorn" them and chamfer all the bolt holes in the lower end along with the oil squirt holes too.

I recently bought a new AMG block and spent about an hour going over it and chamfering holes and deburing the lower end really well.


Good luck and keep us posted on your find.

Missy

[argo]

Dmax, Robyn:

Thanks for the information and advice. The price of this engine was sweet enough that even if the block is useless, there is way more than $150.00 of decent usable parts on it that it was worth it to me. Regardless, I will check it over and if she's not cracked, I'll chamfer the bolt holes and re-assemble it with a stud girdle kit. Thanks guys!

[Robyn]

Be careful on the chamfering. All you need is to break the sharp edges of the holes about 1/32

I will say this, I am not a fan of the little steel stud girdles for these engines.

Installing the Lock and stitch inserts in the center/outer bolt holes is by far a better preventive treatment than the girdle.

Good luck with the project.

Missy

[argo]

Please elaborate:

What is the "lock and stitch" repair you mentioned?
I have heard this term before, but I never got any further than the name. I'll try to look it up later myself. Right now I have a dishwasher to fix. :rolleyes:

[argo]

I know that this thread is old, but I wanted to give an update. I have kids in my auto tech class tearing the engine down and we are at a place where the engine is nearly bare block. We will have the crank out tomorrow or Thurday (i just need to bring in my number stamps and good micrometer set from home). Here is what we have thus far:

The Good:

- No visible cracking in the main area. No oil squirters that I can see, either.

- Crosshatch and no ridge in seven cylinders.

- No evidence of head gasket leakage.

- Small Throat combustion chambers.

- Immaculately clean on the inside.

The Bad:

- Cylinder one looks to have been exposed to rainwater or humid air at some point. The cylinder has a rusty/oily paste on the walls. The engine does turn freely however, and the piston top is black, suggesting that this is not an issue from when the engine was running, rather it is a storage issue.

- Every exhaust manifold bolt is badly rusted. The donor truck saw too much Pennsylvania road salt.

- The bolt heads for some of the glow plugs have disolved completely away. Further evidence of the brutal PA winters it once lived through.

- Somebody cut the block heater cord. I am debating whether I will omit the heater and install an aftermarket "in the heater hose" type instead.

The Ugly:

- Coagulated oil in the bottom of the pan that looks kind of like the phlegm you'd see come from someone who smokes two packs of unfiltered Camels a day.

- Flexplate is bent pretty bad (probably from it's time in storage).

[argo]

It is an oil squirter block after all. It has no cracks at all. What can I do to ensure that it stays that way? How do I properly chamfer the main bolt holes? Can I do anything to strengthen the block where the oil squirters are? The block is currently in pristine condition. If I run this engine at a non-turbo 150-160 HP level, could it last 300,000 miles or longer? The engine needs to be able to do everything my 300 CI six can. At 150 HP it will match my six for power as well as torque. I just want this engine to be as reliable as my old 300. I am open for suggestions as to how I can maximize this engine's durability.

[Yukon6.2]

Hi Argo
If i had the money....
Get the rotating assembally balanced
Get a Fluiddamper
Lockstitch the outside holes
Stud girdle
And a set of timing gears.
I have a new 6.5 that has run about 100 miles,i'm going to use it in my truck and will want to help it live a long life,but i don't have the time to tear it down for balancing ect.Or the money really.So i will do the gears,stud girdle and fluiddamper,and hope for the best.
Good Luck
Thomas

[argo]

What is "lockstitch"? I have heard it before, but I do not know what it is.

[Robyn]

Lock and stitch has several products, but the item we refer to for the 6.2/6.5 mains is the "Full Torque" insert".

These are a solid insert that has the standard threads on the inside, either 12mm or 10mm depending on what the block had originally.

These inserts are solid and not like a Helicoil.

The outside has a special thread that looks like the limbs on a christmas tree.
The threads angle toward the part line of the main and when the bolt is tightened they actually try to pul the cracked area together rather than spread it as do regular threads.

This method of repair is the only proven one for these blocks.

As long as the crack has not gone outside the bolt holes depth you can repair it.

If the cracks are deeper than the bottom of the hole (into the web area) then the block is a door stop.

Some blocks will crack right at the register fit where the cap sits into the block. If this has happened the block is junk.


Lock and stitch also makes a pinning product for repairing water jacket cracks.

I have no experience with these.


Missy

[argo]

Can this method be used pre-emtively? My block has no cracks and I aim to keep it that way. If I used this product on a block with no cracks, is it more likely to stay crack free? Looking at the paperwork that the engine came with (from the dealer that installed it into the donor vehicle) this engine only saw about 13,000 miles of use in the K5 it came out of. That was at the 135 HP C code power level. I did notice that this engine does infact have the outer bolt holes drilled all the way through.